Research ArticleCorrosion and Corrosion Inhibition of HighStrength Low Alloy Steel in 20 M Sulfuric Acid Solutionsby 3-Amino-123-triazole as a Corrosion Inhibitor
El-Sayed M Sherif12 Adel Taha Abbas1 D Gopi34 and A M El-Shamy2
1 Mechanical Engineering Department College of Engineering King Saud University PO Box 800 Riyadh 11421 Saudi Arabia2 Electrochemistry and Corrosion Laboratory Department of Physical Chemistry National Research Centre (NRC)Dokki Cairo 12622 Egypt
3 Department of Chemistry Periyar University Salem 636 011 Tamil Nadu India4Centre for Nanoscience and Nanotechnology Periyar University Salem 636 011 Tamil Nadu India
Correspondence should be addressed to El-Sayed M Sherif esherifksuedusa
Received 8 May 2014 Revised 8 August 2014 Accepted 1 September 2014 Published 11 September 2014
Academic Editor Sylvain Franger
Copyright copy 2014 El-Sayed M Sherif et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited
The corrosion and corrosion inhibition of high strength low alloy (HSLA) steel after 10min and 60min immersion in 20MH2SO4solution by 3-amino-124-triazole (ATA) were reported Several electrochemical techniques along with scanning electron
microscopy (SEM) and energy dispersive X-ray (EDS) were employed Electrochemical impedance spectroscopy indicated that theincrease of immersion time from 10min to 60min significantly decreased both the solution and polarization resistance for thesteel in the sulfuric acid solution The increase of immersion time increased the anodic cathodic and corrosion currents whileit decreased the polarization resistance as indicated by the potentiodynamic polarization measurements The addition of 10mMATA remarkably decreased the corrosion of the steel and this effect was found to increase with increasing its concentration to50mM SEM and EDS investigations confirmed that the inhibition of the HSLA steel in the 20M H
2SO4solutions is achieved via
the adsorption of the ATA molecules onto the steel protecting its surface from being dissolved easily
1 Introduction
High strength low alloy (HSLA) steels are designed to providebetter mechanical properties andor greater resistance toatmospheric corrosion than conventional carbon steels inthe normal sense because they are designed to meet specificmechanical properties rather than a chemical composition[1] HSLA steels have been widely used in many applicationsin industry these include gun barrel food sterilizationsintering of components from powders hypersonic windtunnels power generation and water jet cutting [1 2] Thereis a great economical incentive in developing methods andmaterials to alleviate corrosion which comes only froma good understanding of the mechanisms and processesinvolved in this complex phenomenon [3 4]
Acid solutions are widely used in many applicationssuch as acid pickling industrial acid cleaning acid descalingand oil well acidizing [5] Due to the corrosivity of acidsolutions corrosion inhibitors are commonly added to theirsolutions in order to reduce their aggressive attack on thestructure to be protected [5ndash10] Inhibitors are generally usedin this process to control the metal dissolution as well as acidconsumption [5] It has been reported [11ndash16] that organiccompounds containing polar groups including nitrogensulfur and oxygen and heterocyclic compounds with polarfunctional groups and conjugated double bonds have beenknown to be good corrosion inhibitorsThe inhibiting actionof these compounds is usually attributed to their interactionswith themetal via their adsorption onto the surfaceHoweverthe adsorption of an inhibitor on a metal surface depends on
Hindawi Publishing CorporationJournal of ChemistryVolume 2014 Article ID 538794 8 pageshttpdxdoiorg1011552014538794
2 Journal of Chemistry
the nature and the surface charge of themetal the adsorptionmode its chemical structure and the type of the electrolytesolution [17]
In the present work we reported the effect of immersiontime namely 10min and 60min on the electrochemicalcorrosion behavior of the HSLA steel in 20M sulfuric acidsolutions The effect of adding different concentrations of3-amino-124-triazole (ATA) on the inhibition of this steelafter the different exposure periods in the acid solutionwas also reported The experimental part of this study wascarried out using open-circuit potential (OCP) electrochem-ical impedance spectroscopy (EIS) and potentiodynamicpolarization measurements Characterization of the surfaceof the steel after its immersion in the acid solution aloneand in the acid solution containing ATA molecules wasperformed using scanning electron microscopy (SEM) andenergy dispersive X-ray (EDS) analyses
and acetone (C3H6O Merck 990) were used as received
The HSLA steel electrode with a square shape and surfacedimensions of 1times1 cmwas employed for the electrochemicaltests The chemical composition of the employed ultrahighstrength steel (in wt) was as follows C = 00309 Si =0177 Mn = 0201 P = 0007 Cr = 1553 Mo =0617 Ni = 3208 Nb = 0002 Al = 0006 Cu =0098 Co = 0011 B = 0001 V = 0223 Sn =0002 and N = 0017 and the balance (sim93566) was FeA conventional electrochemical cell accommodating only200mL with a three-electrode configuration was used Thethree electrodes were the steel rod platinum foil and anAgAgCl electrode (in 30MKCl) and were used as workingcounter and reference electrodes respectively The workingelectrode for electrochemical measurements was prepared byattaching an insulated copper wire to one face of the sampleusing an aluminum conducting tape and cold mounted inresin The surface of the steel electrode to be exposed to thesolution was first ground successively with metallographicemery paper of increasing fineness of up to 600 grits andfurther with 5 1 05 and 03 120583m alumina slurries (Buehler)The electrode was then washed with doubly distilled waterdegreased with acetone washed using doubly distilled wateragain and finally dried with tissue paper
22 Electrochemical Measurements An Autolab Potentiostat(PGSTAT20 computer controlled) operated by the GeneralPurpose Electrochemical Software (GPES) version 49 wasused to perform the electrochemical experiments The open-circuit potential (OCP) curves obtained for the steel electrodein sulfuric acid in the absence and presence of ATAwere donefor 60min The electrochemical impedance spectroscopy(EIS) tests were performed at corrosion potentials over afrequency range of 100 kHz to 100mHz with an AC waveof plusmn5mV peak-to-peak overlaid on a DC bias potential
3
21
minus300
minus310
minus320
minus330
minus340
minus3500 500 1000 1500 2000 2500 3000 3500 4000
Time (s)
E(m
V v
ersu
s Ag
AgC
l)
Figure 1 Change of the open-circuit potential versus time for theHSLA steel in 20MH
2SO4solutions in the absence (1) and presence
(2) of 10mM ATA and (3) 50mM ATA respectively
and the impedance data were collected using Powersinesoftware at a rate of 10 points per decade change in frequencyThe potentiodynamic polarization curves were obtained byscanning the potential in the forward direction from minus10 Vto minus02V versus AgAgCl at a scan rate of 0001 Vs Eachexperiment was carried out using fresh steel surface andnew portion of the sulfuric acid solution in the absenceand the presence of the ATA molecules All electrochemicalexperiments were carried out at room temperature
23 SEM and EDS Investigations The SEM images wereobtained by using a JEOL model JSM-6610LV (Japanesemade) scanning electron microscope with an energy disper-sive X-ray analyzer attached for acquiring the EDS analysis
3 Results and Discussion
31 Open-Circuit Potential (OCP) Measurements Figure 1shows the OCP curves of the steel electrode in aeratedstagnant 20M H
2SO4solutions in the absence (1) and
presence (2) of 10mM and (3) 50mM ATA respectivelyIt is seen that the potential of the steel in the sulfuric acidsolution without inhibitor (curve 1) increased towards themore negative values in the first 300 s of the steel immersionas a result of the dissolution of a preoxide film via theaggressiveness action of the acid solution The potential thenshifted again in the less negative direction through another300 s before stabilizing a slight shift in the same directionwithtime till the end of the run
The addition of 10mM ATA (curve 2) showed almostthe same behavior but with a positive shift in the absolutepotential which indicates that ATA molecules at this con-centration have an ability to decrease the severity of the acidsolution Increasing ATA concentration to 50mM (curve 3)presented more positive shifts in the absolute potential of thesteel for thewhole time of the experimentThe change ofOCPwith time measurements thus indicated that the presenceof ATA molecules decreases the aggressiveness action ofH2SO4by shifting its potential in the less negative direction
and this effect was found to increase with increase of theconcentration of ATA
Journal of Chemistry 3
(a) (b)
NNi
Ni Ni
Fe
Fe
Fe
V
V
O
Cu
CuCu
C
Cr
Cr
0 2 4 6 8 10 12
3
(c)
Figure 2 SEM micrographs obtained for the HSLA steel after 24 h immersion in 20M H2SO4solutions (a) without ATA and (b) with
50mM ATA present and (c) EDS profile analysis corresponding to the surface shown in Figure 2(b) respectively
32 SEM and EDS Investigations In order to investigate theeffect ofH
2SO4in the absence andpresence ofATAmolecules
on the corrosion of the HSLA steel SEM micrograph andEDS profile analysis were carried out Figure 2 shows theSEM micrographs obtained for the HSLA steel after 24 himmersion in 20M H
2SO4solutions (a) without ATA and
(b) with 50mM ATA present and (c) EDS profile analysiscorresponding to the surface shown in Figure 2(b) respec-tively The SEM micrograph shown in Figure 2(a) shows atotal deterioration for the surface of steel which was due tothe aggressiveness attack of the sulfuric acid solution TheEDS profile analysis taken for the steel at this condition [7]indicated that its surface has the main alloying elements inaddition to the presence of carbon sulfur and oxygen Thepresence of C O and S was due to the effect of sulfuric acidsolutions as well as the exposure of the steel surface to air afterremoving it from the acid solution
