无损检测概述NondestructivetestingOv

郑州铁路职业技术学院无损检测概述NondestructivetestingOverview车辆检测技术Vehicledetectiontechnology主讲人：时蕾FUNDAMENTALSOFSENSORTECHNOLOGYLecturer:ShiLei无损探伤的基本概念人们在使用各种材料（尤其是金属材料）的长期实践中，观察到大量的断裂现象，它曾给人类带来许多灾难事故，涉及舰船、飞机、轴类、压力容器、宇航器、核设备等。Inthelong-termpracticeofusingvariousmaterials(especiallymetalmaterials),alargenumberoffracturephenomenahavebeenobserved,whichhasbroughtmanydisasterstohumanbeings,involvingships,aircraft,axes,pressurevessels,spacevehicles,nuclearequipmentandsoon.路轨断裂事故Railbreakageaccident无损探伤的方法对缺陷的检测手段有破坏性试验和无损探伤。由于无损探伤以不损坏被检验对象为前提，所以得到广泛应用。Thedetectionmethodsfordefectsincludedestructivetestandnon-destructivetesting.Sincenondestructivetestingisbasedonthepremiseofnotdamagingthetestedobject,itiswidelyused无损检测的方法有磁粉检测（MT）射线检测（RT）超声波检测（UT）渗透检测（PT）涡流检测（ET）和Methodsofnon-destructivetestingareMagneticParticleDetection(MT)RadiographicInspection(RT)UltrasonicInspection(UT)PenetrationTesting(PT)EddyCurrentTesting(ET)目录CATALOGPART

01磁粉检测（MT）MagneticParticleDetection(MT)PART

02射线检测（RT）RadiographicInspection(RT)PART

03超声波检测（UT）UltrasonicInspection(UT)PART

04渗透检测（PT）PenetrationTesting(PT)PART

05涡流检测（ET）EddyCurrentTesting(ET)磁粉检测（MT）MagneticParticleDetection(MT)Part

01车辆检测技术Vehicledetectiontechnology一.磁粉检测（MT）将铁磁性材料直接通以电流或置于磁场中，使其磁化。磁力线遇到缺陷时，会绕过缺陷而产生漏磁，漏磁场将吸引磁粉，在合适的光照下形成目视可见的磁痕，从而显示出缺陷的位置、大小、形状和严重程度。Aferromagneticmaterialismagnetizedbypassinganelectriccurrentdirectlyorbyplacingitinamagneticfield.Whenthemagneticfieldlineencountersadefect,itwillbypassthedefectandproducemagneticleakage,whichwillattractmagneticpowderandformvisualmagneticmarksundertherightlight,thusshowingthelocation,size,shapeandseverityofthedefect基本原理fundamental（一）一.磁粉检测（MT）优缺点relativemerits（二）缺点

drawback只能探测铁磁性材料，不能发现内部缺陷，难于确定缺陷深度。Onlyferromagneticmaterialscanbedetected,internaldefectscannotbefound,anditisdifficulttodeterminethedepthofdefects.优点

merit灵敏度高、速度快、操作简单、费用低廉，直观显示缺陷的位置、形状和大小。Highsensitivity,fastspeed,simpleoperation,lowcost,intuitivedisplayofdefectlocation,shapeandsize.一.磁粉检测（MT）使用范围usablerange（三）磁粉检测仪磁悬液检测铸件、锻件、焊缝和机械加工零件等铁磁性材料。主要检测铁磁性材料的表面和近表面缺陷，如裂纹。Inspectferromagneticmaterialssuchascastings,forgings,weldsandmachinedparts.Itmainlydetectssurfaceandnear-surfacedefectsofferromagneticmaterials,suchascracks.Magneticparticledetectormagneticsuspension射线检测（RT）RadiographicInspection(RT)Part

