采用化学成分分析、金相检验、扫描电镜及能谱分析等方法 ,对多管贯流式蒸汽锅炉下集箱搭接处的泄漏进行了分析。结果表明 ,集箱搭接处存在的焊接应力 ,使该处内壁的垢下腐蚀速度加快。垢下腐蚀是以电化学腐蚀形式进行 ,氧化铁及氧化铜垢与集箱组成微电池 ,集箱为阳极失去电子 ,从而使集箱不断遭到腐蚀 ,最终最致集箱泄漏。 The chemical composition analysis, metallographic examination, scanning electron microscopy and energy spectrum analysis were used to analyze the leakage at the junction of the lower header of the multi-tubular tubular steam boiler. The results show that the welding stress existing at the overlap of the header causes the corrosion rate of the inner wall of the header to be accelerated. Under the scale corrosion is electrochemical corrosion form, iron oxide and copper oxide scale and the header composed of micro-battery, the header for the anode to lose electrons, so that the header has been corroded, and ultimately the most cause the header leakage.