On the other hand the SEM micrograph shown inFigure 2(b) proved that the surface of the steel is coveredwith a homogeneous layer of the adsorbed ATA moleculesThis was confirmed by the EDS profile analysis shown inFigure 2(c) where the atomic percentages of the elementsfound on the steel surface were 544 C 093 N 5365 O734 S 069 V 249 Cr 077 Ni 012 Cu and 2858Fe The presence of nitrogen in the analysis confirms thatthe ATA molecules are included in the layer present on thesurfaceThe presence of very high amount of Cr compared tothat originally present in the steel in addition to the very highpercent of oxygen indicates that the surface is also passivated
through the formation of chromium oxide layer along withthe adsorbed layer of the ATA molecules Moreover thepresence of very low amounts of Fe and Ni reveals that theformed ATA layer is thick and is homogenously distributedon the surface Another proof for the ability of the ATAmolecules to inhibit the HSLA steel corrosion in the sulfuricacid test solution was the black color of the solution whichdid not have any ATA compound and was due to the severedissolution of the steel while the color of the acid solutioncontaining 50mM ATA was clear and unchanged even after24 h of the steel immersion It has been reported [9 18ndash20] that the inhibition of metal corrosion by using similarcompounds to ATA is achieved by the adsorption of theirmolecules onto the metal surface preventing it from beingattacked by corrosive media
33 Electrochemical Impedance Spectroscopy (EIS) Measure-ments It has been reported [10 20ndash22] that EIS is a pow-erful method in understanding the corrosion and corrosioninhibition for different metals and alloys in aggressive envi-ronments In this work we employed the EIS experimentsto obtain the kinetic parameters for the steelsulfuric acidsolution interface after different exposure periods In orderto report the effect of immersion time on the corrosion of theHSLA steel in 20M H
2SO4solution the EIS measurements
were conducted after (1) 10min and (2) 60min immersionand the Nyquist spectra were plotted respectively as shownin Figure 3
4 Journal of Chemistry
0 2 4 6 8 10
0
1
2
3
4
5
2
1
minus1
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 3 Nyquist plots for the HSLA steel after its immersion for(1) 10min and (2) 60min in the 20MH
2SO4solutions respectively
It is clearly seen that the steel in the acid solutionshows only one distorted semicircle whose diameter gotsmaller with the increase of immersion time from 10minto 60min This indicates that the increase of the time ofimmersion increases the dissolution of steel in sulfuric acidsolution through decreasing its corrosion resistanceThis wasconfirmed by fitting the EIS data to the best equivalent circuitmodel which is shown in Figure 4 This equivalent circuitmodelwas also used to fit the EIS data obtained from studyingthe corrosion and corrosion inhibition of maraging steel indifferent sulfuric acid solutions [7 9] The parameters of theused circuit can be defined according to usual conventionas follows 119877
119904represents the solution resistance 119876 is the
constant phase elements (CPEs) 1198771199011is the polarization resis-
tance for the solutionsteel interface and can be defined asthe charge transfer resistance [23]119877
1199012is another polarization
resistance for the corrosion productsteel interface and 119871 isthe inductance The values of these parameters are listed inTable 1 It is also seen from Table 1 that the values of 119877
119904 1198771199011
1198771199012 and 119871 decrease while the value of 119876 (CPEs) increases
by the increase of immersion time from 10min to 60minfor the HSLA steel in 20M H
2SO4solutions This is due
to the corrosiveness action of the sulfuric acid solution thatcontinuously attacks the surface of the steel and lowers itsprobability to develop oxide layers or corrosion products andthat effect increases with increasing time of contact betweenthe acid and the steel
The EIS measurements were also employed to report theeffect of ATA molecules on the inhibition of the HSLA steelin 20M H
2SO4solutions Figure 5 shows the Nyquist plots
obtained for the steel after 10min immersion in the acidsolution that contains (1) 00 (2) 10 and (3) 50mM ATArespectively Similar plots were also obtained for the HSLAsteel after its immersion in the acid solution in the absenceand presence of ATA for 60min and the curves are shown inFigure 6 The equivalent circuit shown in Figure 4 was alsoused to represent the best fitting for the data presented inFigures 5 and 6The EIS parameters obtained out of the fitteddata as well as the values of the percentage of the inhibition
Rs
RP1
RP2
Q
L
Figure 4The equivalent circuit used to fit the experimental EIS dataobtained for the HSLA steel after its immersion for different periodsof time in 20M sulfuric acid solution
efficiency (IE) are listed in Table 1 The values of IE werecalculated according to the following equation [18]
IE =119877in119875minus 119877
O119875
119877in119875
(1)
where 119877in119875and 119877O
119875are polarization resistance of the HSLA
steel in the sulfuric acid solution in the presence and absenceof ATA molecules respectively
It is clearly seen from Figure 5 that the addition of 10mMATA within the sulfuric acid solution increased the diameterof the semicircle Increasing the concentration of ATA to50mM further increased the diameter of the semicircleobtained for the steel This indicates that the presence ofATA and the increase of its concentration decrease thecorrosion of the HSLA steel after 10min immersion in 20MH2SO4solutions It has been reported [18 20 24] that ATA
molecules inhibit the corrosion via their adsorption ontothe surface of metals (such as iron [20] and copper [18 24])and the ability of ATA as a corrosion inhibitor increaseswith the increase of its concentration This agrees with thecurrent results as indicated by the parameters recorded inTable 1 where the values of 119877
1199041198771199011 1198771199012 and 119871 as well as IE
increased with the increase of ATA concentrationIt is obvious from Figure 6 for the steel after 60min
in the acid solution without and with ATA present thatthe presence of 10mM ATA decreased the aggressivenessaction of the sulfuric acid solution by increasing its corrosionresistanceThis was revealed by increasing the diameter of thesemicircle obtained for the steel in the presence of 10mMATA compared to its diameter in the blank solution Furtherincreasing the ATA concentration to 50mM produced fur-ther increase in the diameter of the semicircle after 60minTable 1 also confirmed that the presence of ATA and theincrease of its concentration increased the values of 119877
119904 1198771199011
1198771199012 and 119871 The increase of 119877
119904 1198771199011 and 119877
1199012in the presence
of ATA and with the increase of its content indicates thatATA molecules have the ability to increase the solution andcorrosion resistance of the HSLA steel surface and that effectincreases with increasing ATA concentration in the acidsolutionThe values of CPEs with their n values close to unityrepresent double layer capacitors decreased in the presenceof ATA and with the increase of its content which wasexpected to cover up the charged surfaces [23] Moreover thevalues of IEwere found to increase not only with increasingconcentration of ATA from 10mM to 50mM but also withincreasing the immersion time as can be seen from Table 1
Journal of Chemistry 5
Table 1 Parameters obtained by fitting the EIS data with the equivalent circuit shown in Figure 4 for theHSLA steel in 20MH2SO4 solutions
Figure 5 Nyquist plots for the HSLA steel after its immersion for10min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
0 2 4 6 8 10 12
0
2
4
6
3
2
1
minus2
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 6 Nyquist plots for the HSLA steel after its immersion for60min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
The outcome of the EIS experiments proves that ATA can beemployed tomitigate the corrosion of theHSLA steel in 20MH2SO4solutions and its ability as a good corrosion inhibitor
increases with the increase of its concentration as well as theincrease of the time of immersion before measurement
34 Potentiodynamic Polarization Measurements The effectof increasing the immersion time on the dissolution of theHSLA steel in 20M H
2SO4solutions was investigated using
potentiodynamic polarization measurements The potentio-dynamic polarization curves obtained for HSLA steel after itsimmersion in 20M H
2SO4solutions for (1) 10min and (2)
60min are shown in Figure 7The corrosion potential (119864Corr)corrosion current density (119895Corr) cathodic (120573c) and anodic(120573a) Tafel slopes polarization resistance (119877
119901) and corrosion
rate (119877Corr) that were obtained from polarization curves arelisted inTable 2The values of these parameterswere obtainedas previously reported [17ndash21] It is clearly seen from Figure 7and Table 2 that the increase of immersion time increases thevalues of 119895Corr cathodic and anodic currents and 119877Corr whileit decreases the values of 119877
119901 This was due to the continuous
dissolution of the HSLA steel under the harsh attack of theconcentrated solution of the sulfuric acid which does notallow the surface of steel to form protective layers andorcorrosion products At this condition the cathodic reactionfor the steel in the sulfuric acid solution has been reported tobe the hydrogen evolution reaction as follows [7 9 25]
2H+ + 2eminus = H2
(2)
On the other hand the anodic reaction of the HSLAsteel is the dissolution of its iron according to the followingequation [7 9]
Fe = Fe2+ + 2eminus (3)
The resulting ferrous cations (Fe2+) are not stable and oxidizeto ferric cations (Fe3+) as follows
Fe2+ = Fe3+ + eminus (4)
The severity of these reactions increases with increase ofthe immersion time which could lead to the increaseddissolution of steel and also explain the increased currentsand corrosion rate with increasing the time of immersion
