ASTM E587-2000(2005) Standard Practice for Ultrasonic Angle-Beam Examination by the Contact Method《用触点法作超声波斜束检验的标准规程》.pdf

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1、Designation: E 587 00 (Reapproved 2005)Standard Practice forUltrasonic Angle-Beam Examination by the Contact Method1This standard is issued under the fixed designation E 587; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、 of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers ultrasonic examination of materialsby the pulse-echo technique, using continuous coupling of

3、angular incident ultrasonic vibrations.1.2 The values stated in inch-pound units are regarded asstandard. The SI equivalents are in brackets and may beapproximate.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the

4、user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E114 Practice for Ultrasonic Pulse-Echo Straight-BeamExamination by the Contact MethodE 317 Practice for Eval

5、uating Performance Characteristicsof Ultrasonic Pulse-Echo Testing Systems Without the Useof Electronic Measurement InstrumentsE 543 Practice for Agencies Performing NondestructiveTestingE 1316 Terminology for Nondestructive Examinations2.2 ASNT Documents:3SNT-TC-1A Recommended Practice for Nondestr

6、uctiveTesting Personnel Qualification and CertificationANSI/ASNT CP-189 Standard for Qualification and Certi-fication of Nondestructive Testing Personnel2.3 Military Standards:4MIL-STD-410 Nondestructive Testing Personnel Qualifica-tion and Certification2.4 Aerospace Industries Association Document:

7、5NAS 410 Certification and Qualification of NondestructiveTesting Personnel3. Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice, see Terminology E 1316.4. Significance and Use4.1 An electrical pulse is applied to a piezoelectric trans-ducer which converts electrical to mechan

8、ical energy. In theangle-beam search unit, the piezoelectric element is generallya thickness expander which creates compressions and rarefac-tions. This longitudinal (compressional) wave travels through awedge (generally a plastic). The angle between transducer faceand the examination face of the we

9、dge is equal to the anglebetween the normal (perpendicular) to the examination surfaceand the incident beam. Fig. 1 shows the incident angle fi, andthe refracted angle fr, of the ultrasonic beam.4.2 When the examination face of the angle-beam searchunit is coupled to a material, ultrasonic waves may

10、 travel in thematerial. As shown in Fig. 2, the angle in the material(measured from the normal to the examination surface) andmode of vibration are dependent on the wedge angle, theultrasonic velocity in the wedge, and the velocity of the wavein the examined material. When the material is thicker th

11、an afew wavelengths, the waves traveling in the material may belongitudinal and shear, shear alone, shear and Rayleigh, orRayleigh alone. Total reflection may occur at the interface.(Refer to Fig. 3.) In thin materials (up to a few wavelengthsthick), the waves from the angle-beam search unit traveli

12、ng inthe material may propagate in different Lamb wave modes.4.3 All ultrasonic modes of vibration may be used forangle-beam examination of material. The material forms andthe probable flaw locations and orientations determine selec-tion of beam directions and modes of vibration. The use ofangle bea

13、ms and the selection of the proper wave modepresuppose a knowledge of the geometry of the object; theprobable location, size, orientation, and reflectivity of the1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee

14、 E07.06 onUltrasonic Method.Current edition approved January 1, 2005. Published January 2005. Originallyapproved in 1976. Last previous edition approved in 2000 as E 587 - 00.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For

15、 Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from TheAmerican Society for Nondestructive Testing (ASNT), P.O.Box 28518, 1711 Arlingate Lane, Columbus, OH 43228-0518.4Available from Standardization Documents Order Desk, B

16、ldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.5Available fromAerospace IndustriesAssociation ofAmerica, Inc., 1250 Eye St.NW, Washington D.C. 20005.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.expecte

17、d flaws; and the laws of physics governing the propa-gation of ultrasonic waves. Characteristics of the examinationsystem used and the ultrasonic properties of the material beingexamined must be known or determined. Some materials,because of unique microstructure, are difficult to examineusing ultra

18、sonics. Austenitic material, particularly weld mate-rial, is one example of this material condition. Caution shouldbe exercised when establishing examination practices for thesetype materials. While examination may be possible, sensitivitywill be inferior to that achievable on ferritic materials. Wh

19、enexamining materials with unique microstructures, empiricaltesting should be performed to assure that the examination willachieve the desired sensitivity. This may be accomplished byincorporating known reflectors in a mock up of the weld or partto be examined.4.3.1 Angle-Beam Longitudinal WavesAs s

