Eighth Edition
Volume l
VVELDING
HANDBOOK
Leonard P.Connor
Editor
AMERICAN VVELDING SOCIETY
550 N.W.LeJeune Road
P.0.Box 351040
Miami,FL 33135
WELDING TECHNOLOGY
1
The Three Volumes of
the VVeldin9 1`・・landbook.
Eighth Edition
2
。
1)WELDING TECHNOLOGY
2)WELDING PROCESSES
3)MATERIALS AND APPLICATIONS
L.M.Friedman,Chairman
Westingbot4seEectγic
C○γpoγatl0,7
XVバV. Canary
Teldyれe CAE
P・J.Konko1
USX Co巾oγatlon
S. D. Reynolds Jr・
Westingb014seEectγic
Co巾07ati0,1
一三~~~……・、。
PREPARED BY A
COMMITTEE CONSISTING
OF:
VVELDING
METALLURGY禍IELDING HANDBOOKCOMMIITTEE IVIEMBERzL・ J. Privoznik
WestingbouseElectγic
Coゆor討jo,z
103
Weldability of Commercial AIloys
::||
lntroduction
General Metallurgy
The Metallurgy of Welding
jll
112
Supplementary Reading List 123
Brazing and Soldering Metallurgy
Weldability Testin9 119
-
122
- … … …
3
CONTENTS
WELDING HANDB00K V
VI
1
CHAPTER I, SURVEY OF JOINING AND CUTTING PROCESSES …………………24678912356670
111122222223
rnd6747
66688
1243048niu
33345556
Resistance
Flash
Oxyfuel Gas
Solid State
Electron Beam W
Laser Beam W
Adhesive
Thermal
Thermal Cutting
Supplementary
CHAPTER 2, PHYSICS OF
Energy Sources for
Metal T
Melting
Physical Properties of Metals and Shielding
Suppleme由ry R
CHAPTER 3, HEAT FLOW IN
Fundamentals of Heat
Solidification
Supplementary
V
㎜ ■ ■ ■ ■ ㎜ ㎜ ■
CONTENTS
7
CHAPTER 4, WELDING MET,WWXWXWr
ll-fjfj
111
General
The Metallurgy of
Weldability of Commercial
Weldability
Brazing and Soldering
Supplementary
1;
1;
1:
1!
CHAPTER 5, DESIGN FOR WGeneral
SIS N ~f l WWg
Design
Properties of
Welded Design
Sizing of Steel
Aluminum
Design of Welded
Structural Tubular
Supplementary
CHAPTER 6, SYMBOLS FOR WELDING AND INSPECT10N ……………………… 1!WS~SS 9
22
Welding
Brazing
Nondestructive Examination
2‘CHAPTER 7, RESIDUAL STRESSES AND DISTORT10N ……………………,‥‥‥ZZZZZZ22
Weld
Residual
Causes of Residual
Effects of Residual
Measurement of Residual SIresses in
Typical Residual Stresses in
Reducing Residual Stresses and
Supplementary
CHAPTER 8, WELDING AND CUTI・ING COSTS: ESTIMATES AND CONTROLS ….2t6j 5j
Estimating Weldin9
Vi
50356
78888
22222
CONTENTS
Capital
Control of Welding
Economics of Brazing and
Economics of Thermal
SupplementarY
CHAPTER 9, FIXTURES AND POSIT10 7820
8891
2223
Supplementary
レに……::j CHAPTER 10,AUTOMAT10N AND 122365357
31311323233343434
Procurement
Fundamentals of Welding
Brazing
Arc Welding
Resistance Welding
Problems of
Supplementary
CHAPTER 11, WELD 902249692
45556677
333333333
8
Discontinuities in Fusion Weldin9
Significance of Weld
SupplementarY
Causes and Remedies for Fusion Weld
Discontinuities in Brazed and Soldered
Discontinuities in Resistance and Solid State
CHAPTER 12, TESTING FOR EVALUAT10N OF WE567825799
383838394040404040
Tensile Properties-Strength and
Fracture T
Corrosion Factors Affecting the Testing and Performance of Welded
Fatigue Properties of Welded Structural
Supplementary
Elevated Temperature
Tests of Thermal Spray
Vii
6
CONTENTS
411
412
413
413
415
CHAPTER 13, CODES AND OTHER STAN
78915234
33355666
44444444
666788000455691222‐6no
4141引414141む一″`’一`’″’む一む一む一む’n”`”り’り’り43
American Welding
American Bureau of
American Association of State Highway and Transportation
SAE
Federal
Compressed Gas
American lnstit由of Steel
American Petroleum l
American National Standards l
American Railway Engineering
American Waterworks
American SocietY for Testing and
American SocietY for Mechanical Engi
Association of American