In order to evaluate the effect of ATA as a corrosioninhibitor after the different stated exposure intervals thepotentiodynamic polarization measurements were also car-ried out Figure 8 shows the potentiodynamic polarizationcurves obtained for the HSLA steel after its immersion in
6 Journal of Chemistry
Table 2 Corrosion parameters obtained from the potentiodynamic polarization measurements for the HSLA steel electrode that wasimmersed for different periods of time in 20M H2SO4 solutions with and without ATA molecules
Figure 7 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for (1) 10min and (2) 60min in 20MH2SO4solutions
20M H2SO4solutions for 10min in (1) the absence and the
presence of (2) 10mM and (3) 50mM ATA respectivelyIn order to study the effect of immersion time on theefficiency of ATA molecules the polarization measurementswere performed after 60min and the curves are shown inFigure 9The values of the parameters obtained from Figures8 and 9 as well as the calculated values of IE are alsolisted in Table 2 The values of IE were obtained from thepolarization data according to the following equation [9 1718]
IE =119895Corr minus 119895
oCorr
119895Corrtimes 100 (5)
where 119895Corr and 119895oCorr are the corrosion current densities in the
absence and presence of ATA molecules respectivelyThe addition of 10mM ATA within the acid solution
after all immersion periods of time remarkably decreasedthe anodic cathodic and corrosion currents The data listedin Table 2 also indicated that the values of 119895Corr and 119877Corrdecreased while the value of 119877
119901increased in the presence
of 10mM ATA compared to those recorded in its absenceThis was perhaps due to the ability of ATA molecules tobe adsorbed onto the steel surface where the adsorption of
1
2
3
10minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 8 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 10min in 20M H
2SO4in the
absence (1) and the presence of (2) 10mMATAand (3) 50mMATArespectively
2
3
110minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 9 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 60min in 20M H
2SO4in the
absence (1) and the presence (2) of 10mMATAand (3) 50mMATArespectively
Journal of Chemistry 7
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
the nature and the surface charge of themetal the adsorptionmode its chemical structure and the type of the electrolytesolution [17]
In the present work we reported the effect of immersiontime namely 10min and 60min on the electrochemicalcorrosion behavior of the HSLA steel in 20M sulfuric acidsolutions The effect of adding different concentrations of3-amino-124-triazole (ATA) on the inhibition of this steelafter the different exposure periods in the acid solutionwas also reported The experimental part of this study wascarried out using open-circuit potential (OCP) electrochem-ical impedance spectroscopy (EIS) and potentiodynamicpolarization measurements Characterization of the surfaceof the steel after its immersion in the acid solution aloneand in the acid solution containing ATA molecules wasperformed using scanning electron microscopy (SEM) andenergy dispersive X-ray (EDS) analyses
and acetone (C3H6O Merck 990) were used as received
The HSLA steel electrode with a square shape and surfacedimensions of 1times1 cmwas employed for the electrochemicaltests The chemical composition of the employed ultrahighstrength steel (in wt) was as follows C = 00309 Si =0177 Mn = 0201 P = 0007 Cr = 1553 Mo =0617 Ni = 3208 Nb = 0002 Al = 0006 Cu =0098 Co = 0011 B = 0001 V = 0223 Sn =0002 and N = 0017 and the balance (sim93566) was FeA conventional electrochemical cell accommodating only200mL with a three-electrode configuration was used Thethree electrodes were the steel rod platinum foil and anAgAgCl electrode (in 30MKCl) and were used as workingcounter and reference electrodes respectively The workingelectrode for electrochemical measurements was prepared byattaching an insulated copper wire to one face of the sampleusing an aluminum conducting tape and cold mounted inresin The surface of the steel electrode to be exposed to thesolution was first ground successively with metallographicemery paper of increasing fineness of up to 600 grits andfurther with 5 1 05 and 03 120583m alumina slurries (Buehler)The electrode was then washed with doubly distilled waterdegreased with acetone washed using doubly distilled wateragain and finally dried with tissue paper
22 Electrochemical Measurements An Autolab Potentiostat(PGSTAT20 computer controlled) operated by the GeneralPurpose Electrochemical Software (GPES) version 49 wasused to perform the electrochemical experiments The open-circuit potential (OCP) curves obtained for the steel electrodein sulfuric acid in the absence and presence of ATAwere donefor 60min The electrochemical impedance spectroscopy(EIS) tests were performed at corrosion potentials over afrequency range of 100 kHz to 100mHz with an AC waveof plusmn5mV peak-to-peak overlaid on a DC bias potential
3
21
minus300
minus310
minus320
minus330
minus340
minus3500 500 1000 1500 2000 2500 3000 3500 4000
Time (s)
E(m
V v
ersu
s Ag
AgC
l)
Figure 1 Change of the open-circuit potential versus time for theHSLA steel in 20MH
2SO4solutions in the absence (1) and presence
(2) of 10mM ATA and (3) 50mM ATA respectively
and the impedance data were collected using Powersinesoftware at a rate of 10 points per decade change in frequencyThe potentiodynamic polarization curves were obtained byscanning the potential in the forward direction from minus10 Vto minus02V versus AgAgCl at a scan rate of 0001 Vs Eachexperiment was carried out using fresh steel surface andnew portion of the sulfuric acid solution in the absenceand the presence of the ATA molecules All electrochemicalexperiments were carried out at room temperature
23 SEM and EDS Investigations The SEM images wereobtained by using a JEOL model JSM-6610LV (Japanesemade) scanning electron microscope with an energy disper-sive X-ray analyzer attached for acquiring the EDS analysis
3 Results and Discussion
31 Open-Circuit Potential (OCP) Measurements Figure 1shows the OCP curves of the steel electrode in aeratedstagnant 20M H
2SO4solutions in the absence (1) and
presence (2) of 10mM and (3) 50mM ATA respectivelyIt is seen that the potential of the steel in the sulfuric acidsolution without inhibitor (curve 1) increased towards themore negative values in the first 300 s of the steel immersionas a result of the dissolution of a preoxide film via theaggressiveness action of the acid solution The potential thenshifted again in the less negative direction through another300 s before stabilizing a slight shift in the same directionwithtime till the end of the run
The addition of 10mM ATA (curve 2) showed almostthe same behavior but with a positive shift in the absolutepotential which indicates that ATA molecules at this con-centration have an ability to decrease the severity of the acidsolution Increasing ATA concentration to 50mM (curve 3)presented more positive shifts in the absolute potential of thesteel for thewhole time of the experimentThe change ofOCPwith time measurements thus indicated that the presenceof ATA molecules decreases the aggressiveness action ofH2SO4by shifting its potential in the less negative direction
and this effect was found to increase with increase of theconcentration of ATA
Journal of Chemistry 3
(a) (b)
NNi
Ni Ni
Fe
Fe
Fe
V
V
O
Cu
CuCu
C
Cr
Cr
0 2 4 6 8 10 12
3
(c)
Figure 2 SEM micrographs obtained for the HSLA steel after 24 h immersion in 20M H2SO4solutions (a) without ATA and (b) with
50mM ATA present and (c) EDS profile analysis corresponding to the surface shown in Figure 2(b) respectively
32 SEM and EDS Investigations In order to investigate theeffect ofH
2SO4in the absence andpresence ofATAmolecules
on the corrosion of the HSLA steel SEM micrograph andEDS profile analysis were carried out Figure 2 shows theSEM micrographs obtained for the HSLA steel after 24 himmersion in 20M H
2SO4solutions (a) without ATA and
(b) with 50mM ATA present and (c) EDS profile analysiscorresponding to the surface shown in Figure 2(b) respec-tively The SEM micrograph shown in Figure 2(a) shows atotal deterioration for the surface of steel which was due tothe aggressiveness attack of the sulfuric acid solution TheEDS profile analysis taken for the steel at this condition [7]indicated that its surface has the main alloying elements inaddition to the presence of carbon sulfur and oxygen Thepresence of C O and S was due to the effect of sulfuric acidsolutions as well as the exposure of the steel surface to air afterremoving it from the acid solution
On the other hand the SEM micrograph shown inFigure 2(b) proved that the surface of the steel is coveredwith a homogeneous layer of the adsorbed ATA moleculesThis was confirmed by the EDS profile analysis shown inFigure 2(c) where the atomic percentages of the elementsfound on the steel surface were 544 C 093 N 5365 O734 S 069 V 249 Cr 077 Ni 012 Cu and 2858Fe The presence of nitrogen in the analysis confirms thatthe ATA molecules are included in the layer present on thesurfaceThe presence of very high amount of Cr compared tothat originally present in the steel in addition to the very highpercent of oxygen indicates that the surface is also passivated
through the formation of chromium oxide layer along withthe adsorbed layer of the ATA molecules Moreover thepresence of very low amounts of Fe and Ni reveals that theformed ATA layer is thick and is homogenously distributedon the surface Another proof for the ability of the ATAmolecules to inhibit the HSLA steel corrosion in the sulfuricacid test solution was the black color of the solution whichdid not have any ATA compound and was due to the severedissolution of the steel while the color of the acid solutioncontaining 50mM ATA was clear and unchanged even after24 h of the steel immersion It has been reported [9 18ndash20] that the inhibition of metal corrosion by using similarcompounds to ATA is achieved by the adsorption of theirmolecules onto the metal surface preventing it from beingattacked by corrosive media
