Influence of sheared edges on the susceptibility to hydrogen embrittlement in third-generation AHSS

Hydrogen embrittlement remains a critical barrier to the effective development and deployment of advanced high-strength steels (AHSS) in automotive applications.The interplay between multiple hydrogen sources and the mechanical stresses inherent to AHSS manufacturing and service conditions contributes to a complex phenomenon that has garnered considerable interest from both industry and academia.In this context, the deformation and defects generated along sheared edges, commonly produced during stamping operations, serve as preferential sites for hydrogen-induced damage, especially delayed cracking.These localized imperfections act as stress concentrators, intensifying the material's susceptibility to embrittlement under hydrogen exposure.This study investigates the combined effect of hydrogen and varying shear cutting conditions on a third-generation AHSS with a tensile strength of 1000 MPa.To this end, specimens electrochemically pre-charged with different hydrogen concentrations and subjected to distinct cutting conditions were evaluated under constant load.The findings quantify the impact of sheared edge quality on the material's susceptibility to hydrogen embrittlement, showing that suboptimal cutting conditions can reduce the critical hydrogen threshold by up to 60% compared to the optimal condition for the steel under study.These results underscore the importance of controlling edge quality during forming operations to mitigate hydrogen-related failures in AHSS components.