【摘要】 锅炉旋风分离器中心筒上部吊挂腰筋和腰筋附近的筒体裂开,筒体上大面积出现蜂窝状剥落坑,筒体变径处出现大量贯穿性孔洞。采用化学成分分析、宏观和金相检验等方法对中心筒进行了分析。结果表明,中心筒焊补区存在未熔合缺陷,裂纹在未熔合缺陷处萌生和长大形成宏观裂纹,导致材料失效;中心筒存在许多铸造皮下气孔,此为形成剥落坑的主要原因;剥落坑附近析出许多块状和棒状碳化物,在晶界处有链状碳化物,这是产生宏观剥落坑的诱因。更多还原

【Abstract】 The cracks appear around the reinforce-tendon and hanging-end, where are at the upside of the central canister of boiler vortex segregator. There are lots of honeycomb desquamative holes in the canister body and impenetrated holes at the diameter change points. The chemical composition analysis, macro-examination and metallographic examination are used to analyze the central canister. The results show that there are unmelted disfigurements in the jointing areas of the central canister. The cracks germinate and grow up to macrocracks in the disfigurements points, and lead to the invalidation of the canister finally. The primary reason of the desquamative holes appearance is that there are many subcutaneous pores. The inducement is that there are many nubby and clubbed types of carbide separated out near the desquamative holes and catenarian carbides exist in the crystal boundary.更多还原