摘要
利用扫描电镜、原子力显微镜、恒电位脉冲等研究了2205双相不锈钢在中性含Cl-环境下氧化物引起点蚀萌生的机理。实验发现MgO-Al_2O_3系夹杂物中MgO偏聚处以及MgO-Al_2O_3-CaO系夹杂物中CaO富集处会引起夹杂物处基体同周围基体接触电势差增加。此外,CaO富集处易使夹杂物表面出现显微缝隙并使基体裸露,产生亚稳态蚀坑。经Ce处理后发现夹杂物成分变为含Ce_2O_3·11Al_2O_3或Ce_2O_3·Al_2O_3为主的复合夹杂,夹杂物与基体接触电势差减小并且在含Ce_2O_3复合夹杂物处未发现点蚀萌生现象,最后阐述了非金属氧化物引起点蚀的机理以及Ce与氧化物反应的机制。
By means of scanning electron microscope（SEM）,atomic force microscopy（AFM）,potentiostatic pulse technique（PPT）,pitting initiation mechanism of 2205 stainless steel in neutral chloride ion environment caused by oxide was studied.It was found that contact potential difference（CPD）increased sharply at MgO segregation in the MgO-Al2O3 inclusions and CaO enrichment zone in the MgO-CaO-Al2O3 inclusions.The enrichment of CaO was easy to cause the appearance of micro cracks on the surface and the exposure of matrix,which leads to galvanic corrosion.After treated by Ce,the inclusions were transformed into complex inclusions containing Ce2O3·11Al2O3 or Ce2O3·Al2O3.CPD decreased and pitting initiation phenomenon did not emerge.Finally,the pitting initiation mechanism caused by oxides inclusions and mechanism of Ce reacted with inclusion were explained.
作者
庞宗旭
朱荣
涂凯路
唐天平
张艺博
PANG Zongxu ZHU Rong TU Kailu TANG Tianping ZHANG Yibo(Beijing Key Laboratory of Special Melting and Preparation of High-End Metals, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2017年第16期81-88,111,共9页
Materials Reports
基金
国家自然科学基金重点项目(51334001)
国家自然科学基金面上项目(51674021)
关键词
含Ce2O3氧化物
亚稳态点蚀
接触电势差
恒电位脉冲
Ce2O3-contained oxide
metastable pitting
contact potential difference
potentiostatic pulse test
