Effect of Long-Term Pre-oxidation on the Corrosion Rate of 316L Stainless Steel in a High-Temperature Water Environment

The aim of this study was to investigate the effect of pre-oxidation treatment at 400 degrees C for 1000 h on the corrosion behavior of 316L stainless steel in a high-temperature water environment. The oxide film was characterized via x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The weight gain of the pre-oxidized samples was lower than that of samples without pre-oxidation treatment. An (Ni,Fe)Fe2O4 outer layer with a spinel structure and an inner layer consisting of fine spinel oxides (FexCryNizO4) were formed on the surface of the untreated sample. In contrast, the pre-oxidized samples showed the formation of a triple layer: a hydroxide outer layer, a Cr-rich middle layer, and an Fe-rich inner layer. Moreover, the oxide film thickness was thinner than that of the sample without treatment. The results clearly indicate that the selected pre-oxidation process improved the corrosion resistance of 316L stainless steel in a high-temperature water environment.

Automated summary

The aim of this study was to investigate the effect of pre-oxidation treatment on the corrosion behavior of 316L stainless steel in a high-temperature water environment. The results indicate that the selected pre-oxidation process improved the corrosion resistance of 316L stainless steel in a high-temperature water environment and formed a triple layer oxide film.