Effect of Microstructure on the Instantaneous Springback and Time-dependent Springback of DP600 Dual Phase Steel

2018 2nd International Conference on Advanced Technologies in Manufacturing and Materials Engineering

Li, Rongting^1,2 ; Mai, Ruimin^1,2 ; Jin, Yongxi^1,2 ; Han, Ruiguo^1,2 ; Wang, Shu^1,2

Science and Technology on Transient Impact Laboratory, Beijing

102202, China^1

No.208 Research Institute of China Ordnance Industries, Beijing

102202, China^2

关键词: Dual-phase steel;    Elastic recovery;    Finite element simulations;    Martensite phase;    Martensite volume fraction;    Phase volume fraction;    Real microstructure;    Representative volume element (RVE);   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/389/1/012012/pdf
DOI  :  10.1088/1757-899X/389/1/012012

来源: IOP

【 摘 要 】

Springback subject to tensile test of dual phase steel DP600 with different phase volume fractions has been observed and investigated in this study. Finite element simulations using representative volume element (RVE) generated from the real microstructure are carried out. It's revealed after tensile test unloading that the instantaneous springback values (l is) of DP600 increases with the martensite volume fraction increasing, and the proportion ψ of the time-dependent springback value (l tds) in total springback (l tds+l is) increases with martensite volume fraction decreasing. In FE simulation of the RVEs, the effective plastic stress (EPS) σ e is extracted to represent the residual stress and the higher l is with more martensite volume fraction corresponds to larger variation Δσ eM of martensite phase in RVE during instantaneous springback period, which agrees with the present accepted law that the instantaneous springback is the residual stress-driven elastic recovery. After unloading finishing, the time-dependent springback proportion ψ increases with the proportion ν of EPS of ferrite phase (σ eF) in total of RVE (σ eRVE) increasing, which verifies the influence of the residual stress in "softer phase" on the time-dependent springback.