Preface ...................................................... xvii
List of Symbols ............................................... xix
Abbreviations ................................................. xxi
PART I: SCIENCE
CHAPTER 1 General Introduction ................................. 3
CHAPTER 2 Microstructure and Properties ........................ 9
2.1 Introduction ............................................... 9
2.2 Microstructure ............................................. 9
2.2.1 Solidification ..................................... 11
2.2.2 Interfaces ......................................... 17
2.3 Properties ................................................ 24
2.3.1 Physical Properties ................................ 26
2.3.2 Chemical Properties ................................ 26
2.3.3 Mechanical Properties .............................. 26
2.3.4 Electrical Properties .............................. 28
2.3.5 Magnetic Properties ................................ 29
2.3.6 Thermal Properties ................................. 30
Literature ................................................ 30
CHAPTER 3 Plasticity .......................................... 33
3.1 Introduction .............................................. 33
3.2 Fundamentals .............................................. 33
3.2.1 Flow Stresses and Strains .......................... 33
3.2.2 Generalized Stresses and Strains ................... 35
3.2.3 Yield Criteria ..................................... 37
3.3 Stress-Strain Relations ................................... 39
3.4 Plastic Anisotropy ........................................ 42
3.5 Fracture .................................................. 46
3.5.1 Failure Mechanisms ................................. 48
Literature ................................................ 54
CHAPTER 4 Work Hardening ...................................... 57
4.1 Introduction .............................................. 57
4.2 'Low' Temperature ......................................... 57
4.2.1 Basic Microscopic Mechanisms ....................... 57
4.2.2 Influence of Alloying Elements ..................... 67
4.2.3 Microscopic Hardening Laws ......................... 72
4.3 Hot Deformation ........................................... 75
4.3.1 Flow Stresses ...................................... 75
4.3.2 Hot Deformation Microstructures .................... 79
Literature ................................................ 81
CHAPTER 5 Softening Mechanisms ................................ 85
5.1 Introduction .............................................. 85
5.2 Recovery .................................................. 86
5.2.1 Recovery Mechanisms ................................ 88
5.2.2 Recovery Kinetics .................................. 90
5.2.3 Structural Changes During Recovery ................. 91
5.2.4 Extended Recovery/Continuous Recrystallization ..... 92
5.3 Recrystallization ......................................... 94
5.3.1 Sources of Recrystallized Grains ................... 95
5.3.2 Recrystallization Mechanisms ....................... 98
5.3.3 Recrystallization Kinetics ........................ 100
5.3.4 Role of Second Phase .............................. 101
5.3.5 Dynamic Recrystallization ......................... 102
5.4 Grain Coarsening ......................................... 105
5.4.1 Theories of Grain Coarsening ...................... 106
5.4.2 Factors Affecting Grain Growth .................... 106
Literature ............................................... 108
CHAPTER 6 Alternative Deformation Mechanisms ................. 111
6.1 Introduction ............................................. 111
6.2 Deformation Mechanism Maps ............................... 111
6.3 Creep .................................................... 113
6.3.1 The Creep Curve ................................... 113
6.3.2 Creep Mechanisms .................................. 115
6.3.3 Influence of the Microstructure ................... 116
6.4 Grain Boundary Sliding ................................... 116
6.4.1 GBS and Superplasticity ........................... 116
6.4.2 Conditions for Superplasticity .................... 118
6.5 Twinning ................................................. 121
6.5.1 Introduction ...................................... 121
6.5.2 Twinning Mechanism ................................ 122
6.5.3 Influence of Some Parameters on Twinning .......... 123
6.5.4 Twinning and Deformation .......................... 124
Literature ............................................... 126
CHAPTER 7 Phase Transformations .............................. 129
7.1 Introduction ............................................. 129
7.2 The Thermodynamic Basics ................................. 130
7.3 Nucleation and Growth-Type Transformation ................ 132
7.3.1 Nucleation ........................................ 133
