S.H.VijapurT.D.HallE.J.TaylorM.E.Inman

M.Brady(ORNL)

Electrodeposited Inconel and Stellite like Coatings for Improved Corrosion

Resistance in Biocombustors

slide 2

Problem/ Oppurtunity •  Advantages of state of the art combustion systems

–  Higher Efficiency •  Reduce CO2 and poisonous gas emissions •  Lower Fuel Cost

•  Challenge: –  Requires higher operating temperatures –  Potentially requires the use of exotic process

streams •  Supercritical CO2 •  Supercritical Steam

–  Must be durable to range of burnable materials •  Wood, Gas, Coal, Waste ….

!  Need to develop novel material systems to durably perform in these

environments

slide 3

Direct Current Electrodepositable Materials (from Literature)

Ia IIa IIIa IVa Va VIa VIIa VIII Ib IIb IIIb IVb Vb VIb VIIb ο1 H

2 He

3 Li

4 Be

5 B

6 C

7 N

8 O

9 F

10 Ne

11 Na

12 Mg

13 Al

14 Si

15 P

16 S

17 Cl

18 Ar

19 K

20 Ca

21 SC

22 Ti

23 V

24 Cr

25 Mn

26 Fe

27 Co

28 Ni

29 Cu

30 Zn

31 Ga

32 Ge

33 As

34 Se

35 Br

36 Kr

37 Rb

38 Sr

39 Y

40 Zr

41 Nb

42 Mo

43 Tc

44 Ru

45 Rh

46 Pd

47 Ag

48 Cd

49 In

50 Sn

51 Sb

52 Te

53 I

54 Xe

55 Cs

56 Ba

57 La

72 Hf

73 Ta

74 W

75 Re

76 Os

77 Ir

78 Pt

79 Au

80 Hg

81 Tl

82 Pb

83 Bi

84 Po

85 At

86 Rn

Electrodeposition is a scalable cost efficient technique to obtain surfaces with controllable physical, catalytic, and structural properties. These properties can potentially be enhanced and cost effectively scale to production levels Eliaz, N., et al., “Induced Codeposition of Alloys of Tungsten, Molybdenum and Rhenium

with Transition Metals” Modern Aspects of Electrochemistry 42 Springer, NY, (2008), p 191, Ch. 4

slide 4

Direct Current Electrodepositable Alloy Materials from Water Based Solution (from Literature)

AuPt X

Ir XRe X

W X XSb X X

Sn X X X XIn X X X

Cd X X X X X XAg X X X X X X X X X

Pd X X X XRh X X X X X X

Ru X X X XMo X X X X

Zr XSe X X X X

Zn X X X X X X X X X X XCu X X X X X X X X X X X X X

Ni X X X X X X X X X X X X X X X XCo X X X X X X X X X X X X X X

Fe X X X X X X X X X X X X XMn X X X X X X X X X X

Cr X X X X X X X X X X XV X X X X X

Ti X X X X X X

With Alloy materials the composition may also be varied to obtain the variance in the desired physical properties •  Electrical Resistance •  Wear Resistance •  Thermal Resistance •  Thermal Expansion Match

Eliaz, N., et al., “Induced Codeposition of Alloys of Tungsten, Molybdenum and Rhenium with Transition Metals” Modern Aspects of Electrochemistry 42 Springer, NY, (2008), p 191, Ch. 4

slide 5

Global Initiative

•  Why: –  Nearly 4.3 Million deaths a year are due to smoke inhalation

•  Incomplete combustion producing CO and carcinogens –  Nearly $40 Billion spent annually on fuel sources

•  Some families spend up to 2 hr a day or 1/3 of income acquiring fuel

–  1 Billion Tons of CO2 year from open fires

!  Must improve burning efficiency ! Must operate at higher

temperatures !  Must design low cost material

systems to durably perform in these environments

Create more efficient, longer lasting, cleaner, and cost effective cookstoves for use in burning biomaterials

slide 6

DOE Focus Program on Low Cost CoatingsProblem:

–  Biomass combustion reactors are subjected to various corrosive attacks due to the wide range of potential materials that will be burned in them, including:

•  Gasoline, grass and other carbon based waste

–  These give off mixtures of: •  Alkali halides (fly ash particulate) •  Halogen Acids •  Water •  Sulfur and Nitrogen Oxides

Potential Solutions: 1.  Replace the composition of the internal materials used within bio-

combustors. "  Corrosion resistant SS, Ni Alloys, or Co alloys (THESE ARE COST PROHIBITIVE)

