Effect of Inorganic Zn-primer Coating on Corrosion Resistance of Fe-Cr and Fe-Cr-Al Alloys in High Chloride Environments

It is well known that the corrosion resistance of steels is improved by the addition of alloying elements. For stainless steels, a large amount of Cr is added to obtain good corrosion resistance and the addition of rare metals such as Mo and Ni etc. are applied for further improvement of the corrosion resistance depending on corrosion environments. On the other hand, we investigated the effects of combining the addition of alloying elements and surface treatment aiming to develop new corrosion resistant steel at lower cost by reducing the content of alloying elements. We found that 6% Cr contained steel with inorganic zinc primer showed excellent anti-rust resistance in high chloride environments. Besides, the apparent rust area and maximum corrosion depth of 6% Cr contained steel were largely reduced by the addition of Al.