对比分析了中俄东线管道工程穿越段焊接工艺评定用俄罗斯标准 《西伯利亚力量焊接及无损检测技术要求,包括穿越地震断裂带》 和中国企业标准Q/SYGD 0503.12《中俄东线天然气管道工程技术规范第12部分:线路焊接》.分析认为:两国的焊接工艺评定标准在使用特点、 焊接材料选择、 坡口设计、 评定准则、 试件检验和验收要求等方面具有一定的差异;中国标准Q/SYGD 0503.12侧重于探索和试验的研究积累,俄罗斯标准涵盖内容更为详细,要求更为严格,对中俄东线过境段控制性工程更具有针对和指导性.

As a new type of pipe,bimetal composite pipe not only ensures corrosion resistance,but also reduces the cost,which has been widely used in oil and gas mining.The welding of bimetal composite pipe requires that the weld has the corrosion resistance of the clad metal and the mechanical properties of the base metal.Automatic welding can improve the welding efficiency and ensure the quality of welding.Therefore,more and more automatic welding technology is applied in the construction of bimetal composite pipe.The paper introduces the application of bimetal composite pipe,the development of welding technology,and the structure characteristics of bimetallic composite pipe and the existing problems in welding,introduces the advanced automatic welding technology.Look forward the prospects of development of automatic welding technology of bimetal composite pipe,and provide a reference for automatic welding of double metal composite tube in our country.

N80Q钢管作为一种主要的石油套管,在井矿区应用较广泛,主要用于盐井技术套管和表层管及深井注水系统,处在高温高压以及Cl-的腐蚀环境中.石油套管由接箍和管体组成,连接方式主要是螺纹连接.但是在运输、安装及在腐蚀环境中工作,丝扣易受损,造成在安装不到位或在投产后穿漏.一旦穿漏,将影响到采输卤生产,严重时造成大面积环境污染.因此,开展石油套管焊接连接的可行性及焊接接头性能的研究,为套管的现场安装提供了又一种连接方法[1-2].

通过对镍基合金的焊接性进行分析, 确定了大口径镍基复合管的焊接工艺, 采用背部充氩的钨极氩弧自动焊进行根焊、气体保护自动焊进行填充盖面的自动焊焊接工艺, 并且对焊接接头进行了常规力学性能、过渡层化学成分、显微硬度进行了研究.结果表明: 该焊接工艺切实可行, 焊缝成分能保证复合管焊接过程中的力学要求.

In this article, it utilized plate tensile test to carry out defect evaluation tests for X70 line pipe circumferential weld, combining with the finite element simulation analysis. It studied the mechanical deformation and crack opening variation behavior of weld with 3.5 mm ×50 mm size defect, and evaluated the safety of weld with defects combining with metallographic structure analysis. The results indicated that the appropriate welding process of X70 circumferential weld with high strength match, under condition of containing crack defects with 3.5 mm ×50 mm size, the pipeline overall axial strain can reach 3.2%, the crack does not occur unstable extension, and pipeline operation is still reliable.

Based on the mechanical performance testing,the failure assessment to X80 pipeline steel welded joint with crack defect was studied by adopting BS 7910—2005 standard of British Standards Institution under two kinds of different welding process.The results showed that in secondary assessment for the same weld,due to 2B assessment adopted true stress-true strain data,so it reflects the anti-fracture ability of material better than 2A assessment.For the surface crack and hidden crack with the same size,the danger of surface crack is greater than that of hidden crack;the hidden crack,whose location in welded joint can affect assessment result,is closer to the surface,the more dangerous will be.In case of a 3.2 mm×1 mm crack exists in circumferential weld joint,all assessment points are in the range of acceptable assessment curve,it proves the structure of welded joint is safety.