酸性停堆温度对模拟压水堆一回路环境中304L不锈钢表面氧化膜的影响  

Effect of Acidic Shutdown Temperature on Oxide Film on Surface of 304L Stainless Steel in Simulated PWR Primary Circuit Environment

作　　者：高中宇 田朝晖 刘灿帅 艾彪 孙云[1] GAO Zhongyu;TIAN Zhaohui;LIU Canshuai;AI Biao;SUN Yun(Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou 215008,China)

机构地区：[1]苏州热工研究院有限公司,苏州215008

出　　处：《腐蚀与防护》2024年第6期1-7,共7页Corrosion & Protection

基　　金：江苏省自然科学基金(BK20220257)。

摘　　要：以压水堆一回路系统构件常用材料304L不锈钢为研究对象,采用高温高压循环回路模拟现场工艺在材料表面制备氧化膜,在此基础上开展了两种温度的酸性停堆工艺试验,并对比分析了酸性停堆温度对材料表面氧化膜的形貌、元素组成和物相结构的影响。结果表明:经预处理1000 h后,304L不锈钢表面形成了双层氧化膜结构,外层氧化膜为镍铁尖晶石Ni_(x)Cr_(y)Fe_(3-x-y)O_(4),内层氧化膜为富铬尖晶石Ni_(x)Fe_(y)Cr_(3-x-y)O_(4),其厚度均小于0.1μm;经170℃酸性停堆工艺处理480 h后,304L不锈钢内外层氧化膜均发生了显著的溶解,内层氧化膜的溶解导致氧化膜与金属基体的界面模糊;经60℃酸性停堆工艺处理480 h后,304L不锈钢表面尖晶石氧化物并未发生显著溶解,表面分布少量大颗粒状尖晶石氧化物,氧化膜与金属基体的界面较为清晰。Taking 304 L stainless steel,the key material of the primary loop system of pressurized water reactor(PWR)as the research object,the oxide film was prepared on surface of the material by using the high temperature and high pressure circulation loop to simulate the on-site process.On this basis,the acid shutdown process at two temperatures was carried out,and the effects of acid shutdown temperature on the morphology,element composition and phase structure of the oxide film on the material surface were compared and analyzed.The results show that after pretreatment for 1000 h,a double-layer oxide film structure was formed on the surface of 304L stainless steel.The outer oxide film was Ni-Fe spinel Ni_(x)Cr_(y)Fe_(3-x-y)O_(4),and the inner oxide film with thickness less than 0.1μm was Cr-rich spinel Ni_(x)Fe_(y)Cr_(3-x-y)O_(4).After 480 h of acidic shutdown treatment at 170℃,the inner and outer oxide films of 304 L stainless steel were significantly dissolved,and the dissolution of the inner oxide film led to the blurring of the interface between the oxidation film and the metal matrix.After 480 h of acid shutdown treatment at 60℃,the spinel oxides on surface of 304 L stainless steel did not dissolve significantly,and a small amount of large granular spinel oxides were distributed on the surface,and the interface between the oxidation film and the metal matrix was clear.

关 键 词：酸性停堆 压水堆一回路 氧化膜 304L不锈钢 

分 类 号：TK112[动力工程及工程热物理—热能工程]