核电冷却循环水管道主要材料为Q345、直径大、钢板厚、焊缝多、加固环间距小、拘束度大，焊接时较容易产生焊接应力，焊后进行热处理是消除焊接应力的重要措施。文章对核电冷却循环水大口径管道的热处理施工方法和技术进行了探讨，分析了焊后热处理的工艺参数及质量检验，为同类大口径管道的焊后热处理施工提供借鉴。

The main material used in the cooling circulation water pipe for nuclear power is Q345, large diameter, thick plate, a plurality of weld seam, short space distance between reinforcement ring, and big constraint. Heat treatment shall be conducted as a whole in the furnace after the completion of welding operation in order to eliminate the stress. The heat treatment procedure is that the temperature of 600 ℃ shall be reached by heating and keep it for 2h then cool it in the furnace naturally .