IN-SITU OBSERVATION AT SURFACE AND INTERFACE WITH LOCALIZED CORROSION PROCESS BY MEANS OF MICRO-RAMAN SPECTROSCOPY -SECM-AFM SYSTEM

利用改进扫描电化学显微镜（SECM）的三种模式，成功地原位观察了以电解液侧为中心的微观区域（1mum*emum）中H^+和Cl^-反应物质的局部分布，并确定了不同耐蚀性奥氏体不锈钢基体表面点蚀的前驱体位点。利用原位拉曼光谱首次在坑前驱体区识别出硝酸盐离子。采用氚电磁自显影法和氢含量测定法研究了硼的加入对Ni_3 （Si, Ti）金属间化合物晶界氢偏析行为的影响。

We have successfully performed in-situ observation of the localized distribution of reaction species of H^+ and Cl^- in microscopic region (1mum*emum) focused on the electrolyte solution side and identifying precursor sites for pitting on the substrate surface of austenitic stainless steels with different corrosion resistance by using the three modes of modified scanning electrochemical microscopy (SECM). Using in-situ Raman spectroscopy nitrate ions at the pit precursor region are identified for the first time. Tritium E.M.autoradiography and hydrogen content measurement are carried out to examine the effect of boron addition on the behavior of hydrogen segregation at the grain boundary in Ni_3 (Si, Ti) intermetallic.