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A CV joint outer race is an important load-supporting part in cars. Its geometry is very complicated. Traditional hot and cold forging methods have their own limitations to produce such a complex shaped part. Therefore, multistage forging may be advantageous to produce this part. The key point of outer race is performing the geometry of ball grooves with negative slope angle. Traditional methods form the ball groove by machining that takes long time and waste many portions of the material. Thus near net shape forging is an attractive option for producing of outer race. In this study, the process sequence in the multistage forging of a CV joint outer race has been investigated by using the rigid plastic finite volume method and forging process sequence is designed which can produce a near net-shape housing without defects within a given press capacity. Finally physical modelling with commercial lead is used to verify the reliability of numerical simulation results.

The outer race of a constant velocity (CV) joint is an important automotive component that is difficult to be forged because its shape is very complicated and the required precision is high. Since traditional cold forging methods are not always capable of producing complexly shaped parts, such parts are often made by processes, which require intense machining operations at relatively high costs. Thus near net shape forging is an attractive option for producing of outer race. Actual problems in final ironing sequence are prevention of ductile fracture and surface defects in final product and true formation of internal ball grooves of the workpiece. In this study Cockroft&Latham failure criterion was applied to final ironing sequence. Finally physical modeling is down using lead. In order to investigate the flow of the billet material during forging, the experimentally obtained section profile of internal grooves as measured by a CMM is compared with simulation based profile.