Study of the process stability of cross wedge rolling

Abstract

The process stability and acceptable quality of forgings should be assured during properly designed cross wedge rolling (CWR). As shown in industrial practice, the slipping occurring between the forging being formed and a tool segment is the most important factor disturbing the CWR process. Furthermore, forging necking (in the case of conventional CWR) or buckling (for CWR with upsetting) and additionally, central cavities and surface lapping, may occur. On the basis of theoretical analysis, the ranges of basic parameters for tool segments (i.e. forming angle α and spreading angle β) ensuring process stability have been determined in the present study. Examples of typical ranges for the presumed forming conditions are shown in the diagrams. The results obtained from analysis have been compared with the results of experimental studies included in the references to enable the assessment of the accuracy of the solution. Proper consistency has been demonstrated by this comparison.