Corrosion of HSLA and Mild Steels Beneath Vehicles

High-strength low-alloy (HSLA) steels are being considered as replacements for mild steel for certain vehicle structural parts for weight saving and additional safety. Their corrosion behavior in this environment had not previously been investigated in detail.

Vehicles subjected to southern Ontario winters were fitted with samples and used to compare corrosion of HSLA steels and mild steel. Our results indicate that both types of steel undergo uniform corrosion and pitting. The HSLA steels mostly show similar weight loss and were equal to or better than the mild steel from a pitting standpoint. Two of the six HSLA steels tested showed definite susceptibility to crevice corrosion.