33 Electrochemical Impedance Spectroscopy (EIS) Measure-ments It has been reported [10 20ndash22] that EIS is a pow-erful method in understanding the corrosion and corrosioninhibition for different metals and alloys in aggressive envi-ronments In this work we employed the EIS experimentsto obtain the kinetic parameters for the steelsulfuric acidsolution interface after different exposure periods In orderto report the effect of immersion time on the corrosion of theHSLA steel in 20M H
2SO4solution the EIS measurements
were conducted after (1) 10min and (2) 60min immersionand the Nyquist spectra were plotted respectively as shownin Figure 3
4 Journal of Chemistry
0 2 4 6 8 10
0
1
2
3
4
5
2
1
minus1
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 3 Nyquist plots for the HSLA steel after its immersion for(1) 10min and (2) 60min in the 20MH
2SO4solutions respectively
It is clearly seen that the steel in the acid solutionshows only one distorted semicircle whose diameter gotsmaller with the increase of immersion time from 10minto 60min This indicates that the increase of the time ofimmersion increases the dissolution of steel in sulfuric acidsolution through decreasing its corrosion resistanceThis wasconfirmed by fitting the EIS data to the best equivalent circuitmodel which is shown in Figure 4 This equivalent circuitmodelwas also used to fit the EIS data obtained from studyingthe corrosion and corrosion inhibition of maraging steel indifferent sulfuric acid solutions [7 9] The parameters of theused circuit can be defined according to usual conventionas follows 119877
119904represents the solution resistance 119876 is the
constant phase elements (CPEs) 1198771199011is the polarization resis-
tance for the solutionsteel interface and can be defined asthe charge transfer resistance [23]119877
1199012is another polarization
resistance for the corrosion productsteel interface and 119871 isthe inductance The values of these parameters are listed inTable 1 It is also seen from Table 1 that the values of 119877
119904 1198771199011
1198771199012 and 119871 decrease while the value of 119876 (CPEs) increases
by the increase of immersion time from 10min to 60minfor the HSLA steel in 20M H
2SO4solutions This is due
to the corrosiveness action of the sulfuric acid solution thatcontinuously attacks the surface of the steel and lowers itsprobability to develop oxide layers or corrosion products andthat effect increases with increasing time of contact betweenthe acid and the steel
The EIS measurements were also employed to report theeffect of ATA molecules on the inhibition of the HSLA steelin 20M H
2SO4solutions Figure 5 shows the Nyquist plots
obtained for the steel after 10min immersion in the acidsolution that contains (1) 00 (2) 10 and (3) 50mM ATArespectively Similar plots were also obtained for the HSLAsteel after its immersion in the acid solution in the absenceand presence of ATA for 60min and the curves are shown inFigure 6 The equivalent circuit shown in Figure 4 was alsoused to represent the best fitting for the data presented inFigures 5 and 6The EIS parameters obtained out of the fitteddata as well as the values of the percentage of the inhibition
Rs
RP1
RP2
Q
L
Figure 4The equivalent circuit used to fit the experimental EIS dataobtained for the HSLA steel after its immersion for different periodsof time in 20M sulfuric acid solution
efficiency (IE) are listed in Table 1 The values of IE werecalculated according to the following equation [18]
IE =119877in119875minus 119877
O119875
119877in119875
(1)
where 119877in119875and 119877O
119875are polarization resistance of the HSLA
steel in the sulfuric acid solution in the presence and absenceof ATA molecules respectively
It is clearly seen from Figure 5 that the addition of 10mMATA within the sulfuric acid solution increased the diameterof the semicircle Increasing the concentration of ATA to50mM further increased the diameter of the semicircleobtained for the steel This indicates that the presence ofATA and the increase of its concentration decrease thecorrosion of the HSLA steel after 10min immersion in 20MH2SO4solutions It has been reported [18 20 24] that ATA
molecules inhibit the corrosion via their adsorption ontothe surface of metals (such as iron [20] and copper [18 24])and the ability of ATA as a corrosion inhibitor increaseswith the increase of its concentration This agrees with thecurrent results as indicated by the parameters recorded inTable 1 where the values of 119877
1199041198771199011 1198771199012 and 119871 as well as IE
increased with the increase of ATA concentrationIt is obvious from Figure 6 for the steel after 60min
in the acid solution without and with ATA present thatthe presence of 10mM ATA decreased the aggressivenessaction of the sulfuric acid solution by increasing its corrosionresistanceThis was revealed by increasing the diameter of thesemicircle obtained for the steel in the presence of 10mMATA compared to its diameter in the blank solution Furtherincreasing the ATA concentration to 50mM produced fur-ther increase in the diameter of the semicircle after 60minTable 1 also confirmed that the presence of ATA and theincrease of its concentration increased the values of 119877
119904 1198771199011
1198771199012 and 119871 The increase of 119877
119904 1198771199011 and 119877
1199012in the presence
of ATA and with the increase of its content indicates thatATA molecules have the ability to increase the solution andcorrosion resistance of the HSLA steel surface and that effectincreases with increasing ATA concentration in the acidsolutionThe values of CPEs with their n values close to unityrepresent double layer capacitors decreased in the presenceof ATA and with the increase of its content which wasexpected to cover up the charged surfaces [23] Moreover thevalues of IEwere found to increase not only with increasingconcentration of ATA from 10mM to 50mM but also withincreasing the immersion time as can be seen from Table 1
Journal of Chemistry 5
Table 1 Parameters obtained by fitting the EIS data with the equivalent circuit shown in Figure 4 for theHSLA steel in 20MH2SO4 solutions
Figure 5 Nyquist plots for the HSLA steel after its immersion for10min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
0 2 4 6 8 10 12
0
2
4
6
3
2
1
minus2
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 6 Nyquist plots for the HSLA steel after its immersion for60min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
The outcome of the EIS experiments proves that ATA can beemployed tomitigate the corrosion of theHSLA steel in 20MH2SO4solutions and its ability as a good corrosion inhibitor
increases with the increase of its concentration as well as theincrease of the time of immersion before measurement
34 Potentiodynamic Polarization Measurements The effectof increasing the immersion time on the dissolution of theHSLA steel in 20M H
2SO4solutions was investigated using
potentiodynamic polarization measurements The potentio-dynamic polarization curves obtained for HSLA steel after itsimmersion in 20M H
2SO4solutions for (1) 10min and (2)
60min are shown in Figure 7The corrosion potential (119864Corr)corrosion current density (119895Corr) cathodic (120573c) and anodic(120573a) Tafel slopes polarization resistance (119877
119901) and corrosion
rate (119877Corr) that were obtained from polarization curves arelisted inTable 2The values of these parameterswere obtainedas previously reported [17ndash21] It is clearly seen from Figure 7and Table 2 that the increase of immersion time increases thevalues of 119895Corr cathodic and anodic currents and 119877Corr whileit decreases the values of 119877
119901 This was due to the continuous
dissolution of the HSLA steel under the harsh attack of theconcentrated solution of the sulfuric acid which does notallow the surface of steel to form protective layers andorcorrosion products At this condition the cathodic reactionfor the steel in the sulfuric acid solution has been reported tobe the hydrogen evolution reaction as follows [7 9 25]
2H+ + 2eminus = H2
(2)
On the other hand the anodic reaction of the HSLAsteel is the dissolution of its iron according to the followingequation [7 9]
Fe = Fe2+ + 2eminus (3)
The resulting ferrous cations (Fe2+) are not stable and oxidizeto ferric cations (Fe3+) as follows
Fe2+ = Fe3+ + eminus (4)
The severity of these reactions increases with increase ofthe immersion time which could lead to the increaseddissolution of steel and also explain the increased currentsand corrosion rate with increasing the time of immersion
In order to evaluate the effect of ATA as a corrosioninhibitor after the different stated exposure intervals thepotentiodynamic polarization measurements were also car-ried out Figure 8 shows the potentiodynamic polarizationcurves obtained for the HSLA steel after its immersion in
6 Journal of Chemistry
Table 2 Corrosion parameters obtained from the potentiodynamic polarization measurements for the HSLA steel electrode that wasimmersed for different periods of time in 20M H2SO4 solutions with and without ATA molecules
Figure 7 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for (1) 10min and (2) 60min in 20MH2SO4solutions
20M H2SO4solutions for 10min in (1) the absence and the
presence of (2) 10mM and (3) 50mM ATA respectivelyIn order to study the effect of immersion time on theefficiency of ATA molecules the polarization measurementswere performed after 60min and the curves are shown inFigure 9The values of the parameters obtained from Figures8 and 9 as well as the calculated values of IE are alsolisted in Table 2 The values of IE were obtained from thepolarization data according to the following equation [9 1718]
IE =119895Corr minus 119895
oCorr
119895Corrtimes 100 (5)
where 119895Corr and 119895oCorr are the corrosion current densities in the
absence and presence of ATA molecules respectivelyThe addition of 10mM ATA within the acid solution
after all immersion periods of time remarkably decreasedthe anodic cathodic and corrosion currents The data listedin Table 2 also indicated that the values of 119895Corr and 119877Corrdecreased while the value of 119877
119901increased in the presence
