1、Designation: E114 10Standard Practice forUltrasonic Pulse-Echo Straight-Beam Contact Testing1This standard is issued under the fixed designation E114; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This practice2covers ultrasonic examination of materi-al
3、s by the pulse-echo method using straight-beam longitudinalwaves introduced by direct contact of the search unit with thematerial being examined.1.2 This practice shall be applicable to development of anexamination procedure agreed upon by the users of thedocument.1.3 The values stated in inch-pound
4、 units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand 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 therespo
5、nsibility of the 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:3E317 Practice for Evaluating Performance Characteristicsof Ultrasonic Pulse-Echo Testing Ins
6、truments and Systemswithout the Use of Electronic Measurement InstrumentsE543 Specification for Agencies Performing Nondestruc-tive TestingE1316 Terminology for Nondestructive Examinations2.2 ASNT Standards:4SNT-TC-1A Recommended Practice for Personnel Qualifi-cation and Certification in Nondestruct
7、ive TestingANSI/ASNT CP-189 ASNT Standard for Qualification andCertification of Nondestructive Testing Personnel2.3 Other Documents:NAS-410 Certification and Qualification of NondestructiveTest Personnel53. Terminology3.1 Refer to Terminology E1316 for definitions of termsused in this practice.4. Ba
8、sis of Application4.1 Purchaser-Supplier Agreements:The following items require agreement between the usingparties for this practice to be used effectively:4.1.1 Qualification of Nondestructive Testing AgenciesAgreement is required as to whether the nondestructive testingagency, as defined in Specif
9、ication E543 must be formallyevaluated and qualified to perform the examination. If suchevaluation and qualification is specified, a documented proce-dure such as Specification E543 shall be used as the basis forevaluation.4.1.2 Personnel QualificationNondestructive testing(NDT) personnel shall be q
10、ualified in accordance with anationally recognized NDT personnel qualification practice orstandard such asANSI/ASNT CP-189, SNT-TC-1A, NAS-410,or a similar document. The practice or standard used and itsapplicable revision shall be specified in the contractual agree-ment between the using parties.4.
11、1.3 Extent of ExaminationThe extent of the examina-tion shall be determined by agreement of the using parties.4.1.4 Time of ExaminationThe time of examination shallbe determined by agreement of the using parties.4.1.5 Interpretation CriteriaThe criteria by which theultrasonic signals and part accept
12、ability will be evaluated andshall be determined by agreement of the using parties.5. Significance and Use5.1 This practice employs the use of normal-incident, orstraight beam, longitudinal wave ultrasound for the detectionand evaluation of discontinuities in materials requiring volu-metric examinat
13、ion.1This 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 15, 2010. Published July 2010. Originallyapproved in 1955. Last previous edition approved in 2005 as
14、 E114 - 95 (2005). DOI:10.1520/E0114-10.2For ASME Boiler and Pressure Vessel Code applications see related PracticeSE-114 in Section II of that Code.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStanda
15、rds 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., Columbus, OH 43228-0518, http:/www.asnt.org.5Available from Aerospace Industries Association of America, Inc.
16、(AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 Although not all requireme
17、nts of this practice can beapplied universally to all inspection situations and materials, itdoes provide the basis for establishing contractual criteriabetween suppliers and purchasers of materials for performingcontact longitudinal wave pulse-echo examination and may beused as a guide for writing
18、detailed procedures for particularapplications.5.3 Types of information that may be obtained from thepulsed-echo straight-beam practice are as follows:5.3.1 Apparent discontinuity size (see Note 1) by compari-son of the signal amplitudes from the test piece to theamplitudes obtained from a reference
19、 standard.5.3.2 Depth location of discontinuities by calibrating thehorizontal scale of the A-scan display.5.3.3 Material properties as indicated by the relative soundattenuation or velocity changes of compared items.5.3.4 The extent of bond and unbond (or fusion and lack offusion) between two ultra
20、sonic conducting materials if geom-etry and materials permit.NOTE 1The term “apparent” is emphasized since true size depends onorientation, composition, and geometry of the discontinuity and equip-ment limitations.6. Apparatus6.1 Complete ultrasonic apparatus shall include the follow-ing:6.1.1 Instr
21、umentationThe ultrasonic instrument shall becapable of generating, receiving, and amplifying high-frequency electrical pulses at such frequencies and energylevels required to perform a meaningful examination and toprovide a suitable readout.6.1.2 Search UnitsThe ultrasonic search units shall becapab
22、le of transmitting and receiving ultrasound in the materialat the required frequencies and energy levels necessary fordiscontinuity detection. Typical search unit sizes usually rangefrom18 in. 3.2 mm in diameter to 118 in. 28.6 mm indiameter with both smaller and larger sizes available forspecific a
23、pplications. Search units may be fitted with specialshoes for appropriate applications. Special search units encom-passing both a transmitter and a receiver as separate piezoelec-tric elements can be utilized to provide some degree ofimproved resolution near the examination surface.6.1.3 CouplantAco
24、uplant, usually a liquid or semi-liquid,is required between the face of the search unit and theexamination surface to permit or improve the transmittance ofultrasound from the search unit into the material under test.Typical couplants include water, cellulose gel, oil, and grease.Corrosion inhibitor
25、s or wetting agents or both may be used.Couplants must be selected that are not detrimental to theproduct or the process. The couplant used in standardizationshould be used for the examination. During the performance ofa contact ultrasonic examination, the couplant layer betweensearch unit and exami
26、nation material must be maintained suchthat the contact area is held constant while maintainingadequate couplant thickness. Lack of couplant reducing theeffective contact area or excess couplant thickness will reducethe amount of energy transferred between the search unit andthe examination piece. T
27、hese couplant variations in turn resultin examination sensitivity variations.6.1.3.1 The couplant should be selected so that its viscosityis appropriate for the surface finish of the material to beexamined. The examination of rough surfaces generally re-quires a high-viscosity couplant. The temperat
