Application of transient nonlinear thermal analysis on quenching of hot die steel

Abstract

Hot die steels contact with high temperature metals, and possess well thermal conductivity, wear resistance and red hardness. The carbon content should be controlled in the range of 0.3wt.% to 0.6wt.%, and added alloy elements to improve hardenability. The complex composition of the alloy affects its thermal and physical properties. For billets with large volume, it is difficult to measure the temperature of all parts. Through numerical simulation, the temperature field distribution in quenching process of hollow steel pipe with a length of 7 m is obtained by adopting the transient nonlinear thermal analysis algorithm of general finite element software. The results show that the steel temperature decreases to the target temperature of 19°C, it takes about 10 to 12 minutes for the thin wall and 18 to 20 minutes for the thick wall. It is about 4 minutes to descend martensite transition temperature of 265°C at the thick end. Steel temperature decreases to medium temperature, with the wall thickness increases, time slightly longer. The characteristics and phase changing latent heat of hot die steel quenching process are taken into account, and the corresponding treatment is carried out when setting thermophysical parameters. The accurate simulation results are obtained and have certain significance for the research of related materials heat treatment.