Principles of Foundry Technology

Second Edition

P. L. JAIN

Pro/ruor rllld Head Producliotl &/#",er;,., DtptJflmtll'

Notiang/ lnJtitute 0/ Foundry and Forit Tttlrll()Io6Y ROllchf

MIKIELVG S.\PI\.·O TEe! .: 1 '.\ L T. ~ ITlV'l

P.O ~

REFERE,'CE LIBRARY

Tata McGraw-HilI Publishing Compa.y LImited NEWDBLHI

CONTENTS

Foreword Preface to the First Edition Preface to the Second Edition

1. INTRODUCTION

%. TECHNOLOCY OF PAnERNMAKING

2.1 Requirement 5 2.2 Pattern materials 5

2.3 Machines and tools for pattcrnmaking U 2.4 Allowances and other technological considerations

2.5 Metal patterns 43 2 .• Life expectancy of patterns 44

2.7 Pattern storage and repair 45

3. TECHNOLOGY Of MOULDING AND COREMAKINC

3.1 MOUlding sands 46

3.2 Sand conditioning 68

3.3 Moulding processes 73

3.1 Core sands and coremaking 77

3.5 Machine moulding 81

3 .• 'Special' sand moulding processes 88

•• TECHroiOLOGY OF METAL MOULD CASTING PROC£SSES

4.1 Permanent mould casting J09

4.2 Pressure die casting J 11 4.3 Low pressure die casting J 18 4.4 Squeeze casting 119 4.5 Centrifugal casting 1/9 4 .• Continuous casting 111

4.7 Electra-slag casting 122

,. CATING AND RISERINC OF CASTINGS

5.1 Gating system 123 5.2 Risering of castings 132

5.3 Casting design 138

U

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'" b

1

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..

'09

, TECHNOLOGY OF MELTING AND CASTING

6 1 Melting equipment for foundries 143 6.2 Refractories for melting units 171 6.3 Metallurgical characteristics of cast metals 175

7. DEFECTS IN CASTING AND QUALITY CONTROL

7.1 Defects in castings 194 7.2 Inspection and testing of castings 199 7.3 Quality control in foundries 110

•. FEITUNG AND HEAT TREATMENT OF CASTINGS

8.1 Feltling and repair of castings 211 8.2 Heat treatment of castings 211

...

9. MODERNISATION AND MECHANISATION OF FOUNDRIES 238

9.1 Need for modernisation and mechanisation 238 9.2 Arcas of mechanisation 139 9.3 Pollution control in foundries 247 9.4 Plant layout for foundries 152

Suggesud Reading Index

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257 264

INDEX

Acid demand value, 52

Acid refractories, 173

Acurad process, 114

Additives, 65

Advanll,e' of cutin,s. 2

Aeration, 71 After-burner, 252 Allowances. pattern, 24

contraction, 24

distortion, 28 draft. 2. macblnio •• 28

flppio •• 27 Aluminium allo,.s, 189

AooeaJiol. 227 rull,227 bomo.eni"liOD,228

isotbermal,228

aoft,231 AotiO_kiD •• 232

Arc·air proceu, 216

Atomic bydrocen welding, 219

Auslemperiol. 230

Band ... , 16

Baioltc, 225

Base silica sand, choke of. 61

B.si~ rdrlctories, 111

Bmlooitc,63 BiDders,6S

Boadioa <:'1),1, 63

C.rbon dioside mouldiol. 89

Carbon equivalent, 201

Casting de.i,n, J 38

Cutin, desi,D, computer aided, 141

Ca,dlll tolerances. 140

CeDl1'if",a' u.tln •• 119

Ceramic mouldioa:. 10)

