Numerical simulation of spray quenching heat-treatment process of backup roll

摘要

This article uses Finite-difference time-domain (FDTD) method in the spray quenching process of the backup roll, which calculated the temperature field, the phase transformation and the hardness of the backup roll. The results showed that there was high temperature gradient on the surface of back up roll at the beginning of the spray quenching process and the temperature decreased rapidly. The beginning of the spray quenching process is a key stage. The radius martensite content decreases from outside to inside gradually, the maximum depth that martensite occurs was about 150mm from the surface. Martensite point affected the surface hardness very slightly, whereas impacted the hardening depth strongly.