The oxidation behaviour of 304 stainless steel in oxygenated high temperature water

Characteristics of the oxide films formed on 304 stainless steel immersed in 290 °C oxygenated water for different duration time were examined. The results show that the oxide film is mainly composed of outer irregularly shaped α-(Fe, Cr)₂O₃ and minor spinel in the inner layer. The morphology and chemical composition of the oxide film evolve with increasing immersion time. The surface layer is first enriched in Cr and then enriched in Fe. It is proposed that the oxide nucleated by solid-state reactions with the selective dissolution of Fe and Ni, and grew up through precipitation of extraneous metallic ions from solution.