Abstract
Contents
Nomenclature
Chapter 1 Introduction
Chapter 2 Martensitic Stainless Steel and Solid state Phase Transformation
  2.1 Introduction
  2.2 Martensitic stainless steel and 15 5PH
  2.3 Phase transformation of martensitic steel
    2.3.1 Phase transformation of austenite during heating
    2.3.2 Phase transformation of martensite during cooling
    2.3.3 Main factors of influence on transformation
    2.3.4 Phase transformation models
  2.4 Austenitic grain size and its influences
    2.4.1 Grain size calculation model
    2.4.2 Effect on mechanical properties
  2.5 Measurement of phase proportions
  2.6 Phase transformation induced plasticity (TRIP)
    2.6.1 TRIP mechanisms
    2.6.2 TRIP models
  2.7 Multiphase mechanics and models
    2.7.1 Formulation of the problem
    2.7.2 Mechanical models of multiphase
  2.8 Summary
Chapter 3 Damage Mechanics and Welding Damage
  3.1 Introduction
  3.2 Phenomenological aspects
    3.2.1 Damage variable
    3.2.2 Effective stress
    3.2.3 Strain equivalence principle
    3.2.4 Damage measurement
  3.3 Thermodynamics of isotropic damage
    3.3.1 State potential
    3.3.2 Dissipation potential
    3.3.3 Triaxiality and damage equivalent stress
    3.3.4 Threshold and critical damage
  3.4 Ductile damage models
    3.4.1 Introduction
    3.4.2 Models based on porous solid plasticity
    3.4.3 Models based on continuum damage mechanics
    3.4.4 Anisotropic damage
    3.4.5 Conclusion
  3.5 Welding damage
    3.5.1 Introduction
    3.5.2 Heat affected zone (HAZ) of weld
    3.5.3 Damage and cracking induced by welding
  3.6 Summary
Chapter 4 Evolution Damage Multiphase Modelling
  4.1 Introduction
  4.2 Definition of damage in multiphase
  4.3 A proposed damage equation
  4.4 Constitutive equations of mesoscopic model in multiphase
    4.4.1 State potential
    4.4.2 Dissipation potential
  4.5 Constitutive equations of two scale multiphase model
    4.5.1 Introduction
    4.5.2 Strain localization
    4.5.3 Mechanics in martensite
    4.5.4 Mechanics in austenite
    4.5.5 Memory effect during phase change
    4.5.6 Stress and damage homogenization
    4.5.7 An example in one dimension
  4.6 Conclusion
Chapter 5 Experimental Study and Identification of Damage and Phase Transformation Models
  5.1 Introduction
  5.2 Design of specimens
  5.3 Experimental devices
  5.4 Measurement
    5.4.1 Temperature
    5.4.2 Force and displacement
    5.4.3 Stress
    5.4.4 Strain
    5.4.5 Damage
  5.5 Digital image correlation (DIC)
  5.6 Experimental programs
    5.6.1 Round bar tests
    5.6.2 Tensile tests of flat notched specimen
  5.7 Experimental results and identification of parameters
    5.7.1 Thermal and metallurgical data
    5.7.2 Mechanical data
    5.7.3 Identification of parameters of transformation plasticity model
    5.7.4 Identification of parameters of damage model
    5.7.5 Comparative analysis of flat notched specimen
  5.8 Microstructure characterization of 15 5PH
  5.9 Conclusion
Chapter 6 Numerical Simulation and Implementation of Constitutive Equations
  6.1 Introduction
  6.2 Metallurgical calculation
    6.2.1 Phase transformation calculation
    6.2.2 Grain size calculation
    6.2.3 Calculation of transformation plasticity
  6.3 Numerical implementation of the two scale model
    6.3.1 Introduction
    6.3.2 Algorithm
  6.4 Numerical verification of the models
    6.4.1 Phase transformation and transformation plasticity verification
    6.4.2 Numerical verification of flat notched bars
  6.5 Simulation of a disk heated by laser
    6.5.1 Introduction
    6.5.2 Finite element simulation
    6.5.3 Thermal and metallurgical results
    6.5.4 Mechanical results
  6.6 Conclusion
Chapter 7 Conclusions and Perspectives
Bibliography
Appendix A Experimental Devices
  A.1 Strain and stress measurements
  A.2 Microscopic equipments
Appendix B Experimental Results of 15 5PH in Details
  B.1 Test results of round bar
    B.1.1 Material properties
    B.1.2 Force vs. displacement
    B.1.3 Stress vs. strain
  B.2 Damage results and fitting
  B.3 Test results of flat notched specimen
Appendix C Example of Multiphase Program in CAST3M
List of figures
List of tables