无损检测简介

1、无损检测技术无损检测技术Nondestructive Testing大连交通大学机械工程学院大连交通大学机械工程学院 丁彦闯丁彦闯 课程基本情况课程基本情况l课程面向：课程面向： 高等学校无损检测、测控技术、应用物理、材料高等学校无损检测、测控技术、应用物理、材料加工、机械制造等相关专业本科学生加工、机械制造等相关专业本科学生l学时：授课学时：授课4848学时学时l学分：学分：3 3学分学分l学生先修课程：高等数学、大学物理、大学化学学生先修课程：高等数学、大学物理、大学化学、金属材料及金属加工工艺基础、电工与电子技、金属材料及金属加工工艺基础、电工与电子技术、微机原理及应用术、微机原理及应用

2、课程内容课程内容内容如下内容如下教学目的与要求教学目的与要求l掌握掌握X X射线照相法检测原理、方法、设备及射线照相法检测原理、方法、设备及应用应用l掌握超声波检测原理、方法、设备及应用掌握超声波检测原理、方法、设备及应用l掌握磁粉检测原理、方法、设备及应用掌握磁粉检测原理、方法、设备及应用l掌握渗透检测原理、方法、设备及应用掌握渗透检测原理、方法、设备及应用l了解无损检测新技术及发展了解无损检测新技术及发展考核评定方式考核评定方式l闭卷考试（填空、简答、选择、计算题、闭卷考试（填空、简答、选择、计算题、设计分析等题型），考试成绩占总评成绩设计分析等题型），考试成绩占总评成绩80%80%。l平

3、时出勤、作业、实验成绩占总评成绩平时出勤、作业、实验成绩占总评成绩20%20%。教材及参考资料教材及参考资料l 教材教材 杨宝清等杨宝清等. . 无损检测技术（讲义）无损检测技术（讲义）. . 大连交通大学测控教研室大连交通大学测控教研室l 参考资料：参考资料： 刘贵民主编刘贵民主编. . 无损检测技术无损检测技术. . 北京：国防工业出版社，北京：国防工业出版社，2006.1 2006.1 中国机械工程学会无损检测分会编中国机械工程学会无损检测分会编. . 无损检测无损检测级培训教材级培训教材 射线检测射线检测（第（第3 3版）版）. .北京：机械工业出版社，北京：机械工业出版社，2004.

4、22004.2 中国机械工程学会无损检测分会编中国机械工程学会无损检测分会编. . 无损检测无损检测级培训教材级培训教材 超声波检超声波检测（第测（第2 2版）版）. .北京：机械工业出版社，北京：机械工业出版社，2004.22004.2 中国机械工程学会无损检测分会编中国机械工程学会无损检测分会编. . 无损检测无损检测级培训教材级培训教材 磁粉检测磁粉检测（第（第2 2版）版）. .北京：机械工业出版社，北京：机械工业出版社，2004.22004.2 李喜梦主编李喜梦主编. . 无损检测无损检测. . 北京：机械工业出版社，北京：机械工业出版社，2001.22001.2 www.ndt-e

5、Introduction to Nondestructive Testing无损检测简介无损检测简介大连交通大学机械学院大连交通大学机械学院 丁彦闯丁彦闯E-mail:Outline（提纲）（提纲）l什么是无损检测？什么是无损检测？(Introduction to NDT)l重要性及意义重要性及意义 l无损检测的方法无损检测的方法l典型应用典型应用(Selected Applications)l无损检测的特点无损检测的特点l国内外发展状况国内外发展状况l无损检测技术面临的问题无损检测技术面临的问题前提：不损害被检对象的使用性能前提：不损害被检对象的使用性能方法：物理原理、化学现象方法

6、：物理原理、化学现象对象：各种工程材料、零部件、结构对象：各种工程材料、零部件、结构目的：评价完整性、连续性、安全可目的：评价完整性、连续性、安全可 靠性及某些物理性能。靠性及某些物理性能。i.e. Inspect or measure without doing harm. （Nondestructive TestingNDT）什么是无损检测？什么是无损检测？“隔皮猜瓜隔皮猜瓜”无无损损“切开看瓜切开看瓜”有有损损l重要性重要性共性技术（产品质量、设备安全）共性技术（产品质量、设备安全） WTO（市场竞争、质量竞争）（市场竞争、质量竞争） 质量保证的重要手段质量保证的重要手段 制造过程的缺陷

