Effect of Oxidizing Decontamination Process on Corrosion Property of 304L Stainless Steel

Abstract

Corrosion behaviors of 304L stainless steel (SS) and 304L SS with oxides film (preoxidation 304L SS) in 1 g/L potassium permanganate solution of various pH values were investigated by using mass loss, electrochemical measurement and scanning electron microscope (SEM) observation. The results showed that mass loss of 304L SS increases with the increase of sodium hydroxide or nitric acid concentration in 1 g/L potassium permanganate solution. The polarization curves of 304L SS in potassium permanganate solution show that passive zones are destroyed more easily in acid potassium permanganate solution than alkaline potassium permanganate solution. The corrosion ability of acid potassium permanganate (NP) decontamination solution used for 304L SS is more aggressive than alkaline potassium permanganate (AP) solution. The oxide film on the surface of preoxidation 304L SS can be removed completely in two oxidation reduction decontamination cycles, oxidizing solution of which comprised 0.4g/L sodium hydroxide and 1g/L potassium permanganate. The 304L SS and preoxidation 304L SS performed alkaline oxidation reduction decontamination of 3 cycles were reoxidation. The micromorphology of reoxidation specimens was similar to preoxidation 304L SS. Therefore the chemical decontamination of alkaline oxidizing and acid reducing steps had no negative effect on corrosion of 304L SS and reoxidation of 304L SS carried out decontamination.