Modeling and experimental verification of martensitic transformation plastic behavior in carbon steel for quenching process

Abstract

The objective of this paper is to extend the capability to analyze the evolution with coupling behavior of temperature, stress and strain at the macroscopic and microscopic viewpoints in quenching process together with the kinetic theory of phase transformation. Strain due to phase transformation, transformation plasticity and thermal expansion is a dominated load in the simulation of quenching process. The microstructure evolution also influences the constitutive equations. In particular, as the temperature changes from the high temperature level to phase transformation point and room temperature, stress–strain relationship changes from elastic–plastic strain. Therefore, in order to obtain a high strength and ductility product of carbon steels, transformation plasticity often has a major affect in increasing of the residual stress during quenching process. In this paper, the experimental results of measured temperature change and distortion in quenching process of carbon steel (SCr420) by thermal simulation machine (Gleebler 1500) are used to determine the parameter of transformation plasticity due to generation of martensite. The modeling of martensitic transformation plasticity also is verified by using of computational simulation of quenching process, which couples the knowledge of temperature, phase transformation and stress–strain.