亚临界循环流化床锅炉水冷壁焊缝开裂原因分析  

Cause Analysis of Weld Cracking on Water-Wall Tube in Subcritical Circulating Fluidized Bed Boiler

作　　者：陈浩[1] 张涛[1] 郑建军 谭晓蒙 史贤达 CHEN Hao;ZHANG Tao;ZHENG Jianjun;TAN Xiaomeng;SHI Xianda(Inner Mongolia Power Research Institute,Hohhot 010020,China)

机构地区：[1]内蒙古电力科学研究院,呼和浩特010020

出　　处：《内蒙古电力技术》2020年第6期77-79,共3页Inner Mongolia Electric Power

基　　金：内蒙古电力科学研究院科技项目“基于因子关联技术的电站金属设备大数据分析系统建设及应用”(2018-05)。

摘　　要：利用宏观检验、化学成分分析、显微组织检验、扫描电子显微镜(SEM)形貌分析及能谱分析等试验方法对某亚临界锅炉水冷壁焊缝开裂原因进行了试验分析。结果表明,因水冷壁钢管防磨涂层未打磨干净,使得硫元素含量较高的涂层熔入焊缝内,改变了焊缝金属的化学成分,在焊缝凝固时形成结晶裂纹;随着锅炉的运行,结晶裂纹不断扩展直至贯穿整个管壁,造成水冷壁钢管开裂泄漏。为避免类似问题再次发生,建议施焊前将坡口附近的防磨喷涂层彻底清除。The cracked water-wall tube used in subcritical circulating fluidized bed boiler is investigated by means of Macro-morphology inspection,chemical composition analysis,microstructure analysis,SEM morphology analysis and energy-dispersive X-ray analysis.The result shows that the coating with high sulfur content has melted into the weld because the anti-wear coating on water-wall tube has not been completely removed.When the weld solidifies,the solidification cracking can be formed.During the operation of the boiler,the crack can expand continuously until it penetrates the whole tube wall,resulting in the leakage of water-wall tube.

关 键 词：水冷壁钢管 焊缝 焊接热裂纹 失效分析 预防措施 

分 类 号：TM621.6[电气工程—电力系统及自动化]