Strain-Hardening Prediction of DP600 Steel Considering the Heterogeneous Deformation Between Ferrite and Martensite

• Published in: Archives of metallurgy and materials Vol. 68; no. No 4; pp. 1555 - 1562
• Main Authors: Rui-Bin, Gou, Wen-Jiao, Dan, Yong-Sheng, Xu, Min, Yu, Tong-Jie, Li
• Format: Journal Article
• Language: English
• Published: Polish Academy of Sciences 01-01-2023
• Subjects: dp600; gnds; heterogeneous deformation; mechanical behaviors; strain-hardening model
• ISSN: 2300-1909; 2300-1909
• DOI: 10.24425/amm.2023.146222

Dual-phase steels have received extensive attention in autobody frame manufacturing due to the resulting characteristics of an interesting combination of ductile ferrite and hard martensite. Moreover, the ductile ferrite and hard martensite lead to heterogeneous deformation in the boundary between the two phases. Then, geometrically necessary dislocations (GNDs) are created to accommodate a lattice mismatch due to the deformation incompatibility of the boundary in straining. In this study, a new empirical GND model is developed, in which the GND density is a function of local plastic deformation; the GND density is distributed in the phase boundary in accordance with an “S” model of material plastic strain. The boundary conditions are applied to define the parameters. The proposed model is verified with DP600 steel. The effects of the GNDs and the width between ferrite and martensite on the strain hardening of DP600 steel are evaluated.