【作者】 江山；

【导师】 霍立兴；

【作者基本信息】 天津大学 ， 材料加工工程， 2006， 硕士

【摘要】 海底管线作为一种工程结构,在实际中有着广泛而重要的应用,担负着输送诸如石油、天然气等介质的重要任务。同时,作为一种焊接结构,管线的焊接接头也不可避免的会存在各种可能的焊接缺陷。随着工程实际应用的发展,人们逐渐以“合于使用”的思想原则来对焊接缺陷可能给结构带来的影响进行合理的评价,而不再采用以往使用的“完美无缺”的经验方法来要求结构中不能存在任何的焊接缺陷。本文以“合于使用”的思想为原则,依据在国际上广泛使用的标准BS7910,对中国石油总公司渤海石油公司(COOEC)所开发的旅顺至大连间海底石油传输管线X56海底管线进行3C级断裂评估。我们首先对BS7910:1999标准进行了解和掌握。为了获得进行3C级评估所需的管道材料的性能数值,我们以对管道供应商提供的数据进行分析的方式获得母材金属的拉伸力学性能;通过对焊缝金属进行力学性能实验的方式获得其力学性能,并通过测定J阻力曲线确定热影响区和焊缝金属分别具有的断裂韧性。在3C级断裂评估中,J积分是一个非常重要的参量,也是研究弹塑性断裂力学的重要内容之一。我们在广泛查阅大量国内外科技文献资料的基础上,收集并整理料国内外的J积分估算方法。提出了计算含环向穿透裂纹管道J积分估算方法:LBB.ENG2方法;提出了计算含表面裂纹管道J积分估算方法:SC.ENG1和SC.ENG2方法。我们通过对管道模型的等效简化,推导出其运算公式,避免了复杂的弹塑性断裂分析和有限元计算,适用于弹性到弹塑性整个范围。在以上工作的基础上,我们对X56海底管线进行3C级断裂评估,得出了3C级评估的失效评定图与一系列评定点,并进行安全性能分析。更多还原

【Abstract】 As a kind of engineering structure ,the submarineline has the abroad and important applications, which always is used to deliver the oil and the gas. In the same time , as a kind of welded structure ,the welded joint of the pipeline always has the inevitable welding defects.With the development of the engineering practice , people gradually use the principle of the“fitness for use”to assess the influence of the welding defects on the structures, and don’t required that the structure should not contain any welding defects.This paper uses the principle of the“fitness for use”and the regulation of the BS7910:1999 to make an 3C assessment for the submarineline which is developed by the COOEC and is located between Lvshun and Dalian..To finish the assessment, at first ,we understand the regulations and the theories of the BS7910:1999. Then ,we obtain the tensile property of the X56 pipe by the analysis of the tensile and yield strength value which is obtained from the mill certificates, obtain the tensile property of the weld by performing the tensile testing of the weld metal and obtain the fracture toughness of the HAZ and the weld metal by determining the J-R cure of them.In the fracture assessment of 3C,J-integer is a very important parameter,which is also an important contents in the elastic-plastic fracture mechanics.In this paper,the available domestic ana foreign J-integeral estimation methods were collected and digested on extensively reading science and technology bibilographic references.We brought forward LBB.ENG2 J-integral estimation methods for pipesWith circuferential through-wall crack ,and we brought forward SC.ENG1 and SC.ENG2 J-integral estimation methods for pipes with circuferential surface crack.We developed the equivalent reduced section analogies and derived the function equations,which avoid especially complex elastic-plastic fracture analyses and finite element numerical computations.These estimation methods can be applied in the complete range between elastic and fully plastic condition.We assessed x56 seaside pipeline in 3C level based on the above work,obtaining 3C level invalidation assessment chart and a series of assessment points, catching through safety performance analysis。更多还原