Prediction of Necking Points and Microstructure in Sheet Metal Forming

The automotive industries are trying to optimize the forming and process parameters to reduce the weight of vehicle. Also, these optimized results are helpful to the manufacturer during decision making, so that overall product development or manufacturing time is reduced. In this paper, comparison of the strain paths, necking and fracture behaviors among the steel materials is performed. In this paper, the formability parameters such as strain path, thinning and contact pressures between die sets are studied. The strain path points are predicted by using FEA simulation in Pamstamp software for AISI304 and AISI409L grade material. The major and minor points are predicted at necking points for various specimens and these points are represented on FLD curve for both the materials. It is observed that AISI304 grade material showed higher formability i.e. 17% higher formability than the AISI409L grade material. The simulated and experimental results showed a closed match with good correlations though the variation between them is nearly 7%. Also, the microstructures are investigated by following standard metallographic process and after investigation it is observed that as the microstructure changes the locations of the deformed sheet parts also get changed.