【作者】 卢雪峰；

【导师】 石凯； 杨忠文；

【作者基本信息】 西安石油大学 ， 材料加工工程， 2009， 硕士

【摘要】 连续管作业与常规作业相比有安全、经济、高效的特点,在油气田的应用越来越广泛。但我国连续管还依赖从国外进口,因此生产国产连续管是我国的迫切要求。在连续管的制造过程中,焊缝碾压形变热处理被安排在钢带与钢带的焊接连接工序之后,起着对焊接接头的组织细化、消除焊接应力和力学性能改善的重要作用,是决定连续管质量和使用寿命的重要生产工艺手段。本课题作为“国家高技术研究发展计划”国家863项目中的研究内容之一,采用该项目研发的CT80连续管用钢板,针对由STT和TIG两种焊接方法完成的板-板对接焊焊缝开展了焊缝碾压形变热处理的研究。旨在掌握连续管板-板对接焊焊缝碾压形变热处理的方法；获得焊缝碾压形变热处理工艺参数对碾压效果的影响规律；提出适合生产要求的焊缝碾压形变热处理工艺的方案。本研究工作在国内尚属首次,因而主要研究内容和精力放在了试验方案、试验数据、试验结果的制订、归纳、分析方面,而在机理方面的探讨较少。另外,该项目许多内容属于技术机密,因而论文中有些材料、处理手段、以及一些工艺参数采用代号表示或被省略。首先采用正交试验的方法,确定了焊缝碾压形变热处理的主要影响因素。以抗拉强度、延伸率、弯曲和硬度作为评价指标,研究了焊缝碾压形变热处理对焊接接头性能的影响规律。研究表明,对焊缝进行碾压形变热处理之后焊缝晶粒有着明显的细化,但其对力学性能的作用不明显。试验结果表明,在室温至900℃之间,随着碾压温度的升高,焊接接头的抗拉强度和延伸率都呈先增大后减小的趋势。通过对STT焊缝和TIG焊缝在300℃和500℃焊缝碾压形变热处理后焊接接头的抗拉强度、延伸率和弯曲性能的对比发现,TIG焊缝在碾压形变热处理之后的焊接接头的抗拉强度、延伸率都比STT焊接接头高,而且弯曲性能好于STT焊接接头。由于在连续管辊制成型之后,要对连续管进行整体管热处理。在300℃和500℃对TIG焊缝进行碾压形变热处理之后对焊接接头进行一次与整体管热处理相同的热处理,可以使焊接接头的综合性能接近于母材。更多还原

【Abstract】 The coiled tubing technique is used more and more widely in oil and gas fields by its characters of safety, economy and high efficiency ,compared with conventional methods.It is essential to manufacture domestic coiled tubings as we have to import them abord now. Thermomechanical Treatment with Rolling is arranged after completing the plate-plate butt weld and plays a very important role in removing welding stress and improving machamcal properties of weld joints during manufacturing processes of coiled tubing.It is also an important process and method which determines the quality and service life of coiled tubing.This subject a part of the "National high-tech research development plan"National 863 Project.After completing the plate-plate butt weld by means of STT and TIG welding ,adopting the coiled tubing tube sheet created by this project, Thermomechanical Treatment with Rolling was studied.Reseaching contents and vigor were aimed at mastering technigical parameters Influencing on effect of Thermomechanical Treatment with Rolling of weld seam and offering methods can satisfy the requirement of manufucturing of coiled tubing .By the way ,since many contents are technical secrets,some materials, measure and processing parameters were replaced by code name or excluded from the paper. Because it is the first time that this subject is studied in China,the research and vigour was mainly spent on arangements,induction and analysis of experimental schemes,datas and results.By orthogonal experiments, the main influencing factors of the Thermomechanical Treatment with Rolling process were found out.Taking tensile strength, elongation,3-point bending and hardness as evaluating indicaors, the law of Thermomechanical Treatment with Rolling impcating on properties of weld joint is studied.The research indicates Thermomechanical Treatment with Rolling can cause crystal grain of weld joints become finer,while its effect on mechanical properties is not obvious.When the temperature of Thermomechanical Treatment with Rolling is between room temperature and 950℃, The research indicates that the tensile strength and the elongation raise at first, then the strength and the elongation decrease with the increasing of rolling temperature.Thermomechanical Treatment with Rolling of TIG weld seam shows that tensile strength, elongation,3-point bending of TIG welded joint is better when Thermomechanical Treatment with Rolling was applied at 300℃and 500℃,comparing with STT weld joint.After shaping the strip into tubing form through forming rollers, the pipe should be carried out for the integral heat treatment At the temperature of 300℃and 500℃for Thermomechanical Treatment with Rolling, then heat treatment implemented which is the same as the integral heat treatment, the comprehensive mechanical properties are close to the base metal.更多还原