of 10mM ATA compared to those recorded in its absenceThis was perhaps due to the ability of ATA molecules tobe adsorbed onto the steel surface where the adsorption of
1
2
3
10minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 8 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 10min in 20M H
2SO4in the
absence (1) and the presence of (2) 10mMATAand (3) 50mMATArespectively
2
3
110minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 9 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 60min in 20M H
2SO4in the
absence (1) and the presence (2) of 10mMATAand (3) 50mMATArespectively
Journal of Chemistry 7
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
Figure 2 SEM micrographs obtained for the HSLA steel after 24 h immersion in 20M H2SO4solutions (a) without ATA and (b) with
50mM ATA present and (c) EDS profile analysis corresponding to the surface shown in Figure 2(b) respectively
32 SEM and EDS Investigations In order to investigate theeffect ofH
2SO4in the absence andpresence ofATAmolecules
on the corrosion of the HSLA steel SEM micrograph andEDS profile analysis were carried out Figure 2 shows theSEM micrographs obtained for the HSLA steel after 24 himmersion in 20M H
2SO4solutions (a) without ATA and
(b) with 50mM ATA present and (c) EDS profile analysiscorresponding to the surface shown in Figure 2(b) respec-tively The SEM micrograph shown in Figure 2(a) shows atotal deterioration for the surface of steel which was due tothe aggressiveness attack of the sulfuric acid solution TheEDS profile analysis taken for the steel at this condition [7]indicated that its surface has the main alloying elements inaddition to the presence of carbon sulfur and oxygen Thepresence of C O and S was due to the effect of sulfuric acidsolutions as well as the exposure of the steel surface to air afterremoving it from the acid solution
On the other hand the SEM micrograph shown inFigure 2(b) proved that the surface of the steel is coveredwith a homogeneous layer of the adsorbed ATA moleculesThis was confirmed by the EDS profile analysis shown inFigure 2(c) where the atomic percentages of the elementsfound on the steel surface were 544 C 093 N 5365 O734 S 069 V 249 Cr 077 Ni 012 Cu and 2858Fe The presence of nitrogen in the analysis confirms thatthe ATA molecules are included in the layer present on thesurfaceThe presence of very high amount of Cr compared tothat originally present in the steel in addition to the very highpercent of oxygen indicates that the surface is also passivated
through the formation of chromium oxide layer along withthe adsorbed layer of the ATA molecules Moreover thepresence of very low amounts of Fe and Ni reveals that theformed ATA layer is thick and is homogenously distributedon the surface Another proof for the ability of the ATAmolecules to inhibit the HSLA steel corrosion in the sulfuricacid test solution was the black color of the solution whichdid not have any ATA compound and was due to the severedissolution of the steel while the color of the acid solutioncontaining 50mM ATA was clear and unchanged even after24 h of the steel immersion It has been reported [9 18ndash20] that the inhibition of metal corrosion by using similarcompounds to ATA is achieved by the adsorption of theirmolecules onto the metal surface preventing it from beingattacked by corrosive media
33 Electrochemical Impedance Spectroscopy (EIS) Measure-ments It has been reported [10 20ndash22] that EIS is a pow-erful method in understanding the corrosion and corrosioninhibition for different metals and alloys in aggressive envi-ronments In this work we employed the EIS experimentsto obtain the kinetic parameters for the steelsulfuric acidsolution interface after different exposure periods In orderto report the effect of immersion time on the corrosion of theHSLA steel in 20M H
2SO4solution the EIS measurements
were conducted after (1) 10min and (2) 60min immersionand the Nyquist spectra were plotted respectively as shownin Figure 3
4 Journal of Chemistry
0 2 4 6 8 10
0
1
2
3
4
5
2
1
minus1
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 3 Nyquist plots for the HSLA steel after its immersion for(1) 10min and (2) 60min in the 20MH
2SO4solutions respectively
It is clearly seen that the steel in the acid solutionshows only one distorted semicircle whose diameter gotsmaller with the increase of immersion time from 10minto 60min This indicates that the increase of the time ofimmersion increases the dissolution of steel in sulfuric acidsolution through decreasing its corrosion resistanceThis wasconfirmed by fitting the EIS data to the best equivalent circuitmodel which is shown in Figure 4 This equivalent circuitmodelwas also used to fit the EIS data obtained from studyingthe corrosion and corrosion inhibition of maraging steel indifferent sulfuric acid solutions [7 9] The parameters of theused circuit can be defined according to usual conventionas follows 119877
119904represents the solution resistance 119876 is the
constant phase elements (CPEs) 1198771199011is the polarization resis-
tance for the solutionsteel interface and can be defined asthe charge transfer resistance [23]119877
1199012is another polarization
resistance for the corrosion productsteel interface and 119871 isthe inductance The values of these parameters are listed inTable 1 It is also seen from Table 1 that the values of 119877
119904 1198771199011
1198771199012 and 119871 decrease while the value of 119876 (CPEs) increases
by the increase of immersion time from 10min to 60minfor the HSLA steel in 20M H
2SO4solutions This is due
to the corrosiveness action of the sulfuric acid solution thatcontinuously attacks the surface of the steel and lowers itsprobability to develop oxide layers or corrosion products andthat effect increases with increasing time of contact betweenthe acid and the steel
The EIS measurements were also employed to report theeffect of ATA molecules on the inhibition of the HSLA steelin 20M H
2SO4solutions Figure 5 shows the Nyquist plots
obtained for the steel after 10min immersion in the acidsolution that contains (1) 00 (2) 10 and (3) 50mM ATArespectively Similar plots were also obtained for the HSLAsteel after its immersion in the acid solution in the absenceand presence of ATA for 60min and the curves are shown inFigure 6 The equivalent circuit shown in Figure 4 was alsoused to represent the best fitting for the data presented inFigures 5 and 6The EIS parameters obtained out of the fitteddata as well as the values of the percentage of the inhibition
Rs
RP1
RP2
Q
L
Figure 4The equivalent circuit used to fit the experimental EIS dataobtained for the HSLA steel after its immersion for different periodsof time in 20M sulfuric acid solution
efficiency (IE) are listed in Table 1 The values of IE werecalculated according to the following equation [18]
IE =119877in119875minus 119877
O119875
119877in119875
(1)
where 119877in119875and 119877O
119875are polarization resistance of the HSLA
steel in the sulfuric acid solution in the presence and absenceof ATA molecules respectively
It is clearly seen from Figure 5 that the addition of 10mMATA within the sulfuric acid solution increased the diameterof the semicircle Increasing the concentration of ATA to50mM further increased the diameter of the semicircleobtained for the steel This indicates that the presence ofATA and the increase of its concentration decrease thecorrosion of the HSLA steel after 10min immersion in 20MH2SO4solutions It has been reported [18 20 24] that ATA
molecules inhibit the corrosion via their adsorption ontothe surface of metals (such as iron [20] and copper [18 24])and the ability of ATA as a corrosion inhibitor increaseswith the increase of its concentration This agrees with thecurrent results as indicated by the parameters recorded inTable 1 where the values of 119877
1199041198771199011 1198771199012 and 119871 as well as IE
increased with the increase of ATA concentrationIt is obvious from Figure 6 for the steel after 60min
in the acid solution without and with ATA present thatthe presence of 10mM ATA decreased the aggressivenessaction of the sulfuric acid solution by increasing its corrosionresistanceThis was revealed by increasing the diameter of thesemicircle obtained for the steel in the presence of 10mMATA compared to its diameter in the blank solution Furtherincreasing the ATA concentration to 50mM produced fur-ther increase in the diameter of the semicircle after 60minTable 1 also confirmed that the presence of ATA and theincrease of its concentration increased the values of 119877
119904 1198771199011
1198771199012 and 119871 The increase of 119877
119904 1198771199011 and 119877
1199012in the presence
of ATA and with the increase of its content indicates thatATA molecules have the ability to increase the solution andcorrosion resistance of the HSLA steel surface and that effectincreases with increasing ATA concentration in the acidsolutionThe values of CPEs with their n values close to unityrepresent double layer capacitors decreased in the presenceof ATA and with the increase of its content which wasexpected to cover up the charged surfaces [23] Moreover thevalues of IEwere found to increase not only with increasingconcentration of ATA from 10mM to 50mM but also withincreasing the immersion time as can be seen from Table 1
Journal of Chemistry 5
Table 1 Parameters obtained by fitting the EIS data with the equivalent circuit shown in Figure 4 for theHSLA steel in 20MH2SO4 solutions
Figure 5 Nyquist plots for the HSLA steel after its immersion for10min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
0 2 4 6 8 10 12
0
2
4
6
3
2
1
minus2
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 6 Nyquist plots for the HSLA steel after its immersion for60min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
The outcome of the EIS experiments proves that ATA can beemployed tomitigate the corrosion of theHSLA steel in 20MH2SO4solutions and its ability as a good corrosion inhibitor
increases with the increase of its concentration as well as theincrease of the time of immersion before measurement
