STAMPING APPRAISAL DEVICE AND METHOD OF A STEEL SHEET

摘要

The appts. comprises a lower die (10) and an upper die (9) on which is mounted a lock head. A test specimen (7) is inserted between the upper and lower dies and clamped along the circumferential edge of the specimen by means of the lock head so that the specimen is mobilised into the upper die. A punch (21) is elevated to apply a stretch forming force onto the test specimen and then the plane stretch formability is evaluated based on the fracture limit punch height at the instant of the fracture. The punch has a saddle like semi-cylindrical shape.