20、hown in Fig.4, angle-beam longitudinal waves with refracted angles in therange from 1 to 40 (where coexisting angle-beam shear wavesare weak, as shown in Fig. 3) may be used to detect fatiguecracks in axles and shafts from the end by direct reflection orby corner reflection. As shown in Fig. 5, with

21、 a crossed-beamdual-transducer search unit configuration, angle-beam longitu-dinal waves may be used to measure thickness or to detectreflectors parallel to the examination surface, such as lamina-tions. As shown in Fig. 6, reflectors with a major plane at anangle up to 40 with respect to the examin

22、ation surface,provide optimum reflection to an angle-beam longitudinalwave that is normal to the plane of the reflector. Angle-beamlongitudinal waves in the range from 45 to 85 become weakeras the angle increases; at the same time, the coexistingangle-beam shear waves become stronger. Equal amplitud

23、eangle beams of approximately 55 longitudinal wave and 29shear wave will coexist in the material, as shown in Fig. 7.Confusion created by two beams traveling at different anglesand at different velocities has limited use of this range of anglebeams.4.3.2 Angle-Beam Shear Waves (Transverse Waves)Angl

24、e-beam shear waves in the range from 40 to 75 are themost used angle beams. They will detect imperfections inmaterials by corner reflection and reradiation (as shown in Fig.8) if the plane of the reflector is perpendicular to a materialsurface, and by direct reflection if the ultrasonic beam isnorma

25、l to the plane of the reflector (as shown in Fig. 9).Reflectors parallel to the examination surface (such as lamina-tions in plate, as shown in Fig. 10) can rarely be detected by anangle beam unless accompanied by another reflector; forexample, a lamination at the edge of a plate (as shown in Fig.11

26、) can be detected by corner reflection from the laminationand plate edge. Generally, laminations should be detected andevaluated by the straight-beam technique. Angle-beam shearwaves applied to weld testing will detect incomplete penetra-tion (as shown in Fig. 12) by corner reflection, incompletefus

27、ion (as shown in Fig. 13) by direct reflection (when thebeam angle is chosen to be normal to the plane of the weldpreparation), slag inclusion by cylindrical reflection (as shownin Fig. 14), porosity by spherical reflection, and cracks (asshown in Fig. 15) by direct or corner reflection, depending o

28、ntheir orientation. Angle-beam shear waves of 80 to 85 arefrequently accompanied by a Rayleigh wave traveling on thesurface. Confusion created by two beams at slightly differentangles, traveling at different velocities, has limited applicationsin this range of angle beams.4.3.3 Surface-Beam Rayleigh

29、 WavesSurface-beam Ray-leigh waves travel at 90 to the normal of the examinationsurface on the examination surface. In material greater thantwo wavelengths thick, the energy of the Rayleigh wavepenetrates to a depth of approximately one wavelength; but,due to the exponential distribution of the ener

30、gy, one half of theenergy is within one-quarter wavelength of the surface. Surfacecracks with length perpendicular to the Rayleigh wave can bedetected and their depth evaluated by changing the frequencyof the Rayleigh wave, thus changing its wavelength and depthof penetration. Wavelength equals velo

31、city divided by fre-quency.l5VfSubsurface reflectors may be detected by Rayleigh waves ifthey lie within one wavelength of the surface.4.3.4 Lamb WavesLamb waves travel at 90 to the normalof the test surface and fill thin materials with elliptical particlevibrations. These vibrations occur in variou

32、s numbers of layersand travel at velocities varying from slower than Rayleigh upto nearly longitudinal wave velocity, depending on materialthickness and examination frequency. Asymmetrical-typeLamb waves have an odd number of elliptical layers ofvibration, while symmetrical-type Lamb waves have an e

33、vennumber of elliptical layers of vibration. Lamb waves are mostuseful in materials up to five wavelengths thick (based onRayleigh wave velocity in a thick specimen of the samematerial). They will detect surface imperfections on both theexamination and opposite surfaces. Centrally located lamina-tio

34、ns are best detected with the first or second mode asym-metrical Lamb waves (one or three elliptical layers). Smallthickness changes are best detected with the third or highermode symmetrical or asymmetrical-type Lamb waves (five ormore elliptical layers). A change in plate thickness causes achange

