Mathematical Model for Microstructural Changes and Mechanical Properties in Microalloyed Steels in Continuous Casting-Direct Rolling Process

Abstract

A microstructural control model for conventional reheating and rolling process has been applied to computer simulation of microstructural changes in direct rolling process. Results are summarized as follows:
(1) Effects of secondary cooling conditions in continuous casting on carbonitride precipitation behaviours predicted by the model are in good agreement with those observed by hot ductility simulation tests.
(2) It is known that effect of charging temperature on kinetics of phase transformation and grain growth and low temperature toughness is distinctive: The computer simulation results show that low temperature toughness of steel plate deteriorates if hot charging temperature is higher than Ar₁. This result is consistent with that of laboratory rolling experiment.
(3) The mathematical models for carbonitride precipitation, phase transformation and grain growth for the conventional process can be applicable to microstructural control in continuous casting-direct rolling process.