34 Potentiodynamic Polarization Measurements The effectof increasing the immersion time on the dissolution of theHSLA steel in 20M H
2SO4solutions was investigated using
potentiodynamic polarization measurements The potentio-dynamic polarization curves obtained for HSLA steel after itsimmersion in 20M H
2SO4solutions for (1) 10min and (2)
60min are shown in Figure 7The corrosion potential (119864Corr)corrosion current density (119895Corr) cathodic (120573c) and anodic(120573a) Tafel slopes polarization resistance (119877
119901) and corrosion
rate (119877Corr) that were obtained from polarization curves arelisted inTable 2The values of these parameterswere obtainedas previously reported [17ndash21] It is clearly seen from Figure 7and Table 2 that the increase of immersion time increases thevalues of 119895Corr cathodic and anodic currents and 119877Corr whileit decreases the values of 119877
119901 This was due to the continuous
dissolution of the HSLA steel under the harsh attack of theconcentrated solution of the sulfuric acid which does notallow the surface of steel to form protective layers andorcorrosion products At this condition the cathodic reactionfor the steel in the sulfuric acid solution has been reported tobe the hydrogen evolution reaction as follows [7 9 25]
2H+ + 2eminus = H2
(2)
On the other hand the anodic reaction of the HSLAsteel is the dissolution of its iron according to the followingequation [7 9]
Fe = Fe2+ + 2eminus (3)
The resulting ferrous cations (Fe2+) are not stable and oxidizeto ferric cations (Fe3+) as follows
Fe2+ = Fe3+ + eminus (4)
The severity of these reactions increases with increase ofthe immersion time which could lead to the increaseddissolution of steel and also explain the increased currentsand corrosion rate with increasing the time of immersion
In order to evaluate the effect of ATA as a corrosioninhibitor after the different stated exposure intervals thepotentiodynamic polarization measurements were also car-ried out Figure 8 shows the potentiodynamic polarizationcurves obtained for the HSLA steel after its immersion in
6 Journal of Chemistry
Table 2 Corrosion parameters obtained from the potentiodynamic polarization measurements for the HSLA steel electrode that wasimmersed for different periods of time in 20M H2SO4 solutions with and without ATA molecules
Figure 7 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for (1) 10min and (2) 60min in 20MH2SO4solutions
20M H2SO4solutions for 10min in (1) the absence and the
presence of (2) 10mM and (3) 50mM ATA respectivelyIn order to study the effect of immersion time on theefficiency of ATA molecules the polarization measurementswere performed after 60min and the curves are shown inFigure 9The values of the parameters obtained from Figures8 and 9 as well as the calculated values of IE are alsolisted in Table 2 The values of IE were obtained from thepolarization data according to the following equation [9 1718]
IE =119895Corr minus 119895
oCorr
119895Corrtimes 100 (5)
where 119895Corr and 119895oCorr are the corrosion current densities in the
absence and presence of ATA molecules respectivelyThe addition of 10mM ATA within the acid solution
after all immersion periods of time remarkably decreasedthe anodic cathodic and corrosion currents The data listedin Table 2 also indicated that the values of 119895Corr and 119877Corrdecreased while the value of 119877
119901increased in the presence
of 10mM ATA compared to those recorded in its absenceThis was perhaps due to the ability of ATA molecules tobe adsorbed onto the steel surface where the adsorption of
1
2
3
10minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 8 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 10min in 20M H
2SO4in the
absence (1) and the presence of (2) 10mMATAand (3) 50mMATArespectively
2
3
110minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 9 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 60min in 20M H
2SO4in the
absence (1) and the presence (2) of 10mMATAand (3) 50mMATArespectively
Journal of Chemistry 7
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
Figure 3 Nyquist plots for the HSLA steel after its immersion for(1) 10min and (2) 60min in the 20MH
2SO4solutions respectively
It is clearly seen that the steel in the acid solutionshows only one distorted semicircle whose diameter gotsmaller with the increase of immersion time from 10minto 60min This indicates that the increase of the time ofimmersion increases the dissolution of steel in sulfuric acidsolution through decreasing its corrosion resistanceThis wasconfirmed by fitting the EIS data to the best equivalent circuitmodel which is shown in Figure 4 This equivalent circuitmodelwas also used to fit the EIS data obtained from studyingthe corrosion and corrosion inhibition of maraging steel indifferent sulfuric acid solutions [7 9] The parameters of theused circuit can be defined according to usual conventionas follows 119877
119904represents the solution resistance 119876 is the
constant phase elements (CPEs) 1198771199011is the polarization resis-
tance for the solutionsteel interface and can be defined asthe charge transfer resistance [23]119877
1199012is another polarization
resistance for the corrosion productsteel interface and 119871 isthe inductance The values of these parameters are listed inTable 1 It is also seen from Table 1 that the values of 119877
119904 1198771199011
1198771199012 and 119871 decrease while the value of 119876 (CPEs) increases
by the increase of immersion time from 10min to 60minfor the HSLA steel in 20M H
2SO4solutions This is due
to the corrosiveness action of the sulfuric acid solution thatcontinuously attacks the surface of the steel and lowers itsprobability to develop oxide layers or corrosion products andthat effect increases with increasing time of contact betweenthe acid and the steel
The EIS measurements were also employed to report theeffect of ATA molecules on the inhibition of the HSLA steelin 20M H
2SO4solutions Figure 5 shows the Nyquist plots
obtained for the steel after 10min immersion in the acidsolution that contains (1) 00 (2) 10 and (3) 50mM ATArespectively Similar plots were also obtained for the HSLAsteel after its immersion in the acid solution in the absenceand presence of ATA for 60min and the curves are shown inFigure 6 The equivalent circuit shown in Figure 4 was alsoused to represent the best fitting for the data presented inFigures 5 and 6The EIS parameters obtained out of the fitteddata as well as the values of the percentage of the inhibition
Rs
RP1
RP2
Q
L
Figure 4The equivalent circuit used to fit the experimental EIS dataobtained for the HSLA steel after its immersion for different periodsof time in 20M sulfuric acid solution
efficiency (IE) are listed in Table 1 The values of IE werecalculated according to the following equation [18]
IE =119877in119875minus 119877
O119875
119877in119875
(1)
where 119877in119875and 119877O
119875are polarization resistance of the HSLA
steel in the sulfuric acid solution in the presence and absenceof ATA molecules respectively
It is clearly seen from Figure 5 that the addition of 10mMATA within the sulfuric acid solution increased the diameterof the semicircle Increasing the concentration of ATA to50mM further increased the diameter of the semicircleobtained for the steel This indicates that the presence ofATA and the increase of its concentration decrease thecorrosion of the HSLA steel after 10min immersion in 20MH2SO4solutions It has been reported [18 20 24] that ATA
molecules inhibit the corrosion via their adsorption ontothe surface of metals (such as iron [20] and copper [18 24])and the ability of ATA as a corrosion inhibitor increaseswith the increase of its concentration This agrees with thecurrent results as indicated by the parameters recorded inTable 1 where the values of 119877
1199041198771199011 1198771199012 and 119871 as well as IE
increased with the increase of ATA concentrationIt is obvious from Figure 6 for the steel after 60min
in the acid solution without and with ATA present thatthe presence of 10mM ATA decreased the aggressivenessaction of the sulfuric acid solution by increasing its corrosionresistanceThis was revealed by increasing the diameter of thesemicircle obtained for the steel in the presence of 10mMATA compared to its diameter in the blank solution Furtherincreasing the ATA concentration to 50mM produced fur-ther increase in the diameter of the semicircle after 60minTable 1 also confirmed that the presence of ATA and theincrease of its concentration increased the values of 119877
119904 1198771199011
1198771199012 and 119871 The increase of 119877
119904 1198771199011 and 119877
1199012in the presence
of ATA and with the increase of its content indicates thatATA molecules have the ability to increase the solution andcorrosion resistance of the HSLA steel surface and that effectincreases with increasing ATA concentration in the acidsolutionThe values of CPEs with their n values close to unityrepresent double layer capacitors decreased in the presenceof ATA and with the increase of its content which wasexpected to cover up the charged surfaces [23] Moreover thevalues of IEwere found to increase not only with increasingconcentration of ATA from 10mM to 50mM but also withincreasing the immersion time as can be seen from Table 1
Journal of Chemistry 5
Table 1 Parameters obtained by fitting the EIS data with the equivalent circuit shown in Figure 4 for theHSLA steel in 20MH2SO4 solutions
Figure 5 Nyquist plots for the HSLA steel after its immersion for10min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
0 2 4 6 8 10 12
0
2
4
6
3
2
1
minus2
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 6 Nyquist plots for the HSLA steel after its immersion for60min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
The outcome of the EIS experiments proves that ATA can beemployed tomitigate the corrosion of theHSLA steel in 20MH2SO4solutions and its ability as a good corrosion inhibitor
increases with the increase of its concentration as well as theincrease of the time of immersion before measurement