35、of vibrational mode just as a lamination causes a modeFIG. 1 RefractionE 587 00 (2005)2change. The mode conversion is imperfect and may produceindications at the leading and the trailing edges of the lamina-tion or the thin area.5. Basis of Application5.1 Purchaser-Supplier Agreements: The following

36、 itemsrequire agreement between using parties for this practice to beused effectively:5.1.1 Personnel QualificationIf specified in the contrac-tual agreement, personnel performing examinations to thispractice shall be qualified in accordance with a nationallyrecognized NDT personnel qualification pr

37、actice or standardsuch as ANSI/ASNT-CP-189, SNT-TC-1A, MIL STD-410,NAS-410, or a similar document and certified by the employeror certifying agency, as applicable. The practice or standardused and its applicable revision shall be identified in thecontractual agreement between the using parties.NOTE

38、1MIL STD-410 is canceled and has been replaced withNAS-410, however, it may be used with agreement between contractingparties.FIG. 2 Mode of VibrationFIG. 3 Effective Angles in the Steel versus Wedge Angles in Acrylic PlasticFIG. 4 AxleFIG. 5 ThicknessFIG. 6 Angle LongitudinalFIG. 7 Coincident Beams

39、E 587 00 (2005)35.1.2 Qualification of Nondestructive AgenciesIf speci-fied in the contractual agreement, NDT agencies shall bequalified and evaluated as described in Practice E 543. Theapplicable edition of Practice E 543 shall be specified in thecontractual agreement.5.2 For material with unique m

40、icrostructures as described in4.3, a technique and procedure shall be agreed upon betweencontracting parties.6. Apparatus6.1 A complete ultrasonic system shall include the follow-ing:6.1.1 InstrumentationThe ultrasonic instrument shall becapable of generating, receiving, amplifying, and displayinghi

41、gh-frequency electrical pulses.6.1.2 Search UnitsThe ultrasonic search units shall becapable of transmitting and receiving ultrasonic waves in thematerial at frequencies and energy levels necessary for discon-tinuity detection as determined by the standardization proce-dure. The search units are fit

42、ted with wedges in order totransmit ultrasonic waves into the examination object at thedesired angle and mode of operation.6.1.3 CouplantA couplant, usually a liquid or semiliquid,is required between the face of the search unit and theexamination surface to permit the transmission of ultrasonicwaves

43、 from the search unit into the material under examina-tion. Typical couplants include glycerin, water, cellulose gel,oil, water-soluble oils, and grease. Corrosion inhibitors orwetting agents or both may be used. Couplants must beselected that are not detrimental to the product or the process.The co

44、uplant used in standardization should be used for theFIG. 8 CornerFIG. 9 Normal PlaneFIG. 10 LaminarFIG. 11 Edge LaminationFIG. 12 Incomplete PenetrationFIG. 13 Incomplete FusionFIG. 14 Slag and PorosityFIG. 15 CracksE 587 00 (2005)4examination. The standardization and examination surfacetemperature

45、s should be within 625F 14C to avoid largeattenuation and velocity differences in the wedge material.6.1.3.1 The coupling medium should be selected so that itsviscosity is appropriate for the surface finish of the material tobe examined. The examination of rough surfaces generallyrequires a high-vis

46、cosity couplant. The temperature of thematerials surface can change the couplants viscosity. As anexample, in the case of oil and greases, see Table 1.6.1.3.2 At elevated temperatures (above 125F 52C),heat-resistant coupling materials such as silicone oils, gels, orgreases should be used. Further, i

47、ntermittent contact of thesearch unit with the surface or auxiliary cooling of the searchunit may be necessary to avoid temperature changes that affectthe ultrasonic wave transmission properties of the wedgematerial or the characteristics of the transducer. At highertemperatures, certain couplants b

48、ased on inorganic salts orthermoplastic organic materials, high-temperature wedge ma-terials, and transducers that are not damaged by high tempera-tures, may be required.6.1.3.3 Where constant coupling over large areas is needed,as in automated examination, or where severe changes insurface roughnes

49、s are found, other couplings such as liquid-gap coupling will usually provide a better examination. In thiscase, the search unit face does not contact the examinationsurface but is spaced from it a distance of about 0.02 in. (0.5mm) by integral rails or a fixture. Liquid flowing through thesearch unit fills the gap. The flowing liquid provides thecoupling path and has the additional advantage of keeping thesearch unit temperature low if the examination surface is hot.6.1.3.4 An alternative means of direct contact coupling isprovided by the wheel search