1、Designation: B548 03 (Reapproved 2017)Standard Test Method forUltrasonic Inspection of Aluminum-Alloy Plate for PressureVessels1This standard is issued under the fixed designation B548; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers pulse-echo ultrasonic inspectionof aluminum-alloy plate of thickness equal to o
3、r greater than0.500 in. (12.7 mm) for use in the fabrication of pressurevessels. The ultrasonic test is employed to detect gross internaldiscontinuities oriented in a direction parallel to the rolledsurface such as cracks, ruptures, and laminations, and toprovide assurance that only plate that is fr
4、ee from rejectablediscontinuities is accepted for delivery.1.2 The inspection method and acceptance criteria includedin this standard shall be limited to plate of the followingaluminum alloys: 1060, 1100, 3003, Alclad 3003, 3004, Alclad3004, 5050, 5052, 5083, 5086, 5154, 5254, 5454, 5456, 5652,6061,
5、 and Alclad 6061.1.3 This test method applies only to ultrasonic tests usingpulsed longitudinal waves which are transmitted and receivedby a search unit containing either a single crystal or acombination of electrically interconnected multiple crystals.Ultrasonic tests employing either the through-t
6、ransmission orthe angle-beam techniques are not included.1.4 This test method shall be used when ultrasonic inspec-tion as prescribed herein is required by the contract, purchaseorder, or referenced plate specification.1.5 The values stated in inch-pound units are to be regardedas standard. The valu
7、es given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 esta
8、blish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopm
9、ent of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 The following documents of the issue in effect on dateof material purchase form a part of this specification to theextent reference
10、d herein:2.2 ASTM Standards:2E114 Practice for Ultrasonic Pulse-Echo Straight-BeamContact TestingE214 Practice for Immersed Ultrasonic Testing by the Re-flection Method Using Pulsed Longitudinal Waves (With-drawn 2007)3E317 Practice for Evaluating Performance Characteristics ofUltrasonic Pulse-Echo
11、Testing Instruments and Systemswithout the Use of Electronic Measurement Instruments2.3 Other Standards:ASNT Recommended Practice for Nondestructive TestingPersonnel Qualification and CertificationUltrasonicTesting MethodSNT-TC-1A43. Summary of Method3.1 The plate is inspected ultrasonically by scan
12、ning onerolled surface with a beam of pulsed longitudinal waves whichis oriented in a direction perpendicular to the entry surface ofthe plate. The ultrasound is transmitted into the plate either bythe direct contact, immersion, or liquid-column couplingmethod. During the scan, an indication represe
13、nting the firstback reflection is observed on the A-scan screen of the testinstrument.3.2 When the test system sensitivity level is appropriatelyadjusted, a discontinuity is detected during the scan by noting1This test method is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys
14、and is the direct responsibility of Subcommittee B07.03 onAluminum Alloy Wrought Products.Current edition approved July 1, 2017. Published July 2017. Originally approvedin 1971. Last previous edition approved in 2009 as B548 03 (2009). DOI:10.1520/B0548-03R17.2For referenced ASTM standards, visit th
15、e 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 ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available fromAm
16、erican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance wi
17、th internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1an isolated indication associated with a
18、 loss of the first backreflection indication. The apparent size of the discontinuity isdetermined by measuring the total area in the scanned entrysurface of the plate where the isolated indication and the lossof back reflection persist. The estimated discontinuity size andlocation are then compared
19、with suitable acceptance criteria.NOTE 1Additional information describing ultrasonic tests by thedirect contact method and by the immersion method is available inPractices E114 and E214.4. Significance and Use4.1 A number of factors such as the condition of the entryand back surfaces of the plate, t
20、he inclination of the ultrasonicbeam with respect to the entry surface, and the performancecharacteristics of the test system may cause either a reductionof isolated indications or a substantial loss of back reflectionand thereby could seriously impair the reliability of the testprocedure outlined i
