无损检测技术

1、1无损检测技术绪论无损检测技术绪论 不改变被检对象的原有形状与使用性能对其不改变被检对象的原有形状与使用性能对其实施检测的技术称为无损检测技术实施检测的技术称为无损检测技术 1. 1. 无损检测的目的无损检测的目的 2. 2. 无损检测技术的发展无损检测技术的发展 3. 3. 无损检测方法分类无损检测方法分类 4. 4. 无损检测的依据无损检测的依据 5. 5. 不合格品的处理不合格品的处理 6. 6. 检测档案检测档案21. 1. 无损检测的目的无损检测的目的 确定被检确定被检 对象对象 是否具有是否具有“符合性符合性”质量质量质量特性的指标是否满足相应质量特性的指标是否满足相应标准、规范、

2、合同或第三方的有关规定标准、规范、合同或第三方的有关规定 3阶阶 段段 名名 称称 内内 容容1 1NDINDI 产品最终检验，以检测产品产品最终检验，以检测产品缺陷为目的缺陷为目的 2 2NDTNDT 产品生产过程的检验与控制产品生产过程的检验与控制 3 3NDENDE 对决定产品质量特性指标的对决定产品质量特性指标的因素进行分析和评价因素进行分析和评价 2. 2. 无损检测技术的发展无损检测技术的发展Inspection Testing Evaluation43.3. 无损检测方法分类无损检测方法分类 射射 线线 方方 法法声声 学学 方方 法法电电 学学 方方 法法磁磁 学学 方方 法法

3、微 波 与 介 电 方 法光 学 方 法渗渗 透透 方方 法法 渗 漏 方 法X 射射 线线 与与 射射 线线中中 子子 射射 线线 射射 线线 计计 算算 机机 层层 析析 ( ( C C T T ) )射 线 与 射 线 测 厚超超 声声 检检 测测声声 发发 射射 检检 测测声 振 检 测声声 成成 像像 与与 声声 全全 息息声声 显显 微微 镜镜涡涡 流流 检检 测测电 位 差 和 交 流 场 检 测电 流 微 扰 检 测 磁磁 粉粉 检检 测测漏漏 磁磁 场场 检检 测测B a r k h a u s e n 噪 声 检 测磁 声 发 射 检 测微 波 检 测介 电 测 量 检 测

4、目 视 检 验光 全 息 术 检 测错 位 散 斑 干 涉无损检测方法54.4. 无损检测的依据无损检测的依据 施工图样和定货合同施工图样和定货合同 相关的技术标准和规范相关的技术标准和规范 检测的工艺性文件检测的工艺性文件 65.5. 不合格品的处理不合格品的处理 报废报废 返修返修 回用回用 降低使用条件降低使用条件 76.6. 检测档案检测档案 检测记录检测记录 检验证书检验证书 检测档案检测档案 （包括施工图样、检测记录、检验（包括施工图样、检测记录、检验 单据、检测报告和检验证书等）单据、检测报告和检验证书等） 8一、（熔）焊接缺陷及其危害一、（熔）焊接缺陷及其危害1. 1. 缺陷的

5、分类缺陷的分类 2. 2. 机械加工中的常见缺陷机械加工中的常见缺陷 3. 3. （熔）焊接缺陷（熔）焊接缺陷4. 4. 缺陷的危害缺陷的危害 91. 缺陷的分类 按形态按形态 面积型缺陷面积型缺陷 体积型缺陷体积型缺陷 按位置按位置 表面缺陷表面缺陷 内部缺陷内部缺陷 按尺寸按尺寸 宏观缺陷宏观缺陷 微观缺陷微观缺陷 按性质按性质 形状与尺寸缺陷形状与尺寸缺陷 工艺性缺陷工艺性缺陷 性能缺陷（力学、性能缺陷（力学、物理或化学性能）物理或化学性能）102. 机械加工中的常见缺陷常见的机械加工缺陷 材料与加工工艺 常见的缺陷 复 合 材 料 未熔合、脱粘、粘合不良、水溶胀、柔化等 非金属材料 塑

6、 料 气孔、夹杂、分层等 陶 瓷 气孔、夹杂、裂纹等 混凝土 空洞、裂纹等 金 属 型 材 板 材 夹层、夹灰、裂纹等 管 材 裂纹、夹杂、翘皮、折叠等 棒 材 夹杂、缩孔、裂纹等 金属加工工艺 焊 接 气孔、夹杂、裂纹、未熔合、未焊透 铸 造 气孔、缩孔、裂纹、冷隔、疏松 锻 造 缩孔、偏析、疏松、夹杂、裂纹、白点 热处理裂纹、变形、脱碳、过烧、过热 11 Casting Defects12 Defects in Forged PartsFigure 14.20 Examples of defects in forged parts. (a) Labs formed by web buckl

