模拟压水堆一回路水中预充氢对316L不锈钢氧化膜的影响

Effect of Pre-charged Hydrogen on the Oxide Film of 316LStainless Steel in Simulated PWR Primary Water

采用扫描电镜和X射线光电子能谱仪,分析了有无充氢冷加工316L不锈钢在300℃除氧的模拟压水堆一回路水中浸泡168 h后,其表面氧化膜的厚度及成分。结果表明:有无充氢试样表面形成的氧化膜均为双层结构,外层氧化膜的氧化物颗粒富含Fe,内层氧化膜的氧化物颗粒富含Cr。与未充氢试样比,充氢试样氧化膜的厚度较厚,外层氧化膜的氧化物颗粒较大且Fe与Cr的质量分数比较大;充氢导致试样内层氧化膜Fe含量升高,OH-与O2-的原子分数比增大,抑制了Cr氧化物的形成,使氧化膜中Cr含量下降,从而降低了氧化膜的保护性,加速基体的氧化。

Through scanning electron microscopy and X-ray photoelectron spectroscopy, the thickness and composition of the oxide films formed on the surfaces of cold-worked 316 L stainless steel with and without hydrogen-charging after immersion in deoxidized simulated PWR primary water at 300 ℃ for 168 h were analyzed. The results show that the oxide films of samples with and without hydrogen-charging were all double-layer structures. The oxide particles of the outer oxide film were rich in Fe, and the oxide particles of the inner oxide film were rich in Cr. The thickness of the hydrogen-charging sample oxide film increased, the oxide particles of the outer oxide film were larger and the ratio of Fe mass fraction to Cr mass fraction was greater, compared to the sample without hydrogen-charging. The hydrogen charging increased the Fe content of the inner oxide film of sample, increased the OH- and O2- atomic fraction ratio, inhibitted the formation of Cr oxide, and reduced the Cr content of oxide film, thereby reducing the protection of the oxide film and accelerating the oxidation of the substrate.