循环流化床锅炉水冷壁钢管氢腐蚀爆管原因分析

Analysis on Hydrogen Corrosion of Water-Wall Tube in Circulating Fluidized Bed Boiler

采用宏观检验、化学成分分析、显微组织检验、SEM形貌分析及力学性能检测等试验方法对某循环流化床锅炉水冷壁爆管原因进行了试验分析。结果表明,水冷壁发生氢腐蚀,氢在晶界聚集,与钢管中的碳反应生成CH4,从而造成钢管内壁组织脱碳,同时在金属内部产生巨大的应力,导致水冷壁钢管沿晶开裂爆管。建议对锅炉水冷壁系统进行全面检查,加强锅炉水质监督,定期对受热面进行除垢处理。

The cracked water-wall tube of circulating fluidized bed boiler is investigated by means of Macro-morphology inspection,chemical composition analysis,microstructure analysis,SEM morphology analysis and mechanic performance testing.The result shows that due to hydrogen corrosion of the water-wall tube,hydrogen atoms gather at the grain boundary continuously and react with carbon to form CH4,resulting in decarburization of the tube and huge stress between the grains.Therefore,under the action of internal pressure,the water-wall tube finally cracked along the grain boundary.Put forward conducting a full inspection to the water-wall tube,strengthening boiler water quality supervision,and descaling the heating surface of boiler timely.