The science and practice of welding VOLUME 2

The practice of welding

A.C.OA V I ES H-St: f London Ho"", and [.i,up""/, r. FJl!( ., If. I. h.E .. Fellow of Ih" Weldmg l nSliluU

EIGHTH EDTTTON

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CAMBR I DGE UN I VERSITY PRESS

Cambridge

London New York Ne\\' Rochelle

M elhourne Sydney

Contents

Preface " Preface to the seventh edition ,;

Manual metal arc "dding The electric 3TC

Electrode classification 13 Welders" accessories 20 The practice of manual metal arc weldmg 29 Welding of pipeline~ 71

Welding of carbon and carbon-manganese and low-alloy steels 76

1 Gas shieldt'd metal arc 'H'lding 84 Metallic inerl gas (MIG ). metallic acth'c gas (MAG) including CO: and mixed gas processes 84 Techniques 111 CO: "elding of mild steel 121 Automatic welding 123 MIG pulsed arc welding 129

3 Tungsten electrode, inert gas shieldt'd ,,· .. Iding proc£'Slit's (fIG), and the plasmllo aTC pr~ss 134 Technology and equipment 134 Welding techniques 159 AUIOmatic welding 17 1 Plasma welding 176

4 Rcsb1ancc IoIclding Itnd Hash butt ","clding 183 Spot welding 183 Electrodes 190 Seam welding 194 Projection welding 197 Resistance bun \\elding 198 Flash butt welding 199

, ; ConlellfS

5 Additional processes or welding 202 Submerged arc welding 202 El«troslag welding 210 Mechanized MIG welding with robots (robotics) 212 I'ressufc welding 217 Friction welding 218 Electron bcllm welding 223 Laser beam .... tkling 225 Stud welding 128 CapacilOT discharge stud "cldmg 23J Explosive \\(~Iding 233 Gravity welding 236 Thermit wclding 237 Undcf\l.atcr .... dding 239

6 OX),-acClylellc ltckiinJ,( 241 Principles and equipment 2-11 Methods of wekling 260 Cast iron "clding 272 Braze wckling and bronze welding 274 Copper weldmg 284 Aluminium .... clding '" Welding of nickel and nickel alloys 292 Hard surfacing and sleHiting 296 Brazing 30) General precautions 309

7 Cullin~ processes 312 Gb cutting of iron and steel J12 Oxygen or thermic lam:c J19 Flame gougmg by the oxy-acclyknc proC\::ss 322 Oxy-arc culling proce~s 324 Arc-air tuning and gouging pf()(;C~ J21 Pla~ma Culling 326 Powder injcction cuttlllg J3l Underwater cutting l37 Appendixes I Welding ~ymhols ]4(1 2 Simplified notes on the operation of an SCR J40

(th)"ristor) 345 J Proprietary gases and mixtur~s J48

• 4 TeSb for wear-resistant surfaces J50 5 Com'ersion factors J51 6 Notes on fire t!.'(tinguishing 352 7 Tables of brazing alloys and fluxes J57

Contents vii

City and Guilds of London Institute Examination questions 369 Manual metal arc 369 Gas )hieldcd metal arc (MIG and TIG) 382 Other welding processes 399 Cutting processes 402 Oxy-aeetylene 404 Multiple choice 409 Welding engineering craft studies 415 Fabrication and welding engineering (t«hnical grade) 438 Index 440

Index

abrasion surfacing 350 MMA 5662 oxy-acctylcnc 296--302

a.c. wave balance control 149 acetylene

absorption by acetone; dissolved 243 4 flash back. arrestor 257-8 gauge 247-52 generator medium pressure 241 impurities in 243; safety precautions

244-6: storage 244; test for leaks 245 alloy steel, welding of 62-7, 76 9 all position rightward welding 270 aluminium and its alloys

filkr rods: oxy-atctylenc 290; manual metal arc 50

filler wire: TIG 161; MIG 118. 161 manual metal arc welding 49 51 MIG 117-18 oxy-acelylene welding 287-92 TTG welding 160

aluminium bronu oxy-acctylene welding 283-4 11G welding 169

'" alternating current 2 bare wire 2 blow 4 characteristics of 4-5 oontrol (types of automatic

distribution of heat in energy) 86--9 energy 3 forces 4 metal \-5 non-transferred 177 181 plasma 176 shielded 2 striking 32 TIG 135 transference of meml in 3--4 tnlnsrerrcd 177 81 voltage drop 2, 86

are-air cutting 325-6 argon 102

flo,\mcter 103, 150--1 gas regulator 151 M IG welding 84 T1G welding 135

austenitic stainless steel welding MMA 63- 7 M1G 107, 115-16 oxy-acetylc:nc: 294-6 TIG 165

automatic welding MIG 123--6

spot MIG 129 seam 194 TlG 174

back chipping 115, 117 back purging 115 backfire 256 backing bar 39, 41 , 49,113,167-8 backing strip 113,207 10 bell and spigot joint 75 ben hole welding 71 beryllium, welding or 175 block welding 268 blow pipe, oxy-acetylene 252 1'/ sl'q.

