高耐蚀含铝奥氏体不锈钢在超临界水中腐蚀行为研究  

Study on Corrosion Behavior of High-corrosion Resistance AFAs in Supercritical Water

作　　者：高阳 郭相龙 姜钰凡 伍建文 唐睿[1] 黄彦平[1] 张乐福[2] Gao Yang;Guo Xianglong;Jiang Yufan;Wu Jianwen;Tang Rui;Huang Yanping;Zhang Lefu(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610213 [2]上海交通大学核科学与工程学院,上海200240

出　　处：《核动力工程》2024年第6期271-279,共9页Nuclear Power Engineering

基　　金：国家重点研发计划项目(2018YFE0116200)。

摘　　要：为解决传统不锈钢在超临界水冷堆(SCWR)堆芯高温高压、强腐蚀性服役环境中不适用的问题,针对性地设计制备了新型含铝奥氏体不锈钢(AFAs),采用高压釜浸泡试验研究了其在600℃/25 MPa超临界水中的腐蚀行为。利用多种先进微观分析技术研究了AFAs在超临界水中腐蚀后试样表面氧化膜形貌、成分及结构特征,用以探究合金在超临界水中的耐腐蚀机制及氧化铝成膜行为。研究结果表明:AFAs在600℃超临界水中能形成连续的氧化铝膜从而具备优异的耐腐蚀性能,1000 h腐蚀增重量低于10 mg/dm^(2),优于文献报道的在相同条件下腐蚀的C276合金和310-ODS合金。该氧化铝膜与合金基体结合紧密无明显分界,能有效阻碍超临界水中氧化介质与合金基体的直接接触,抑制合金中Fe的外扩散,为合金提供优异的保护性。然而,AFAs中的Laves相会影响局部氧化铝膜的均匀性,导致外层MnCr_(2)O_(4)颗粒的形成。因此,AFAs需要在维持氧化铝连续成膜的同时严格控制Laves相含量,从而满足SCWR的应用需求。本文研究结果可为SCWR用含铝奥氏体不锈钢研发设计提供数据及理论支撑。To address the inapplicability of traditional stainless steel in the high-temperature,high-pressure and highly corrosive service conditions of supercritical-water cooled reactor core,a novel alumina-forming austenitic stainless steels(AFAs)was designed and prepared,and its corrosion behavior in supercritical water at 600℃/25 MPa was studied by autoclave immersion test.The morphology,composition and structural characteristics of the oxide scale on the surface of AFAs after corrosion in supercritical water were studied by using a variety of advanced micro-analysis techniques to explore the corrosion resistance mechanism of the alloy in supercritical water and the scale-forming behavior of alumina.The results show that the AFAs offered excellent corrosion resistance by forming a continuous alumina scale in supercritical-water at 600℃,with a 2 corrosion weight gain of less than 10 mg/dm after 1000 h of exposure,which is better than that of C276 and 310-ODS alloys corroded under the same conditions reported in the literature.The alumina scale is densely and tightly combined with the alloy matrix without obvious separations,effectively hindering the direct contact between the oxidizing media and the alloy matrix,and inhibiting the external diffusion of Fe in the alloy,thus providing excellent protection for the alloy.However,the Laves in the AFAs can affect the uniformity of the localized alumina scale,leading to the formation of MnCr_(2)O_(4) particles.Therefore,AFAs need to maintain continuous formation of alumina scale while strictly controlling the Laves phase level to satisfy the requirements of supercritical water-cooled reactor applications.The results of this paper can provide data and theoretical support for the development and design of aluminum-forming austenitic stainless steels for supercritical water-cooled reactors.

关 键 词：超临界水冷堆(SCWR) 含铝奥氏体不锈钢(AFAs) 均匀腐蚀 氧化铝膜 LAVES相 

分 类 号：TG172.82[金属学及工艺—金属表面处理] TL341[金属学及工艺—金属学]