奥氏体不锈钢在含锌PWR一回路水中的均匀腐蚀行为

General Corrosion Behaviors of Austenitic Stainless Steels in Zinc Containing PWR Primary Water

通过模拟压水堆一回路水环境,对304和316L两种不锈钢进行了在含锌10μg/kg,320℃高温溶液中浸泡1 000h的腐蚀试验,并对试验后的试样氧化膜进行SEM和XPS分析。结果表明,304不锈钢的腐蚀增重率高于316L,且其氧化膜较316L疏松;两种试样均形成了富铁、锌内富铬的氧化膜;外层氧化膜以(Zn,Fe,Ni)(Fe,Cr)2O4为主,内层以ZnCr2O4为主,氧化膜与基体过渡层以Cr2O3为主。

General corrosion of 304 and 316L stainless steels was studied in simulated pressurized water reactor(PWR)primary water environment containing 10μg/kg zinc.After exposion for 1 000h,the oxide films formed on the surface of specimens were analyzed by scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).The results showed that the corrosion weight gain of 304 stainless steel was higher than that of 316L,and the oxide film on 304 was looser than that on 316L.The oxide film was a double layer structure,in which the outer layer was thin and rich in Fe and Zn,while the inner layer was rich in Cr.The chemical composition analysis showed that the outer layer was mainly made up of(Zn,Fe,Ni)(Fe,Cr)2O4,the inner layer was ZnCr2O4,and the transition layer between oxide film and matrix metal was mainly Cr2O3.