Contact Heat Transfer Coefficient Determined Based On The No. 45 Hot Deformation Conditions

In the finite element simulation of forging, the heat transfer coefficient play a important role in temperature distribution simulating. It is important to determine the heat coefficient in order to design the new technology and control the metal forming processes.This research tries to find a method that can determine the magnitude of heat transfer coefficient through the temperature information obtained from hot upsetting. And on the basis of this information ,this paper try to investigate the influences of pressures, deformation rates and oxide layer on the heat transfer coefficient.The main conclusions of this research include: it is linear relationship between the heat transfer coefficient and temperature during no deformation when contact, the heat transfer coefficient slowly increases with increasing of temperature, the main factors that influence the heat transfer coefficient is micro-case of contact between the mold and the workpiece,like oxide lyaer. During deformation, the heat transfer coefficient increases with increasing of pressure, the main factors that influence the heat transfer coefficient is pressure. In addition, the deformation rates,oxide layer will influence the heat transfer coefficient too. And with the deform rate increasing,the heat transfer coefficient decreasing.Based on this test, I analyse the different factors that influence the heat transfer coefficient. In the end, I build mathematical model of 45 steel during only contact and deform .