高级别管线钢断裂韧性测试技术研究(硕士毕业论文)

1、硕士学位论文高级别管线钢断裂韧性测试技术研究申请人：陈生圣学科专业：材料科学与工程指导教师: 赵文轸教授冯耀荣教授2009年5月PDF 文件使用 pdfFactory Pro 试用版本创建PDF 文件使用 pdfFactory Pro 试用版本创建Study on test methods of fracture toughness of high gradepipeline steelsA thesis submitted toXian Jiaotong Universityin partial fulfillment of the requirementfor the degree ofM

2、aster of Engineering ScienceByChen Shengsheng(Materials Science and Engineering)Supervisor: Prof. Zhao WenZhenFeng YaoRongMay 2009PDF 文件使用 pdfFactory Pro 试用版本创建IIPDF 文件使用 pdfFactory Pro 试用版本创建摘 要论文题目：高级别管线钢断裂韧性测试技术研究学科专业：材料科学与工程学位申请人：陈生圣指导教师：赵文轸教授 冯耀荣教授摘 要随着石油和天然气的大量开发，世界各国的油气输送量成倍增长。管道输送作为石油、天然气最经济

3、、合理的运输方式，获得迅速发展。现代石油输送管道正向着大管径、高压力和海底管道厚壁化的方向进行，这就给输送管道材料的各种性能提出了更高的要求，而断裂韧性是其中十分重要的技术参量之一。断裂韧性测试方法，国内外都有现成的标准，但是这些标准对管线钢管一般并不适用，这是因为管线钢的厚度有限，不能满足标准中规定的平面应变条件，特意制作的厚试样，不能反映管材的实际服役情况，测试值无工程意义，更何况加厚试样的工艺和组织不可能与管材相同。所以研究在非平面应变条件下薄壁管线钢的断裂韧性测试方法，对于开发、评价各个厂家的产品和预测管线钢的寿命具有重要意义。本课题选择高级别管线钢：X70、X80、X100和做对比试

4、验的钻挺钢，每种材料采用三种不同厚度的三点弯曲试样，进行了断裂韧性K值和J积分的测试，比较分析试验结果，选择比较合理可行的高级别管线钢的断裂韧性测试方法，对各种材料的试样断口特征进行分析，从微观上定性评价结果的准确性。结果发现，国家标准试验规范不适合X70、X80钢的断裂韧性KIC和JIC的测试，平面应力层的存在是试样无法满足平面应变条件的主要原因；但X100钢能测得有效的JIC，进一步分析得出J积分中的塑性能部分Jp与裂纹稳态扩展量呈线性关系；分开处理X100钢J积分测试结果中塑性项Jp和弹性项Je的方法与国标法的结果比较而言，分开法求得的结果数据保持了相对保守和稳定的态势，此方法可用于评价

5、高级别管线钢的断裂韧性；为了强化试样在测试时的平面应变程度，进而设计了侧切三点弯曲试样方法并进行了相应的试验。得出：侧切三点弯曲试样法虽然未能实现理想的脆断曲线，但能保持试样断口的平面应变形貌特征；可作为新的试样用于断裂韧性测试中。关 键 词：管线钢；断裂韧性；测试方法；侧切三点弯曲论文类型：应用基础IPDF 文件使用 pdfFactory Pro 试用版本创建西安交通大学硕士学位论文IIPDF 文件使用 pdfFactory Pro 试用版本创建ABSTRACTTitle: Study on test methods of fracture toughness of high grade p

6、ipeline steels Speciality: Materials Science and EngineeringApplicant: Chen ShengshengSupervisor: Prof. Zhao Wenzhen Feng YaoRongABSTRACTWith the huge amount of oil and natural gas being explored everyday, pipeline transportation of oil and gas has developed rapidly all over the world. These days, p

7、ipeline transportation has become the most economical and reasonable transportation solution. Modern petroleum transportation calls for transportation pipes with larger diameter, higher pressure resistance and the thick wall pipe in seabed, and this inevitably gives rise to a higher demand of the pe

8、rformances of pipeline steel. Among them, the fracture toughness is considered as one of the key technical parameters for evaluating the pipeline performances.Although the standard test methods of fracture toughness have been made in various countries and states, These standards are not generally su

9、itable for the steel pipeline. This is because the thickness of steel is limited, and the thickness of pipeline steel generally can not satisfy the condition of the plane strain in those standard test methods. Thus, if the samples are fabricated specifically, it does not reflect the actual service s

10、teels and have no practical meaning unless the samples are fabricated in the service steels. Moreover, the processes and the microstructure of the special thick samples and of the service steel are different. Therefore, the search of the pipeline steel in the fracture toughness on condition of out-o

11、f-plane strain is of great importance for developing as well as evaluating and predicting the duration span of the products produced by different corporations.In the present study, we have carried out the relevant tests by using four kinds of casing pipes (APIX70,APIX80,APIX100 and 4145 drill collar

12、 steel). The parameters of plane-strain fracture toughness KIC and J-integral are measured by three-point-bending tests. We have found the appropriate methods to evaluate the fracture toughness of the high-grade pipeline steel with different thickness. Through the observation of the fracture morphol

13、ogy of the specimen, we have analyzed the experimental results in the microscope scale.The results show that Standard test method for plane-strain fracture toughness of metallic materials (GB 4161-84) and Metallic materials-Standard test method for JIC (GB 2038-91) are not appropriate for APIX70 and