Canadian Standards
National Fire Protection
lntemational Organization for
Underwriters
Pipe Fabrication
National Board of Boiler and Pressure Vessel
Manufacturers’
CHAPTER 14, QUALIFICAT10N AND CERTIFICA
Procedure
Qualification of Welding Procedure
Performance
〔luality Control and lnspection
Standardization of〔lualification
Supplementary
566785
666661
44444Ln
CHAPTER 15, 1NS
Requirements for
Welding l
lnspection
Nondestructive
Destructive T
Viii
CONTENTS
516
517
Brazed
Supplementary
9076030
122344Ln
5555551jl
CHAPTER 16, SAFEGeneral Weldin9
Electrical
Fumes and
Handling of Compressed
Supplementary
一l一
59
1
iX
・ 一 一 一 一 一
90 Welding Meta川u「9y
WELDINGMETALLURGY
WELDING INVOLVESλ/IANY nletallurgical phenolnena.ing of welding metanurgy requires a broad knowledge of
general metallurgy. For thisreason,general metallurgy
is addressed first, and then the specific aspects of weld-
ing metallurgy are discussed. The survey of general
metallurgy is by no means eχhaustive, and those who
wish to increase their knowledge of the discipline are
directed to spedfic references in the Supplemcりtary
Reading List. ……,……………
INTRODUCTION
gical principles to the welding process.
MZelding metallurgy differs from conventional metal-
1urgy ill certain important respects, but an understand-
transformations,thermal strains
can cause nlany practical probk
be avoided or solved by apply≒
These phenonlenasuch as melting,
GENERAL METALLURGY
STRUCTURE OFMETALS E2ch g13111 il1 3 p111e “le゛h1 311y p3111c山“elllpe13`
ture has the same crystallme structure and the same
SOLID METALS HAVE a crystalline structure in which the atomic spacing as an other grains. However,each grain
atoms of each crystal arearranged in a specific geometric grows independently of every other grain, and the orien-
pattem. This orderlyarrangement of the atoms, called a tation of the grain lattice differs from one grain to
lattice,is responsible for many of the properties of met- another. The periodic and orderlyarrangement of the
als.The most common lattice structures found in metals atoms is disruPted where the grains meet, and the grain
are listed in Table 4.1,and their atomicarrangemellts bound21‘ies form a continuous network throughout the
are nlustrated in Figure 4.1. meta1. Becauseof this grain boundary disorder, there
ln the liquid state, the atoms composing metals have often aredifferences in the behavior of the metal at those
no orderlyarrangement. As the liquid metal apProaches locations.
the solidification temperature, solid partides called Up to this point, only Pure metals have been consid-
nuclei begin to form at Preferred sites, as shown in Fig- ered. However, most common engineering metalscon-
ure 4.2(A).Solidification proceeds, Figure 4.2(B),as the tain residual or intentionally added metanic and
individual nudei grow into larger solid partides called nonmetallic elements dissolved in the matrix. These
grains. As the amount of solid metal increases, of ingrediellts,called alloying elements, affect the proper-
course,the amount of liquid metal decreases propor- ties of the base metal. The atomicarrangement(crystal
tionately, and the grains grow larger until there is no liq- structure),the chemical composition, and the thermal
uid between them. The grains meet at irregular and mechanical history have aninfluence on the Proper-
boundaries called grain boundaries, Figure 4.2(C). ties of an anoy.
