蒸汽发生器焊趾裂纹修复及焊道回火方案设计研究

Research on Scheme Design Improvement of Repairing of Weld Toe Crack and Bead Tempering of Steam Generator

蒸汽发生器二次侧人孔与筒节马鞍型焊缝结构焊接难度大,尤其是筒体内壁,拘束度大,焊缝表面为典型的高拉应力集中区域。制造过程中,焊趾部位为缺陷高发区。针对工程项目中马鞍形焊缝多发性焊趾缺陷,完成了缺陷整圈打磨返修工艺设计及评价,并完成了返修方案实施,有效避免了返修焊缝缺陷重发。在此基础上,对二次侧人孔与筒节马鞍型焊缝进行了制造工艺优化设计,要求马鞍型焊缝进行盖面焊道回火,以提高盖面焊道的焊接质量。

It is difficult to weld the saddle type welding structure between the manhole of secondary side and the shell of the steam generator, especially the inner wall of the shell, which has a large degree of restraint, and the weld surface is a typical high tensile stress concentration area. During the manufacturing process, the weld toe area is a high-risk area. Aiming at multiple weld toe defects of the saddle-shaped weld in the project, the process design and evaluation of circle grinding repair of the defect were completed. The repair plan was completed, which effectively avoided the recurrence of repair defects.Based on this, the manufacturing process optimization design of saddle type weld between secondary manhole and shell was carried out. It was required to adopt cover weld bead tempering of the saddle type weld in order to improve the welding quality of the cover weld bead.