2.  Apply a high value coating to existing bio-combustors or lower cost steels. "  Coating could consist of corrosion resistant alloys like Stellite 21 or Inconel 740

slide 7

Objective of Program•  Develop a cost effective, scalable, and flexible electrodeposition based

coating process that can be applied to the corrosion sensitive regions of existing and next generation bio-combustors –  Ni and Co based alloys have been shown to possess excellent alkali/

halide attack resistance –  Co based alloys have been shown to possess sulfidation resistance –  Mo additions into the metal alloys also seem to improve corrosion

resistance and high temperature stability. –  Cr improves temperature stability and corrosion resistance in high

temperature systems Alloy Co Ni Cr Fe Mo W

Inconel® 740 20 (base) 25 0.5 – Inconel® 718 - (base) 19 25 3 - Haynes® 25 (base) 10 20 – 15 Stellite® 21 (base) 3 29 6 –

slide 8

Experimental Plan Outline•  Substrate:

–  Low cost ferritic or austenitic steels •  304 SS, 410 SS, 441 SS; 1” x 4” dual sided

•  Coating compositions –  [Co/Ni] – Cr – [Mo/Fe] (composition variance)

•  Testing Parameters: –  CTE (quick CTE test at Faraday within muffle furnace) –  Coating composition

•  XRF –  High temperature corrosion test at 700°C in Air

•  500 hr Salt Spray (Remove after every 100 hr for weight and reapplication)

•  High salt loading (3 mg/cm2) and low salt loading (1 mg/cm2) –  Cross-sectional SEM analysis of oxidation

slide 9

Electrolyte Development•  Used a Hull Cell to Rapidly design electrolyte and

processing conditions to deposit binary and ternary alloys consisting of [Ni/Co]-Cr-[Mo/Fe]

•  Used XRF to measure the deposit composition

Distance from high current

edge, cm

Elemental composition, % Cr Co

1 17.2 82.0 3 7.7 91.5

Standard Cr3+ plating solution + 43.13 g/L CoSO4⋅7H2O (0.154 M Co2+)

Distance from high current

edge, cm

Elemental composition, %

Cr Co 3.8 2.3 93.5

Standard Cr3+ plating solution + 21.65 g/L CoSO4⋅7H2O (0.077 M Co2+)

Anode

Cathode6.3 cm

12.8 cm

4.8 cm

slide 10

Compositional Screening: Ni-Cr and Ni-Co-Cr w/ Hull Cell

Hull Cell study shows that a wide range of potential deposit composition can be obtained controlling the Ni concentrations

slide 11

Compositional Screening: Ni-Cr-Fe w/ Hull Cell

slide 12

Compositional Screening: Ni-Co-Cr-Mo w/ Hull Cell

Alloy Co Ni Cr Mo Inconel® 740 20 (base) 25 0.5 Stellite® 21 (base) 3 29 6

slide 13

Scale up to 1” x 4” Coupons•  Using the electrolyte designed within the Hull Cell study and approximate applicable current

densities we transitioned to coupon studies •  Cell

–  3: 1” x 4” samples prepared simultaneously –  29 L cell Volume –  FARADAYIC®

Flow Assembly* •  Samples prepared

–  Pure Ni (Wood’s bath) •  Varying Thickness

–  Pure Cr (1411 and 1318) •  Varying Thickness

–  NiCr (Varying Ni Conc. / Thickness) •  1411 •  1318

–  NiCrFe (Thickness) •  1411 •  1318

−  NiCoCr and CoCr (Varying Thickness) −  1411

*Gebhart, L.E., and Taylor, E.J., U.S. Patent 8,329,006, December 11, 2012.

slide 14

As Plated Samples

NiCrFe

NiCoCr NiCr

Ni: 25, Cr: 20, Co:55

CoCr

Cr: 15, Co:85 Cr: 20, Co:80

slide 15

Corrosion Studies Baseline•  100 h salted oxidation [~3 mg/cm2 - high salt loading and 1

mg/cm2 – low salt loading: sea salt applied to surface from 3.5 w/w% solution prior to corrosion test]

•  Five consecutive 100 h salted oxidation •  Thermal Cycle

–  Ramping from room temperature to 100°C at 10°C/min –  Dwelling at 100°C for 30 minutes –  Ramping from 100°C to 450°C at 1-2°C/min –  Dwelling at 450°C for 60 min –  Ramping from 450°C to 700°C at 10°C/min –  Dwelling at 700°C for 100 hours –  Ramping from 700°C to room temperature at 10°C/min

slide 16

Comparison Between Substrates and Coated Parts after 500h Salted Oxidation Trials [1 mg/cm2]

Cross-Sections Post 500 h Cycle

Surface Images Post 500 h Cycle Mass-Loss Post 500 h Cycle

Ni

304 SS

316 SS

Panels A/B

slide 17

Comparison Between Substrates after 500 h Salted Oxidation Trials with High Salt Loading [3 mg/cm2]

Surface Images Post 500 h Cycle Mass-Loss Post 500 h Cycle

SS substrates 100h Salted oxidation 500h Salted oxidation

SS substrates 100h Salted oxidation 500h Salted oxidation

60Ni-40Cr

70Ni-20Cr-10Al

Ni

500h Salted oxidation

slide 18

Comparison Between Substrates and Coated Parts after 500h Salted Oxidation Trials with High Salt Loading [3 mg/cm2]