34 Potentiodynamic Polarization Measurements The effectof increasing the immersion time on the dissolution of theHSLA steel in 20M H
2SO4solutions was investigated using
potentiodynamic polarization measurements The potentio-dynamic polarization curves obtained for HSLA steel after itsimmersion in 20M H
2SO4solutions for (1) 10min and (2)
60min are shown in Figure 7The corrosion potential (119864Corr)corrosion current density (119895Corr) cathodic (120573c) and anodic(120573a) Tafel slopes polarization resistance (119877
119901) and corrosion
rate (119877Corr) that were obtained from polarization curves arelisted inTable 2The values of these parameterswere obtainedas previously reported [17ndash21] It is clearly seen from Figure 7and Table 2 that the increase of immersion time increases thevalues of 119895Corr cathodic and anodic currents and 119877Corr whileit decreases the values of 119877
119901 This was due to the continuous
dissolution of the HSLA steel under the harsh attack of theconcentrated solution of the sulfuric acid which does notallow the surface of steel to form protective layers andorcorrosion products At this condition the cathodic reactionfor the steel in the sulfuric acid solution has been reported tobe the hydrogen evolution reaction as follows [7 9 25]
2H+ + 2eminus = H2
(2)
On the other hand the anodic reaction of the HSLAsteel is the dissolution of its iron according to the followingequation [7 9]
Fe = Fe2+ + 2eminus (3)
The resulting ferrous cations (Fe2+) are not stable and oxidizeto ferric cations (Fe3+) as follows
Fe2+ = Fe3+ + eminus (4)
The severity of these reactions increases with increase ofthe immersion time which could lead to the increaseddissolution of steel and also explain the increased currentsand corrosion rate with increasing the time of immersion
In order to evaluate the effect of ATA as a corrosioninhibitor after the different stated exposure intervals thepotentiodynamic polarization measurements were also car-ried out Figure 8 shows the potentiodynamic polarizationcurves obtained for the HSLA steel after its immersion in
6 Journal of Chemistry
Table 2 Corrosion parameters obtained from the potentiodynamic polarization measurements for the HSLA steel electrode that wasimmersed for different periods of time in 20M H2SO4 solutions with and without ATA molecules
Figure 7 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for (1) 10min and (2) 60min in 20MH2SO4solutions
20M H2SO4solutions for 10min in (1) the absence and the
presence of (2) 10mM and (3) 50mM ATA respectivelyIn order to study the effect of immersion time on theefficiency of ATA molecules the polarization measurementswere performed after 60min and the curves are shown inFigure 9The values of the parameters obtained from Figures8 and 9 as well as the calculated values of IE are alsolisted in Table 2 The values of IE were obtained from thepolarization data according to the following equation [9 1718]
IE =119895Corr minus 119895
oCorr
119895Corrtimes 100 (5)
where 119895Corr and 119895oCorr are the corrosion current densities in the
absence and presence of ATA molecules respectivelyThe addition of 10mM ATA within the acid solution
after all immersion periods of time remarkably decreasedthe anodic cathodic and corrosion currents The data listedin Table 2 also indicated that the values of 119895Corr and 119877Corrdecreased while the value of 119877
119901increased in the presence
of 10mM ATA compared to those recorded in its absenceThis was perhaps due to the ability of ATA molecules tobe adsorbed onto the steel surface where the adsorption of
1
2
3
10minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 8 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 10min in 20M H
2SO4in the
absence (1) and the presence of (2) 10mMATAand (3) 50mMATArespectively
2
3
110minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 9 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 60min in 20M H
2SO4in the
absence (1) and the presence (2) of 10mMATAand (3) 50mMATArespectively
Journal of Chemistry 7
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
Figure 5 Nyquist plots for the HSLA steel after its immersion for10min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
0 2 4 6 8 10 12
0
2
4
6
3
2
1
minus2
minusZ998400998400
(Ωcm
2)
Z998400 (Ω cm2)
Figure 6 Nyquist plots for the HSLA steel after its immersion for60min in 20MH
2SO4solutions in (1) the absence and the presence
of (2) 1mM ATA and (3) 5mM ATA respectively
The outcome of the EIS experiments proves that ATA can beemployed tomitigate the corrosion of theHSLA steel in 20MH2SO4solutions and its ability as a good corrosion inhibitor
increases with the increase of its concentration as well as theincrease of the time of immersion before measurement
34 Potentiodynamic Polarization Measurements The effectof increasing the immersion time on the dissolution of theHSLA steel in 20M H
2SO4solutions was investigated using
potentiodynamic polarization measurements The potentio-dynamic polarization curves obtained for HSLA steel after itsimmersion in 20M H
2SO4solutions for (1) 10min and (2)
60min are shown in Figure 7The corrosion potential (119864Corr)corrosion current density (119895Corr) cathodic (120573c) and anodic(120573a) Tafel slopes polarization resistance (119877
119901) and corrosion
rate (119877Corr) that were obtained from polarization curves arelisted inTable 2The values of these parameterswere obtainedas previously reported [17ndash21] It is clearly seen from Figure 7and Table 2 that the increase of immersion time increases thevalues of 119895Corr cathodic and anodic currents and 119877Corr whileit decreases the values of 119877
119901 This was due to the continuous
dissolution of the HSLA steel under the harsh attack of theconcentrated solution of the sulfuric acid which does notallow the surface of steel to form protective layers andorcorrosion products At this condition the cathodic reactionfor the steel in the sulfuric acid solution has been reported tobe the hydrogen evolution reaction as follows [7 9 25]
2H+ + 2eminus = H2
(2)
On the other hand the anodic reaction of the HSLAsteel is the dissolution of its iron according to the followingequation [7 9]
Fe = Fe2+ + 2eminus (3)
The resulting ferrous cations (Fe2+) are not stable and oxidizeto ferric cations (Fe3+) as follows
Fe2+ = Fe3+ + eminus (4)
The severity of these reactions increases with increase ofthe immersion time which could lead to the increaseddissolution of steel and also explain the increased currentsand corrosion rate with increasing the time of immersion
In order to evaluate the effect of ATA as a corrosioninhibitor after the different stated exposure intervals thepotentiodynamic polarization measurements were also car-ried out Figure 8 shows the potentiodynamic polarizationcurves obtained for the HSLA steel after its immersion in
6 Journal of Chemistry
Table 2 Corrosion parameters obtained from the potentiodynamic polarization measurements for the HSLA steel electrode that wasimmersed for different periods of time in 20M H2SO4 solutions with and without ATA molecules
Figure 7 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for (1) 10min and (2) 60min in 20MH2SO4solutions
20M H2SO4solutions for 10min in (1) the absence and the
presence of (2) 10mM and (3) 50mM ATA respectivelyIn order to study the effect of immersion time on theefficiency of ATA molecules the polarization measurementswere performed after 60min and the curves are shown inFigure 9The values of the parameters obtained from Figures8 and 9 as well as the calculated values of IE are alsolisted in Table 2 The values of IE were obtained from thepolarization data according to the following equation [9 1718]
IE =119895Corr minus 119895
oCorr
119895Corrtimes 100 (5)
where 119895Corr and 119895oCorr are the corrosion current densities in the
absence and presence of ATA molecules respectivelyThe addition of 10mM ATA within the acid solution
after all immersion periods of time remarkably decreasedthe anodic cathodic and corrosion currents The data listedin Table 2 also indicated that the values of 119895Corr and 119877Corrdecreased while the value of 119877
119901increased in the presence
of 10mM ATA compared to those recorded in its absenceThis was perhaps due to the ability of ATA molecules tobe adsorbed onto the steel surface where the adsorption of
1
2
3
10minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 8 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 10min in 20M H
2SO4in the
absence (1) and the presence of (2) 10mMATAand (3) 50mMATArespectively
2
3
110minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 9 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 60min in 20M H
2SO4in the
absence (1) and the presence (2) of 10mMATAand (3) 50mMATArespectively
Journal of Chemistry 7
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
Table 2 Corrosion parameters obtained from the potentiodynamic polarization measurements for the HSLA steel electrode that wasimmersed for different periods of time in 20M H2SO4 solutions with and without ATA molecules
Figure 7 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for (1) 10min and (2) 60min in 20MH2SO4solutions
20M H2SO4solutions for 10min in (1) the absence and the
presence of (2) 10mM and (3) 50mM ATA respectivelyIn order to study the effect of immersion time on theefficiency of ATA molecules the polarization measurementswere performed after 60min and the curves are shown inFigure 9The values of the parameters obtained from Figures8 and 9 as well as the calculated values of IE are alsolisted in Table 2 The values of IE were obtained from thepolarization data according to the following equation [9 1718]
IE =119895Corr minus 119895
oCorr
119895Corrtimes 100 (5)
where 119895Corr and 119895oCorr are the corrosion current densities in the
absence and presence of ATA molecules respectivelyThe addition of 10mM ATA within the acid solution
after all immersion periods of time remarkably decreasedthe anodic cathodic and corrosion currents The data listedin Table 2 also indicated that the values of 119895Corr and 119877Corrdecreased while the value of 119877