care of 256 cleaning 256, 257 cutting 312-15 high pressure 252, 253 low pressure 252, 253 nozzles 252 overheating 256 Se(' also toreh

boom ram 124, 126 braze welding 274 1'/ sl'q. brazing 303, 357--68

aluminium 306--8 bronze welding, olly-acc:lylc:ne 274 ('f seq.

aluminium bron7£ 283-4 galvanized iron 279 gilding metal 283 malleable: cast iron 278 tin bronze

bumbad:: control 113 butt welding

CO, 121-2 MMA 38--40 olly-acetylene 261 - 2. 263-4

capacitor discharge stud welding 231- 2 capillarity 305 carbon equivalent 77 cast iron

bronze wc:1ding 276-8 MMA wc:1ding 51-4 MIG welding 119 20 oxy-acetylenc welding 272- 4

characteristics of power units MIG 88- 91 TIG 142 3

chromium and nickel steels MMA welding 62- 7 MIG welding 115-16 TIG wc:1ding 165

Index

City aod GUilds of London Institute Questions

MMA 36\1 112 M IG. T IG 382 99 other processes 399-401 cUlling 402-4 oxy·a<.-e\ylenc: 404-g multiple cho.ce 408- 14 craft studies 414 311 technician grade 4311 \I

clad steels. MMA welding of 6\1 71 CO2 w'elding 121-3 coffer dam 240 consumable gUide wekling 21 1-12 contact tube

MIG 94, 98.112 13 submerged are 203

copper alloy tiller rods 170 bronl./,! wekhng of 280 oxy·aeetylene 284 87 MMA 55 MIG w-eldlng 119, 120 TIG welding 167-71

copper aluminiUm (alumiruum bronze), TIC welding 169

copper silicon alloy~ MIG welding 119 TIG welding 169

cratcr filhnS control 144 cross wire weld1l1g 197 eupro-nlckels

MIG welding 11\1 TlG \I'eldlng 169

current con\rol by thyristo~ SCR'~ 145, 347

cutter (gas) o~y':I~-etylcne 312 15 oxy·prop.!ne 315

cutting pr~ 312-38 alloy steel 326, 336 are air 325 carbon arc 326 cast iron 321 effect on steel 31&-19 machines 320 oxy·acetylenc 315 o.y·arc 324 oxy·h~drogen 315 oxy·natuntl gas 315 o~y·propanc 315 plasma 326 31 powder injection 33J 7 stack cutting 321 safcty precaullons 339 thcnnic lance 319 under watcr 337 9

CUlling tools (tipping) MMA 60 oxy·acetylene 299

cyclc-arc weldon!! 129

cylinders (gas) MIG 102-8 oxy·acetylene 241 4 T IG lJ5

deep penetration electrode \I degreasing 117 degrCt.'S of freedom (robot) 214 deioni7cd waler 3J I 2 droxidilers 106

.41

diffUSible hydrogen on weld metal 11 9 d.p tr4l11,fer 87 dissol"ed acetylene 243 4

douhle operator oxy·acctylcne welding 265 6

drdwn arc stud \I-cldlng 228 30 drooping characteristK"li 88-9 droplet, Sl'P trdnsfcr of metal in arc duty cycle 143-4

eccc:ntricity of elcc::trodc core 5 6.7 electrode

claSSification of: British 13 19; American 19-20

composition of coating 16--17 decp pcnctrauon \I drying nf 12 13 ea:elltricilles of core wire 5 6.7 cffieiell(.), 6 Hux cored 109-11 grinding (TIG) 155 h)drogcn controlled 8. 12 13 hydrogen rcJeasm!! 8 iron powder 7 manual metal arc welding S. 13-20 metnClItion 35 1 MIG welding 91.106 polarit)': MIG 85; TIG 134, 135, 136 storage 10 11 tungsten 154 S

electrode holder: MIC 94 f'I $('11., MMA 20, TIC 152

ekctron beam welding 212-5 eb;tro slag welding (submerged melt)

