Advanced High Strength Steel (eBook)

Dr Tapas Kumar Roy is a Principal Scientist  in the Research and Development (R&D) Division of Tata Steel Limited in Jamshedpur, India. He holds  M. Tech and PhD degrees from the Indian Institute of Technology Kanpur, India. Dr Roy  has been associated with Tata Steel  for over 20 years and during this period he has worked in various functions like Scientific Services, Long Product Technology, Flat Product Technology before being moved to R&D from 2016. His areas of interest include steelmaking,  secondary refining, continuous casting, inclusion engineering, ferro-alloys, defectology, mould powder, process design and improvement.  He has authored over 40 scientific research papers in National and International journals and conferences. Dr Basudev Bhattacharya is working as Principal Scientist in the Research and Development (R&D) Division of Tata Steel Limited in Jamshedpur, India. He holds M. Tech and PhD degrees from the Indian Institute of Technology in Kanpur, India. From 1997 to 2007, Dr Bhattacharya has worked in the Cold Rolling Mill and Flat Product Technology Group in Tata Steel. From 2007 onwards he has been in the R&D Division at Tata Steel. His areas of interest include physical metallurgy and materials science, phase transformation, designing of steel chemistry, X-ray diffraction, electron microscopy, etc. He has been granted 4 patents, and he has authored over 30 scientific research papers. Dr Chiradeep Ghosh is a Principal Researcher in the Research and Development (R&D) Division of Tata Steel Limited in Jamshedpur, India, where he has been working since 2003. He holds a M. Tech degree from the Indian Institute of Technology Kanpur, India and a PhD from McGill University, Montreal, Canada.  His areas of interest include Thermomechanical controlled processes, phase transformation and related phenomenon, characterization of materials and electron microscopy. Dr. Ghosh has been granted 6 patents, and has authored over 35 scientific research papers and served as an editor for 2 conference proceedings. In addition he has also authored a book titled “The Dynamic Transformation of Deformed Austenite” (Scholars Press). He serves as a reviewer for multiple high impact journals and is an editorial board member of Current Smart Materials. Dr Satish Kumar Ajmani is Chief Researcher in the Steelmaking & Casting Research Group in Research and Development (R&D) of Tata Steel Limited in Jamshedpur, India. He holds M. Tech and PhD degrees from the Indian Institute of Technology Kanpur and Kharagpur respectively. His areas of interest include steelmaking, physical and numerical modeling, continuous casting, inclusion engineering, product - process design & optimization and mould powder development. Dr Ajmani has worked at Tata Steel for over 30 years, and has been the Chief researcher for the last 2 years. He has authored over 100 scientific research papers in National and International journals and conferences.  

Preface 6
Contents 8
About the Editors 11
1 Dynamic Transformation During the Torsion Simulation of Plate and Strip Rolling 13
Abstract 13
1 Introduction 13
2 Experimental Procedure 14
3 Results 15
3.1 Strip Rolling 15
3.2 Plate Rolling 16
4 Discussion 18
4.1 Critical Strains 18
5 Conclusions 20
Acknowledgements 20
References 20
2 Microstructure Engineering of High-Performance Steels 22
Abstract 22
1 Introduction 22
2 Process Models 24
2.1 State Variable Approach 24
2.2 Phase Field Modeling 25
3 Results 26
3.1 Intercritical Annealing 26
3.2 Heat-Affected Zone 27
4 Conclusions 29
References 29
3 Recent Topics on Development of Automotive High-Strength Sheet Steels 31
Abstract 31
1 Introduction 31
2 Development of 1180 MPa Grade Cold-Rolled Sheet Steel with Good Practical Performance 32
