An Investigation into Deep Drawing Parameters on Deformation-Induced Martensitic Microstructure Transformation of an Austenitic Stainless Steel

摘要

Stainless steel is one of the most widely used engineering materials due to high strength and excellent corrosion resistance. In this paper, the deformation-induced martensitic behavior of austenitic stainless steel 304 was investigated by the finite element method. For this purpose, the process parameters of forming speed and punch corner radius were examined during the warm deep drawing process under gradient condition from room temperature to 300?°C for sheets with 1?mm thickness. Also, their effects were studied on deformation-induced martensitic transformation. To apply thermal gradient, the blank in flange region was heated by die heating, and the blank center has been cooled by water circulating punch for strength enhancement. Results showed that when the temperature was increased to 150 and 300?°C, the martensitic transformation stopped in wall and flange regions, and the maximum punch force decreased. In addition, the faster forming speed and the sharper punch corners transformed higher martensitic content especially in the punch corner regions.