9
g
Welding Meta目u「9y 91
B.Body Centered Cubic
Chromium
|「onb
Molybdenum
Columbium
【Figure 4.1(B)】
Titaniumc
Tungsten
Vanadium
Zirconiumc
SOLID GRAINS Table 4.1
Crystal Structures of Common Metals
A.Face Centered Cubic[Figure 4.1(A)】
Aluminum lronb
Cobalta Lead
Copper Nickel
Gold Silver
INITIAL CRYSTAL SITES
SOLID GRAINS WITH
GRAIN BOUNDARIES
a.CobaFt is face・centered cubic at high temperalure and transforms to
hexagonal c10se packed al lower temperatures.
b.lron is body-centered cubic near the melting temperature and again at low
temperatures,but at intermediate temperatures iron is face-centered cubic.
c. Titanium and Zjrconium are body・centered cubic at high temperature and
heχagonal c10se packed at lowertemperature&
C.Hexa9onal Close Packed [Figure 4.1(C)]
Cobalta Titaniumc
Magnesium Zinc
Tin Zirconiumc
(B)Continued
Solidification
(A)lnitial Crystal
Formation
(A)Face-Centered
Cubic
(B)Body Centered
Cubic
(C)Heχa9onal-Close
Packed
(C)Complete Solidification
Figure4.2-Solidification of a Metal
A110ying elements, caUed solz4。s,are located in the
parent metal matrix inoneof two ways. The solute
atoms mayoccuPy lattice sites replacing some atoms of
the Parent metal atoms, called the so4zg耐.Alternatively,
if the solute atoms are smallenough,they may fit into
spacesbetween the solvent atoms.
Substitutional AIloyin9. lf the solute atoms occupy
sites at the lattice locations as shown in Figure 4.3(A),
then the type of alloy is called a substitutional solid solu-
tion. Examples of substitutional solid solutions are gold
dissolved in silver, and copper dissolved in nickel.
lnterstitial AIloyin9.Wyhen the alloying atoms are
smalhn relation to the parent atoms, they can locate (or
dissolve)in the spacesbetween the parent metal atoms
without occupying lattice sites. This type of solid solu-
tion is called 加たr兌丿庇z/,and is illustrated in Figure
4,3(B).Small amounts of carbon, nitrogen, and hydro-
gencanalloy interstitiany in iron and other metals.
MUltiphaSe AI10yS
FREQUENTLY,THE ALLOYING atoms cannot dissolve
completely,either interstidaUyor substitutionally.The
Figure4.1-The Three Most Common Crystal
Structures in Metals
92 Welding Meta川urgy
(A)
(A)
(B)
(B)
result,in such cases, is the formation of miχed atomic
groupings(different crystamne structures)within a sin-
gle alloy. Each different crystalline structure is referred
Figure4.3-Schematic lllustration of Substitutional
and lnterstitial Solid Solutions
ferrite and the darkareas arepearUte. The latter struc‘
ture is comPosed of two Phases, ferrite and iroil carbide.
Figure 4.4(B)shows multiple Phases within the grains of
an aluminum-silicon alloy。
Commercial metals consist of a primary or basic ele-
ment and smaller amounts of one or more alloying ele-
ments. The alloying elements lllay be intentionally
to as a phase, and the alloy is called a multiphase alloy.
The individual phases rnay be distinguished one from
- ---another,under a microscope at magnificationsof50to
2000 times, when the alloy is suitably polished and added,or they may be residual (tramp)elements.Com-
etched. The process of Polishing, etching, and exalnin’ mercial metals may be single or multiphase alloys. Each
ing metals at some magnification is called metallogra- phase will have its own characteristic crystalline
phy.Metallographic eχamination isonexvay of studying structure.
