16Mn管线钢管在役焊接修复的研究

在役管道焊接修复可以解决泄压停输修复中的修复工期长，经济损失及环境污染较大等问题，具有很广的应用前景。研究了16Mn管线钢管在役焊接修复过程中接头的组织与性能，研究结果发现：焊接电流为110A时，增大冷却速度，焊缝出现更多的侧板条铁素体和上贝氏体，热影响区(HAZ)甚至出现了M-A组元；在流动水冷却下，增大焊接电流，侧板条铁素体减少，焊缝的柱状晶比例减小，等轴晶比例增加；采用多层多道焊可以改善结晶条件，细化组织，降低硬度，对焊接接头有益。

Study of Service Welding Repair of 16Mn Pipeline

Service pipeline welding repair may solve problem of long repair term, big economic loss and environment pollution, etc.. and has broad application prospect. The structure and properties of joint of 16Mn pipeline during service welding repair is studied. The studies results show that weld appear more side plate ferrite and acicular constituent and HAZ even appear M-Au-nit to increase cooling speed when welding current is 110A. To increase welding current and side plate ferrite will decrease and the ratio of column crystal in weld will decrease and the ratio of equal axis crystal will increase. However,to adopt multi-layer and multi-passes welding may improve crystal condition, fine structure and decrease hardness to good to weld joint.