Analysis of Temperature, Stress and Metallic Structure in Carburized-Quenched Gear Considering Transformation Plasticity

A method for the simulation of carburized-quenching process is presented in this paper, which takes into account the coupling effect of temperature, stress and metallic structure. Here, emphasis is placed on the role of transformation plasticity. The constitutive equation of the transformation plastic strain was determined experimentally assuming that the strain rate is proportional to the applied stress for both pearlitic and martensitic transformations. The carburized-quenching process of a steel gear of 1.8%Ni-0.6%Cr-0.25%Mo with 0.2%C (SNCM420HK) was analyzed by use of the finite element method, and the calculated results of carbon content, temperature, metallic structure and stress were compared with the experimental data. The distribution of the residual stress revealed that the transformation plasticity should be introduced in the simulation.