焊接拘束条件下油气管道焊接接头的断裂韧性

发布时间：2018-04-10 04:01

本文选题：油气管道　切入点：焊接接头　出处：《油气储运》2017年04期

【摘要】：在油气管道连头焊缝及金口焊接过程中,管道强力组对,工况复杂,存在较大的拘束应力,造成金口焊接接头成为薄弱环节,易发生泄漏或开裂。为了提高焊接接头的断裂韧性,设计了自拘束焊接装置,模拟金口在不同拘束条件下的焊接过程,并对焊接接头的断裂韧性CTOD(Crack Tip Opening Displacement)值进行测试和计算。结果表明:在拘束条件下,焊缝区的CTOD值与自由状态下的CTOD值相差不大;热影响区的CTOD值则明显低于自由状态下的CTOD值,且拘束应力越大,CTOD值下降越明显,韧性越差。油气管道在拘束条件下进行焊接,一定程度上降低了焊接接头的抗开裂性能,建议在金口焊接时尽量降低拘束应力,以减少对焊接接头断裂韧性的不利影响。
[Abstract]:In the process of joint weld and gold joint welding of oil and gas pipeline, the working condition of pipeline is complex and there is a large restraint stress, which makes the joint of gold mouth become weak, and it is easy to leak or crack.In order to improve the fracture toughness of welded joints, a self-restraint welding device was designed to simulate the welding process under different restraint conditions. The fracture toughness CTOD(Crack Tip Opening displacementation of welded joints was measured and calculated.The results show that the CTOD value of weld zone is not different from that of CTOD value under free condition, and the CTOD value of heat affected zone is obviously lower than that of CTOD value in free state, and the greater the restraint stress is, the more obvious the decrease of CTOD value is and the worse the toughness is.The cracking resistance of welded joints is reduced to a certain extent by welding of oil and gas pipelines under restraint conditions. It is suggested that the restraint stress should be reduced as far as possible in order to reduce the adverse effect on fracture toughness of welded joints.
【作者单位】：广东大鹏液化天然气有限公司;天津大学材料学院;
【基金】：中国海洋石油总公司青年科技创新资助项目“在役陆上长输天然气管道含缺陷焊缝适用性评价关键技术研究”,JZTW2015KJ24
【分类号】：TE973.3

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