21、n this standard.4.2 Accurate evaluations of discontinuity size also may belimited significantly by variations in beam characteristicswhich exist in most search units. For this reason, discontinuitysize as determined by the test procedure outlined in this methodis regarded as “apparent” or “estimated
22、” in recognition of thelimited quantitative value of the measurement.4.3 Because a large number of interacting variables in a testsystem can adversely influence the results of an ultrasonic test,the actual quantitative effects of detected discontinuities uponthe mechanical properties of the inspecte
23、d plate are difficult toestablish. Consequently, this ultrasonic inspection method isnot applicable as an exclusive indicator of the ultimate qualityand performance of pressure vessels but provides a reliablecontrol of plate quality to avoid failure during the formingprocess for fabrication of vesse
24、ls.5. Apparatus5.1 Test InstrumentAny electronic device that producespulsed longitudinal waves and displays ultrasonic reflectionson an A-scan indicator when used with an appropriate searchunit is satisfactory. The instrument shall provide stable, linearamplification of received pulses at a selected
25、 test frequency andshall be free from significant interface signal interference at therequired sensitivity level.5.2 Search UnitThe search unit recommended for thisstandard is the flat nonfocusing type, and contains a piezoelec-tric crystal which generates and receives longitudinal waves atthe rated
26、 frequency when connected to the test instrumentthrough a suitable coaxial cable. A dual-crystal search unitcontaining both a transmitting and a receiving crystal in onecontainer may be used provided the test instrument willaccommodate two-crystal operation and the resulting pulse-echo test is equiv
27、alent to that obtained with a search unitcontaining a single-crystal.5.2.1 The total effective area of the crystal or combinationof crystals in the search unit used for initial scanning shall notbe less than 0.4 in.2(2.6 cm2) nor greater than 3.0 in.2(19.4cm2).5.2.2 The effective diameter of the rou
28、nd search unit used toevaluate discontinuity size shall not exceed 0.75 in. (19 mm).NOTE 2For control purposes, the performance characteristics of thetest instrument and search unit may be established in accordance withprocedures outlined in Practice E317.5.3 TankFor tests by the immersion method, a
29、ny containeris satisfactory that will facilitate the accurate, stable position-ing of both the search unit and the plate to be inspected.5.4 Scanning ApparatusDuring the inspection procedure,the search unit is supported by any one of the followingdevices. The scanning apparatus shall permit measurem
30、ent ofboth the scan distance and the index distance within 60.1 in.(62 mm).5.4.1 Manipulator and BridgeWhen a manipulator is usedin tests by the immersion method, the manipulator shalladequately support a search tube containing a search unit andshall provide fine adjustment of angle within 1 in two
31、verticalplanes that are perpendicular to each other. The bridge shall beof sufficient strength to provide rigid support for the manipu-lator and shall allow smooth, accurate positioning of the searchunit. Special search unit supporting fixtures may be usedprovided they meet the requirements prescrib
32、ed for a manipu-lator and bridge.5.4.2 Liquid Coupling NozzleFor tests by the liquid-column coupling method, the nozzle is usually positionedmanually and shall be capable of containing the couplant whilerigidly supporting the search unit with its active surfaceimmersed in the couplant. The couplant
33、distance shall bemaintained so that the second couplant reflection is to the rightof the first back reflection on the instrument cathode ray tube(CRT). The couplant path shall not vary more than 614 in.(6.4 mm) during calibration, initial scanning, and discontinuityevaluation. The recommended minimu
34、m inside dimension ofthe nozzle is 1.0 in. (25 mm) greater than the maximumdimension of the crystal surface in the search unit. Provisionsalso should be included for adjustment of search unit inclina-tion within 1 in two vertical planes that are perpendicular toeach other.NOTE 3Nozzles containing ei
35、ther sealed or unsealed openings may beused for inspecting plate provided the test results obtained with eitherdevice are equivalent to those obtained by the immersion method.5.4.3 Contact Scanning UnitDuring tests by the contactmethod, the search unit usually is supported and positionedmanually on
