Effects of Zn Injection on the Oxide Film of 316LN Stainless Steel in Simulated Condition of PWR

The oxide film of 316 LN stainless steel exposed to 300℃ dynamic high temperature water up to 1 200 h with 10 ppb and 50 ppb Zn injection has been investigated by corrosion weight loss analysis, X-ray photoelectron spectroscopy (XPS), SEM, GIXRD. Through comparative analysis found that with 50 ppb Zn addition, oxide film is much thinner and grain size is much smaller than that of 10 ppb Zn addition. The distribution of the oxide film grain size follows Gauss function. Low Gibbs energy compounds ZnCr₂O₄ and ZnFe₂O₄ were formed on the surface of the sample which make the oxide film much more stable than that of the Zn free sample.