锅炉高过出口管道焊接接头边缘偏差超标分析

Analysis of Excessive Weld Edge Deviations in a Boiler High Temperature Super⁃heater Outlet Pipes

高过出口管道是电站锅炉重要的高温高压部件,因其材料等级高、管壁厚、制造工艺复杂,在焊接过程中易产生未熔合、裂纹等超标缺陷,其焊接质量和受力状况对锅炉机组安全运行具有重要影响。《锅炉安全技术规程》和相关技术标准也对管道的焊接接头型式、材料控制、焊缝表面质量等方面提出了严格要求。某330 MW机组亚临界锅炉内部检验时发现高过出口管道材料钢印与设计不符、焊接接头边缘偏差超标等问题,威胁机组安全运行。通过宏观检验、资料核查、现场检测、建模模拟等方法,对该锅炉高过出口管道焊接接头边缘偏差严重超标进行了分析,找出缺陷产生的原因并提出了处理方法和具体的防控措施,对提升锅炉制造质量、保障锅炉机组运行安全具有一定意义。

The outlet pipe of high temperature super⁃heater is an important high temperature and high pressure component of power plant boil⁃er.Because of its high material grade,thick pipe wall and complex manufacturing process,it is easy to produce excessive defects such as lack of fusion,cracks and so on in the welding process,and its welding quality and stress condition have an important impact on the safe operation of the boiler unit.“Regulation on Safety Technology for Boiler”and related technical standards also put forward strict requirements on the type of welded joints,material control,weld surface quality and so on.During the internal inspection of a subcritical boiler of a 330 MW unit,it was found that the steel seal of the outlet pipe material was inconsistent with the design,and the edge deviation of the welded joint exceeded the standard,which threatened the safe operation of the unit.By means of macroscopic inspection,data verification,on⁃site inspection,mod⁃eling and simulation,the edge deviation of the welded joint of the outlet pipe of the boiler was analyzed,and the causes of the defect were found out,and the treatment methods and specific prevention and control measures were put forward,which has certain significance for impro⁃ving the quality of boiler construction and ensuring the safe operation of boiler units.