02车辆检测技术Vehicledetectiontechnology二.射线检测（RT）利用射线源向工件发出射线，因工件的材料结构或缺陷的存在，使透过工件的射线强度发生不均匀变化，经照相底片感光和显影处理后，获得该工件结构和缺陷相对应的投影图像。通过对图像的观察分析，确定工件内缺陷的种类、大小和分布状况。Theraysourceisusedtoemitraystotheworkpiece.Duetotheexistenceofthematerialstructureordefectoftheworkpiece,therayintensitythroughtheworkpiecechangesunevenly.Afterthephotographicplateissensitizedanddeveloped,theprojectedimagecorrespondingtothestructureanddefectoftheworkpieceisobtained.Throughtheobservationandanalysisoftheimage,thetype,sizeanddistributionofthedefectsintheworkpiecearedetermined.基本原理fundamental（一）优缺点relativemerits（二）缺点defect检验成本高，工件厚度受限制，对人体有伤害，需考虑安全防护问题Theinspectioncostishigh,thethicknessoftheworkpieceislimited,anditisharmfultothehumanbody,andsafetyprotectionneedstobeconsidered优点merit不受工件形状限制，能永久保存，记录缺陷直观。Itisnotlimitedbytheshapeoftheworkpiece,canbepermanentlystored,andthedefectsarerecordedintuitively.二.射线检测（RT）使用范围usablerange（三）主要用于检测铸件和焊件等构件的内部缺陷，尤其是体积型缺陷，如气孔、夹渣、缩孔、疏松等，对片状缺陷检出较难。Itismainlyusedtodetecttheinternaldefectsofcastingsandweldparts,especiallythevolumedefects,suchaspores,slaginclusion,shrinkageholes,porosity,etc.,anditisdifficulttodetectsheetdefects.二.射线检测（RT）X光探伤X-raydetection计算机断层成像技术(CT)是一种重要的无损检测技术(NDT)，是物理学与计算机科学的发展产物。它是基于射线与物质的相互作用原理，通过投影重建方法获取被检测物体的数字图像，全面解决了传统x射线摄影装置的影像重叠、密度分辨率低等缺点。ComputedTomography(CT)isanimportantnondestructivetestingtechnique(NDT),whichisaproductofthedevelopmentofphysicsandcomputerscience.Itisbasedontheprincipleofinteractionbetweenraysandmatter,andobtainsthedigitalimageofthedetectedobjectthroughprojectionreconstructionmethod,whichcomprehensivelysolvestheshortcomingsoftraditionalX-rayphotographicdevicessuchasimageoverlapandlowdensityresolution.二.射线检测（RT）计算机断层成像技术(CT)探伤Computedtomography(CT)detection超声波检测（UT）UltrasonicInspection(UT)Part

03车辆检测技术Vehicledetectiontechnology基本原理fundamental（一）利用超声波入射被检工件，当超声波遇到缺陷时会全部或部分反射，反射回来的超声波被探头接收，通过仪器内部的电路处理，在仪器的荧光屏上就会显示出不同高度和有一定间距的波形。可以根据波形的变化特征，判断缺陷在工件中的深度、位置和形状。Theuseofultrasonicwaveincidenttotheworkpiecetobeexamined,whenultrasonicdefectswillbereflectedinwholeorinpart,thereflectedultrasonicwaveisreceivedbytheprobe,processedbythecircuitinsidetheinstrument,andthewaveformofdifferentheightsandacertaindistancewillbedisplayedonthefluorescentscreenoftheinstrument.Accordingtothechangingcharacteristicsofthewaveform,thedepth,positionandshapeofthedefectintheworkpiececanbejudged.三.超声波检测（UT）优缺点relativemerits（二）缺点defect显示不直观，技术难度大，容易受到外界因素影响，并且结果不便于永久保存，对工件表面要求平滑，难于对缺陷作精度定性和定量，要求工作人员经验丰富，才能辨别缺陷种类。Thedisplayisnotintuitive,thetechnicaldifficultyislarge,itiseasytobeaffectedbyexternalfactors,andtheresultsarenoteasytobepermanentlypreserved,thesurfaceoftheworkpieceissmooth,itisdifficulttomakethequalitativeandquantitativeaccuracyofthedefects,andthestaffisrequiredtobeexperiencedinordertoidentifythetypesofdefects.优点merit检测厚度大、灵敏度高、速度快、费用低廉、对人体无害，能对缺陷进行定位和定量。Thedetectionthicknessislarge,thesensitivityishigh,thespeedisfast,thecostislow,thehumanbodyisharmless,andthedefectscanbelocatedandquantified.三.超声波检测（UT）使用范围usablerange（三）适用于金属、非金属及符合材料的铸、锻、焊件与板材，主要检测工件的内部缺陷，同时也可发现工件表面的裂纹。Itissuitableformetal,non-metalandconformingmaterialscasting,forging,weldingpartsandplates,mainlydetecttheinternaldefectsoftheworkpiece,andalsofindthecracksonthesurfaceoftheworkpiece.起始波

缺陷工件缺陷反射波底波三.超声波检测（UT）滑板式探头钢轨探伤车三.超声波检测（UT）rail-defectdetectorcarSlideprobe铁路钢轨探测用的滚轴式探头（也称做轮式探头）Rollerprobe(alsocalledwheelprobe)高速钢轨探伤车High-speedrailflawdetectioncar三.超声波检测（UT）铁路钢轨探头