the mally characteristics of metals alld alloys. The overall allrangelllent of the grains, grain bounda-
Two examples of multiphase alloysareshown in Fig- ries, and phasespresent in a metal alloy is called the
ure 4.4. The typical microstructure of low-carbon pearl- micTostn4ct14Teof the anoy. The microstructure is
itic steehs shown in Figure 4.4(A).The light areas are largely responsible for the physical and mechanica1
Figure 4.4-Typical Microstructure of Tvifo Phase
Pearlitic Low Carbon Steel. (A)Light Areas are
Ferrite,and Dark Areas are Pearlite. (B)Fine Grain
SamDle with Small Pearlite Patches
metal.Microstructule is affected by welding because of
the thermal or mechanical effects, or both, but the
changes are confined to the local region of the weld. The
metaUurgical changes in the local region of the base
meta1(called the heat4ffected zone)can have a
properties of the metj. lt is affected by chemical coIIlpo’
sition,thermal treatment, and mechanical history of the
||
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A 1 1 s o h d a l l o y s i n t h i s d i a
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i n b o t h
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94 welding Metallu,gy
The silver-copper system exhibits a more compleχ
phase diagram, Figure 4.6.This diagram is used eχten-
sively in designing brazing alloys. All compositions in
this system are entirely liquid at temPeratures above the
liquidus.Similarly,all compositions aresolid at temper-
atures below the solidus. However, the solid eχists as a
single phase in two areas of the diagram and as two
phases in anotherarea.The silver-rich phase is called
alpha(α),and the copper-rich phase is called beta (β).
Both phases are face-centered cubic, but the chemical
compositions and the crystal dimensions aredifferent.ln
the region between the solidus and liquidus lines, the liq-
uid solution is in equilibrium with either αoΓβphase.
Finally,thearealabeledα十βcontains grains of both
alpha and beta。
This phase diagram illustrates another feature-the
どgなdj(;poj耐.A110ys of eutectic comPosition solidify at
a constant temperature. The eutectic composition solidi-
fies differently than pure metals in that small quantities
of alpha and beta phases freezealtemately eχhibiting
intermingled grains ofαandβin the microstructure. For
thls reason, eutectlc composlt10n rnlcrostructureshave a
● ● ●dlstmctlve appearance。
The boundary between the βand the α十βΓegionsin
Figure 4.6 represents the solubility limit of silver in
coPper. The βsolubility increaseswith increasing tem-
perature, which is tyPical for most liquid and solid
solutions.
載匹一.E1 一肌rk
’一
.E一一一一一一一一
一一一・=一一・・・・=一一・一一’」E=”‘
一一一一t’・一一
一 一一一E‘=-・・・・‘・f‘t・fJ‘’、ま.
’t’。’万.4.・.、.
DefOrmatiOn and Annealin9 Of MelalS
WHEN METALS ARE Plastically deformed at room tem-
perature,a number of changes take place in the micro`
structures. Each individual grain must change shape to
achieve the overall deformation. As deformation pro-
ceeds,each grain is deformed, and as a result becomes
stronger, making it more difficult to deform it further,
This behavior is called z4ノo飛haγdeni,lg.The effect of
cold working on the strength and ductihty of a metahs
illustrated in Figure 4.7(A).The original properties are
Partially or completely lrestol°ed by heat treatlllellt as
shown in Figure 4.7(B).The microstructures of mildly
deformed,heavily deformed, and stress-relieved metals
areshown in Figures 4.8(A),(B),and(C)respectively・
When the metal is deformed below a critical tempera-
ture,there is a gradual increase in the hardness and
strength of the metal and a decrease in duφlity. This
phenonlenonis knovvn asCOld UノOγkiれg。
lf the same metal is worked moderately [Figure
4.8(A)]or severely [Figure 4.8(B)]and then heated to
progressively higher temperatures5several things hap-
Pen. At temPeratures up to about 400°F (205°C)μhere
is a steady dedine in the residual stress level but virtually ,
no change in microstructure or properties. Atabout400 `
to 450°F (205 to 230°C),the residual stress has
decreased to a relatively low level, but the microstruc-
ture has not changed [Figure 4.8(A)and(B)].The
strength of the metal is still relatively high and the ductil-
ity,while improved, iss磁l rather low. The reduction in
stress level and the improvement in ductility are attrib-
uted to the metanurgical phenomenon called γecotノどり,a
term indicating a reduction in crystalline stresses with-
out accomPanying microstructural changes。
When the cold-worked metal is heated to a tempera-
ture above 450°F(230°C),mechanical proPerty
changes become apparent, as do changes in microstruc-
ture.ln place of the deformed grains found in Figure
4.8(A)or(B),a group of new grains for111 and grow [Fig-
ure 4.8(C)1.These grains consume the old grains, and
eventually all signs of the deformed grains disappear.
