1、Designation: E587 10Standard Practice forUltrasonic Angle-Beam Contact Testing1This standard is issued under the fixed designation E587; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parenth
2、eses indicates the year of last reapproval. Asuperscript epsilon () 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 ofangular incident ultrasonic vibrations.
3、1.2 This practice shall be applicable to development of anexamination procedure agreed upon by the users of thepractice.1.3 The values stated in inch-pound units are regarded asstandard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand
4、 are not considered standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations
5、 prior to use.2. Referenced Documents2.1 ASTM Standards:2E114 Practice for Ultrasonic Pulse-Echo Straight-BeamContact TestingE317 Practice for Evaluating Performance Characteristicsof Ultrasonic Pulse-Echo Testing Instruments and Systemswithout the Use of Electronic Measurement InstrumentsE543 Speci
6、fication for Agencies Performing Nondestruc-tive TestingE1316 Terminology for Nondestructive Examinations2.2 ASNT Documents:3SNT-TC-1A Recommended Practice for NondestructiveTesting Personnel Qualification and CertificationANSI/ASNT CP-189 Standard for Qualification and Certi-fication of Nondestruct
7、ive Testing Personnel2.3 Military Standards:4MIL-STD-410 Nondestructive Testing Personnel Qualifica-tion and Certification2.4 Aerospace Industries Association Document:5NAS 410 Certification and Qualification of NondestructiveTesting Personnel3. Terminology3.1 DefinitionsFor definitions of terms use
8、d in this prac-tice, see Terminology E1316.4. Significance and Use4.1 An electrical pulse is applied to a piezoelectric trans-ducer which converts electrical to mechanical energy. In theangle-beam search unit, the piezoelectric element is generallya thickness expander which creates compressions and
9、rarefac-tions. This longitudinal (compressional) wave travels through awedge (generally a plastic). The angle between transducer faceand the examination face of the wedge is equal to the anglebetween the normal (perpendicular) to the examination surfaceand the incident beam. Fig. 1 shows the inciden
10、t 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 travel in thematerial. As shown in Fig. 2, the angle in the material(measured from the normal to the examination surface) andmode of
11、 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 than afew wavelengths, the waves traveling in the material may belongitudinal and shear, shear alone, shear and Rayleigh, orRayleigh al
12、one. 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 traveling inthe material may propagate in different Lamb wave modes.4.3 All ultrasonic modes of vibration may be used forangle-beam examinat
13、ion of material. The material forms and1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.06 onUltrasonic Method.Current edition approved June 1, 2010. Published July 2010. Originally approvedin 1976. Last pr
14、evious edition approved in 2005 as E587 - 00(2005). DOI:10.1520/E0587-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe A
15、STM website.3Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.d
16、aps.dla.mil.5Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the probable flaw
17、locations and orientations determine selec-tion of beam directions and modes of vibration. The use ofangle beams and the selection of the proper wave modepresuppose a knowledge of the geometry of the object; theprobable location, size, orientation, and reflectivity of theexpected flaws; and the laws
18、 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 ultrasonics. Austenitic ma
19、terial, 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. Whenexamining materials
20、 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 shown in Fig.4, angle-
21、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 a crossed-beamdual-t
22、ransducer 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 examination surface,provide
23、 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 amplitudeangle beams of appro
24、ximately 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)Angle-beam shear waves in
25、 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 isnormal to the plane of the
26、 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) can be detected by
27、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, incompletefusion (as shown in Fig.
28、 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 ontheir orientation. A
29、ngle-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 WavesSurface-beam Ra
30、y-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 energy, one half of theen
31、ergy 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 velocity divided by fre-q
32、uency.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 various numbers of layersan
33、d 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 evennumber of elliptic
34、al 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-tions are best detected
35、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 of vibrational mode j
36、ust as a lamination causes a modeFIG. 1 RefractionE587 102change. 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 itemsrequire agreement betwe
37、en 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 practice or standardsuch as ANS
38、I/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 1MIL STD-410 is canceled and
39、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 BeamsE587 1035.1.2 Qualification o
40、f Nondestructive AgenciesIf speci-fied in the contractual agreement, NDT agencies shall bequalified and evaluated as described in Specification E543. Theapplicable edition of Specification E543 shall be specified inthe contractual agreement.5.2 For material with unique microstructures as described i
41、n4.3, 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 displayinghigh-frequency electrical pulse
42、s.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 fitted with wedges in order totr
43、ansmit 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 from the search unit into th
44、e 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 couplant used in standardizatio
45、n 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 CracksE587 104examination. The standardization and examination surfacetemperatures should be within 625F (14C) to avoi
46、d 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-viscosity couplant. The temperature of
47、 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, intermittent contact of thesearch u
48、nit 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 based on inorganic salts orthermopl
49、astic 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 roughness 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 the
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