Estimation of optimum quenching process using response surface method

Quenching process is utilized to enhance the hardness and strength of large-scale roller. The main effective parameters on quenching results are the heat transfer coefficient and cooling time. In this paper, the effects of quenching process parameters on the hardened depth and residual stresses were analyzed by using response surface methodology (RSM) based on design of experiments (DOE). A step linearity function model of heat transfer coefficient with time was presented with the objective: depth of hardened layer and residual stresses. The numerical simulation was carried out by means of thermo-elastic-plasticity theory coupling with phase transformation for a sufficient number of process parameters combinations to predict the hardened layer thickness and residual stresses distribution. Finally, mathematical models of response surface were gained by the stepwise regression method.