Effects of surface nanocrystallization on the oxide film formed on 316LN stainless steel in a high‐temperature aqueous environment

Abstract

A newly developed technology, rotationally accelerated shot peening (RASP), was used to produce the nanocrystals on the surface of 316LN stainless steel.The effect of surface nanocrystallization on the oxide film properties of the steel in a high temperature and high-pressure aqueous environment was studied. It was found that the outer layer of the oxide film consisted of Ni-Fe 2 O 4 with a loose spinel structure. The inner layer distributed tiny Cr 2 O 3 particles compactly. The oxide films that grew on the RASP-treated 316LN showed thicker and denser with higher corrosion resistance than on the asreceived steel. The nanostructures produced by RASP enhanced the formation of the superior oxide film. However, the deformation defects caused by RASP were harmful to the corrosion resistance. The results in this paper provide an easy way to enhance the corrosion resistance of the steel served in a hightemperature aqueous environment.