The paper describes a numerical simulation of the current technology of heat treatment of closed-die forgings made of the 25CrMoS4 steel. The aim of this simulation was to create a temperature model enabling a temperature analysis of closed-die forgings during the heating to the austenitization temperature. This model would permit the heating and soaking times to be reduced. The paper also describes a numerical simulation and material/technological modelling of the current forming technology and the subsequent still-air cooling of a selected type of closed-die forgings for the automotive industry. This numerical simulation provides information on the material flow, the part size and the deformation rate during forming and on the temperature conditions during handling, forming and subsequent still-air cooling. Using the material/ technological modelling, samples corresponding to the selected locations of a forging can be obtained. By combining these two techniques, controlled cooling of closed-die steel forgings will be developed and optimized as a substitute for heat treatment. It is also possible to optimize the process in terms of both quality and energy consumption. Both numerical simulations were applied to the technology of forming and heat treatment of closed-die forgings of microalloyed steel, chromium-molybdenum 25CrMoS4, at the company of Kovarna VIVA a.s.
