Study on electric pulse effect on steel DP780 during roll forming

Abstract

The electrophysical impact on metals introduces a novel optimization avenue for roll forming. This study explores the influence of different electric pulse parameters (peak current and frequency) on the roll forming behavior of DP780 high-strength steel. Through electric pulse-assisted tensile, bending, and roll forming experiments, coupled with microstructure and fracture morphology analyses, the study comprehensively assesses the impact of electric pulses on the mechanical properties and springback mechanism of DP780 sheets. Results indicate that electric pulses reduce deformation resistance and enhance the plasticity of DP780 sheets by repairing defects, promoting dislocation slip, and changing the fracture form of the material. Moreover, electric pulses effectively inhibit springback in roll forming, particularly at larger bending angles and under specific E-pulsing parameters. This is attributed to the promotion of residual stress release by electric pulses, leading to a reduction in springback. In conclusion, electric pulse assistance optimizes the roll forming process of DP780 high-strength steel, evidenced by decreased deformation resistance, improved material plasticity, and effective suppression of springback. These findings open up a new optimization pathway for sheet metal forming.