超超临界锅炉集箱角焊缝开裂分析及优化  

Analysis and Optimization on Cracking Failure of Header Fillet Weld in an Ultra-supercritical Boiler

作　　者：董鹏 李海阳 赖威龙 周彦兴 李林浩 李金伟 杨浩 罗官睿 Dong Peng;Li Haiyang;Lai Weilong;Zhou Yanxing;Li Linhao;Li Jinwei;Yang Hao;Luo Guanrui(Guoneng Qingyuan Power Generation Co.,Ltd.,Yingde 513052,Guangdong Province,China)

机构地区：[1]国能清远发电有限责任公司,广东英德513052

出　　处：《发电设备》2024年第3期177-181,193,共6页Power Equipment

摘　　要：针对某电厂超超临界锅炉延伸侧墙出口集箱角焊缝开裂的问题,从材料成分、显微组织、硬度测试及运行工况等方面综合分析该集箱角焊缝失效的原因,并且从焊接工艺、热处理工艺及焊缝形式出发综合提出优化方案。结果表明:集箱管材料为12Cr1MoVG,失效集箱角焊缝的化学成分、显微组织及硬度均符合标准,裂纹起裂于角焊缝外表面,并向内表面扩展。开裂原因为焊接残余应力与服役过程应力产生复杂叠加。通过采用降低角焊缝处应力集中的优化措施,延长材料使用寿命,可以为同类型电站锅炉管道的日常监督与质量控制提供重要的借鉴。To solve the problem of the cracking failure of the fillet weld at extended side wall outlet header in an ultra-supercritical boiler of a power plant, comprehensive analyses were conducted on the cracking failure reasons of the fillet weld from the aspects of material chemical composition, microstructure, hardness tests and service condition, while optimization measures were synthetically proposed based on welding process, heat treatment process and weld form. Results show that, the header material is 12Cr1MoVG, and the chemical composition, microstructure and hardness of the leaked header fillet weld all can meet the requirements of standards. The complex additive effects of welding residual stress and service stress result in the cracking failure. The service time can be prolonged by adopting the optimization measure of reducing the concentrated stress in fillet weld. This can provide an important reference for the daily supervision and quality control of similar boiler tubes in power plants.

关 键 词：锅炉 角焊缝 12CR1MOVG 开裂 焊接残余应力 焊后热处理 

分 类 号：TM621.25[电气工程—电力系统及自动化]