1. FE-FE₃C PHASE DIAGRAM 1
1.1 EQUILIBRIUM REACTIONS 1
Free-Energy Diagram 1
Transformation of Pure Iron 2
Gibbs Phase Rule 4
Equilibrium Fe-C Phase Diagram 4
1.2 NON-EQUILIBRIUM REACTIONS 7
PROBLEMS 9
2. MECHANISMS OF STRENGTHENING AND SOFTENING 11
2.1 IDEAL STRENGTH 11
Theoretical Cohesive Strength of Metals 11
Theoretical Shear Strength of Metals 12
2.2 SOLID-SOLUTION HARDENING 14
Dislocation-Solute Interaction 14
2.3 PRECIPITATION HARDENING 18
Non-deformable Particles 18
Deformable Particles 20
Massive Second-phase Particles or Aggregates 22
2.4 WORK HARDENING 22
Recovery 25
Recrystallization 28
2.5 STRENGTHENING BY GRAIN REFINING 29
2.6 PHASE TRANSFORMATION HARDENING 30
2.7 ANISOTROPIC STRENGTHENING 31
PROBLEMS 32
3. EFFECTS OF ALLOYING ELEMENTS 33
3.1 INTERSTITIAL ALLOYING ELEMENTS 33
Solubility of Carbon in α Iron 34
Diffusivity and Internal Friction 35
Yield Point Phenomenon 37
Strain Aging 40
3.2 SUBSTITUTIONAL ALLOYING ELEMENTS 42
Effects of Substitutional Alloying Elements on Mechanical Properties 43
Interaction Between Solute Atoms 44
PROBLEMS 46
4. PROCESSING OF STEELS 47
4.1 DEFORMATION 47
Hot Deformation 47
Cold working 48
The Anisotropy Ratio 48
Forming Limit Diagram 51
4.2 HEAT TREATMENT 52
Homogenization 52
Annealing Heat Treatments 53
Normalizing 54
Spheroidizing 54
PROBLEMS 55
5. LOW-CARBON STEELS 57
5.1 STRENGTH AND TOUGHNESS 58
Strengthening Factors 58
Ductile-brittle Transition 59
Ferrite and Pearlite 61
Superplasticity 67
Bake Hardening(BH) 68
5.2 PRECIPITATION AND INCLUSIONS 69
Precipitation of Carbides and Nitrides 69
Inclusions 71
Magnetic Aging 72
5.3 HSLA 73
Design of the Chemical Composition 73
Particle Pinning Force Against Grain Growth 74
Controlled Rolling, Controlled Cooling 76
Variety of Microstructure 77
Weathering Steels 78
5.4 SURFACE TREATMENT 78
Galvanizing 78
Enamelling 78
PROBLEMS 80
6. MARTENSITIC STEELS 81
6.1 MARTENSITIC STEELS AND HARDENABILITY 82
Martensitic Transformation 82
6.2 HARDENABILITY 87
Martensitic Steels with Improved Toughness 89
6.3 TEMPERING OF MARTENSITE 90
Tempering Stages 90
Tempering Parameter 93
6.4 TEMPER EMBRITTLEMENT 93
Tempered Martensite Embrittlement 93
Temper Embrittlement 94
Mechanism of Embrittlement 95
Remedies 96
6.5 BAINITIC STEELS 96
Transformation and Mechanical Properties 96
Martempering and Austempering 99
Patenting 100
Thermo-Mechanical Treatment(TMT) 100
6.6 STEELS FOR SPRINGS AND BEARINGS 101
PROBLEMS 103
7. TOOL STEELS 105
7.1 TOOL STEELS 105
Classification of Tool Steels: Variety of Hardenability 105
High Speed Tool Steels and Secondary Hardening 107
Retained Austenite and the Conditioning Heat Treatment 108
7.2 SURFACE HARDENING 108
Carburizing 108
Nitriding 110
Carbonitriding 110
Induction Hardening 110
Laser Hardening 111
7.3 SUPER-HARD MATERIALS FOR TOOLS 111
PROBLEMS 112
8. STAINLESS STEELS 113
8.1 TYPES OF STAINLESS STEELS 113
Compositional Variation 113
Fe-Cr Binary System and Spinodal Decomposition 114
Fe-Ni Binary System 118
Fe-Ni-Cr Ternary Alloys and Phase Stability 119
8.2 CORROSION AND STAINLESS STEELS 120
8.3 AUSTENITIC STAINLESS STEELS 121
8.4 FERRITIC STAINLESS STEELS 123
Martensitic Stainless Steels of High Strength 124
Duplex Stainless Steels with High Intergranular Corrosion Resistance 125
Precipitation-Hardened Stainless Steels of Added Strength 125
PROBLEMS 127
9. HIGH ALLOY STEELS 129
9.1 THEORY OF CREEP 130
9.2 ALLOYING EFFECTS 130
Effects of Alloying Elements 130
The γ' Precipitates and Anomalous Yielding 131
9.3 MARAGING STEELS 133
Martensite Formation and Aging 134
Strengthening by Coherent Particles 134
9.4 TRIP STEELS 135
9.5 THEORIES OF BRITTLE FRACTURE 136
Griffith Theory of Brittle Fracture 136
Dislocation Theory of Brittle Fracture 137
9.6 HADFIELD STEEL 138
PROBLEMS 139
10. SPECIAL STEELS 141
10.1 MAGNETIC PROPERTIES OF ELECTRIC STEELS 141
Ferromagnetic Properties 141
Core Loss 142
10.2 UTILIZATION OF TEXTURE IN ELECTRIC STEELS 143
Si-Irons 143
10.3 CRYOGENIC STEELS - TEMPERATURE DEPENDENCE OF THE FLOW STRESS 144
Alloying Effect on Toughness 146
PROBLEMS 148
ANSWERS TO PROBLEMS 149
INDEX 155