The new microstructure resembles the microstructure
prior to cold-working, and the metal is now softer 皿d
more ductile than it was in the cold-worked condition.
This Process is called rEじりぶなz//咄咄0,7,a necessary part
of annealing procedures. (Annealing refers to a heating
and cooling process usually aPPlied to induce softening.)
When heated to higher temPeratures, the grains begin to
grow and the hardness and strength of the metal are sig-
nificantly reduced. Metalsareoften annealed prior to
further cold working or machining・
EFFECTS OF DEFORMAT10N AND HEAT
TREATMENT
00 00 00 00
8 7 6 5
1
μ2
jo 3un1vu3d
1300
1200
1100
1000
900uo]rDトく∝山Is』]ト
400
300
200
40 60
COPPER,PERCENT
0 80 10020
Figure4.6-Silver-CopperPhase dia9『am
Welding Meta目urgy 95
10 20 30 40 50 60
AMOUNT OF COLD WORK, %
(A)
400
AIU3dOUd
トフご犬ANNEALづ[RECOVERYIRECRYSTALIZEI GRAIN GROWTH I
1000
(B)
1200200 600 800
TEMPERATURE °F
Figure 4.7-(A)The Effect of Cold Work on Strength and Ductility of Metals. (B)The Effect of Post Cold Work
Steehs an iron alloy containing less than two Percent
carbon.The presence of carbon alters the temperatures
at which freezing and Phase transformations take place・
The addition of other alloying elements also affects the
(A) (B) (C)
Figure4.8-Grain Structureof(A)Lightly Cold Worked,(B)Serverely Cold Worked,and
(C)Cold Worked and Recrystallized
PhaSe TranSfOrmaliOnS in lrOn and Steel
STEEL AND oTHER iron alloys are the most common
commercial alloys inuse. The properties of iron and
metals. the various phases (austenite,ferrite,and cementite).
Pure iron, as mentioned earlier, solidifies as a body- The iron-carbon Phase diagram is shown in Figure 4.9,
centered cubic structure called delta iron or delta涙雨咆.
0n further cooling, it transforms to a face-centered Delta Ferrite to Austenite (on coolin9).This transfor-
cubic structure called gamma iron ot a14stentte、The aus- mation occurs at 2535°F (1390°C)in essentially pure
tenite subsequently transforms back to a body-centered iron,but in steel, thc transformation temperature
cubic structure known as alpha iron oralPha ferγite. increases with increasing carbon content to a maχimum
steel are govemed by the phase transformations they transformation temperatures. Variations in carboncon-
1111de啄o d111rillg processing. Understanding these trans- tent have a profound affect on both the transformation
formations is essential to thesuccessful welding of these temperatures and the proportions and distributionsof
96 Welding Meta川urgy
Figure4.10-Typical LamellarAppearance of Pearlite
400
tenite at the expense of delta and alpha ferrite. The
lower temperature of therange(AI)remains at 1333 °F
200 (723°C)for all plain carbon steels, regardless of the car-
bon leve1.
Austenite can dissolve up to 2.0 percent of carbon in
600
゜C
1600゜F
2800
800
Ausienit● to Ferrite Plus lion Carbide(on coolin9)・
This isoneof the most imPortant transformations in
steel.Control of it is the basis for most of the heat treat-
ments used for hardening steel。
This transformation occurs in essentially Pure iron at
1670°F(910°C).ln steel with increasing carboncon-
(1)Ferrite-A solid solution of carbon in alpha ilon
(2)Pearlite-A miχture of cementite and ferrite that
forms in plates or lamehe
(3)Cementite-lron carbide, Fe3C,present in pearlite
or as rnassive carbides in high carbon steels
tent, however, it takes place over a range of tempera-
tures between boundaries A3 and AI, Figure 4.9.The When carbon steels are slowly cooled from the austen-
upper limit of this temperature range (A3)varies from itic temperature range, the relative amounts of these
1670°F(910°C)down to 1333°F (723°C).For eχam- three constituents at room temperature depend on the
Ple, the A3 of a 0.10 percent carbon steehs 1600°F chemical composition. However, austenite decomposi-
(870°C),while for a 0.50 Percent carbon steel it is tion is suPpressed when the cooling rate is accelerated。
1430°F(775°C).Thus,both at high and low temPera- When transformation does begin, it Progresses more
ture the presence of carbon promotes the stability of aus- rapidly, and larger volumes of pearlite are formed. As
Figuie 4.9-Thelron-Carbon Phase Dia9「am `‘「」`F・“゛゛`゛`゛゛゛“J“・・・`・・“・ ゜`・u゛“゛●Allしゝ・lala6・ゝよよa- tlc lamellar structure3 known as pearlite, is shown in
Figure 4.10.
