锅炉后包墙下集箱密封板处焊缝裂纹原因分析及防控

Cause Analysis and Control Measures of Weld Crack on the Below Back Cover Wall Sealing Plate in Boiler

本文主要介绍了锅炉后烟井后包墙过热器下集箱密封板与集箱处焊缝裂纹产生的原因及应对措施,分析认为裂纹为现场管屏与集箱拼接后,密封板与管子现场焊接后的纵向焊缝裂纹,同时焊缝裂纹扩展至集箱筒体,导致集箱筒体产生开裂。裂纹的产生主要和锅炉安装时密封板与管屏焊接工艺、热处理不合理有关,同时3条焊缝(接管座角焊缝、密封板下方横向焊缝与密封板纵向焊缝)的交汇设计存在一定的不合理之处,为裂纹的产生创造了条件。

This paper mainly introduces the causes and prevention and control measures of weld crack of the smoke well after the cladding wall superheater under the header sealing plate and the header in boiler.The analysis shows that the crack is caused by the longitudinal weld crack of sealing plate after field tube panel and container splicing and the weld crack extends to the header cylinder,which results in the cracking of the header cylinder.The main cause of crack formation is welding technology of sealing plate and tube panel during boiler installation,irrationality of heat treatment and the intersection design of three welds(fillet welds of the nozzle seat,transverse welds under the sealing plate and longitudinal welds of the sealing plate)has some irrationality,which creates the conditions for the occurrence of cracks.