2025 Volume 74 Issue 3 Pages 46-51
Type 430 stainless steel showed different corrosion behavior from Type 304 in a non-aqueos electrolyte containing LiPF6 in terms of potential dependency. At 4 V (Li/Li+), Type 430 was highly susceptible to corrosion while Type 304 was resistant. At 5 V (Li/Li+), Type 430 was passivated as well as Type 304. X-ray photoelectron spectroscopy (XPS) analysis revealed that Type 430 was protected by two-layer of passivation film at 5 V (Li/Li+). The outer layer consited of Fe-fluoride (FeF3) and smaller amount of oxide of Fe and Cr. It was suggested that FeF3 played an essential role in the passivation of Type 430 at 5 V (Li/Li+). The higher corrosion susceptiblity of Type 430 at 4 V (Li/Li+) was ascribed to the difficulty of forming of FeF3, and the lower corrosion resistance of the pristine film as compared with Type 304.