COMPUTER SIMULATION OF MECHANICAL PROPERTIES OF QUENCHED AND TEMPERED STAMPING PUNCH

摘要

The mathematical model and method of computer simulation for the prediction of mechanical properties and microstructure distribution in quenched and tempered steel was developed. The numerical modeling of steel hardening is consisted of numerical calculation of transient temperature field in process of cooling, and of numerical calculation of mechanical properties and microstructure distribution. Physical properties that were included in the model, such as heat conductivity coefficient, heat capacity and surface heat transfer coefficient were obtained by the calibration. The hardness in as quenched steel has been predicted by the conversion of calculated time of cooling from 800 to 500°C at specimen points to the hardness. Conversion of cooling time results to the hardness was done based on Jominy hardenability curve. Hardness of quenched and tempered steel was expressed as function of maximal hardness of actual steel and representatives of chemical diffusivity of steel according to the time and temperature of tempering. After that, distribution of other relevant mechanical properties was found out based on predicted as quenched and tempered hardness of steel. The established procedure for estimation of quenched and tempered properties of steel was applied in computer simulation of mechanical properties of quenched and tempered steel workpiece.