Railprobe三.超声波检测（UT）缺陷defect焊缝铁路钢轨探伤用滑板式探头铁路钢轨对接焊缝探测用探头ProbesfordetectingbuttweldsofrailwayrailsSlideprobeforrailwayrailflawdetectionweldseam管道环焊缝超声波检测装置PipegirthweldUltrasonictestingdevice三.超声波检测（UT）三.超声波检测（UT）管道环焊缝超声波检测装置原理Principleofultrasonictestingdeviceforpipelinegirthweld三.超声波检测（UT）超声探伤仪reflectoscope三.超声波检测（UT）构件的超声探伤Ultrasonicflawdetectionofcomponents三.超声波检测（UT）构件的超声探伤Ultrasonicflawdetectionofcomponents三.超声波检测（UT）超声探伤的计算显示器的x轴为10

s/div(格)，现测得B波与T波的距离为6格，F波与T波的距离为2格。Thexaxisofthedisplayis10s/div(grid).ThedistancebetweenBwaveandTwaveis6grids,andthedistancebetweenFwaveandTwaveis2grids.设1）t

及tF

；求：2）钢板的厚度

及缺陷与表面的距离xF

。CalculationofultrasonicflawdetectionThicknessofthesteelplate

andthedistancebetweenthedefectandthesurfacexF三.超声波检测（UT）解1）tδ=10μs/div×6div=60μs=0.06ms，

tF=10μs/div×2div=20μs=0.02ms2）查表得到纵波在钢板中的声速v=5.9×103m/s则：δ=tδ×vL/2=（0.06×10-3×5.9×103/2）m≈0.2mXF=tF×vF/2=（0.02×10-3×5.9×103/2）m≈0.1mLookupthetabletogetthesoundvelocityofp-waveinsteelplate渗透检测（PT）PenetrationTesting(PT)Part

04车辆检测技术Vehicledetectiontechnology基本原理fundamental（一）在清洗过的工件表面施加含有色泽和荧光物质的渗透剂，渗透剂渗入缺陷并留在空腔内，然后洗去表面多余的渗透剂，再涂上一层显影剂，借毛细管吸附作用，使缺陷中的渗透剂吸出。通过色泽对比或紫外线照射激发荧光物质发光，从而将缺陷的图像显现出来。Anpenetrantcontainingcolorandfluorescentsubstancesisappliedonthesurfaceofthecleanedworkpiece,andthepenetrantpenetratesintothedefectandremainsinthecavity,andthenwashesofftheexcesspenetrantonthesurface,andthencoatsalayerofdeveloper,andsucksoutthepenetrantinthedefectbycapillaryadsorption.Theimageofthedefectcanberevealedbycolorcontrastorultravioletirradiationtostimulatetheluminescenceofthefluorescentmaterial.四.渗透检测（PT）优缺点meritanddemerit（二）缺点defect只能检测表面缺陷，不能显示缺陷的深度、缺陷内部的形状和尺寸，无法或难于检查多孔材料，检测结果受表面粗糙度影响。Onlysurfacedefectscanbedetected,andthedepthofthedefect,theshapeandsizeinsidethedefectcannotbedisplayed.Itisimpossibleordifficulttocheckporousmaterials,andthedetectionresultsareaffectedbysurfaceroughness.优点merit操作简单、设备简单、投资小，效率高，对表面缺陷，一般不受试件材料种类及其外形轮廓限制。Theoperationissimple,theequipmentissimple,theinvestmentissmall,theefficiencyishigh,andthesurfacedefectsaregenerallynotlimitedbythetypeofspecimenmaterialanditscontour.四.渗透检测（PT）使用范围usablerange（三）主要用于检验有色和黑色金属的铸件、锻件、粉末冶金件以及各种陶瓷、塑料、玻璃制品的裂纹、气孔、分层等缺陷。Itismainlyusedtotestthedefectsofnonferrousandferrousmetalcastings,forgings,powdermetallurgypartsandvariousceramics,plastics,glassproductssuchascracks,pores,delaminationandsoon.汽车平衡杆缺陷-荧光渗透荧光渗透缺陷四.渗透检测（PT）Automotivebalancebardefect-fluorescentpenetrationFluorescentpermeabilitydefect涡流检测（ET）EddyCurrentTesting(ET)Part

05车辆检测技术Vehicledetectiontechnology基本原理fundamental（一）将载有交变或脉冲电流的试验线圈靠近导电工件时，在工件表面由电磁感应产生涡电流，而感生的涡电流又产生磁场，反作用到原试验线圈的磁场，形成叠加磁场。当工件内有缺陷时，涡电流因流动途径的变化，使涡电流磁场也相应变化，经试验线圈检出异常磁场的变化量，可以得到缺陷的信息。Whenthetestcoilcarryingalternatingorpulsecurrentisclosetotheconductingworkpiece,theeddycurrentisgeneratedbyelectromagneticinductiononthesurfaceoftheworkpiece,andtheinducededdycurrentgeneratesamagneticfield,whichreactstothemagneticfieldoftheoriginaltestcoiltoformasuperimposedmagneticfield.Whentherearedefectsintheworkpiece,theeddycurrentmagneticfieldchangescorrespondinglyduetothechangeofflowpath.Thedefectinformationcanbeobtainedbydetectingthecha