316L不锈钢在高温高压水中沿晶应力腐蚀开裂裂尖钝化膜的微纳米尺度行为研究

项目名称： 316L不锈钢在高温高压水中沿晶应力腐蚀开裂裂尖钝化膜的微纳米尺度行为研究

项目编号： No.51201009

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 金属材料学科

项目作者： 陈旭

作者单位： 北京科技大学

项目金额： 25万元

中文摘要： 本课题将在前期研究的基础上，开展核电高温高压水环境下316L不锈钢IGSCC裂尖钝化膜行为的微纳米尺度研究。采用SKPFM、SVET、LEIS等微区测试手段建立316L不锈钢晶界微纳米尺度的化学成分和结构的差别与其微区电化学行为之间的关系。采用三点弯、恒载荷和慢拉伸等加载方式，结合SEM和微区电化学研究IGSCC裂尖钝化膜结构、电化学行为演化规律，在微纳米尺度上揭示高温高压水环境下316L不锈钢IGSCC萌生的原因，同时将这个结果与大尺度宏观电化学对比，通过电化学噪声技术关联SCC过程中裂纹的萌生和扩展；采用SEM、TEM、EBSD等对SCC实验后的316L不锈钢合金晶界特征进行研究，揭示IGSCC裂纹的扩展路径，在微纳米尺度上揭示不锈钢IGSCC过程晶界化学成分、微区电化学行为、钝化膜特性、晶界特性、力学行为之间的协同作用的深层次机理。

中文关键词： 316L不锈钢；应力腐蚀开裂；钝化膜；高温高压水；微纳米尺度

英文摘要： The behaviors of intergranular grain stress corrosion cracks tip passivation film of 316L stainless steel in nuclear power high temperature and pressure water medium will be studied on the micro-nano scale based on the previous work. The SKPFM, SVET, LEIS etc.localized measuring methods will be used to establish the relation between the difference of chemical compositions and grain boundary structure of stainless steel on the micro-nano scale and the localized electrochemical behaviors. The load modes of the three point bending, constant load, and slow strain rate will employed with SEM and localized electrochemical technique to investigate the structure and the electrochemical behaviors of intergranular grain stress corrision cracks tip passivation film. The rason of the intergranular grain corrosion cracks initiation will be revealed on the mico-nano scale. The result will be comparison with that of the macroscale electrochemical and it may become possible to identify characteristic signal parameters in macroscopic noise signals which can be correlated with the onset of SCC. The grain boundaries characteristics of 316L stainless steel will be investigated before and after SCC experiments by SEM, TEM and EBSD. The synergistic effects of grain boundaries local chemical compositions, localized electrochemical be

英文关键词： 316L stainless steel；SCC；passivation film；high temperature and high press water；micro-mano scale