0f2718°F(1492°C).Steels with more than 0.5 percent Most of the common anoying elements added to steel
carbon freeze diredy to austenite at a temperature further alter the transformat19n temperatures. Room
below 271 8 °F (1492°C)and therefore, delta ferrite tell11??tt111e 1111c??t°ctures of lron-carbonalloy? at the
does not eχist in these ste
:1s. equUlbrlum condltlons coyered by 少ls dlag聊m mdude
one or rnoreof the fonowmg constltuents:
solid solution, but ferrite can dissolve only 0.025。-・p9-
cent. At the Al temperature, austenite transforms to ferj
rite and an intermetallic compound of iron and carbon
(Fe3C),called cE謂ε耐丿&.Ferrite and cementite in adja-
cent Platelets form a lamellar structure. The characteris-
0
WEIGHT PERCENTAGE CARBON
place. A TTT
steehs shown
To Produce
bon steel were austenitized at 1550°F (845°C).The
samples were then quenched to a variety of temPeratures
below 1300°F in molten salt baths. Each specimen was
’diagram for 0.80 percent plain carbon
1n Figure 4.12.
this diagram, samples of 0.80 percent car-
一
1 1 1~~・U・
1 ほI’
Welding Meta目urgy 97
The lSOthermal TranSfOrmatiOn OrTIIT Dia9「amS
THE IRON-CARj30N PHASE diagram is very usefuI. How-
ever,itdoesnot(1)provide information about the trans-
formation of austenite to any structure other than
equilibrium structuies, (2)furnish details on the sup-
pression of the austenite transformation, nor(3)show
the relationship between the transformation products
and the transformation temperature. A more practical
diagram is the isotbemlal t7a,lsfoTmation or zj削ど-teyyl-
peγatuγe一飢z心かアフ心哨077 j必g77z777. lt is also knoxvn as a
ΥΥΥd≒rΓα朋.This diagram graphically describes the
time delay and the reaction rate of the austenite transfor-
mation to Pearlite, bainite5 or martensite. lt also shows
the temperature at which these transformations take
cooling.
月
COntinUOUS COOling TranSfOrmatiOn Dia9「amS
TTT DIAGRAMs HELP to understand the isothermal
transformation of austenite. ln most heat treating
Processes,induding welding, austenite transforms dur-
ing the cooling Process. A diagram, simnar to TTT
curves,called a 6o耐加μ0μscoo/加g沁z心八)r777討j0,7 jiz-
salt bath. The reaction start times and completion times
were plotted as shown in Figure 4.13.
As shown in Figure 4,12,austenite at 1300°F
grams ol many ‘
1000°F(540°C).
At temperatures below the nose, the transformation
products change from pearlite to bainite and martensite
with their characteristic feathery and acicular structures。
As carbon and aUoy content increases, the TTT
curvesshift to the right. When the curves move to the
right, the steels can transform to martensite at slower
cooling rates. These steels are said to have higher
hardenability.
carbides in ferrite is formed instead of pearlite. This
feathery arrangement of shear needles with fine carbides
in a fe雨te matriχ is called baiれite、lt has significantly
higher strength and hardness and lower ductility thanhigher strength and haldness and lower ductility than (700°C)begins to transform after about 480seconds(8
fine pearlitic structures. minutes),and the reaction is complete after about 7200
With very fast cooling