7.3.2 Growth ............................................ 135
7.3.3 Kinetics .......................................... 137
7.3.4 Formation of Metastable Phases .................... 138
7.3.5 Invariant Plane Strain Transformation ............. 140
7.3.6 Selected Examples on Different Mechanisms and/or
Structures ........................................ 142
7.4 Spinodal Decomposition ................................... 149
CHAPTER 8 Textural Developments During Thermo-Mechanical
Processing .................................................... 153
8.1 Introduction ............................................. 153
8.2 Graphical Representation of Texture Data ................. 154
8.2.1 Grain Orientation ................................. 154
8.2.2 Pole Figures ...................................... 155
8.2.3 Inverse Pole Figures .............................. 157
8.2.4 Orientation Distribution Functions ................ 159
8.3 Some Important Cold Deformation Textures ................. 165
8.3.1 Introduction ...................................... 165
8.3.2 Axisymmetric Deformation .......................... 166
8.3.3 Plane Strain Deformation of fee Materials ......... 168
8.3.4 Plane Strain Deformation of bec Materials ......... 172
8.3.5 Plane Strain Deformation of Hexagonal Materials ... 172
8.4 Recrystallization Textures ............................... 174
8.4.1 Introduction ...................................... 174
8.4.2 Oriented Nucleation or Oriented Growth: Half
a Century of Discussions .......................... 175
8.4.3 Some Important Recrystallization Textures in
Rolled fee Metals ................................. 176
8.4.4 Some Important Recrystallization Textures in
Rolled bec Metals ................................. 179
8.5 Textures in Hot Deformed Materials ....................... 180
8.5.1 Introduction ...................................... 180
8.5.2 Hot Deformation Textures in Al Alloys ............. 181
8.5.3 Transformation Textures in Steel .................. 181
Literature ............................................... 183
CHAPTER 9 Residual Stress .................................... 187
9.1 Introduction ............................................. 187
9.2 Types of Residual Stress ................................. 188
9.3 Continuum Approach to Residual Stress .................... 189
9.4 Origin of Residual Stress ................................ 190
9.5 Residual Stress Measurements ............................. 192
9.6 Micro-Stress Analysis - A Tool for Estimating
Dislocation Densities .................................... 197
9.7 Residual Stress and Crystallographic Texture ............. 199
Literature ............................................... 201
CHAPTER 10 Modelling .......................................... 205
10.1 Introduction ............................................. 205
10.2 Deformation Textures ..................................... 206
10.2.1 Principles of Deformation Texture Formation ....... 207
10.2.2 Simulated Deformation Textures .................... 214
10.3 Recovery and Recrystallization ...................... 215
10.3.1 General Transformation Kinetics ................... 218
10.3.2 Recovery Kinetics ................................. 221
10.3.3 Recrystallization ................................ 223
Literature ............................................... 231
PART II: TECHNOLOGY
CHAPTER 11 Forming Techniques ................................. 237
11.1 General Introduction ..................................... 237
11.1.1 Friction and Lubrication .......................... 237
11.1.2 TMP Furnaces ...................................... 244
Literature ............................................... 246
11.2 Rolling .................................................. 246
11.2.1 Introduction ...................................... 246
11.2.2 Rolling Equipment ................................. 248
11.2.3 Mechanics ......................................... 251
11.2.4 Typical Rolling Schedules ......................... 258
Literature ............................................... 262
11.3 Extrusion ................................................ 262
11.3.1 Introduction ...................................... 262
11.3.2 Deformation Conditions ............................ 264
11.3.3 Steels and High Melting Temperature Alloys ........ 266
11.3.4 Aluminium Alloys .................................. 267
Literature ............................................... 269
11.4 Wiredrawing .............................................. 269
11.4.1 Introduction ...................................... 269
11.4.2 Wire Drawing Machines ............................. 270
11.4.3 Wire Drawing Dies ................................. 271
11.4.4 The Drawing Force ................................. 273
11.4.5 Some Important Metallurgical Factors .............. 275
