15CrMoG钢水冷壁爆管原因  

Causes of 15CrMoG steel water cooled wall pipe burst

作　　者：张路[1] 蒙新明[1] 赖云亭[1] ZHANG Lu;MENG Xinming;LAI Yunting(Suzhou Nuclear Power Institute Co.,Ltd.,Suzhou 215004,China)

机构地区：[1]苏州热工研究院有限公司,苏州215004

出　　处：《理化检验(物理分册)》2025年第4期82-85,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某电厂水冷壁发生爆管事故。采用宏观观察、化学成分分析、力学性能测试、金相检验、扫描电镜及能谱分析等方法研究了水冷壁爆管的原因。结果表明:管子向火侧有大量横向穿晶裂纹,向火侧组织老化级别高于背火侧,但无明显过热特征,裂纹内含有S等腐蚀性元素;机组频繁调峰以及直流锅炉运行工况不稳定,使管子温度波动幅度较大的蒸发段区域发生热疲劳开裂,腐蚀性烟气加速了裂纹的扩展,最终导致水冷壁发生爆管事故。A water cooled wall pipe burst accident occurred in a certain power plant.The causes of water cooled wall pipe bursting were studied using macroscopic observation,chemical composition analysis,mechanical property testing,metallographic examination,scanning electron microscopy and energy spectrum analysis.The results show that there were a large number of transverse transgranular cracks on the fire side of the tube,and the aging level of the tissue on the fire side was higher than that on the back side,but there was no obvious overheating characteristic.The cracks contained corrosive elements such as S.Frequent peak shaving of the unit and unstable operating conditions of the once-through boiler caused thermal fatigue cracking in the evaporation section where the temperature fluctuation of the pipes was large.Corrosive flue gas accelerated the propagation of cracks,ultimately led to pipe bursting accidents in the water cooled wall pipes.

关 键 词：15CrMoG钢 水冷壁 爆管 热疲劳 腐蚀 

分 类 号：TB31[一般工业技术—材料科学与工程] TG115.2[金属学及工艺—物理冶金]