高压主汽调节阀接管焊接修复技术

Research on techniques of high pressure main steam regulating valve of powerplant

某电厂百万机组高压主汽调节阀在进行材质检验时发现,进、出汽接管材质与设计要求材质不符,对机组的使用功能和安全保障有很大影响,需要更换和修复。本次修复将原有非对称型坡口优化为对称型坡口形式,采用分散焊接顺序,在不妨碍装焊的原则下适当加装固定拉筋,防止修复过程产生焊接变形和位移;焊接过程中,严格控制预热温度和层间温度,焊后及时进行热处理。结果表明,焊接修复后的接头组织为回火马氏体,阀门变形在设计允许范围内,焊接质量达到了JB/T4730-2005I级合格标准。

A problem has been found that the material of pipe connector of 1 000 MW Uhra-supercritical High Pressure Main Steam was not in conformity with design requirements when a certain power plant test, and it will have a great influence on use function and security of the units and it have to repair. The asymmetric welding groove type was instead for Symmetrical welding groove in technology,and a distributed welding sequence was not only used but also equipped with fixed brace in order to prevent the welding deformation and displacement. We must strict control of preheating temperature and interpass temperature and postweld heat treatment is applied in timely during the welding process. The results show that the organizations of welding joint is tempered martensite and the deformation in the design of the valve within the allowable range,the welding quality has reached JB/T4730-2005 Hevel eligibility criteria.