11.4.6 Drawing of Metal Fibres ........................... 278
Literature ............................................... 279
11.5 Forging .................................................. 279
11.5.1 Introduction ...................................... 279
11.5.2 Forging Equipment ................................. 280
11.5.3 Forging Dies ...................................... 282
11.5.4 Friction and Lubrication in Forging ............... 284
11.5.5 Forging Optimization .............................. 284
11.5.6 Forgability ....................................... 287
Literature ............................................... 289
11.6 Pilgering ................................................ 289
11.6.1 Introduction ...................................... 289
11.6.2 Pilgering Equipment and Process ................... 291
11.6.3 Optimization in Pilgering ......................... 295
11.6.4 Materials Aspects ................................. 296
Literature ............................................... 297
11.7 Sheet Metal Forming ...................................... 297
11.7.1 Introduction ...................................... 297
11.7.2 Plastic Anisotropy ................................ 298
11.7.3 Forming Limit Diagrams ............................ 301
11.7.4 Stretch Forming ................................... 304
11.7.5 Deep Drawing ...................................... 306
11.7.6 Bending and Folding ............................... 311
11.7.7 Other Techniques .................................. 314
Literature ............................................... 317
11.8 Hydroforming ............................................. 317
11.8.1 Introduction ...................................... 317
11.8.2 Sheet Hydroforming ................................ 318
11.8.3 Tube Hydroforming ................................. 318
11.8.4 Important Parameters .............................. 320
Literature ............................................... 322
11.9 Hipping .................................................. 322
11.9.1 Introduction ...................................... 322
11.9.2 Densification Mechanisms .......................... 322
11.9.3 Hipping Equipment ................................. 325
11.9.4 Typical Applications .............................. 326
Literature ............................................... 327
11.10 Superplastic Forming .................................... 327
11.10.1 Technology ....................................... 327
11.10.2 Thinning ......................................... 329
11.10.3 Cavitation ....................................... 330
Literature ............................................... 332
CHAPTER 12 Defects in Thermo-Mechanical Processing ............ 335
12.1 Introduction ............................................. 335
12.2 Form Defects ............................................. 336
12.3 Surface Defects .......................................... 336
12.3.1 Deformation or Forming Process-Induced Surface
Defects ........................................... 338
12.3.2 Environment-Induced Surface Defects ............... 341
12.3.3 Surface Defects Related to Coating ................ 343
12.4 Fracture-Related Defects ................................. 344
12.4.1 Edge Cracking ..................................... 344
12.4.2 Alligatoring ...................................... 344
12.4.3 Central Burst ..................................... 346
12.4.4 Wire-Drawing Split ................................ 346
12.5 Strain Localizations ..................................... 347
12.6 Structural Defects ....................................... 348
Literature ............................................... 348
CHAPTER 13 Physical Simulation of Properties .................. 351
13.1 Introduction ............................................. 351
13.2 Tensile Testing .......................................... 352
13.3 Hot Torsion Tests ........................................ 352
13.4 Compression Tests ........................................ 355
13.4.1 Uniaxial Compression .............................. 355
13.4.2 Plane Strain Compression .......................... 357
13.5 Mixed Strain Path Tests .................................. 361
13.5.1 Lab-Scale Tests ................................... 361
13.5.2 Downgrading of Industrial Processes ............... 361
13.6 Typical Sheet Formability Tests .......................... 362
13.6.1 Bending ........................................... 363
PART III: CASE STUDIES
CHAPTER 14 Thermo-Mechanical Processing of Aluminium Alloys ... 367
14.1 Aluminium Beverage Cans .................................. 367
14.1.1 Introduction ...................................... 367
14.1.2 The Production of a Beverage Can .................. 369
14.1.3 The Production of Can Body Sheet .................. 375
14.1.4 Recycling ......................................... 382