Cbamotlc, 62

ChapelS, 81 Chemical t"tin •• 201

Chills,137 Chill test, 207

Chromit. sand, ~2

Cl.,.. 47. 61

Cl.y conlenl determinalion, 49

Coal dUlt, 5' Cold ben; process, 98

Colour s.cbeme, patterns. 36

Comparative sieve dcsi,Dations,.so

Computer-aided castin, desiJD, 141

Continuous castio" 121

Conveyers, aproD,244 belt, 243 bucket, 243

flicht,244

rnono-rail,244 overhead, 245

pallet,24S plate band, 246

roller, 2« Copper allo)'l. 189

Cores, 78 bliaDced, 79 cover, 79

W,ID.,79 kiu, 79 rarn-up, 79

.ioa. 80 Core blower, 87

Core ball, 32 Core dryina, SO Cored structure, 177

Core prloll" 29

Core sandl, 77 Cr}'Italllructure, 222

Cupola runaace, 148

cbaraea. I SO cokeleu, 159

diflded blut, 160 elIkiODC)'. ISS

cmiuiona, 241

bot blut, 1S7 operation, 148

DSJlCn-enricbed blut, "9

.ater-cooled, 1 SI

CJcfooe, ~

cold cracks, 199 cold shut, 199 dirt, 196 drop, 196 fin, 195 ps holes, rH bot tears, 199 metal pcmetration, 196 misrun,l99 'pin holes, J96 porosity, 196 scabs, 197 shrinkage cavity, 196 shift, )94 slal bole, 196 swell, 195 warped ca"int:, 195

Dendritic structure, 178 Depsainl, 179 Design considerations, 139 Dn.trio, 65 Die cutiol, 109

ac:urad proceSl, 114 dies,loo. III cold cbambers, 113 loose oeck, 114 hot chamber, 112 low prcuure, 118 machines, I1I multiphasc injection, 113

Dimensional iospection, 200 DireC'lional solidification, 133 Drawback, 39 Dust and fume control, 249 Dye penetrant inspection, 205

Economic considerations, 141 Eddy current IUI, 206 Etl'ectivc clay, 49 Elecukal (onduclivity Icst, 205 Electric rurnace, 161

basic alal process, 164 direct arc, 161 indirect arc, 169 induction, 169 steel meltinl practice, 1604

E1ectrO<kp(J$ition,IO Electrosl., Quinl, III Elevator, buclr:lIt, 243 EmistioDl in meltinl, 241 Equilibrium diqram, 179 EquilibriuQI moisture cooleDl, 6 Etcbinl reqentl, 209 Elb)'1 .ilicate, 103 ----

Epolt)' resin alien, :uo EpolY resin pattern', 11 Eltothcrmic material., 136 Expanded polystyrene, 13

ferrosilicon process, 91 Feltlinl,212 fibre satUratiOn point, 6 Fibret1s material., 66 Fillets, pattern, 36 Filtcr, dust control, 250 Flow weldiDS, 220 Fluid ~nd mouldin" 92 Fracturqlest,208 Full mOl.lld caslinl, 105 Funn sand process, 99 Furnaces, melting. 143

air rUrnaces, 146 crucible type, 143 cupola, 148 e1eclric, 161 rOlO1'1, 146

Gates, 127 botlom,l29 finger, 127 born, 129 parlinll.127 pencil. 127 shrink bob, 127 skim bob, 127 skimming, 127 lop, 127 wedge, 127 whirlpool, 128

Gating ratio, 130 Gatins system, 123 Grain shape, sand, 47 Grain size. sand, 43 Gravity die casling, 109

Hand tools, mouldintl, ',6 Hand tools, panernmnkinll, 21 Hardenins. 228 Heal treatmeot, 222

problemS, 232 High pressure moulding. 86 High silica sand, 60 Hiah temperature testing, sand, 58 Homolenisation, 228, 236 Hol bolt mould in" 98 Hol spots, 138 Hydroblast, 214

Impact tcst, 203

Inert P' arc weldifll, 21S Invcstmenl castinl, 101 Iron , 179

acicular. 186 ductile, 185 grey, ISO, 234 hip duty, 184 malleable, IS4, 235 special. 186 production, 184

Jointer , wood, 17 Jolt Jqueeze moulding machine, S2

Life expectancy of patterns, 44 Linseed oil,66 Loose pieces, 34 UlW mellinl point alloy patterns, 10

Machine moulding, 81 Machines for metal paUernmakinl, 23 Machines for wood patternmakinl, J4 Ma8net!c particle inspection, 20S Magnetic separalor, 71 Malleable iron, 184, 235 Martempering,230 Match plate patterns, 39 Material handlin8. 242 Mechanical colleclor. 2S1 Mechanicalleslinl,201 Mechanisation, foundry, 238 Metc .. t process, 10, 104 Mercury patterns, 10 Metallic coatings, patterns, 10 Metal patterns, 10,43 Metal sprayine, 221 Melalluraical characterisliCl J7S Microscopic uaminations, 209 Mlllins machine, pattern, 19 Minimum casling thickness, 140 Modernisation, fouodr)', 238 MOisture content, sand, SI Moiiture determinalion, sand, SI Molasses, 66 Mouldabilily tesling 239 Mould hardness, S3 Mnuldm, processts, 73

bench,7J dressinl.67 dry land, 75 cement, 92 ceramic, 10) cold box, 98 false check, 7)

