Interfacial heat transfer coefficients in cold forging of stainless steel

In numerical simulations of cold forging processes, the heat transfer coefficient has a significant influence on the resulting temperature fields. However, the values determined so far for steel materials are not in the load range of cold forging processes. In this paper, a test stand for the determination of the interfacial heat transfer coefficient under typical loads of metal forming processes is presented. The results are discussed at an example of a cold extrusion forming process. It can be shown that the value increases significantly with increasing contact pressures and are higher compared to values known from literature. The investigations also disclose the influences of lubricants and the mechanical surface treatment on the heat transfer coefficient.