某电站锅炉水冷壁侧包墙管泄漏原因分析  

Analysis on Leakage of Water Wall Side Cladding Tube of Power Plant Boiler

作　　者：季文波[1] 安栋[2] 梁奎[2] 康龙基 王兆民[1] Ji Wenbo;An Dong;Liang Kui;Kang Longji;Wang Zhaomin(Harbin Boiler Company Limited Harbin,150046;China Special Equipment Inspection&Research Institute Beijing,100029)

机构地区：[1]哈尔滨锅炉厂有限责任公司,哈尔滨150046 [2]中国特种设备检测研究院,北京100029

出　　处：《中国特种设备安全》2022年第12期85-88,共4页China Special Equipment Safety

基　　金：国家重点研发计划课题“锅炉受热面材料在超临界CO_(2)环境下典型损伤检测评价技术”(2020YFF0218101)。

摘　　要：某电站锅炉在通过168 h试运行后,运行约2个月出现侧包墙泄漏,检查发现泄漏处为侧包墙管与鳍片角焊缝端部。通过宏观检查、微观检查、化学成分分析、力学性能试验,发现泄漏的原因是焊接不规范(环境温度低而未采取措施、焊缝端部焊接热输入大)造成该处焊接热影响区硬度偏高、塑性降低、焊接应力高,且该处外壁有凹坑焊接缺陷,使该处应力集中,在外界应力的作用下,低塑性脆性裂纹在外壁凹坑处产生并向内壁扩展,最终发生泄漏。After 168 h test run of a power plant boiler, the leakage of the side cladding wall was found after about two months of operation. The leakage was found at the end of the fillet weld between the side cladding wall pipe and the fin. Through macro inspection, micro inspection, chemical composition analysis and mechanical property test, it is found that the leakage is caused by non-standard welding(low ambient temperature without taking measures,large welding heat input at the weld end), which leads to high hardness, reduced plasticity and high welding stress in the welding heat affected zone, and there are dents on the surface of the zone that are not filled with welding materials,resulting in the stress concentration, which is pulled off by the expansion stress of the side cladding wall during the boiler operation. Cracks are generated and propagated at this position, which eventually leads to pipe leakage.

关 键 词：电站锅炉 水冷壁 焊缝 泄漏 

分 类 号：X933.2[环境科学与工程—安全科学]