Springback Control of DP1180 Steel Stamping by Variable Closing Pressure

Abstract

In order to further control the springback of advanced high-strength steel in stamping,a method to reduce the bending springback by increasing the variable closing pressure (VCP) through servo hydraulic equipment without increasing the material forming margin was proposed. For U-shaped benchmark parts of 1 180 MPa dual-phase (DP1180) steel formed by stamping, the feasibility of increasing VCP to control springback was analyzed by using the finite element method, and the mechanism of increasing VCP to reduce springback was studied from the perspective of residual stress and dislocation. The results show that the proposed method can reduce the residual stress and the dislocation density of the formed material, thus increasing the inelastic recovery and achieving the effect of reducing the springback angle of the target part by 22.3%. Because this method is only applied at the end of part forming, which does not affect the plastic flow in the material forming process, there is no need to increase the additional material forming ability and shaping process, which can be applied to actual industry without changing the production rhythm, and has a broad application prospect.

Keywords

• dp1180 steel
• bending springback
• variable closing pressure (vcp)
• residual stress
• dislocation