7、ing during forging; web thickness should be increased to avoid this problem. (b) Internal defects caused by oversized billet; die cavities are filled prematurely, and the material at the center flows past the filled regions as the dies close.133. （熔）焊接缺陷GB 6417GB 6417金属熔化焊焊缝缺陷分类及说明金属熔化焊焊缝缺陷分类及说明 100

8、100 裂纹 (ISO6520编号) 微观裂纹 纵向裂纹 横向裂纹 放射状裂纹 弧坑裂纹 间断裂纹群 枝状裂纹 14Schematic illustration of various Discontinuities in Fusion Welds Source: American Welding Society.Overlap15PinholePorosityConcavityLack of PenetrationLack of FusionMismatchWormhole Porosity16Various types of cracks in butt and T joints.17183

9、.（熔）焊接缺陷 200 200 孔穴 (ISO6520编号) 气孔(球形、均布、局部密集、链状、条形、虫形、表面气孔) 缩孔(结晶缩孔、微缩孔、枝晶间微缩孔、弧坑缩孔) 19203.（熔）焊接缺陷 300 300 固体夹杂固体夹杂 (ISO6520(ISO6520编号编号) ) 夹渣夹渣 焊剂或熔剂夹渣焊剂或熔剂夹渣 氧化物夹杂氧化物夹杂 皱摺皱摺 金属夹杂金属夹杂 21Slag inclusion223.（熔）焊接缺陷 400 400 未熔合与未焊透（未熔合与未焊透（ISO6520ISO6520编号）编号） 未熔合（侧壁、层间、焊根）未熔合（侧壁、层间、焊根） Incompletefusi

10、on 未焊透未焊透23Incomplete FusionSource: American Welding Society.24Incomplete Fusion253.（熔）焊接缺陷 500500 形状缺陷形状缺陷 (ISO6520(ISO6520编号编号) ) 263.（熔）焊接缺陷 600600 其他缺陷 (ISO6520编号) 电弧擦伤 飞溅 钨飞溅 表面撕裂 磨痕 凿痕 打磨过量 定位焊缺陷 层间错位 27The low temperatures of the North Atlantic caused the steel to be brittle.These are the fir

11、st ships mass produced with welds.Fractures occurred mainly in the vicinity of stress raisers.The problem may be prevented by employing higher quality steels and improvement of the design of the ship.Liberty Ships-World War II4. 缺陷的危害 28 29焊接检验标准焊接检验标准 GB J 94 球形储罐施工及验收规范 GB J 236 现场设备、工业管道焊接工程施工及验收

12、规范 GB/T 12467-90 焊接质量保证 一般原则 GB/T 12468-90 焊接质量保证 对企业的要求 GB/T 12469-90 焊接质量保证 钢熔化焊接头的要求和缺 陷分级 ISO 5817-1992 Arc-welded joints in steel Guidance on quality levels for imperfections GB11345-89 钢焊缝手工超声波探伤方法和探伤结果的分级 GB/T 3323-2005 钢熔化焊对接接头射线照相和质量分级 30参考书目参考书目天津大学，中石化第四建设公司。焊接质量管理与检验。北京：机械工业出版社，1993 郑中兴。

13、 材料无损检测与安全评估。北京：中国标准出版社，2004李喜孟。无损检测。北京：机械工业出版社，2001Liquid Penetrant TestingTracy, Noel and Patrick, Moore O., Nondestructive Testing Handbook - Third Edition: Vol. 2, Liquid Penetrant Testing, American Society of Nondestructive Testing, Columbus, OH. (1999).Magnetic Particle TestingBetz, C.E., Prin

14、ciples of Magnetic Particle Testing, Magnaflux, Hardwood Heights, Illinois, (1997).Ultrasonic TestingBuirks, Albert S. (tech. ed.), Green Jr., Robert E. (tech. ed.), and McIntire, Paul (ed.), Nondestructive Testing Handbook, Volume 7, Ultrasonic Testing, American Society of Nondestructive Testing. C

15、olumbus, OH. (1999).Electromagnetic TestingDan, Harvey E., Eddy Current Testing Theory and Practice, (1995).Radiographic TestingRadiography in Modern Industry 4th edition. (2001). Rochester, New York: Eastman Kodak Company.Bryant, Lawrence E. (tech. ed.) and McIntire, Paul (ed.), Nondestructive Test

16、ing Handbook, Volume 3, Radiography and Radiation Testing, American Society of Nondestructive Testing, Columbus, OH. (1999)31二、二、 焊接检验的内容焊接检验的内容 32The ENDIntroduction to Nondestructive TestingOutline Introduction to NDT Overview of Six Most Common NDT Methods Selected ApplicationsThe use of noninvas

