| Abstract Scope |
This study investigates the microstructure and mechanical properties of automotive B-pillars manufactured with different coatings and heat treatments to identify cost-effective alternatives to traditional aluminum-silicon (Al-Si) coatings. B-pillars, critical for passenger safety during side collisions, require ultra-high strength and corrosion resistance. Four specimens were evaluated: Al-Si coated (industry standard), zinc-coated with heat treatments at 775°C and 825°C, and a novel uncoated chromium alloy. Scanning electron microscopy and tensile testing were conducted to assess coating integrity, microstructure, and mechanical performance. The chromium alloy demonstrated superior performance, achieving the highest tensile strength (1,660 MPa) and a fully martensitic microstructure, making it the most viable option. The zinc-coated sample treated at 825°C also performed well, while the Al-Si and lower-temperature zinc coatings fell short of safety standards. These findings highlight the potential of chromium alloys and optimized zinc coatings as cost-efficient, high-performance alternatives for press-hardened automotive components. |