This study considered the replacement of S25C-A with S15C-R in the backward extrusion of a tapered cup using finite element (FE) analysis to evaluate crack prediction, product strength, and forming load.
The FE analysis software was the commercial package Simufact Forming, and the Cockcroft–Latham ductile fracture criterion was employed for crack prediction. As a result of the analysis, S15C-R exhibited no regions exceeding the critical damage value, indicating a low risk of a crack. Subsequently, the product strength was evaluated based on the hardness distribution derived from the equivalent stress distribution. Both S25C-A and S15C-R met the specifications, and their strengths were almost the same.
Furthermore, the forming load for S15C-R was comparable to that of S25C-A, indicating that there were no issues with formability. These results demonstrate that replacing S25C-A with S15C-R does not affect product quality and allows for a reduction in processing steps by eliminating the annealing process.
