1、Designation: E2192 13Standard Guide forPlanar Flaw Height Sizing by Ultrasonics1This standard is issued under the fixed designation E2192; 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 paren
2、theses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This guide provides tutorial information and a descrip-tion of the principles and ultrasonic examination techniques formeasuring the height of planar
3、 flaws which are open to thesurface. The practices and technology described in this stan-dard guide are intended as a reference to be used whenselecting a specific ultrasonic flaw sizing technique as well asestablishing a means for instrument standardization.21.2 This standard guide does not provide
4、 or suggest accu-racy or tolerances of the techniques described. Parameters suchas search units, examination surface conditions, materialcomposition, etc. can all have a bearing on the accuracy ofresults. It is recommended that users assess accuracy andtolerances applicable for each application.1.3
5、This guide does not purport to provide instruction tomeasure flaw length.1.4 This standard guide does not provide, suggest, orspecify acceptance standards. After flaw-sizing evaluation hasbeen made, the results should be applied to an appropriate codeor standard that specifies acceptance criteria.1.
6、5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.6 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
7、-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:3E1316 Terminology for Nondestructive ExaminationsE543 Specification for Agencies Performing NondestructiveTesting2.2 ASNT Standards4SNT-TC-1A Person
8、nel Qualification and Certification inNondestructive TestingANSI/ASNT-CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing Personnel2.3 AIA Standards5NAS-410 Nondestructive Testing Personnel Qualificationand Certification3. Terminology3.1 DefinitionsRelated terminology is d
9、efined in Termi-nology E1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 corner reflectionthe reflected ultrasonic energy re-sulting from the interaction of ultrasound with the intersectionof a flaw and the component surface at essentially 90 degrees.3.2.2 doublettwo ultrasonic signals
10、that appear on thescreen simultaneously and move in unison as search unit ismanipulated toward and away from the flaw. During tip-diffraction flaw sizing, the flaw tip signal and flaw base signal(corner reflector) will appear as a doublet.3.2.3 far-surfacethe surface of the examination pieceopposite
11、 the surface on which the search unit is placed. (Forexample, when examining pipe from the outside surface thefar-surface would be the inside pipe surface).3.2.4 focusthe term as used in this document applies todual crossed-beam search units that have been manufactured sothat they have a maximum sen
12、sitivity at a predetermined depthor sound path in the component. Focusing effect may beobtained with the use of dual-element search units having bothrefracted and roof angles applied to each element.3.2.5 near-surfacethe surface of the examination piece onwhich the search unit is placed. (For exampl
13、e, when examiningpipe from the outside surface the near-surface would be theoutside pipe surface).1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.06 on UltrasonicMethod.Current edition approved June 1, 2013.
14、Published June 2013. Originallyapproved in 2002. Last previous edition approved in 2008 as E2192 - 08. DOI:10.1520/E2192-13.2This Standard Guide is adapted from material supplied toASTM SubcommitteeE07.06 by the Electric Power Research Institute (EPRI).3For referenced ASTM standards, visit the ASTM
15、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 ASTM website.4Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columb
16、us, OH 43228-0518, http:/www.asnt.org5Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700, Arlington, VA22209-3928, http:/www.aia-aerospace.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Har
17、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.6 sizingmeasurement of the through-wall height ordepth dimension of a discontinuity or flaw.3.2.7 30-70-70term that is applied to the technique (andsometimes the search unit) using an incident angle thatproduces a nominal 70
18、 L wave in the examination piece.Provided that a parallel far-surface exists, the 30 shear wave,produced simultaneously at the near surface, reflects as a 30shear wave and generates a nominal 70 L wave as a result ofmode conversion off the far-surface. The 70 L wave reflectsoff a planar flaw and is
19、received by the search unit as a 70 Lwave.4. Summary of Guide4.1 This guide describes methods for the following flawsizing techniques.4.1.1 Far-surface creeping wave or mode conversionmethod,4.1.2 Flaw-tip-diffraction method,4.1.3 Dual element bi-modal method, and4.1.4 Dual element, (focused) longit
20、udinal wave or dualelement, (focused) shear wave methods.4.2 In this guide, ultrasonic sound paths are generallyshown diagrammatically by single lines in one plane thatrepresent the center of the ultrasonic energy.4.3 Additional information on flaw sizing techniques maybe found in the references lis
21、ted in the Bibliography section.5. Significance and Use5.1 The practices referenced in this document are applicableto measuring the height of planar flaws open to the surface thatoriginate on the far-surface or near-surface of the component.These practices are applicable to through-wall sizing of me
22、-chanical or thermal fatigue flaws, stress corrosion flaws, or anyother surface-connected planar flaws.5.2 The techniques outlined describe proven ultrasonic flawsizing practices and their associated limitations, using refractedlongitudinal wave and shear wave techniques as applied toferritic or aus
23、tenitic components. Other materials may beexamined using this guide with appropriate standardizationreference blocks. The practices described are applicable to bothmanual and automated examinations.5.3 The techniques recommended in this standard guide useTime of Flight (TOF) or Delta Time of Flight
24、(TOF) methodsto accurately measure the flaw size. This guide does not includethe use of signal amplitude methods to determine flaw size.5.4 Generally, with these sizing methods the volume ofmaterial (or component thickness) to be sized is divided intothirds; the inner13, the middle13 and the near13.
