Heat treating is the controlled application of time, temperature and atmosphere to produce a predictable change in the microstructure of a material to achieve desired material properties. However, alloys are complex systems where the microstructure and properties depend on both the processing conditions and chemical composition. Variations in heat-to-heat composition, particularly in terms of minor elements, or the extent of inhomogeneity arising from solidification affect properties and processing windows. When these data are not available, Thermo-Calc can be used to fill the gaps and make predictions of material behavior throughout the material’s life cycle as a function of composition, temperature and time.
Thermophysical properties: Specific heat, enthalpy, heat capacity, heat of formation, density, coefficient of thermal expansion, viscosity (of liquid), surface tension (of liquid), interfacial energy, thermal conductivity and electric resistivity
Kinetic properties: Diffusion coefficients, atomic mobility
Mechanical properties: Yield strength, hardness
Properties related to equilibrium and non-equilibrium solidification: Liquidus, solidus, incipient melt temperatures, freezing range, fraction solid curves, solidification path, fraction eutectic, microsegregation, partition coefficients, latent heat, shrinkage, susceptibility to hot tearing and more
Properties specific to steel: A1 and A3 temperatures, martensite start temperature, martensite fractions, and kinetics of pearlite and bainite formation.
Thermo-Calc can simulate the effects of different types of heat treatment – such as homogenization, aging, quenching, surface hardening, stress relief and post-weld heat treatment – to predict the phases/microstructure that form.
Solidification and homogenization
Aging and precipitation