S355J2W钢自阻加热弯曲成形回弹控制与质量分析

In order to investigate the influence of the current density on the springback and quality of S355J2W steel parts formed by resistance heating bending, the V-shaped and cap-shaped resistance heating bending experiments were designed. The springback of steel parts after forming was studied by varying current densities in resistance heating. According to the test results, the quality of the parts with the highest forming accuracy and the smallest springback were selected to compare with the parts formed at room temperature to study the advantage of resistance heating bending. The selected two parts were divided into 9 different regions. The microstructure and mechanical properties of these regions, such as strength, hardness, elongation, and impact toughness were used as the standard to evaluate the quality of the formed parts. Moreover, the differences in mechanical properties of the two parts were explained by the results of microstructural observation. The results showed that the springback of S355J2W steel in resistance heating bending was improved with the increase current density. Compared to the parts formed at room temperature, resistance heating bending process can greatly improve the springback and quality. At the same time, the mechanical properties were also improved in resistance heating bending.