7、排除达不到制造过程的缺陷排除达不到100 运行中产生缺陷运行中产生缺陷l 意义意义 保证材料、构件的质量性能（依据）保证材料、构件的质量性能（依据） 质量控制、改进工艺、节约原材料（手段，监测）质量控制、改进工艺、节约原材料（手段，监测） 预报预测断裂力学计算技术（经济效益）预报预测断裂力学计算技术（经济效益）无损检测的重要性及意义无损检测的重要性及意义前苏联政府把资金拨给了前苏联政府把资金拨给了9个无损检测中心，直接支持了个无损检测中心，直接支持了工业产品，特别是国防工业和航空航天领域的发展。工业产品，特别是国防工业和航空航天领域的发展。 无损检测技术反映着一个国家的工业水平无损检测技术反映

8、着一个国家的工业水平里根曾说，里根曾说，“没有无损检测技术，美国就不能享有众多领域的领先地位。没有无损检测技术，美国就不能享有众多领域的领先地位。” 美国，美国， 有近有近10个无损检测中心，个无损检测中心，100多所大学设置无损检测的课程多所大学设置无损检测的课程 日本认为，“现代工业是建立在无损检测基础之上的”德国在无损检测与评价技术方面比较先进德国在无损检测与评价技术方面比较先进 。 第一、第二汽车制造厂仅对连杆进行无损检测第一、第二汽车制造厂仅对连杆进行无损检测一项，赔偿费用比不采用前下降了一项，赔偿费用比不采用前下降了99.7%99.7%。 统计资料显示：经过无损检测后的产品的增值，

9、机统计资料显示：经过无损检测后的产品的增值，机构产品为构产品为5%5%，国防、宇航、原子能产品为，国防、宇航、原子能产品为12%-18%12%-18%，火箭为火箭为25%25%左右。德国奔驰公司汽车几千个零件经过左右。德国奔驰公司汽车几千个零件经过无损检测后，整车运行公里数提高了一倍。无损检测后，整车运行公里数提高了一倍。 以我国的锅炉和压力容器为例，据不完全统计，近十年间发生爆炸事故2254起，停炉停产重大事故20000起，造成直接经济损失45亿元，间接经济损失80100亿元，因事故而丧生约1200人，受伤约4900人。经济和社会效益显著经济和社会效益显著无损检测的方法无损检测的方法（Met

10、hods of NDT）VisualLiquid PenetrantMagnetic ParticleEddy CurrentUltrasonicX-ray MicrowaveAcoustic EmissionThermographyLaser InterferometryReplicationFlux LeakageAcoustic MicroscopyMagnetic MeasurementsTap Testing射线（射线（X、 、高能射线、中子、质子、电子）、高能射线、中子、质子、电子）声和超声（声振、声阻、声发射、超声脉冲发射、超声和超声（声振、声阻、声发射、超声脉冲发射、超声成象、

11、超声频谱、电磁超声等）声成象、超声频谱、电磁超声等）电学、电磁学（电阻、电位、涡轮、录磁、漏磁、核电学、电磁学（电阻、电位、涡轮、录磁、漏磁、核磁共振、微波等）磁共振、微波等）力学、光学（目视、内窥、荧光、着色、光弹性覆膜力学、光学（目视、内窥、荧光、着色、光弹性覆膜、激光全息等）、激光全息等）热力学（热电势、液晶、红外等）热力学（热电势、液晶、红外等）化学分析（电解、俄歇电子分析、穆斯鲍尔谱等）化学分析（电解、俄歇电子分析、穆斯鲍尔谱等）无损检测的方法无损检测的方法l航空航天、武航空航天、武器器l核工业、电站核工业、电站l造船、铁路造船、铁路l石油化工、锅石油化工、锅炉炉l压力容器压力容器l

12、建筑冶金、建筑冶金、l机械制造等机械制造等典型应用典型应用What are Some Uses of NDE Methods? Flaw Detection and Evaluation Leak Detection Location Determination Dimensional Measurements Structure and Microstructure Characterization Estimation of Mechanical and Physical Properties Stress (Strain) and Dynamic Response Measurement

13、s Material Sorting and Chemical Composition Determination Fluorescent penetrant indicationWhen are NDE Methods Used?To assist in product development To screen or sort incoming materialsTo monitor, improve or control manufacturing processesTo verify proper processing such as heat treatingTo verify pr

