2020 年 61 巻 2 号 p. 295-299
The main purpose of precision blanking in press stamping is to suppress fracture of the cut surface. The principle is attainable by applying hydrostatic stress on the workpiece by various contrivances, so that the workpiece can maintain its ductility for suppression of fracture. Stainless steel, which is commonly used in medical components, is also known to be a ductile material, but one of problematic characteristics of austenitic stainless steel is martensitic transformation. The phenomenon is that the ductile austenite phase is changed to the brittle martensitic one by processing strain. Therefore, in this study, the effect on the cut surface from martensitic transformation near it in the precision blanking process was investigated. As a result, it was proved that there was a difference in the occurrence or non-occurrence of fracture of the cut surface due to the difference in the strain-induced martensitic transformation.