210 11 consumable gUIde 211

explosive welding 233 5 prcpar.ttion 234

eyes. protection of in MM/\ weldmg 23-4. 29 30 III MIG welding I11 m oX),·acetylerlC wcldmg 310 in TIC \OeJd'nl! 158 9

faulls in a \Odd 40

ferritic stamlcss st«1. welding of MMA 63. 66 7 TrG and MIG 166

fillet weld. hon:rontal- "ertlcal MMA 435 MIC 105. 114 o~y'acetylenc: 269 70

442 Index

TlG 164 jigs 24-5

fixtures 25-8 fl.~

adju~lmcnls for weldln8 255

carburiljng 255 culling 315-16 gouging 322 neutral 255 oxidizing 255

Hash back arrestor 257 8 Hash butt wddlng 199 200 Hux hasicity 207 Dux cored electrode "\Iclding 109 II lIux cored self-shielded filler wires 110

free Hight tmnsfer g6 fnetion wcldmg 218 1" sI'q.

foruls for 221

galvanrud anlCies, oxy-acctykne welding

279 gas cUlling. su culling prOCC!i/;eS gas lens 154 .. ~

idenllfication of cylinders 108 inert 102-3 mIxtures 107 table: for MIG welding 107; for T IG

welding 135 gas mixer 133 gas-shielded metal arc weldIng 1-33

globular Imnsfcr 3--4, 87 gouging, l1ame 322--4 gravity welding 236 gUS5Ct bend 75

hard surfacing MMA 56--{i2 pla.o;ma 181 oxy-acetylene 296-302 spray fu5C 302 T IG 171

head shield 22--4 heliwn

In M IG welding 1(14, 107 in T IG weldtnl! 135

high frequency sparlr. gap OS<..,nator (TIG) 139 40

honwntal-.. enical welding MMA 43 5 MIG 105, 114 oxy-acctylene 269. 270 T IG 164

hoses 252 hOI pass or fill 72, 74 hydrogcn-controlkd electrodes 8. ] 2-13

effect on a weld 8 solubility in weld metal 8- 9

ignition ofTIG arc 139 Ions 176-7 Iron, powder electrodes 7

joints bUll 39 horiwntal-vert>calliJ1et 39 lap 39 open COmtT 39

Ir.eyhole welding 180

lamellar tearing 80-1 lascr beam welding 225 8 lens, gas for filling 10 T IG gas nOT.l:le 154

leftward welding (forward welding) 261

Hat butt 261- 2 HV fillet 269 70 "-rrlical 265 overhead 267

lenses for eye protection, Sff c)'e$, protection of

Liodewclding 268 hquef.eld gas

oxy-acetylene 242 MIG 133 storage 244

low alloy steel. weldmg of 76-81

magnesium alloys table of 165 TIG welding 163-5

magnetic arc control 126-8

mallcable Iron, oxy-acety1ent welding 274

manganese. welding or sla:ls contaw1l1g

" manual metal arc welding east iron 51- 3 ooppcr bron7:C and brass 55 6 Hat bun 38 40 hard surfacing 56-9 horizontal bull 47-3 hori~ontal-venical fillet 43- 5

open eomer 40--2 overhead 48 padding 36-7 pipe lines 71 5 safety precautions 29--31 stainless steel 62-7 steel castings 81 stcllitmg 60-2 studding 54 tipping tool sta:l 60 venK:a145

martensitic stainless sta:l, MMA weld,"g

of 62-3,67 metallic mcn gas wcldmg S4-J33

methyl chloride 117 metrication, e\ecuode 351 mild steel welding

CO, 121 3 MMA 384& M IGM oxy-acclylenc 261 11

Index

moncl, welding of, See nickel alloys monochromatic light 226

neutral flame 255 nickel and its alloys

MMA welding 68 9 oxy-acetylene welding 292 3 TIG welding 166-7

nickcl chromium steel. see stainless steel nickel clad steel

NNA welding 70 o~y-acety1ene welding 294

nugget 184 5 nozzle, selection of 256

o rbital pipe welding 172 oscillator (H F) for TIG 139 overhead welding

MMA 48 MIG 114 oxy·acctylene 267

oxidizing flame 255 oxy-acetylcnc flame 255

adjustment 255 oxy-acetylene welding

all position rightward 270-1 aluminium 289-92 block 268 blow pipe 252-4 braze welding and bronze welding