36、the entry surface of the inspected plate. However,special fixtures for contact scanning may be employed pro-vided their use ensures conformance to the requirements in thisspecification.5.5 CouplantClean, deaerated water at room temperatureis the recommended couplant for tests either by the immersion
37、method or by the liquid-column coupling technique. Inhibitorsor wetting agents or both may be used. For tests by the contactmethod, the recommended couplant is clean, light-grade oil.NOTE 4Other coupling liquids may be employed for inspecting plateprovided their use does not adversely affect test re
38、sults.6. Personnel Requirements6.1 The testing operator performing the ultrasonic examina-tion prescribed in this standard shall be qualified and certifiedB548 03 (2017)2to at least a Level IUltrasonic Testing in accordance with theASNT Recommended Practice SNT-TC-1A.6.2 The required documentation s
39、upporting qualificationand certification of ultrasonic testing operators shall be estab-lished by the certifying agency and shall be available uponrequest by the purchaser.7. Condition of Plate7.1 The entry and back surfaces of the inspected plate shallbe sufficiently clean, smooth, and flat to main
40、tain a first backreflection amplitude greater than 50 % of the initial standard-ization amplitude while scanning an area in the plate that doesnot contain significant isolated ultrasonic discontinuities.7.2 The inspected plate shall be at room temperature duringthe test.8. Procedure8.1 Preferred Met
41、hodThe ultrasonic test may be per-formed by either the liquid column coupling, the direct contact,or the immersion methods. However, the immersion method ispreferred.8.1.1 Maintain the couplant distance so that the secondcouplant reflection is to the right of the first back reflection onthe instrume
42、nts A-scan display. The couplant path shall notvary more than 614 in. (6.4 mm) during calibration, initialscanning, and discontinuity evaluation.8.2 Test FrequencyWhen using any of the three methodslisted in 8.1, the recommended test frequency is 5.0 MHz.Other test frequencies between 2.0 MHz and 10
43、.0 MHz may beemployed when necessary to minimize possible adverse effectsof plate thickness, microstructure, and test system characteris-tics upon test results and thereby maintain a clean, easilyinterpreted A-scan screen pattern throughout the inspection.8.3 Sensitivity StandardizationStandardize t
44、he sensitivitylevel of the test system operating at the selected frequency byadjusting the instrument gain control to obtain a first backreflection amplitude of 75 6 5 % of the vertical limit exhibitedby the A-scan indicator when the search unit is positioned overan area free from significant discon
45、tinuities in the plate to beinspected. During tests by either the immersion method or theliquid column coupling method, adjust the angular alignmentof the search unit to obtain a maximum number of backreflections before the final sensitivity level is established.8.4 ScanningWith no further adjustmen
46、ts of the instru-ment gain controls, locate the search unit over one corner of theplate to be inspected so that the edge of the crystal in the searchunit is about 1 in. (25 mm) from either edge of the plate.8.4.1 Subsequent to checking the angular alignment of thesearch unit with respect to the roll
47、ed entry surface to ensure amaximum first back reflection, proceed to scan the platecontinuously by moving the search unit at a constant scanningrate (see 8.6) from the initial starting position to the oppositeedge in a direction perpendicular to the predominant rollingdirection of the plate.8.4.2 D
48、uring the scan, note the occurrence of isolateddiscontinuity indications and monitor the amplitude of the firstback reflection by continuously observing the A-scan indicatorscreen.NOTE 5Auxiliary monitoring devices may be employed in the testsystem to enhance detection reliability during the scan.8.
49、5 Scan IndexWhen the initial scan is completed, movethe search unit over a predetermined scan index distance in adirection parallel to the predominant rolling direction of theplate and proceed with a second scan along a line parallel to theinitial scanning direction while observing the test pattern on theA-scan indicator screen. Calculate the scan index distance asfollows:Scan index distance in.!, Si5 0.810.7 Ds(1)Scan index distance mm!, Si5 2010.7 Ds(2)where:Ds= actual crystal diameter.8.5.1 Continue the inspection by constantly observing thetest patte
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