摘要
国内某电厂一台在用亚临界电站锅炉运行过程中,因高温高压厚壁蒸汽连接管道焊接接头泄漏造成紧急停炉。针对锅炉的蒸汽管道失效焊接接头,采用宏观检查、资料核查、合金成分分析、拉伸性能试验、冲击性能试验、硬度试验、金相检验分析、扫描电镜断口形貌观察等多种试验方法对其开裂原因进行综合分析研究。最终分析结果显示,焊接接头开裂原因是焊接工艺执行不规范及焊后热处理工艺控制不当,促使在热影响区位置产生再热裂纹进而运行时承压扩展致使开裂。根据失效焊接接头开裂原因的分析结果,建议对该锅炉与失效焊接接头具有相同安装工艺的厚壁管道焊缝进行全面检验,以消除锅炉蒸汽管道焊接接头存在的缺陷,保证锅炉的安全运行。
During the operation of a subcritical power plant boiler in a domestic power plant,the emergency shutdown was caused by the leakage of the welded joint of the high-temperature and high-pressure thick-walled steam connection pipes.For the failed welded joints of steam pipes of this boiler,various test methods such as macro inspection,data verification,alloy composition analysis,tensile property test,impact property test,hardness test,metallographic inspection and analysis,and scanning electron microscope fracture morphology observation were used to carry out comprehensive analysis and study to track its cracking reasons.The results showed that the reason for the cracking of the welded joint was the non-standard execution of the welding process and improper control of post-weld heat treatment process,which caused reheat cracks to occur at the heat-affected zone and it expanded under pressure during operation.According to the analysis results of the cracking causes of the failed welded joints,it was recommended to conduct a comprehensive inspection to the thick-walled pipe weld of the boiler with the same installation process as that of the failed welded joints,so as to eliminate the defects of the boiler steam pipe welded joints and ensure the safe operation of the boilers.
作者
王义厢
WANG Yixiang(Huadian Electric Power Research Institute Co.,Ltd.,Hangzhou310018,China)
出处
《新技术新工艺》
2022年第5期77-80,共4页
New Technology & New Process
关键词
锅炉
蒸汽管道
焊接接头
焊接工艺
热处理工艺
开裂
boilers
steam pipes
welded joints
welding processes
heat treatment processes
cracking