Indu 163

"onr, 7)

ps-setting resin, 100 &feen sand, 75 high, pressure, 86 hot box, 98 loam. 76 machine, 81 odd side, 14 plaster, 10) plate, 14 shell,93 staek,14 vacuum, 108

Moulding saod, 46 Moulding lools, 16 Mushy lone, 178 Muller, sand, 11

NlIIural mouldinl sands, 60 Nature of casl metal.$, 175 Neutral refractories. 17)

Nondestructive tesling, 291 Non_ferrous alloys, c:astinl, JBB, 190, Normalising, 227 Nucleation,22S

O liYine S3nd, 62

Padding, 136 Parting agents, 67 Patterns, 37

,lllcd,37 loosc.31 m:ltch plale, 311 shell moulding, 93 Skeleton, 38 sweep, )8

Pallern cnnstruction, 40 Pallern layout, 41 PaUerns materials, 5

epoxy, Il metal,9 f'lastef, 10 plastic, 11 polye5ter resin, 12 polystyrene, IJ polyurethane, IJ waxes, 14 wood,6

Pattern milling machine, 19 Paltem plales, )9 Paltern ~torale and repair, 45 Percussion tesl 203 Permanent mould castilll, 109

•

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164 Indu

: Permeability test sand, j3 Planer, wood, 18 Plant layout, foundry, 2j2 Pollutants, 247 Pollution control, 247 Pouring basin, 124 Pressure test , 204

Quality control, foundry , 210 statistical,210

Radiogrnphic inspection, castings, 204

Redudng agents, 6j

Ref,actorics, 172 acid,l73 basic, 173 neutral,I73 selection, 174

Requirements, patterns, j Riddle, sand, 71 Risering, 132 Risetlcs. desi,n, 138 Riser location, 13j Rou&h ellStinl costs, 141 Runner, 126

Sand,46 ctassifieation. j9 cOre, 77 chamolte,62 chromite,62 ,recn,72 dry, 72 ollyine,62 spedal,61 zircon, 61

Sand blastin" 214 Sand conditioninl, 68

Sand preparatIOn, 69, 239 Sand rammcr, j5

land testing routine, S9 Sander, disc and bobbin, 20

Saws, wood, 16 Scrubber,2SI Seasoning, timber, '1

Selection of metal composition . 182

Shd:eout, sand, 240 Shaper, wood, 18 Shatter test, nnd, 57 Shell mouldinl, 93

pattern, 96 Shot bl"'iDI, 215

Silica sand grains, 48 Silicone rubber, 14 Slinger, sand, SS, 88 Sodium silicate, 66, 89 Soldering, 218 Solidification, castings, 175

So]utionise_quench·:l,e trC3lment, 236

sponge iron, use, 160

Sprue, 125 Squeeze casting, 119 SlatiSlical quality control, 210 Sleel casting, 187 Stop-off, 39 Strength lest, sand, SS Suc" relieving, 231 Sulphur print test, 208

Super cootinS, 224 Synthetic sand, 64

Tempering. 229 Timber, types, 8 Tooll and instruments, patterns, 23

Tou8hncss of sand, 56 Transformation, steel, 225 Transverse sccdon, timber, 1

T-T·T diagrams, 22S Tumblin"21)

Ultrasonic inspection, 206

Vacuum moulding proc«t, 108

Vibratory shake-out, 241 Visual inspectio,}, 199

Weldins, 216 atomic hydrogen, 219 braze, 220 ftow, 220 inert gas metal arc. 218 metal arc, 216 oxy·acetylenc,217 submerged IrC, 219 thermit,219

Wood impregnates, 8 Wood laminates, 8 Wood joioter, 11 Wood planer, 18 Wood worlr.ing lathe, 15

X-ray test, 204

Zircon nnd, 61