14、oper assemblyTo inspect for in-service damageThere are NDE application at almost any stage in the production or life cycle of a component.Five Most Common NDT Methods Liquid Penetrant Magnetic Ultrasonic Eddy Current X-ray A liquid with high surface wetting characteristics is applied to the surface

15、of the part and allowed time to seep into surface breaking defects. The excess liquid is removed from the surface of the part. A developer (powder) is applied to pull the trapped penetrant out the defect and spread it on the surface where it can be seen. Visual inspection is the final step in the pr

16、ocess. The penetrant used is often loaded with a fluorescent dye and the inspection is done under UV light to increase test sensitivity.Liquid Penetrant InspectionMagnetic Particle InspectionThe part is magnetized. Finely milled iron particles coated with a dye pigment are then applied to the specim

17、en. These particles are attracted to magnetic flux leakage fields and will cluster to form an indication directly over the discontinuity. This indication can be visually detected under proper lighting conditions. Magnetic Particle Crack Indications RadiographyThe radiation used in radiography testin

18、g is a higher energy (shorter wavelength) version of the electromagnetic waves that we see as visible light. The radiation can come from an X-ray generator or a radioactive source. High Electrical PotentialElectrons-+X-ray Generator or Radioactive Source Creates RadiationExposure Recording DeviceRad

19、iation Penetrate the SampleConductive materialCoilCoils magnetic fieldEddy currentsEddy currents magnetic fieldEddy Current TestingEddy Current TestingEddy current testing is particularly well suited for detecting surface cracks but can also be used to make electrical conductivity and coating thickn

20、ess measurements. Here a small surface probe is scanned over the part surface in an attempt to detect a crack.Ultrasonic ImagingGray scale image produced using the sound reflected from the front surface of the coinGray scale image produced using the sound reflected from the back surface of the coin

21、(inspected from “heads” side)High resolution images can be produced by plotting signal strength or time-of-flight using a computer-controlled scanning system.Common Application of NDT Inspection of Raw Products Inspection Following Secondary Processing In-Services Damage InspectionInspection of Raw

22、Products Forgings, Castings, Extrusions, etc. Machining Welding Grinding Heat treating Plating etc.Inspection Following Secondary Processing Cracking Corrosion Erosion/Wear Heat Damage etc.Inspection For In-Service DamagePower Plant InspectionProbeSignals produced by various amounts of corrosion thi

23、nning.Periodically, power plants are shutdown for inspection. Inspectors feed eddy current probes into heat exchanger tubes to check for corrosion damage.Pipe with damageWire Rope InspectionElectromagnetic devices and visual inspections are used to find broken wires and other damage to the wire rope

24、 that is used in chairlifts, cranes and other lifting devices. Storage Tank InspectionRobotic crawlers use ultrasound to inspect the walls of large above ground tanks for signs of thinning due to corrosion.Cameras on long articulating arms are used to inspect underground storage tanks for damage. Ai

25、rcraft Inspection Nondestructive testing is used extensively during the manufacturing of aircraft. NDT is also used to find cracks and corrosion damage during operation of the aircraft. A fatigue crack that started at the site of a lightning strike is shown below. Jet Engine Inspection Aircraft engi

26、nes are overhauled after being in service for a period of time. They are completely disassembled, cleaned, inspected and then reassembled. Fluorescent penetrant inspection is used to check many of the parts for cracking. Sioux City, Iowa, July 19, 1989A defect that went undetected in an engine disk

27、was responsible for the crash of United Flight 232. Crash of United Flight 232Pressure Vessel InspectionThe failure of a pressure vessel can result in the rapid release of a large amount of energy. To protect against this dangerous event, the tanks are inspected using radiography and ultrasonic test

28、ing.Rail InspectionSpecial cars are used to inspect thousands of miles of rail to find cracks that could lead to a derailment. Bridge Inspection The US has 578,000 highway bridges. Corrosion, cracking and other damage can all affect a bridges performance. The collapse of the Silver Bridge in 1967 re

29、sulted in loss of 47 lives. Bridges get a visual inspection about every 2 years. Some bridges are fitted with acoustic emission sensors that “listen” for sounds of cracks growing. NDT is used to inspect pipelines to prevent leaks that could damage the environment. Visual inspection, radiography and

30、electromagnetic testing are some of the NDT methods used. Remote visual inspection using a robotic crawler. Radiography of weld joints. Magnetic flux leakage inspection. This device, known as a pig, is placed in the pipeline and collects data on the condition of the pipe as it is pushed along by whatever is being transpor