Effect of initial temperature and cooling practice on thermo-mechanical stress of ring rolling

Ring rolling is a metal forming process used to forge precise, seamless, circular, shaped parts. Due to the unique properties of the produced rings, the application in the advanced industries is high. The most important advantage of the process is the uniform flow of material in the ring after the process. Usually, the working temperature of the device is high during the rolling of super alloys. The high temperature could damage the work rolls. In spite of the cooling practice, the work roll temperature is raised. In general, this reduces the work roll strength. In this research, the effect of various temperature and cooling practice on thermo-mechanical stresses in work roll of ring rolling mill have been investigated. The results show that the amount of produced thermo-mechanical stresses on the work rolls is completely different. In the main roll, the mechanical stress has a greater effect on thermo-mechanical stresses. However, in the mandrel, thermal stress determines the amount of thermo-mechanical stresses. Unlike the mandrel, the effect of cooling practice on thermo-mechanical stresses of the main roll is negligible. The results show that cooling practice increases the amplitude of equivalent stress and reduces the mean stress in the work rolls.