CAJ | 학술논문

某厂锅炉二级过热器管带负荷运行25 h即发生爆管，管壁涨粗，爆裂口张开呈喇叭状。采用化学成分分析、力学性能检测和金相组织分析等检测手段，对该二级过热器管的失效原因进行了分析。结果表明，该管裂口处显微组织随变形方向被拉长，管体组织无明显变化，但钢管外表层氧化和脱碳严重，同时表面出现沿晶小裂纹，说明管壁在短时间内受到较高温的烟气冲刷，导致材料强度下降。短时间内高温过热是过热器管爆管失效的主要原因。
모엄과로이급과열기관대부하운행25 h즉발생폭관，관벽창조，폭렬구장개정나팔상。채용화학성분분석、역학성능검측화금상조직분석등검측수단，대해이급과열기관적실효원인진행료분석。결과표명，해관렬구처현미조직수변형방향피랍장，관체조직무명현변화，단강관외표층양화화탈탄엄중，동시표면출현연정소렬문，설명관벽재단시간내수도교고온적연기충쇄，도치재료강도하강。단시간내고온과열시과열기관폭관실효적주요원인。
After running with load for 25 hours, the secondary superheater tube of boiler exploded, which made the tube thicker and the crack trumpet-shaped open. The analysis for a boiler secondary superheater tube explosion adopts detection modes of chemical component analysis, mechanical properties test and microstructure analysis. The results show that microstructure of the crack was elongated along the deformation direction, and microstructure of the tube was no significant change, but the outside surface of the tube was oxygenated and decarburized severely. Meanwhile the short crack along grain boundaries appeared in the surface. All that means the tube suffered from erosion of high temperature flue gas within a short time. High temperature superheated in a short time is the main reason for the failure of the superheater tube.