14、 APIX80. The main reason lies in the fact that the specimen can not meet the condition of the plane strain due to the existence of plane stress layer. On the other hand, the effective JIC can be tested on the X100 steel. Through theIIIPDF 文件使用 pdfFactory Pro 试用版本创建西安交通大学硕士学位论文further analysis, it is

15、 observed that the integration plastic item of J-integral(Jp) is proportion to the crack stable extension (). The result indicates that the method by separating elastic term J-integral (Je) and the plastic term J-integral (Jp) in dealing with the problems is much safer and more stable when compared

16、with those specimen tested by utilizing the standard test method. Therefore, this method can be used to evaluate the fracture toughness of the plastic material.In order to remove the plane-stress shear lip and strengthen the degree plane-strain，side-cut three-point-bending method is designed to test

17、ify the specimen. It is discovered that although this method can not get the expectable brittle fracture curve, it preserves the characteristic of plane-strain fracture morphology. It is concluded that side-cut three-point-bending method can be used as a new testing solution for evaluating fracture

18、toughness.KEY WORDS: Pipeline steel; Fracture toughness; Test method; Side-cut three-point-bendingspecimenTYPE OF THESIS: Application FoundationIVPDF 文件使用 pdfFactory Pro 试用版本创建目 录目 录1 绪论.11.1 断裂韧性概述.11.1.1 关于断裂韧性KIC.21.1.2 弹塑性断裂力学：J积分理论.21.1.3 裂纹尖端张开位移（CTOD）.41.1.4 裂纹尖端张开角，Crack Tip Opening Angle（简称

19、CTOA）.41.2 断裂韧性的测试方法研究现状.51.2.1 平面应变断裂韧性KIC的测试.51.2.2 金属材料延性断裂韧度JC测试.81.2.3 CTOA试验方法.91.3 各种断裂韧性参量间的相互关系.101.4 本课题的研究意义.111.5 本课题的主要研究内容.111.6 研究路线.112 试验程序.132.1 试验材料.132.1.1 X70钢.132.1.2 X80钢.132.1.3 X100钢.142.1.4 钻挺钢.152.2 K值三点弯曲试样测试.152.2.1 试验步骤.162.3 J值三点弯曲试样测试试验.172.3.1 试验步骤.173 试验结果.193.1 X70

20、钢.193.1.1 K值三点弯曲试样测试试验结果.193.1.2 J值三点弯曲试样测试试验结果.193.2 X80钢.213.2.1 K值三点弯曲试样测试试验结果.213.2.2 J值三点弯曲试样测试试验结果.223.3 X100钢.24 VPDF 文件使用 pdfFactory Pro 试用版本创建西安交通大学硕士学位论文3.3.1 K值三点弯曲试样测试试验结果.243.3.2 J值三点弯曲试样测试试验结果.243.4 钻挺钢.263.4.1 K值三点弯曲试样测试试验结果.264 分析讨论.284.1 断裂韧性KIC分析.284.2 积分塑性能 Jp与的关系.284.3 Jp和Je分开处理法

21、.314.4 K试样的能量积分处理方法.324.5 试样断口特征分析.344.5.1 X70钢断口.354.5.2 X80钢断口.374.5.3 X100钢断口.384.5.4 4145H钻挺钢断口.384.6 本章小结.395 侧切法断裂韧性测试研究.415.1 前言.415.1.1 产生大试样的理论背景.415.1.2 大试样的不合理性.415.1.3 引用侧切小试样的意义.425.1.4 侧切三点弯曲试样的原理.435.2 测试方法.445.2.1 试验步骤.445.2.2 数据处理方法.445.3 试验结果及分析.445.3.1 试验结果.445.3.2 结果分析.465.4 本章小结

22、.486 结论与展望.496.1 结论.496.2 展望.49参考文献.50致 谢.53攻读学位期间取得的研究成果.54 声VIPDF 文件使用 pdfFactory Pro 试用版本创建CONTENTSCONTENTS1 Preface.11.1 The summary of the fracture toughness.11.1.1 On the fracture toughnessKIC.21.1.2 Elastic-plastic fracture mechanics：J-integral theory.21.1.3 Crack Tip Opening Displacement（CTO

23、D）.41.1.4 Crack Tip Opening Angle（CTOA）.41.2 Status quo of testing methods of fracture toughness.51.2.1 The testing of plane strain fracture foughness KIC.51.2.2 The testing of ductile fracture toughness on metal materialsJIC.81.2.3 The method of test by CTOA.91.3 The relationship between fracture t

24、oughness parameters.101.4 Research significance of The topic.111.5 The main research content.111.6 The research route.112 Testing procedures.132.1 Materials for test.132.1.1 X70 pipeline.132.1.2 X80 pipeline.132.1.3 X100 pipeline.142.1.4 drill collar steel.152.2 Test K With Three-point bending speci

25、men.152.2.1 Testing procedures.162.3 Test J-integral with three-point bending specimen.172.3.1 Testing procedures.173 Test results.193.1 Test results of X70 pipeline.193.1.1 The K Test results of Three-point bending specimen.193.1.2 The J-integral Test results of three-point bending specimen.193.2 T

26、est results of X80 pipeline.213.2.1 The K Test results of Three-point bending specimen.213.2.2 The J-integral Test results of three-point bending specimen.223.3 Test results of X100 pipeline.243.3.1 The K Test results of three-point bending specimen.24VIIPDF 文件使用 pdfFactory Pro 试用版本创建 西安交通大学硕士学位论文3.3.2 The J-integral test results of three-point bending specimen.243.4 Test results of drill collar steel.263.4.1 The K Test results of three-point bending specimen.264 Discussion and analysis.284.1 The analysis of