运行管道在线焊接时的氢致开裂与防止方法

油气输送管道于腐蚀或机械损伤引起的减薄区以及由于管道的大段破坏或工艺要求需要安装分输支管、通常要进行现场妆操作。该操作如果在不停输的情况下进行，会大大减少由此引起民的经济损失。但是在不停输情况下焊接，由于管内介质的流动而产生的快冷效果可能会形成热影响区（ＨＡＺ）的氢致开裂。为了避免氢致开裂获得优良的焊接接头。本文 碳钢管的循环试验管道上初步研究了焊接残应力、焊接区冷却速度、焊接工艺条件等因素对运行

Hydrogen Cracking and Its Prevention Method on Field Welding onto Oil and Gas In-service Pipline

The thinned zone of oil and gas pipelines by corrosion or mechanical damage and the installing for side transibutery stream pipelines require commoly the field welding practice. This will result in a large economic losses unless the welding is conducted without interruption of the flow of oil and gas. However, welding on pipelines with flowing oil and gas may cause hydrogen cracking in HAZ located at the fast cooling.In order to prevent from hydrogen cracking and obtain a sound welded joints, the effects of welding residual stress, hydrogen content, welding cooling rate and welding procedures on hydrogen cracking induced in carrier line during welding were studied in this paper. Some beneficial results had been obtained in the experiment, and the direction of futher study was settled.