3 Development of 1800 MPa Grade for Hot Stamping 34
4 Summary 36
References 36
4 An Overview on Structure–Property Relationship of TRIP-Aided Steel 37
Abstract 37
1 Introduction 37
2 Thermal Treatment Design 40
2.1 Prediction of Microstructure Through Artificial Neural Network (ANN) Model 40
2.2 Phase Calculation 40
3 Role of Retained Austenite on the Mechanical Behavior 43
4 Coatability of TRIP-Aided Steel 46
5 Summary of the Work 47
References 47
5 Mechanical Properties and Applications of a New Stainless TWIP Steel 49
Abstract 49
1 Introduction 49
2 Materials 50
3 Results and Discussion 51
3.1 Microstructure After Cold Rolling 51
3.2 Evolution of the Microstructure with Cold Deformation 51
3.3 Microstructure of Specimens Deformed at Low Temperature 53
3.4 Determination of the Stacking Fault Energy 54
3.5 Tensile Properties as a Function of Temperature 54
4 Discussion and Conclusions 56
References 56
6 Evolution of Texture in Some Mn Steel 58
Abstract 58
1 Introduction 58
2 Experimental 60
2.1 Material and Processing 60
2.2 Characterizations 60
3 Results and Discussion 61
3.1 Structural Characterization by X-Ray Diffraction 61
3.2 Evolution of Bulk Texture 61
3.3 Microtexture Evolution 63
3.4 Mechanical Properties 64
4 Conclusions 65
Acknowledgements 65
References 66
7 Development of Advanced High-Strength Steel for Lifting and Excavation Sector at Essar Steel 68
Abstract 68
1 Introduction 68
2 Characteristics of Steels for Earth Moving Equipment 69
3 Alloy Design Concept 69
4 Abrasion Resistant Steel: ROCKSTAR 70
5 High-Strength Thermo-Mechanically Controlled Rolled Plates 73
6 High-Strength Quenched and Tempered Plates: BOOMOR 900 75
7 Conclusions 77
References 78
8 High-Strength Linepipe Steels and Physical Simulation of Production Processes 79
Abstract 79
1 Introduction 79
2 The Role of Physical Modeling on Linepipe Steel Developments 81
2.1 Continuous Casting 81
2.2 Hot Rolling 82
2.3 Cooling After Hot Rolling 85
3 Summary 86
Acknowledgements 86
References 86
9 Recent Advances in Welding of High-Strength Bainitic Steel for Automotive Applications 87
Abstract 87
1 Introduction 88
2 Experimental Details 88
3 Results and Discussion 89
4 Conclusions 92
References 93
10 Mechanical Properties of Copper-Added Ultra-fine Bainitic Steel 94
Abstract 94
1 Introduction 94
2 Experimental Procedure 95
3 Results and Discussions 96
4 Summary 101
References 101
11 Microstructure-Based Deformation Modeling of Dual-Phase Steels 102
Abstract 102
1 Introduction 102
2 Numerical Modeling 103
2.1 RVE Selection 103
2.2 Meshing 104
2.3 Material Properties 104
2.4 Boundary Conditions 105
2.5 FEM Analysis 105
2.6 Homogenization 106
3 Results and Discussion 106
4 Summary and Conclusion 108
References 108
12 Effect of Flash Annealing on Ultra-Fine Grained Low-Carbon Steel Processed Through Equal-Channel Angular Pressing Followed by Cryorolling 109
Abstract 109
1 Introduction 110
2 Experimental Procedure 110
3 Results 111
4 Discussions 116
5 Conclusions 118
References 118
13 Microstructural Evolution in Boron-Added Advanced High-Strength Steel Suitable for Hot Stamping 120
Abstract 120
1 Introduction 121
2 Experimental 121
3 Results and Discussion 122
4 Effect of Cooling After Deformation 123
5 Synergistic Effect of Boron and Molybdenum 126
6 Conclusion 127
Acknowledgements 127
References 128
14 A Novel Low-Carbon High-Strength Steel: Processing, Microstructure and Mechanical Properties 129
Abstract 129
1 Introduction 130
2 Experimental Procedure 131
3 Results and Discussion 131
3.1 Microstructure 131
3.2 Hardness and Tensile Properties 134
3.3 Hot Ductility Behaviour 135
4 Conclusions 136
Acknowledgements 137
References 137
15 Recrystallization Texture Evolution in HSLA Steel 138
Abstract 138
1 Introduction 138
2 Experimental Procedure 139
3 Results 140
