2010 Volume 59 Issue 12 Pages 464-467
It is well known that nitric acid and nitric acid+chromate solution have been applied effectively for surface treatment or passivation treatment of stainless steels. However, recent regulation of waste water quality demands that nitrogen from nitric acid and Cr(VI) ion from chromic oxide have to be removed in the waste water. This study aims to develop alternate effective surface treatment method for passivation treatment of stainless steel. H2O2 and O3 might be candidate chemicals, because they decompose to oxygen and water after reaction which are non toxic to the environment. Effect of concentration of H2O2 and O3 and temperature on the treatment potential was examined. After the treatment, pitting potential was measured to evaluate corrosion resistance of passivated stainless steels. Passivation treatment condition using H2O2+O3 solution to increase pitting potential of SUS 304 and SUS 430 stainless steel was found.