25、 Using thefar-surface Creeping Wave Method the user can qualitativelysegregate the flaw into the approximate13 zone.5.5 The sizing methods are used in13 zones to quantita-tively size the crack, that is, Tip-diffraction for the far13,Bi-Modal method for the middle13, and the Focused Longi-tudinal Wav
26、e or Focused Shear Wave Methods for the near13. These13 zones are generally applicable to most sizingapplications, however, the various sizing methods have appli-cations outside these13 zones provided a proper referenceblock and technique is demonstrated.6. Basis of Application6.1 The following item
27、s are subject to contractual agree-ment between the parties using or referencing this standard.6.2 Personnel Qualification6.2.1 If specified in the contractual agreement, personnelperforming examinations to this standard shall be qualified inaccordance with a nationally or internationally recognized
28、NDT personnel qualification practice or standard such asANSI/ASNT-CP-189, SNT-TC-1A, NAS-410, or a similardocument and certified by the employer or certifying agency,as applicable. The practice or standard used and its applicablerevision shall be identified in the contractual agreement be-tween the
29、using parties.6.3 Qualification of Nondestructive AgenciesIf specifiedin the contractual agreement, NDT agencies shall be qualifiedand evaluated as described in Specification E543. The appli-cable edition of Specification E543 shall be specified in thecontractual agreement.6.4 Procedures and Techniq
30、uesThe procedures and tech-niques to be utilized shall be as specified in the contractualagreement.6.5 Reporting Criteria/Acceptance CriteriaReporting cri-teria for the examination results are not specified in thisstandard, they shall be specified in the contractual agreement.6.6 Reexamination of Re
31、paired/Reworked ItemsReexamination of repaired/reworked items is not addressed inthis standard and if required shall be specified in the contrac-tual agreement.7. Ultrasonic Flaw Sizing Methods7.1 30-70-70 Mode Conversion or Far-surface CreepingWave MethodThe far-surface Creeping Wave or 30-70-70Mod
32、e Conversion method (as illustrated in Fig. 1) providesqualitative additional depth sizing information. This methodhas considerable potential for use when approximating flawsize, or, determining that the flaw is far-surface connected.7.1.1 Excitation of Creeping WavesThe excitation of re-fracted lon
33、gitudinal waves is always accompanied by refractedshear waves. In the vicinity of the excitation, the separationbetween these two wave modes is not significantly distinct. Atthe surface, a longitudinal wave cannot exist independently ofa shear wave because neither mode can comply with theboundary co
34、nditions for the homogeneous wave equation at thefree surface alone; consequently, the so-called headwave isformed. The headwave is always generated if a wave modewith higher velocity (the longitudinal wave) is coupled to awave mode with lower velocity (the direct shear wave) at aninterface. The lon
35、gitudinal wave continuously energizes theshear wave. It can be concluded that the longitudinal wave,which in fact “creeps” along the surface, is completely attenu-ated a short distance from the location of the excitation. (SeeFig. 2 for generation of the near-side creeping wave). With thepropagation
36、 of the near-surface creeping wave and its continu-ous conversion process at each point it reaches, the energyE2192 132converted to shear is directed into the material as shown in Fig.3. Thus, the wave front of the headwave includes the head ofthe creeping wave, direct and indirect shear waves.7.1.2
37、 Far-Surface Creeping Wave GenerationWhen theheadwave arrives at the far-surface of the component, the samewave modes will be generated which were responsible forgenerating the shear wave energy, due to the physical law ofreciprocity. Thus, the indirect shear wave and part of the directshear wave wi
38、ll convert into a far-surface creeping wave and a70-degree longitudinal wave. The far-surface creeping wavewill be extremely sensitive to small surface-breaking reflectorsand the longitudinal wave will be engulfed in a bulk longitu-dinal beam created by beam spread. Additionally, these reflec-tion m
39、echanisms are responsible for a beam offset so that thereis a maximum far-surface creeping wave sensitivity at about 5to 6 mm (0.20 to 0.24 in.) from the ideal conversion point onthe far surface. The sensitivity range of the far-surface creepingwave extends from approximately 2 to 13 mm (0.080 to 0.