3.1 Hot Rolling Microstructure and Texture 140
3.2 Cold-Rolled Microstructure and Texture 140
3.3 Recrystallization Kinetics 141
3.4 Recrystallization Texture 142
3.5 AT Sample 143
3.6 BT Sample 143
3.7 Discussion 143
3.8 Summary 144
References 145
16 Technological Challenges and Solutions for the Production of State-of-the-Art Second- and Third-Generation AHSS Grades 146
Abstract 146
1 Market Drivers and Solutions 147
2 Process Challenges and Solutions 147
3 Slab Caster Design and Adjusted Cooling 148
4 Belt Casting Technology (BCT) for Advanced HSD-TWIP Grades 148
5 Accelerated Cooling Technologies in Hot Rolling 149
6 I-Furnace Technology for Quench and Partitioning Grades 149
7 Quality Management by PQA Software Solution 150
8 Conclusion 151
References 151
17 Gas–Liquid Flows in Ladle Shroud and Their Impact on Tundish Process Performance and Steel Quality 152
Abstract 152
1 Introduction 152
2 Present Work 153
2.1 Physical Modelling 153
2.2 Mathematical Modelling 155
2.3 Results and Discussion 155
3 Conclusions 160
References 160
18 Novel Casting Technology Preventing Slab Transverse Corner Cracks of Typical Micro-alloyed Steels 162
Abstract 162
1 Introduction 163
2 Influence of the Corner Shape on Fluid Flow, Temperature Distribution and Solidification at Slab Corner 163
2.1 Influence of the Chamfer Angle on the Fluid Flow, Heat Transfer and Solidification of the Molten Steel in Mould 163
2.2 The Influence of the Chamfered Length on Fluid Flow, Heat Transfer and Solidification of the Molten Steel in Mould 165
3 The Influence of the Chamfered Shape on the Stress and Strain of the Slab During Straightening Process 166
3.1 The Influence of the Chamfered Angle on the Stress and Strain of Slab During Straightening Process 166
3.2 The Influence of the Chamfered Length on the Stress and Strain of Slab During Straightening Process 168
4 The Application of Chamfered Mould 169
5 Conclusions 172
References 172
19 Non-metallic Particles Benefit or Burden for AHSS? 174
Abstract 174
1 Introduction 174
2 Approach and Results 176
2.1 Fe–Mn–S System 176
2.2 Precipitates Formation During Solidification—TiN During Solidification 177
2.3 Precipitation of Nb(C,N) During Solidification 179
3 Conclusions 182
References 183
20 Advanced High-Strength Steel—Challenges to a Steelmaker 184
Abstract 184
1 Introduction 184
2 Part I—Approach Towards Oxide Inclusions 185
2.1 Deoxidation Products––Reduction in Oxygen Levels 185
2.2 Deoxidation Product––Deoxidation Practice 187
2.3 Deoxidation Products—Efficiency of Removal 188
2.3.1 Size and Morphology of Inclusions 189
2.3.2 Rinsing and Stirring Practices 189
2.3.3 Time for Floatation 190
3 Entrainment and Entrapment of Inclusions 190
3.1 Inclusions from Refractory 190
3.2 Slag Entrainment 190
3.3 Inclusions from Casting Flux 190
4 Reoxidation of Steel 191
4.1 Secondary Metallurgy 192
4.2 Ladle to Tundish 192
4.3 Tundish to Mould 192
5 Part II—Approach Towards Sulphides and Nitrides 193
5.1 Sulphides 193
5.2 Nitrides 194
6 Conclusion 195
References 196
21 Macrosegregation of Multicomponent Steel in Round Billet Continuous Caster 197
Abstract 197
1 Introduction 197
2 Mathematical Model 198
2.1 Geometry Details 199
2.2 Boundary Conditions 200
3 Validation 201
4 Results 202
5 Conclusion 205
References 205
22 Production of High-Strength Plates Through New Plate Mill at RSP 206
Abstract 206
1 Introduction 207
1.1 Modernization Cum Expansion of RSP 207
1.2 Steel Melting Shop 207
1.3 New Plate Mill 208
2 Production of High-Strength Plates 209
2.1 Steelmaking Measures 210
2.2 Control of Steel Sulfur 211
2.3 Control of Steel Phosphorus 211
2.4 Vacuum Treatment of Liquid Steel 213
2.5 Continuous Casting of Steel 213
2.6 Rolling at New Plate Mill 215
2.7 Heats Routed Through RHOB 215
3 Conclusion 216
References 217