南海市发电A厂1号机汽缸裂纹的补焊处理

介绍南海市发电A厂汽缸裂纹补焊的处理工艺和处理过程。汽缸是焊接性差的大型铸钢件，根据现场情况，选用高镍的A507焊条，采用冷焊法进行缺陷补焊处理。利用跟踪锤击方法和焊接自回火效果，充分消除焊接应力，优化焊缝及热影响区的金相组织，避免焊接裂纹的产生，减小缸体的焊接变形，机级投运后历经3年多时间验证，多次复检未发现异常痕迹，设备运行正常，证明这一种可靠、可行的焊接方法。

Repair welding for cracks on No.1 steam turbine cylinder in Nanhai A Power Plant

This paper describes the procedures and process of welding repairfor turbine cylinder cracks in Nanhai A Power Plant. The cylinder is large steel casting with poor weldability. In light of the conditions on site, high nickel A507 electrode and cold welding methodology were selected. By use of follow-up hammering and self-tempering effect in the welding, the welding stresses were minimized, thus optimizing the metallurgical structure of the welded seams and heat-affected zones, preventing welding cracks and reducing welding deformations of the cylinder. No abnormalities were found in the multiple rechecks on the repair-welded zone in over 3 years'operation of the unit thereafter, which proves the reliability and feasibility of the proposed method.