摘要
针对某电厂1号机组锅炉水冷壁管安装过程中发现的内壁类裂纹缺陷,采用化学成分分析、力学性能试验、金相组织分析、扫描电镜和X射线能谱分析等方法进行了系统观察和分析,探讨了类裂纹缺陷的性质和形成原因。研究发现水冷壁管内壁缺陷的性质为裂纹,裂纹最大深度达1.6mm。裂纹处存在非金属夹杂物和磷化、皂化产物。裂纹形成的原因是管坯芯部存在脆性非金属夹杂物,夹杂物在热穿孔时碎化形成微裂纹,微裂纹在冷拔变形中扩展形成裂纹。
In view of the internal wall crack defects found during the installation of the boiler water wall tube of Unit 1 in some power plant,the methods including the chemical composition analysis,mechanical performance test,metallographic analysis,scanning electron microscope and X-ray energy spectrum analysis have been used for systematic observation and analysis.The nature and formation reason of crack-like defects have been discussed.The study has found that the nature of the defect on the inner wall of the water wall tube is a crack,of which the maximum depth is 1.6mm.There are non-metallic inclusions and phosphating&saponification products at the cracks.The reason for the cracks formation is that there are brittle non-metallic inclusions in the core of the tube blank.The inclusions are fragmented to form micro-cracks during hot perforation process,and the micro-cracks propagate to form cracks during cold drawing deformation.
作者
王彩侠
杨兰
陈征
侯召堂
WANG Caixia;YANG Lan;CHEN Zheng;HOU Zhaotang(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,Shaanxi China)
出处
《锻压装备与制造技术》
2021年第4期118-122,共5页
China Metalforming Equipment & Manufacturing Technology
关键词
水冷壁管
无损检测
缺陷
裂纹
Water wall tube
Non-destructive testing
Defect
Crack
