摘要
利用宏观检查、断口分析、硬度测试及微观组织分析等研究了350 MW超临界直流锅炉水冷壁15CrMoG对接接头运行40000 h后的开裂行为特征。结果表明,水冷壁对接接头的焊接工艺参数选择不当、拘束度大,致使焊缝内形成众多的一次结晶裂纹。在锅炉长时间运行过程中的一次、二次应力及接头拘束应力作用下,结晶裂纹扩展至贯通焊缝而引发频繁的开裂泄漏。
The cracking behavior of 15CrMoG butt joint for water wall of 350 MW supercritical concurrent boiler after 40000 h operation was investigated by macroscopic examination,fracture analysis,hardness test and microstructure analysis.The results showed that inappropriate welding parameters and large restraint stress of butt joint in water wall results in numerous crystalline cracks generating in the butt weld.Under the long term operation of boiler,solidification cracks extended through the whole weld and led to the frequent cracking leakage because of the action of primary stress,secondary stress and restraint stress of welded joint.
作者
张涛
陈浩
田峰
郑建军
乔欣
Zhang Tao;Chen Hao;Tian Feng;Zheng Jianjun;Qiao Xin(Inner Mongolia Electric Power Research Institute,Huhhot 010020,China)
出处
《焊接》
2019年第10期58-61,I0005,共5页
Welding & Joining
