Deformation behavior and load analysis of TP304 stainless steel billet during hot expansion process

Abstract

The expansion deformation process of TP304 stainless steel large diameter billet in 60 MN extrusion production line was studied. The numerical simulation method was used to analyze the expansion deformation behavior under different working conditions, and the effects of different process parameters on expansion deformation were studied. The simulation results show that increasing the bell mouth diameter is beneficial to improve the flatness of the upper end face of billet after expansion but has little effect on the expansion load. Increasing the inner hole diameter of billet is beneficial to separate the expansion surplus metal and reduce the expansion load. The bell mouth with diameter of Φ270 mm and the inner hole with diameter of Φ80 mm can achieve the expansion process of billet with diameter of Φ432 mm successfully. The center misalignment between the billet and the expansion cylinder can cause the inclination of the upper end face of billet after expansion directly. Increasing the expansion temperature and reducing the expansion speed are beneficial to reduce the deformation resistance and strain rate, which is beneficial to reduce the expansion load. Based on the simulation results, the reliability of billet shape and process parameter optimization was verified by process tests.