针对超超临界发电机组锅炉Ⅰ级减温器12Cr1MoVG钢集箱三通焊接接头出现裂纹的问题，讨论12Cr1MoVG钢的焊接性和集箱三通焊接接头裂纹修复的技术难点，详细介绍从焊前准备到焊后检验整个过程的焊接规范和焊后热处理工艺。焊接检验结果表明该补焊修复工艺可以保证减温器12Cr1MoVG钢集箱三通焊接接头的补焊修复质量。

Aiming at the cracks of welding joint for 12Cr1MoVG steel header links of the grade I desuperheater of boilers in the ultra-supercritical units, the weldability of 12Cr1MoVG steel and technical difficulties of crack repair welding for the header links are discussed in the paper. The welding conditions and the post-weld heat treatment in the entire process from the pre-welding treatment to welding inspection are introduced. It is shown from the results of welding inspection that the repair welding quality of welding joint for 12Cr1MoVG steel header links in desuperheater can be ensured by the repair welding process.