2009 Volume 58 Issue 1 Pages 20-28
Effect of alloying elements on corrosion behavior of austenitic stainless steels in high temperature chloride environment was investigated by hot corrosion test. The test was cyclic test of dipping in NaCl aqueous solution at room temperature and heating in air at 500–700°C. The main corrosion element was Fe and the main corrosion products was α-Fe2O3. Over 70 percent of corrosion products of Cr existed as Cr2O3 and (Fe, Cr, Ni)3O4 on the specimen surface, and Cr2O3 was not protective. The rest of corrosion products of Cr dissolved in NaCl aqueous solution. Si improved the corrosion resistance remarkably by concentrating as stable Si oxide at the interface between parent metal and corrosion products. Ni and Mo were also effective elements on improving the corrosion resistance.