28、ure 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 as conditions warrant,heat-resistant coupling materials such as silicone oils, gels, orgreases should be used. Further, intermittent contact of t
29、hesearch unit with the surface or auxiliary cooling of the searchunit may be necessary to avoid temperature changes that affectthe ultrasonic wave characteristics of the search unit. At highertemperatures, certain couplants based on inorganic salts orthermoplastic organic materials, high-temperature
30、 delay mate-rials, and search units 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 couplants such as liquid gapcoupling will usually provid
31、e a better examination. In this case,the search unit does not contact the examination surface but isseparated by a distance of about 0.2 in. 0.5 mm filled withcouplant. Liquid flowing through the search unit fills the gap.The flowing liquid provides the coupling path and has theadditional advantage
32、of cooling the search unit if the exami-nation surface is hot.6.1.3.4 An alternative means of direct contact coupling isprovided by the wheel search unit. The search unit is mountedat the required angle to a stationary axle about which rotates aliquid-filled flexible tire. A minimum amount of coupla
33、ntprovides ultrasonic transmission into the examination surfacesince the elastic tire material is in rolling contact and conformsclosely to the surface.6.1.4 Reference StandardsThe production item itself maybe an adequate standard using the height of the back wall echofor reference. For more quantit
34、ative information, machinedartificial reflectors (discontinuities) or charts representingdistance-amplitude relationships of known reflector sizes for aparticular search unit and material may be used for standard-ization. These artificial reflectors may be in the form offlat-bottom holes, side-drill
35、ed holes, or slots. An alternatemethod of fabricating a reference standard may be the intro-duction of known discontinuities during the fabrication processof a production item or other convenient configuration. TheTABLE 1 Suggested ViscositiesOil CouplantsNOTE 1The table is a guide only and is not m
36、eant to exclude the useof a particular couplant that is found to work satisfactorily on a particularsurface.Approximate Surface Roughness Average(Ra), in. mEquivalent Couplant Vis-cosity, Weight Motor Oil5100 0.12.5 SAE 1050200 1.35.1 SAE 20100400 2.510.2 SAE 30250700 6.417.8 SAE 40Over 700 18 cup g
37、reaseE114 102surface finish of the reference standard should be similar to thesurface finish of the production item (or corrected; see 7.3).The reference standard material and the production materialshould be acoustically similar (in velocity and attenuation).The reference standard selected shall be
38、 used by the examineras the basis for signal comparisons.7. Standardization of Apparatus7.1 If quantitative information is to be obtained, vertical orhorizontal linearity or both should be checked in accordancewith Practice E317 or another procedure approved by the usersof the document. An acceptabl
39、e linearity performance may beagreed upon by the users of the document.7.2 Prior to examination, standardize the system in accor-dance with the product specification.7.3 Where the surface finishes of the reference standard andthe production item do not match, or where there is an acousticdifference
40、between the standard and the production item, anattenuation correction should be made to compensate for thedifference. The attenuation correction is accomplished bynoting the difference between signals received from the samereference reflector (that is, back reflection) in the basic stan-dardization
41、 (reference) block and in the production material,and correcting for this difference.7.4 It should be recognized that near-field effects may causesensitivity inconsistencies when searching for discontinuitiessmaller than the effective beam diameter. Suitable delay linesearch units or other means suc
42、h as examining from both sidesof the item may be considered where the application warrantsfine scrutiny. When performing examinations in the far-field, itis recommended that compensation be made for the acousticattenuation of the test material with respect to a certainreference standard. This compen
43、sation may be accomplishedwith multiple depth reference reflectors, electronically, withattenuation curves drawn on the face of the A-scan display, orwith charts for distance-amplitude relationships of knownreflectors. For optimum examination performance, compensa-tions should be made for both near
44、and far-field effects.7.5 Unless otherwise specified, the initial pulse and at leastone back reflection shall appear on the A-scan display whileexamining for discontinuities in materials having parallelsurfaces. The total number of back reflections depends uponequipment, geometry and material type,
45、information desired, oroperator preference. Reduction of the back reflection duringscanning is indicative of increased attenuation or sound scat-tering discontinuities provided that front and back surfaceroughness and parallelism of the production piece are approxi-mately the same as that of the sta
46、ndard. For non-parallelsurfaces, the time trace of the display shall be standardized byusing standards that include the maximum thickness of theproduction item being examined.7.6 For bond/unbond (fusion/lack of fusion) examinations, areference standard should be used similar to the productionitem be
47、ing examined containing areas representing bothbonded (fused) and unbonded (lack of fusion) conditions, ifgeometry and material permit.7.7 Standardization with respect to reference standardsshould be periodically checked to ensure that the ultrasonicsystem standardization is not changing. As a minim
48、um, thestandardization shall be checked each time there is a change ofoperators, when search units are changed, when new batteriesare installed, when equipment operating from one powersource is changed to another power source, or when improperoperation is suspected.8. Procedure8.1 When ultrasonic ex
49、aminations are performed for thedetection or sizing of discontinuities, or both, reflectors notperpendicular to the ultrasonic beam may be detected atreduced amplitudes, with a distorted envelope depending uponthe reflector area, whether it is curved or planar, whether it issmooth or rough, perhaps with reflecting facets. Reflectorcharacteristics may also cause rapid shifts in apparent depth asthe search unit approaches or moves away from the lowamplitude indication. Another effect of these reflectors is theloss of back reflection which o
