几种典型X80管线钢管及其环焊缝性能研究

环焊缝质量是影响高钢级长输管道安全的重要因素之一。国际焊接研究中心(IWTC)针对几种典型X80管线钢的焊接开展了大量研究,测试了钢管管体和环焊缝的组织及关键力学性能,分析了X80管线钢管环焊工艺及环焊缝性能影响因素,给出了推荐工艺参数、控制措施等。采用焊接热模拟试验研究了2种不同Nb含量的X80钢管的焊接性,分析了Nb含量对焊缝区域微观组织的影响机制。结果表明,国内典型的X80管线钢管均具有良好的性能,其管体性能及焊接性满足工程需要;应采用合理的环焊工艺和质量控制措施以保证焊缝的性能;铌含量较高的X80管线钢具有更优越的焊接性,但必须严格遵从焊接工艺规范。

X80 Line Pipes With Several Typical Alloy Designs and Their Girth Welds

The quality of girth weld is one of the important factors affecting the safety of high grade long-distance gas pipelines.The International Welding Technology Center(IWTC),which is a joint initiative of the Chinese National Petroleum Company(CNPC)and its R&D Center,Tubular Goods Research Institute(TGRI),together with CITIC Metals and CBMM,whose vision is to advance welding expertise in China when the demands for more environmentally friendly energy needs are growing at unprecedented rates,has conducted advanced research on high quality X80 steels with different alloy designs,including testing of microstructure and performance of pipes and their seam welds,analysis and optimization of the welding procedure specification and the procedure parameters,and recommendation of the relevant control measurement to improve the quality of girth welds.In addition,the weldability of two steels with different Nb contents has been studied and compared by using thermal simulation.The results testify that the properties of pipe bodies and weldability of studied X80 line pipes are good enough to meet engineering requirements.To guarantee the performance of girth weld,proper welding procedures and quality control measures should be adopted.It also demonstrated that X80 line pipe with higher Nb has better weldability.Certainly,it is all subject to comprehensive weld procedure specifications which must be controlled during construction processes.