40、52in.) in front of the index point. The far-surface creeping wave,as reflected from the base of a far-surface notch or flaw, willconvert its energy into a headwave since the same principlesapply as established earlier for the near-surface creeping wave.The shear wave will continue to convert at mult
41、iple V-paths ifthe material has low attenuation and noise levels.7.1.3 Typical Echoes of the Far-Surface Creeping Wave/30-70-70 Mode Conversion TechniqueWhen the search unitapproaches a far-surface connected reflector, three differentsignals will occur in sequence: (1) 70-degree longitudinal wavedir
42、ect reflection; (2) 30-70-70 mode-converted signal; and (3)FIG. 1 Wave Generation for the Far-surface Creeping Wave/30-70-70 Mode-Conversion Search UnitFIG. 2 Near-Surface Creeping Wave Occurs for a Short Distance in Association with the Incident Longitudinal WaveFIG. 3 Generation of S-Waves (Headwa
43、ves) by an L-Wave with Grazing IncidenceE2192 133A far-surface creeping wave signal, as a result of modeconversion of the indirect shear wave.7.1.3.1 Direct Longitudinal Wave SignalIf the flaw ex-tends to within approximately 10 to 16 mm (0.375 to 0.625 in.)of the scanning surface (near surface), th
44、e direct longitudinalwave will reflect from the upper extremity of the flaw face,which is very similar to the high-angle longitudinal wavesizing method discussed later.7.1.3.2 Mode Converted SignalIf the flaw exceeds aheight of 10 to 20 % of the wall thickness, an indication fromthe mode converted s
45、ignal will occur at a typical wallthickness-related position. This mode converted signal resultsfrom the headwave or direct shear wave, which mode convertsthe 70-degree longitudinal wave that impinges on the reflectorat its highest part; it is reflected as a 70-degree longitudinalwave back to the se
46、arch unit as depicted by position 1 in Fig.4. The presence of the mode-converted echo is a strongindication of a flaw with a height greater than 10 to 20 % of thewall thickness. In the case of smooth or at least open flaws,amplitude versus height function curves can give a coarseestimate of flaw hei
47、ght.7.1.3.3 Far-Surface Creeping Wave SignalIf a far-surfaceconnected reflector is within the range of sensitivity (asdescribed above), the far-surface creeping wave will be re-flected and mode converted into the headwave or shear wavedirected to the search unit (Fig. 5). Since the far-surfacecreepi
48、ng wave is not a surface wave, it will not interact withweld root convexity and will not produce an indication fromthe root as shown by position 1 in Fig. 6. However, if thesearch unit is moved too far toward the weld centerline, thedirect shear wave beam could result in a root signal, but thereis a
49、t least 5 mm (0.2 in.) difference in positioning as shown inFig. 6. The far-surface creeping wave signal is a clear, sharpsignal with a larger amplitude than the mode converted signal.It does not have as smooth an echo-dynamic behavior as doesthe mode converted signal, and it cannot be observed over aslong a distance as shown in Fig. 7.7.2 Tip-Diffraction MethodUltrasonic diffraction is a phe-nomenon where ultrasound tends to bend around sharp cornersor ends of an object placed in its path, as illustrated in Fig. 8.While the flaw tends to cast
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