夏润杰, 汪家梅, 刘峰, 李玉龙, 林有奇, 张乐福(通讯作者). PWR一回路注锌对316L不锈钢及钴基合金腐蚀及腐蚀产物释放的影响规律研究[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.06.20.003
引用本文: 夏润杰, 汪家梅, 刘峰, 李玉龙, 林有奇, 张乐福(通讯作者). PWR一回路注锌对316L不锈钢及钴基合金腐蚀及腐蚀产物释放的影响规律研究[J]. 工程科学学报. DOI: 10.13374/j.issn2095-9389.2023.06.20.003
Effects of zinc addition on corrosion behavior of 316L stainless steel and Stellite 6 cobalt-based alloy in PWR primary water[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.06.20.003
Citation: Effects of zinc addition on corrosion behavior of 316L stainless steel and Stellite 6 cobalt-based alloy in PWR primary water[J]. Chinese Journal of Engineering. DOI: 10.13374/j.issn2095-9389.2023.06.20.003

PWR一回路注锌对316L不锈钢及钴基合金腐蚀及腐蚀产物释放的影响规律研究

Effects of zinc addition on corrosion behavior of 316L stainless steel and Stellite 6 cobalt-based alloy in PWR primary water

  • 摘要: 在模拟压水堆一回路水化学环境中,对主管道316L不锈钢和Stellite 6钴基合金分别开展了0,10,40 ppb三种Zn浓度的均匀腐蚀试验。试验结束后,采用失重法计算两种材料的腐蚀速率和腐蚀产物释放速率,采用SEM和TEM-EDS分析氧化膜表面形貌、截面形貌、厚度及元素分布。结果表明,对于316L不锈钢,10 ppb Zn的注入对腐蚀速率和释放速率影响不显著,增加Zn浓度至40 ppb后,316L不锈钢的腐蚀速率、腐蚀产物释放速率和氧化膜厚度显著降低。对于Stellite 6 钴基合金,10 ppb Zn注入可以显著降低其腐蚀速率和腐蚀产物释放速率,当Zn浓度增加至40 ppb时,钴基合金的腐蚀速率、腐蚀产物释放速和氧化膜厚度进一步降低。微观分析表明,注入的Zn离子会在金属表面形成含Zn的尖晶石结构,显著提高外层氧化膜的致密性,阻碍金属离子向外扩散及氧离子向内扩散,促进内层氧化膜/基体界面处保护性Cr2O3的形成,进而显著降低316L不锈钢和Stellite 6 钴基合金的腐蚀速率、腐蚀产物释放速率和氧化膜厚度。

     

    Abstract: The effects of zinc addition on general corrosion of 316L austenitic stainless steel and Stellite 6 cobalt-based alloy were investigated in simulated PWR primary water with 0, 10 and 40 ppb zinc additions. The corrosion rate and the metal release rate of the two materials were calculated by weight loss method. The surface and cross-sectional morphology, thickness and element distribution of the oxide film were analyzed by SEM and TEM-EDS. The results show that the corrosion rate of 316L stainless steel decreased with the increase in zinc concentrations. For cobalt-based alloy, the corrosion rate and corrosion product release rate decreased with the increase in zinc concentrations. The microstructural analysis of the oxide film indicates that Zn2+ promotes the denser outer oxide film formation by forming the zinc-incorporated spinel, which retards the outward diffusion of metal ions and the inward diffusion of oxygen ions, reduces the oxygen partial pressure at oxide/metal (O/M) interface, and promotes the formation of continuous protective Cr2O3 inner oxide film, and thus significantly suppressing the corrosion and metal release of 316L austenitic stainless steel and Stellite 6 cobalt-based alloy in high temperature water.

     

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