某余热锅炉受热面管腐蚀穿孔原因

Cause of Corrosion Perforation on Heating Surface Tube of a HRSG

某焦炉尾气余热锅炉受热面管发生泄漏,通过宏观分析、金相检验、扫描电镜分析、能谱分析、化学成分分析和硬度测试等方法,分析了受热面管的泄漏原因。结果表明:锅炉内水质不合格,导致受热面管在高温、高压的运行环境中发生了沸腾气泡腐蚀。腐蚀反应侵蚀了管子内壁的钝化层,且管子在水、汽两相区腐蚀反应进行的最剧烈,腐蚀深度最深,形成了不断加深的腐蚀沟槽,最终导致泄漏。

The heating surface tube of a coke oven exhaust HRSG leaked.The causes of leakage on heating surface tube were analyzed by means of macroscopic analysis,metallographic examination,scanning electron microscope analysis,energy spectrum analysis,chemical composition analysis,hardness test.The results show that the water quality in boiler was not up to standard,which led to boiling bubble of heating surface tube in high temperature and high pressure operation environment.The corrosion reaction eroded the passivation layer on the inner wall of tube.The corrosion reaction of tube was the most severe and the corrosion depth was the deepest in the water and steam two-phase region,which formed a deepening corrosion groove and eventually led to leakage.