Prediction of the Evolution of the Surface Roughness in Dependence of the Lubrication System for Cold Forming Processes

Lubricants for cold forging operations do not only enable a reliable forging process, but also affect the results of forging processes. A sound lubrication decreases the occurring forces and may result in a smooth specimen surface. However, some lubricants are known to increase the initial surface roughness of the specimen as a consequence of the forming. Therefore, the decision which lubricant should be used is of special interest for near-net shape operations. The paper at hand presents the results of a finite element investigation of the first stage of an industrial rod extrusion process which was investigated with two different lubrication systems. The numerical investigations focus on a reliable prediction of the development of the surface roughness in due consideration of the lubricant.