大应变管线钢和钢管的关键技术进展及展望

Research progress and prospect of key technologies for high-strain pipeline steel and steel pipes

油气管道工程在途经地震带、滑坡带、矿山采空区、沉陷带等特殊地质环境时,使用的大应变管线钢和钢管的研制及应用配套技术是国际上研究的热点之一,也是我国重要油气管道工程必须破解的重大难题。为此,围绕大应变管线钢和钢管研发应用中的一系列关键技术难题,通过十余年的联合攻关,取得了多项理论技术创新。主要成果包括:①提出了应用多个不同的应力比、屈强比、均匀延伸率等参数联合表征和评价钢管变形行为的方法,建立了X70HD/X80HD大应变管线钢和钢管新产品技术指标体系和标准;②研发形成了X70HD/X80HD钢板制造成套技术,获得了兼备低屈强比、高均匀伸长率、高应力比、高强韧性的大应变钢板;③研发形成了X70HD/X80HD JCOE和UOE大应变直缝埋弧焊管制造技术,解决了钢管母材和焊缝性能合理匹配及成型、焊接、扩径、热涂覆过程性能劣化难题;④自主研制了钢管内压+弯曲大变形实物试验装置,研发形成了钢管实物模拟变形试验技术。X70HD/X80HD大应变管线钢和钢管在西气东输、中缅管道等重大输气管道工程中实现了规模化应用,取得了良好的应用实效。根据复杂地质条件管道建设与长期安全运行的新要求,提出了进一步发展基于应变的管道设计新方法,研发或完善与环焊缝强匹配要求相适应的焊接方法、焊接材料、焊接工艺、环焊缝性能质量及缺陷控制要求等配套技术的建议。

The development and supporting technologies of high-strain pipeline steel and steel pipes used for oil and gas pipeline projects in special geological environments(such as earthquake zone, landslide zone, mine goaf and subsidence zone) is one of the international research hotspots, and it is also a major problem that China’s major oil and gas pipeline projects have to solve. Focusing on a series of key technical difficulties in the research & development and application of high-strain pipeline steel and steel pipes, a number of theoretical and technological innovations have been achieved after more than ten years of joint researches. And the main achievements are as follows. First, the method of applying many different parameters(e.g. stress ratio, yield to tensile ratio and uniform elongation(UEL)) to comprehensively characterize and evaluate the deformation behavior of steel pipes is proposed, and a technical index system and standard for the new products of X70HD/X80HD high-strain pipeline steel and steel pipes are established. Second, a complete set of X70HD/X80HD steel plate manufacturing technology is researched and developed, and the high-strain steel plate with the properties of low yield to tensile ratio, high uniform elongation, high stress ratio and high strength and toughness is worked out. Third, the X70HD/X80HD JCOE and UOE high-strain longitudinal submerged arc welded pipe manufacturing technology is researched and developed, reasonable performance matching between a steel pipe and a welding seam is realized, and the performance deterioration in the process of forming, welding, diameter-expending and thermal coating is solved. Fourth, a full-scale test device of steel pipe internal pressure + bending large deformation is independently developed, and the physical simulation based steel pipe deformation test technology is formed. X70HD/X80HD high-strain pipeline steel and steel pipes have been applied in the West to East Gas pipeline, the China-Myanmar Pipeline and other major gas pipeline projects in the large scale, and their application effects are remarkable. To satisfy the new needs of pipeline construction and long-term safe operation under complex geological conditions, we put forward some suggestions, such as developing new methods of strain-based pipeline design, and researching and developing or improving the supporting technologies suitable for the higher matching requirements of girth weld, such as welding methods, welding materials, welding processes, and girth weld performance quality and defect control requirements.