蒸汽加热器弯头对焊焊缝开裂失效分析

Cracking Failure Analysis of the Butt Welding Seams of the Bends of Steam Heaters

利用光学显微镜、扫描电镜、电子能谱仪等测试手段,从材料成分、微观组织、断口形貌以及腐蚀产物成分等角度,分析了蒸汽加热器弯头对焊焊缝开裂失效的原因——系统操作过程中碱液进入蒸汽加热器所引起的应力腐蚀所致,同时提出了避免蒸汽加热器弯头对焊焊缝开裂失效的防护措施。

The cracking failure cause of the bends of the butt welding seams of a steam heater was analyzed in material components, microstructure, fracture appearance, and components of corrosion products using some measuring methods, such as optical microscope, SEM, and electronic energy spectrum. It is concluded that the cracking was caused with the stress corrosion induced with the alkali liquor that entered the steam heater in operation, and some protection methods for avoiding the cracking failure of the butt welding seams of the bends of steam heaters were proposed.