119901increased in the presence
of 10mM ATA compared to those recorded in its absenceThis was perhaps due to the ability of ATA molecules tobe adsorbed onto the steel surface where the adsorption of
1
2
3
10minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 8 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 10min in 20M H
2SO4in the
absence (1) and the presence of (2) 10mMATAand (3) 50mMATArespectively
2
3
110minus1
10minus2
10minus3
10minus4
j(A
cmminus2)
minus06 minus05 minus04 minus03 minus02
E (V versus AgAgCl)
Figure 9 Potentiodynamic polarization curves obtained for theHSLA steel after its immersion for 60min in 20M H
2SO4in the
absence (1) and the presence (2) of 10mMATAand (3) 50mMATArespectively
Journal of Chemistry 7
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
ATA molecules onto the steel results in the formation of aprotective layer that in turn not only isolates the surface butalso blocks its active sites and thus precludes the corrosion ofthe steel in the corrosive 20M sulfuric acid solution It is alsoseen that the increase of ATA concentration to 50mMgreatlydecreased the values of 119895Corr and 119877Corr and pronouncedlyincreased the value of 119877
119901 particularly when the immersion
time was increasing This means that the increase of ATAconcentration increases the adsorption probability of itsmolecules which increases the efficiency of the formed layersin protecting the steel surface from being corroded easilyThis was also indicated by the increase of the values of IEwith the increase of ATA concentration as listed in Table 2
Although the corrosion of the HSLA steel increased withincreasing the immersion time in 20M H
2SO4solutions in
the absence of ATA molecules the corrosion of the steel wasfound to significantly decrease with the increase of immer-sion time in the presence of ATA and with the increase ofits concentration The increased corrosion of the HSLA steelin the absence of ATA was due to the rapid and harsh attackof the acid molecules toward the steel that makes its surfacefresh active and dissolvable On the other hand the presenceof ATA and the increase of its concentration strongly decreasethe corrosion of the steel with increasing the immersion timeas a result of decreasing the values of anodic and cathodiccurrents 119895Corr and 119877Corr and increasing the values of 119877119901 Thedecrease of the anodic and cathodic currents in the presenceof ATA and with the increase of its concentration confirmthat ATA is a mixed type corrosion inhibitor The decreaseof steel corrosion with time in the presence of ATA is dueto the thickening of the adsorbed ATA layers onto the steelsurface which makes it more protected and precludes itsdissolution This was also confirmed by the large increase inIE values with the increase of immersion time (see Table 2)The results obtained from the potentiodynamic polarizationmeasurements therefore confirm those ones obtained bythe EIS experiments and that the corrosion of HSLA steelincreases with increasing the immersion time in the sulfuricacid solutions It is also agreed that the addition of 10mMATA decreases the corrosion of steel and that effect increaseswith increasing both the concentration of ATA to 50mMandthe time of immersion from 10min to 60min
4 Conclusions
The corrosion and corrosion control of HSLA steel in 20MH2SO4solutions using ATA as a corrosion inhibitor after
different exposure intervals were reported Electrochemicalmeasurements indicated that the increase of immersion timefrom 10min to 60min increased the corrosion of the HSLAsteel in the sulfuric acid solutions On the other hand thepresence of ATA and the increase of its concentration werefound to provide good corrosion inhibition and that effectincreased with increasing the immersion time This wasconfirmed by the increase of the polarization and solutionresistance as well as the decrease of the anodic cathodic andcorrosion currents which in turn decreased the corrosionrate of HSLA in the acid medium Moreover the calculated
value of the inhibition efficiency IE was found to remark-ably increase with increasing both ATA concentration andimmersion time Results collectively were in good agreementwith each other showing clearly that the corrosion of HSLAsteel increases with time and also ATA is a good mixedcorrosion inhibitor due to the adsorption of its moleculesonto the steel surface
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper
Acknowledgment
The authors would like to extend their sincere appreciation tothe Deanship of Scientific Research at King Saud Universityfor its funding of this research through the Research GroupProject no RGP-VPP-160
References
[1] S L Chawla and R K Gupta ldquoMaterials Selection forCorrosion Controlrdquo ASM International 1993 httpwwwasminternationalorg
[2] I B Timokhina P D Hodgson S P Ringer R K Zheng and EV Pereloma ldquoPrecipitate characterisation of an advanced high-strength low-alloy (HSLA) steel using atom probe tomographyrdquoScripta Materialia vol 56 no 7 pp 601ndash604 2007
[3] C A Melendres N Camillone III and T Tipton ldquoLaser ramanspectroelectrochemical studies of anodic corrosion and filmformation on iron in phosphate solutionsrdquo Electrochimica Actavol 34 no 2 pp 281ndash286 1989
[4] J L Yao B Ren Z F Huang P G Cao R A Gu andZ-Q TianldquoExtending surface Raman spectroscopy to transition metalsfor practical applications IV A study on corrosion inhibition ofbenzotriazole on bare Fe electrodesrdquo Electrochimica Acta vol48 no 9 pp 1263ndash1271 2003
[5] F Bentiss M Traisnel L Gengembre and M LagreneeldquoInhibition of acidic corrosion ofmild steel by 35-diphenyl-4H-124-triazolerdquo Applied Surface Science vol 161 no 1 pp 194ndash202 2000
[6] F BGrowcock andV R Lopp ldquoThe inhibition of steel corrosionin hydrochloric acid with 3-phenyl-2-propyn-1-olrdquo CorrosionScience vol 28 no 4 pp 397ndash410 1988
[7] E-S M Sherif and A H Seikh ldquoEffects of immersion timeand 5-Phenyl-1H-tetrazole on the corrosion and corrosionmitigation of cobalt free maraging steel in 05M sulfuric acidpickling solutionsrdquo Journal of Chemistry vol 2013 Article ID497823 7 pages 2013
[8] S L Granese ldquoStudy of the inhibitory action of nitrogen-containing compoundsrdquo Corrosion vol 44 no 6 pp 322ndash3271988
[9] E-S M Sherif ldquoCorrosion inhibition in 20 M sulfuric acidsolutions of high strength maraging steel by aminophenyltetrazole as a corrosion inhibitorrdquo Applied Surface Science vol292 pp 190ndash196 2014
[10] M Lagrenee B Mernari M Bouanis M Traisnel and FBentiss ldquoStudy of the mechanism and inhibiting efficiencyof 35-bis(4-methylthiophenyl)-4H-124-triazole on mild steel
8 Journal of Chemistry
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
corrosion in acidic mediardquo Corrosion Science vol 44 no 3 pp573ndash588 2002
[11] O L Riggs Jr Corrosion Inhibitors 2nd edition edited byC C Nathan National Association of Corrosion EngineersHouston Tex USA 1973
[12] M Bartos and N Hackerman ldquoA Study of inhibition actionof propargyl alcohol during anodic dissolution of iron inhydrochloric acidrdquo Journal of the Electrochemical Society vol139 no 12 pp 3428ndash3433 1992
[13] A M S Abdennabi A I Abdulhadi S T Abu-Orabi andH Saricimen ldquoThe inhibition action of 1(benzyl)1-H-45-dibenzoyl-123-triazole on mild steel in hydrochloric acidmediardquo Corrosion Science vol 38 no 10 pp 1791ndash1800 1996
[14] A Chetouani B Hammouti A Aouniti N Benchat and TBenhadda ldquoNew synthesised pyridazine derivatives as effectiveinhibitors for the corrosion of pure iron in HCl mediumrdquoProgress in Organic Coatings vol 45 no 4 pp 373ndash378 2002
[15] M Elayyachy B Hammouti A El Idrissi and A AounitildquoAdsorption and corrosion inhibition behavior of C38 steelby one derivative of quinoxaline in 1 M HClrdquo PortugaliaeElectrochimica Acta vol 29 no 1 pp 57ndash68 2011
[16] A Zarrouk I Warad B Hammouti A Dafali S S Al-Deyaband N Benchat ldquoThe effect of temperature on the corrosionof CuHNO
3in the Presence of organic inhibitor part-2rdquo
International Journal of Electrochemical Science vol 5 no 10pp 1516ndash1526 2010
[17] E-S M Sherif ldquoCorrosion mitigation of copper in acidic chlo-ride pickling solutions by 2-amino-5-ethyl-134-thiadiazolerdquoJournal of Materials Engineering and Performance vol 19 no6 pp 873ndash879 2010
[18] E-S M Sherif ldquoComparative study on the inhibition ofiron corrosion in aerated stagnant 35 wt sodium chloridesolutions by 5-phenyl-1H-tetrazole and 3-amino-124-triazolerdquoIndustrial and Engineering Chemistry Research vol 52 no 41pp 14507ndash14513 2013
[19] E-S M Sherif A M El Shamy M M Ramla and A O H ElNazhawy ldquo5-(Phenyl)-4H-124-triazole-3-thiol as a corrosioninhibitor for copper in 35 NaCl solutionsrdquo Materials Chem-istry and Physics vol 102 no 2-3 pp 231ndash239 2007
[20] E-S M Sherif and A H Ahmed ldquoSynthesizing new hydrazonederivatives and studying their effects on the inhibition of coppercorrosion in sodium chloride solutionsrdquo Synthesis and Reactiv-ity in Inorganic Metal-Organic and Nano-Metal Chemistry vol40 no 6 pp 365ndash372 2010
[21] E M Sherif and S-M Park ldquoInhibition of copper corrosion inacidic pickling solutions by N-phenyl-14-phenylenediaminerdquoElectrochimica Acta vol 51 no 22 pp 4665ndash4673 2006
[22] S N Banerjee and S Misra ldquo110-phenanthroline as corrosioninhibitor for mild steel in sulfuric acid solutionrdquo Corrosion vol45 no 9 pp 780ndash783 1989
[23] H Ma S Chen L Niu S Zhao S Li and D Li ldquoInhibitionof copper corrosion by several Schiff bases in aerated halidesolutionsrdquo Journal of Applied Electrochemistry vol 32 no 1 pp65ndash72 2002
[24] E-S M Sherif R M Erasmus and J D Comins ldquoCorrosionof copper in aerated synthetic sea water solutions and itsinhibition by 3-amino-124-triazolerdquo Journal of Colloid andInterface Science vol 309 no 2 pp 470ndash477 2007
[25] E S M Sherif ldquoCorrosion behavior of duplex stainless steelalloy cathodically modified with minor ruthenium additions inconcentrated sulfuric acid solutionsrdquo International Journal ofElectrochemical Science vol 6 no 7 pp 2284ndash2298 2011
