Formability of SS304 stainless steel foil at elevated strain-rate

Abstract

Necking and fracture are vital issues during the production of metallic bipolar plates. Therefore, evaluating the formability of thin metallic foil is a critical demand for the fabrication of metallic bipolar plates. Here, the static and dynamic formability of SS304 stainless steel foil with the thickness of 0.1 mm were investigated using traditional rigid-punch bulging and electromagnetically-impacted stamping methods, respectively. The strain rate of the traditional rigid-punch bulging experiment is about 10−3s−1, while the strain rate of the electromagnetically-impacted stamping experiment can reach 102s−1. The experimental limit strains at necking were determined by the position-dependent method, and the simulated limit strains at necking were identified by the time-dependent method. The fracture limit strains were determined by the reverse engineering method. The accuracy of the simulation was subsequently verified. The results show that the dynamic formability at necking and fracture is slightly higher than the static formability. The formability of SS304 stainless steel foil exhibits slight strain rate sensitivity. Furthermore, the fracture locus of the SS304 stainless steel foil was predicted by the Johnson-Cook fracture model.