溶解氢对316L不锈钢在模拟压水堆一回路水中氧化行为的影响

INFLUENCE OF DISSOLVED HYDROGEN ON OXIDATION OF STAINLESS STEEL 316L IN SIMULATED PWR PRIMARY WATER

采用扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和透射电镜(TEM)分析了不同溶解氢含量下,316L不锈钢在325℃的模拟压水堆一回路水中形成的氧化膜的形貌、结构和成份。实验结果表明,316L不锈钢在溶解氢含量为零的高温高压水中形成外层富铁,内层富铬的双层氧化膜。随着水中溶解氢含量的升高,氧化膜外层的大颗粒氧化物尺寸减小,排列更加致密。而氧化膜的物相组成变化不明显,均主要是由尖晶石结构氧化物构成。XPS分析表明,随着水中溶解氢含量的升高,氧化膜厚度逐渐增加,且氧化膜中Ni含量升高,Cr含量降低。

Scanning electron microscope （SEM）, X-ray diffraction （XRD）, X-ray photoelectron spec- troscopy（XPS） and transmission electron microscopy（TEM） were used to analyze the morphology, structure and chemical composition of the oxide films formed on stainless steel（SS） 316L in the simulated pressurized water reactor （PWR） primary water at 325℃. The results showed that the oxide film formed on 316L SS in high-temperature and high-pressure solution without dissolved hydrogen had a double layer structure composed of iron-rich outer layer and chromium-rich inner layer. With increasing dissolved hydrogen, the outer big oxide particles became small and more compact, but all the oxide films were consisted of spinel oxide. XPS results indicated that, with increasing dissolved hydrogen, the thickness of the oxide fihn increased. In addition, the nickel content in the oxide film increased, whereas the chromium content decreased.