通过宏观检验、尺寸测量、金相检验和断口分析等方法, 对锅炉吹灰器附近水冷壁管开裂的原因进行了分析。结果表明: 吹灰器附近水冷壁管与密封板之间的温度偏差及与正常部位水冷壁管之间的温度偏差导致密封板割缝根部产生了较高的峰值热应力, 此应力随着锅炉的启停和吹灰过程而循环交替, 再加上吹灰器附件水冷壁管弯折处割缝根部本身就存在应力集中, 使得吹灰器附件水冷壁管弯折处密封板割缝根部发生了低周疲劳开裂。

The cracking reason of the boiler water cooling wall tubes near the soot blower was analyzed by means of macro examination, size measurement, metallographic examination, fracture analysis and so on. The results showed that temperature difference between the water cooling wall tube near the soot blower and the sealing plates, and temperature difference between the water cooling wall tube near the soot blower and the water cooling wall tube in the normal position led to the higher peak thermal stress in kerf root of the boiler water cooling wall tube near the soot blower. The thermal stress was circulated and alternated with start-stop and blowing of the boiler, and there existed stress concentration in kerf root itself, these led to the low cycle fatigue cracking in kerf root of the boiler water cooling wall tube near the soot blower.