某化工厂电站锅炉15CrMo钢过热器管发生爆管造成整套装置非计划停机。采用宏观检查、化学成分分析、金相检验、管壁形貌分析、硬度测试、胀粗量计算等方法，对过热器管爆管原因进行了分析。结果表明：过热器管爆口有长期过热的特征，由于锅炉超负荷运行及氧化层引起过热器管长期过热，造成管材组织劣化、出现蠕变孔洞及显微裂纹，导致过热器管强度降低最终造成爆管。过热器管的失效模式为长期过热引起的高温蠕变开裂。

Tube burst of the superheater tube of a power plant boiler caused the unplanned shutdown of the entire unit. The causes of superheater tube burst were analyzed by macroscopical examination, chemical composition analysis, metallographic examination, tube wall morphology analysis, hardness test, bulge volume calculation and so on. The results show that the superheater tube burst had the characteristics of long-term overheating. The superheater tube was overheated for a long time due to the over-load operation of the boiler and oxidation layer, which resulted in the deterioration of the tube structure, the appearance of creep holes and microcracks, which led to the decrease of the superheater tube strength and eventually the tube burst. The failure mode of superheater tube was high temperature creep cracking caused by long-term overheating.