14.1.5 An Alternative Material: Steel .................... 385
14.2 Aluminium Sheets for Capacitor Foils ..................... 385
14.2.1 Introduction ...................................... 385
14.2.2 Capacitor Requirements ............................ 386
14.2.3 The Process ....................................... 388
14.2.4 Cube Texture Control Mechanisms ................... 389
14.3 Aluninium Matrix Composites .............................. 390
14.3.1 Introduction ...................................... 390
14.3.2 Processing ........................................ 391
14.3.3 Hot Extrusion ..................................... 391
14.4 Thick Plates for Aerospace Applications .................. 398
14.4.1 Introduction ...................................... 398
14.4.2 Integral Structures ............................... 400
14.4.3 Metallurgical Improvements through TMP ............ 400
Acknowledgements ......................................... 404
Literature ............................................... 404
CHAPTER 15 Thermo-Mechanical Processing of Steel .............. 407
15.1 Steel for Car Body Applications .......................... 407
15.1.1 Introduction ...................................... 407
15.1.2 Batch Annealed Al-Killed Low-Carbon Steel ......... 408
15.1.3 Continuous Annealed Low-Carbon Steel .............. 411
15.1.4 Interstitial-Free Steels .......................... 413
15.1.5 Trend towards Higher Strength Steels .............. 414
15.2 Dual Phase and TRIP Steels ............................... 417
15.2.1 Introduction ...................................... 417
15.2.2 Dual Phase Steel .................................. 417
15.2.3 TRIP Steel ........................................ 419
15.3 Controlled Rolling of HSLA Steels: Pipeline
Applications ............................................. 425
15.3.1 Introduction ...................................... 425
15.3.2 Controlled Rolling ................................ 425
15.3.3 HSLA Steel for Pipelines .......................... 428
15.4 Electrical Steels ........................................ 429
15.4.1 Introduction ...................................... 429
15.4.2 A Few Relevant Basics on Magnetism ................ 430
15.4.3 Role of Chemistry ................................. 432
15.4.4 Role of Crystallographic Texture, Stress and
Grain Size ........................................ 434
15.4.5 Non-Oriented Electrical Steels (CRNO) ............. 437
15.4.6 Grain-Oriented Electrical Steels .................. 438
15.5 Patented Steel Wires - from Bridges to Radial Tyres ...... 442
15.5.1 Introduction ...................................... 442
15.5.2 The Patenting Process ............................. 442
15.5.3 The Mechanical Properties ......................... 445
Acknowledgements ......................................... 448
CHAPTER 16 Thermo-Mechanical Processing of Hexagonal Alloys ... 451
16.1 Zirconium Alloys for Nuclear Industry .................... 451
16.1.1 Introduction ...................................... 451
16.1.2 Zirconium and its Alloys .......................... 453
16.1.3 Structure-Property Correlation in Zr Alloys ....... 456
16.1.4 TMP of Zirconium Components ....................... 459
Literature ............................................... 464
16.2 Titanium Forgings in the Aerospace Industry .............. 464
16.2.1 Introduction ...................................... 464
16.2.2 Some Physical Metallurgy of Ti Alloys ............. 465
16.2.3 Hot Working Conditions ............................ 467
16.2.4 General dЯ Alloys ................................. 468
16.2.5 Near-a Alloys ..................................... 471
16.2.6 Я and Near-/? Alloys .............................. 472
Acknowledgements ......................................... 473
Literature ............................................... 473
CHAPTER 17 New Technologies ................................... 477
17.1 Submicron Materials by Severe Plastic Deformation ........ 477
17.1.1 Introduction ...................................... 477
17.1.2 Geometrical Dynamic Recrystallization ............. 477
17.1.3 Severe Plastic Deformation ........................ 479
17.1.4 Properties of Submicron Materials Obtained by
SPD ............................................... 485
Literature ............................................... 488
17.2 Grain Boundary Engineering for Local Corrosion
Resistance in Austenitic Stainless Steel ................. 488
17.2.1 Introduction ...................................... 488
17.2.2 Sensitization Control ............................. 488
17.2.3 Ability to Alter Grain Boundary Nature ............ 490
17.2.4 Sensitization and Grain Boundary Nature ........... 491
References ............................................... 495
Index ......................................................... 519
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