Surface Images Post 500 h Cycle

Mass-Loss Post 500 h Cycle SS441/1411/60Ni-40Cr

Coated 100h 500h

SS441/1411/25Ni-20Cr-55Co

Coated 100h 500h

SS441/1318/60Ni-40Cr

Coated 100h 400h

SS410/1318/60Ni-40Cr

Coated 100h 400h

slide 19

Corrosion Performance Overview

~ 50 w/w% NiCr alloys improve corrosion resistance of the base SS substrate by at least 70% potentially leading to a 3.4 fold

cookstove lifetime improvement

•  Pure Cr and Ni deposit do not maintain adhesion during salted corrosion studies

•  60/40 ish NiCr and NiCoCr (25/55/20) mixtures seem to have the best corrosion resistance (dependent on thickness)

•  Ternary (Ni/Cr/Fe) deposits did not maintain adhesion during oxidation study (presumably to CTE mismatch)

Composition-Electrolyte Base

Salted oxidation (500 h)

Cr - 1411 − Cr - 1318 −

Ni - Wood’s plating − NiCr - 1411 P NiCr - 1318 O P

NiFeCr - 1411 − NiFeCr - 1318 − CoCr - 1411 −

NiCoCr - 1411 P

slide 20

Baseline Economic Analysis for Exemplar Component

•  Estimate using Cookstove Design from Literature

Patent Application# PCT/US2013/068809

0.61 ft2 internal area exposed to biocombustor

hot zone

$/lb Density (lb/in3)

Cost per Volume of Material ($/in3)

Cost per Area Assume 1/8” Thick Material ($/

ft2)

Cost of 0.61 ft2 exemplar component (Fig Right)

718 IN $ 21.79 0.297 $ 6.47 $ 116.49 $ 71.06 625 IN $ 18.29 0.305 $ 5.58 $ 100.41 $ 61.25 Haynes 25 $ 48.75 0.33 $ 16.09 $ 289.58 $ 176.64 316L SS $ 2.69 0.285 $ 0.77 $ 13.80 $ 8.42 304 SS $ 1.61 0.285 $ 0.46 $ 8.26 $ 5.04 Hastelloy C-22 $ 18.96 0.314 $ 5.95 $ 107.16 $ 65.37 Stellite® 21 $ 54.75 0.301 $ 16.48 $ 296.62 $ 180.94 Stellite® 6 $ 54.03 0.305 $ 16.48 $ 296.62 $ 180.94

Bulk Wrought Material Pricing

slide 21

Initial Electrodeposition Based Economic Analysis

•  Base material cost: $5.04 •  Coating cost is a function of the

number of units produced

Line No. Plant Parameters 10,000 Units 100,000 Units 1,000,000 Units 1 Cylinder Size 0.61 ft2 0.61 ft2 0.61 ft2 2 Run Time (sec) 7200 7200 7200 3 Total Units/Hr 2 16 128 4 Total Hours worked per day 24 24 24 5 Units/Day (24 hr.) 48 384 3072 6 Days worked per year 348 348 348 7 Units/Yr. (348 days) 16,704 133,632 1,069,056 8 Plating Line Cost ($/unit) $0.48 $0.06 $0.06 9 Material Cost ($/unit) $2.03 $1.29 $1.24 10 Labor Cost ($/unit) $12.52 $1.56 $0.39 11 Total Cost ($/unit) $15.03 $2.91 $1.69

Coating Cost Estimate Patent Application# PCT/US2013/068809

slide 22

Overall Conclusions•  Demonstrated a wide range of [Co/Ni] – Cr – [Mo/Fe] alloy coating

compositions can produced •  Demonstrated process scalability from a Hull Cell to flat coupons •  Demonstrated the potential of specific coatings to surpass 500 h accelerate high

temperature corrosion testing –  50 w/w% NiCr alloys improve corrosion resistance of the base SS

substrate by at least 70% potentially leading to a 3.4 fold cookstove lifetime improvement

•  Demonstrated that the process maybe an economically viable approach for improve cook stove biocombustor lifetimes –  Cost estimate for 50 w/w% NiCr coating is $2.93/ in3 or $1.69 per 4 mil

coating on a 0.61 ft2 component produced at 1,000,000 units per year –  This would realize a 89% cost reduction compared to base IN625

materials

slide 23

Next Steps

•  Evaluate the potential of other alloy systems –  Co-Ni-Cr –  Ni-Cr-Mo/W –  Addition of Si or Al to the deposit

•  Validate performance in combustion test rigs at ORNL

slide 24

Special thanks to all our team members for their support

THANK YOU FOR YOUR ATTENTION!

QUESTIONS?

Contact Information:Santosh Vijapur, Tim Hall, Maria Inman, or EJ Taylor

Ph: 937-836-7749 Email: santoshvijapur@faradaytechnology.com

timhall@faradaytechnology.commariainman@faradaytechnology.com

jenningstaylor@faradaytechnology.com