The Numerical Investigation of the Effect of Transformation Plasticity on Quenching Distortion - CANCELLED

Quenching is one of the most important heat treatment processes of metals in which the properties of parts are determined. Although a lot of research has been conducted in the last three decades to develop numerical simulation tools for the prediction of the final state of the quenched parts, there still exists lots of limitation. As quenching simulation is a highly input sensitive process, the accuracy of the input parameters of thermo-property and mechanical property greatly affect reliability of the simulation.

The sensitivity investigation for 18 kinds of input parameters has been performed using orthogonal experiment design method, and these parameters include density, thermal conductivity, specific heat, transformation enthalpy, elastic modulus, Poisson’s ration, thermal expansion coefficient, work hardening factor, transformation kinetics parameter and transformation plasticity parameter. All the input parameters are set as the two levels of plus or minus 10%, respectively, in the orthogonal experiment design. The results got from the simulation, including the starting time and the ending time of the martensitic transformation, the circumferential stress and axial stress in both the surface and the center of the part. Using the method of mathematical statistics, the mean analysis and F variance test have been applied to weigh the influence of input parameters on the accuracy of simulation results. According to the carefully analysis of the significant test, the input parameters can be classified into different levels that have different significant effects on the accuracy of simulation results.

Key words: Quenching simulation, thermo-physical property, orthogonal experiment design