摘要：Hollow or tubular preforms are used to meet lightweight requirements and reduce production costs of cold formed components. In order to increase efficiency of manufacturing, a combined forming process was developed, which will be presented in this paper: manufacturing of hollow preforms by combining processes backward cup extrusion and piercing. With regard to combined forming processes in the field of cold forging, disclosed work consists of numerical identification of significant process input variables, process outcomes, and the process limits.
