Application of 1.7GPa Martensitic Steel in Dash Lower Cross Member to Enhance Automotive Frontal Impact Safety

The rapid growth of electric vehicles (EVs) has led to a significant increase in vehicle mass due to the integration of large and heavy battery systems. This increase in mass has raised concerns about collision energy and the associated risks, particularly in high-speed impacts. As a consequence, crashworthiness evaluations, especially front-impact regulations, have become increasingly stringent. Crash speed between the vehicle and the Mobile Progressive Deformable Barrier (MPDB) is increasing, reflecting the growing emphasis on safety in the automotive industry. Moreover, a new frontal pole crash scenario is under consideration for future regulatory standards, highlighting the continuous evolution of crash testing protocols. To ensure occupant protection and battery safety, manufacturers have traditionally used Hot Blow Forming technology for producing closed-loop dash lower cross member components. However, this process is both costly and energy-intensive, necessitating more efficient alternatives. This study explores the development of a closed-loop dash lower cross member using 1.7 GPa Cold Rolled Martensitic steel, produced through roll forming and CNC bending. The research addresses critical material aspects, including comprehensive hydrogen embrittlement analysis to evaluate the material’s long-term durability and safety. Furthermore, the study focuses on the crash performance of the closed-loop cross-sectional dimensions 1.7 GPa steel grades components. The findings of this study aim to contribute to the design of safer and more efficient structural components for modern EVs, meeting both regulatory requirements and industry needs.