Numerical investigation of geometrical defect in cold forging of an AUV blade pin head

The precision of cold forging parts becomes critical because the process depends on many factors such as the size and complexity of the parts. Defects negatively affect the assembly accuracy and the performance of the parts. Therefore, defects must be detected and prevented as soon as possible before the manufacturing process begins. The paper intends to investigate the geometrical defect of the cold embossing pin head, which may result in an inaccurate assembly of the blade. In this paper, defect formation was studied using DEFORM-2D based on material flow pattern and stress distribution. The defect was measured in terms of incomplete filling and geometries of the bulging. The effect of the distance to the edge (DTE) is significant to the formation of defects. The size of the bulge is reduced and the filling ability shows better performance as the DTE increases. The FE results are in good agreement with the experimental result.