电站锅炉水冷壁管腐蚀失效分析

Failure Analysis for the Explosion of Power Station Boiler Water Wall Tube

为探究电厂水冷壁爆管事故的成因,本文对失效水冷壁管进行了宏观分析与理化分析,采用X射线衍射仪(XRD)、光学显微镜(OM)、扫描电子显微镜(SEM)和能谱仪(EDS)对腐蚀产物的晶体结构、腐蚀部位显微组织进行了细致分析,在此基础上对水冷壁管的腐蚀机理进行了推断,得出了该水冷壁管失效的原因是水冷壁内壁发生了局部氧腐蚀,水中的氯离子作为催化剂加快了氧腐蚀速度。

In order to explore the cause of a water wall tube explosion accident in a power plant, this paper makes a macroscopic analysis, physical and chemical analysis on the disabled water wall tube. Using XRD, OM, SEM and EDS, the crystal structure of the corrosion products and corrosion morphology microstructure are carefully analyzed, and the corrosion mechanism of water wall tube is deduced. It is concluded that the cause of the failure of water wall tube is oxygen corrosion happened in the water wall tube inner wall, the chloride ion in the water as a catalyst speeds up the oxygen corrosion.