274 84 cast iron 272-4 copper 284--7 double operator vertical 265 6 general precauLions 309--11 hard surfacing 296-301 horizontal vertical fillet 269 inconel292 leftward 261 monel292 nickel 292 3 nickel clad steel 294 overhead 267 rightward 263 stainless steel 294-6 table of 1i11er rods 309 tanks 310 technique, see under individual nu'w/J

oxy-are cutting 324--5 o~ygen

as wetting agent 104 compressed 241 2 cylinders 242 liquid 242 safety precautions in the use of 339 tcst for lcaks 242

oxygen lance 319

padding 36-7 pipe lines

MMA welding of 71-5

orbital welding of 172 partial rectification 138 plasma

cutting 326-31 kcyhole welding 180-1 surfacing 181 welding 176 81

polarity of electrode cffect on welding MMA 1,33 MIG 85 TIG 135. 136, 137

positioners 25 scrvo powered 216

powdcr injection culling 333--7 powder surfacing 302, 181 pressure regulator

details of 150. 247-51 single-stage 247 multi-stage 248

pressure welding 217 oold 217

programmable power source for M IG welding 94

projection welding 197 propane 315

443

protection of eyes and skin whcn welding 23-4, 29 31, 158-9

pulsed current wclding MIG 129--32 TIG 155-8

recovery rate 5 reducing valve, see pressure regulator regulator. oxy-acetylene pressure 247 8 rcignition voltage 138-40 reinforcement of a weld 40 resistance bUll wclding 198 restraint in a joint (carbon and alloy

steels) 78-9 rightward welding, all posilional 270-1 robot welding (robotics) 212 17 roll welding 71

safely precautions HF in TIG welding 158 9 in usc of oompT~ gases 311 in use of oxygen 339 MMA 29--31 MIG II1 oxy-acctylene 309--11 tanks 310 TIG 158-9

scratch start 140 seam tracker 128 seam welding 194 SG cast iron, M IG welding of 119 Shaeffier's diagram 67 shafts rebuilding, MMA 36-7 shield, hand and he-dd 22-3 shielded arc, principle of 1-3

444 Index

sbort current transfer (M 10), Si'!' dip transfer

slope in 144 slope out (crater fill) 144 soft start , set' slope in spatter 5 square wave output unit 145--8 spot welding 183--93

electrodes 190--3 MIO 129 TIO 174 SC<juence of welding 189

spray fuse hard surfacing 302 spray transfer (free lIight) 86 stainless steel. table of steels and

cla:trodes 64- 5. 116 stainless steel welding

MIO 115-16 MMA 62-7 olly-acetylene 29+{i TIO 165

stick out (M IG) 112 stubbing 113 studding 54 stud welding

arc 22&--30 capacitor discharge 231-2

suppression of de component (fIG) 141 submerged arc welding 202-9

alllomatic 203 power unit 206 ftlll\CS 207

surge unit 140 symbols, welding 340 4

tack welding 37--8 tantalum welding of 175 tanks, precaution and safety in welding

310 tce joints, set' HV fillets tables

electric arc weldin8 rods 82-3 oxy-acctylene welding rods 309 MIO welding wires 106, 109 si lver brazing alloys and limes 35!1--{i8 TlO welding wires 161, 165, 167, 169 70

thermic lance, oxygen lance 319 thoriated tungsten 154, 155 thcrmit welding 237--8 thyristor, control of current 145, 347 thr~b'bld limit value (fL V) 310 TIG welding

aluminium alloys 160--2 automatic 17 1- 2 copper and alloys 167 71 hardfacing 171 magnesium and alloys 161-2 nickel and alloys 166--7 orbital 172 robot welding 173 spot 174

stainless steel 165 tin bron7-C, oxy-acetylene welding 28) tipping 1001 steel 60 titanium

oxide 16 welding 174-5

torch MIO 94, 98, 99 101 oxy-accty!cnc 252--4 TIG 152 4

traru;fer of metal in arc welding 3 4.86--7 triple dcoxidized wire 106 tung.~ten arc 134-42 tungsten electrode

current r~ings 155 grinding t 55--6 prolrusilln 156 thoriatq 154 zirconiatoo 154

tungsten inert gas welding 134-82

underwater CUlling 337-9 welding 239--40

Ultrasonic welding 218

vertical welding MMA 45-7 MIG 114 oxy-acctylcne 265--6, 270--1 110 162

voltage control in CO, welding 86 M IG 86, 89--90

voltage drop M1G 88-90 MMA 7 TIG 150

water injection plasma cutting 332 wave balance control 149 wear resistant surfaces, building up of

MMA 56--62 oxy-acetylene 296--301 plasma spray 181 spray fuse 302 TIG 171

weaving 35 weld

defects 40 featull:s of a good 40 profiles 40, 341 rotation 10 slope 10

welding gun (spot) MIG 129 TIG 174

welders· accessories 20--4 welding positions 10 will: feed (M IG). control 91--4

zirconiated tungsten 154 5