发电厂水冷壁管腐蚀失效分析  

Corrosion failure analysis on water-cooled wall tubes of power station

作　　者：许宏飞[1] 薛跃军[1] 郑自芹[1] 张永信[1] 张大江[1] 张琼[1] 董园园[1] 

机构地区：[1]中国兵器科学研究院宁波分院,山东烟台264003

出　　处：《兵器材料科学与工程》2013年第2期119-122,共4页Ordnance Material Science and Engineering

摘　　要：针对发电厂锅炉水冷壁管内表面腐蚀坑的成因进行了失效分析。通过微观形貌观察、扫描电镜及能谱仪分析和X射线衍射等手段确定腐蚀产物为Fe3O4;对水冷壁管各典型部位的化学成分(包括残余元素量)、显微组织、晶粒度、非金属夹杂物、脱碳层进行分析,排除引起腐蚀失效的内部因素;通过锅炉水质的碱度、pH值等检测记录,综合分析表明:炉水碱度偏高导致水冷壁内表面发生碱腐蚀反应,即碱腐蚀失效。Failure analysis was carried out to find out the causes of eorrosion pits on the inner surface of boiler water-cooled wall tubes of power station. The corrosion product Fe304 was confirmed by microstructural observation, SEM and EDS and X-ray diffraction; the typical parts of water-cooled wall tube were analyzed, including chemical composition （the amount of residual elements）, microstructure, grain size, nonmetallic inclusions, decarburized layer. According to the results, it is excluded that internal factors may cause corrosion failure. By analyzing testing records of alkalinity and pH value of boiler water, it is fnund that the high alkalinity of boiler water results in alkali corrosion reaction.

关 键 词：水冷壁管 腐蚀 失效分析 碱度 碱腐蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]