17、ive techniques to determine the integrity of a material, component or structure or quantitatively measuresome characteristic ofan object. i.e. Inspect or measure without doing harm.Definition of NDTMethods of NDTVisualLiquid PenetrantMagnetic ParticleEddy CurrentUltrasonicX-ray MicrowaveAcoustic Emi

18、ssionThermographyLaser InterferometryReplicationFlux LeakageAcoustic MicroscopyMagnetic MeasurementsTap TestingWhat are Some Uses of NDE Methods? Flaw Detection and Evaluation Leak Detection Location Determination Dimensional Measurements Structure and Microstructure Characterization Estimation of M

19、echanical and Physical Properties Stress (Strain) and Dynamic Response Measurements 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 ma

20、nufacturing processesTo verify proper processing such as heat treatingTo verify proper assemblyTo inspect for in-service damageThere are NDE application at almost any stage in the production or life cycle of a component.Six Most Common NDT Methods Visual Liquid Penetrant Magnetic Ultrasonic Eddy Cur

21、rent X-rayMost basic and common inspection method.Tools include fiberscopes, borescopes, magnifying glasses and mirrors.Robotic crawlers permit observation in hazardous or tight areas, such as air ducts, reactors, pipelines.Portable video inspection unit with zoom allows inspection of large tanks an

22、d vessels, railroad tank cars, sewer lines.Visual Inspection A liquid with high surface wetting characteristics is applied to the surface 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

23、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 process. The penetrant used is often loaded with a fluorescent dye and the inspection is done under UV light to increase test sensitivity.Liquid Penetrant Inspectio

24、nMagnetic Particle InspectionThe part is magnetized. Finely milled iron particles coated with a dye pigment are then applied to the specimen. These particles are attracted to magnetic flux leakage fields and will cluster to form an indication directly over the discontinuity. This indication can be v

25、isually detected under proper lighting conditions. Magnetic Particle Crack Indications RadiographyThe radiation used in radiography testing 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 r

26、adioactive source. High Electrical PotentialElectrons-+X-ray Generator or Radioactive Source Creates RadiationExposure Recording DeviceRadiation Penetrate the SampleFilm RadiographyTop view of developed film X-ray filmThe part is placed between the radiation source and a piece of film. The part will

27、 stop some of the radiation. Thicker and more dense area will stop more of the radiation. = more exposure= less exposureThe film darkness (density) will vary with the amount of radiation reaching the film through the test object.Radiographic ImagesConductive materialCoilCoils magnetic fieldEddy curr

28、entsEddy 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 thickness measurements. Here a small surface probe is scanned over the part surface i

29、n an attempt to detect a crack.High frequency sound waves are introduced into a material and they are reflected back from surfaces or flaws.Reflected sound energy is displayed versus time, and inspector can visualize a cross section of the specimen showing the depth of features that reflect sound. f

30、platecrack0246810initial pulsecrack echoback surface echoOscilloscope, or flaw detector screenUltrasonic Inspection (Pulse-Echo) Ultrasonic ImagingHigh resolution images can be produced by plotting signal strength or time-of-flight using a computer-controlled scanning system.Gray scale image produce

31、d 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 (inspected from “heads” side)Ultrasonic ImagingHigh resolution images can be produced by plotting signal strength or time-of-flight using a computer-con

32、trolled scanning system.Common Application of NDT Inspection of Raw Products Inspection Following Secondary Processing In-Services Damage InspectionInspection of Raw Products Forgings, Castings, Extrusions, etc. Machining Welding Grinding Heat treating Plating etc.Inspection Following Secondary Proc

33、essing Cracking Corrosion Erosion/Wear Heat Damage etc.Inspection For In-Service DamagePower Plant InspectionProbeSignals produced by various amounts of corrosion thinning.Periodically, power plants are shutdown for inspection. Inspectors feed eddy current probes into heat exchanger tubes to check f

34、or corrosion damage.Pipe with damageWire Rope InspectionElectromagnetic devices and visual inspections are used to find broken wires and other damage to the wire rope that is used in chairlifts, cranes and other lifting devices. Storage Tank InspectionRobotic crawlers use ultrasound to inspect the w

35、alls 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. Aircraft Inspection Nondestructive testing is used extensively during the manufacturing of aircraft. NDT is also used to find cracks and

36、 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 engines are overhauled after being in service for a period of time. They are completely disassembled, cleaned, inspected and then reassemb

37、led. 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 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 testing.Rail InspectionSpecial cars are used to inspect thousands of miles of rail to find cracks that could l