|About this Abstract
|2020 TMS Annual Meeting & Exhibition
|Advanced High Strength Steels IV
|J-5: Solutions to Hydrogen Embrittlement of Ultra-high Strength Press-hardened Steel for Automotive Application
|Lawrence Cho, P.E. Bradley, Matthew Connolly, M.L. Martin, D.S. Lauria, Frank W. Delrio, A.J. Slifka, E.J. Seo, K.R. Jo, S.W. Kim
|On-Site Speaker (Planned)
Improved safety standards and reduced automotive body-in-white weight have led to a strong interest in ultra-high strength press-hardened steels (PHS). However, the martensitic PHS is particularly sensitive to the hydrogen embrittlement. An atmospheric corrosion of the steel or Al-Si coating by water vapor in the furnace atmosphere of hot stamping lines produces hydrogen, leading to the hydrogen uptake of the steel. This hydrogen uptake causes a hydrogen-induced fracture of the PHS during tensile straining. The present contribution reports three methods to address the PHS hydrogen-induced fracture. The first method involves post-bake hardening treatment, which partially removes the diffusible hydrogen in the PHS. Second, use of Zn-coated steel for the hot stamping application reduces the risk of hydrogen embrittlement. Finally, vanadium additions into the steel composition cause an increased density of hydrogen-trapping sites and considerably reduce the negative impact of hydrogen uptake on the mechanical properties of the PHS.
|Planned: Supplemental Proceedings volume