Influence of the cross section area reduction in cross wedge rolling on the multi-directional forging of crankshafts

Abstract Low energy demand and fast processing time are required in each industrial process for the production of crankshafts. A crankshaft is a part of combustion engines. It has a very complex geometry and is forged with a high percentage of flash compared to other forging parts. Recent research showed the feasibility of a flashless forging of crankshafts. One way to forge a flashless crankshaft within three steps, is to use cross wedge rolling, multi-directional forging and final forging. This paper presents the investigation results of the influence of the cross section area reduction in cross wedge rolling on different parameters at multi-directional forging. First the state of research, the process development and tool design of cross wedge rolling and multi-directional forging will be described. Then the parameter field study will be presented and the influence of the cross section area reduction on flash, billet temperature, forming degree, forming forces and stress will be shown. Generally, flash develops because a rotation-symmetric billet is forced into an asymmetric movement. The least amount of flash develops at high cross section area reductions (>40%).