Original scientific paper

https://doi.org/https://doi.org/10.64486/m.66.2.10

Thermo-Mechanical and Damage Evolution at the Sidewall–Bottom-Corner Transition in 22MnB5 Steel during Hot Stamping

Yuanxiang Wang ; State Key Laboratory of Materials for Advanced Nuclear Energy, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Weilun Deng ; State Key Laboratory of Materials for Advanced Nuclear Energy, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
Hongxing Zheng *

* Corresponding author.

Abstract

Hot stamping of 22MnB5 boron steel enables high-strength automotive components, but local deformation and damage may develop in geometrically constrained regions such as the sidewall–bottom-corner transition. A thermo-mechanically coupled DEFORM-3D finite element model was developed to examine local temperature, effective stress, effective plastic strain, and Damage under variations in die-entry temperature, punch speed, and friction coefficient. The deformation-sensitive region remained spatially stable, though its response magnitude varied with process conditions. Increasing die-entry temperature (750–850) °C reduced effective stress through thermal softening, with little change in final effective plastic strain and Damage. Increasing punch speed (50–150) mms1 improved temperature retention and reduced effective stress, but increased effective plastic strain and Damage; increasing friction coefficient (0.3–0.7) substantially increased effective plastic strain and Damage with only limited effects on temperature and stress. Final Damage correlated strongly with final effective plastic strain (R2 = 0.99, partly reflecting the cumulative NCL formulation) but showed a weaker correlation with final effective stress (R2 = 0.62), indicating that instantaneous stress and accumulated Damage may exhibit different process-dependent trends and should therefore be considered jointly when assessing local deformation and damage accumulation.

Keywords

22MnB5 boron steel; hot-stamp bending; finite element simulation; ductile damage; thermo-mechanical response

Hrčak ID:

352430

URI

https://hrcak.srce.hr/352430

Publication date:

1.4.2027.

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