Mathematical modelling and TMCP simulation for optimisation of steel behaviour.

Physically based mathematical models for prediction of steel behaviour and microstructure evolution in connection with thermo-mechanical controlled processing (TMCP) development at the Swedish Institute for Metals Research are discussed. The models can be used for computer predictions of recrystallization and grain growth of austenite after deformation, precipitation or dissolution of microalloying carbonitride in austenite, flow stress during hot working, phase transformation behaviour during accelerated cooling as well as the final microstructure and mechanical properties. The database, which contains information about the steel behaviour for a large number of HSLA steels, is also presented. Optimisation TMCP parameters for improving the properties of steel are discussed in relation to the microstructure and mechanical properties. The effect of TMCP parameters (reheating temperature, rolling schedules and finish rolling temperature as well as accelerated control cooling) on steel properties was studied in laboratory scale.