1、Designation: E 588 03 (Reapproved 2009)Standard Practice forDetection of Large Inclusions in Bearing Quality Steel bythe Ultrasonic Method1This standard is issued under the fixed designation E 588; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, 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. Scope*1.1 This practice covers a procedure for the rating ofrectangular steel sections by immersion
3、ultrasonic techniques.Its purpose is to provide information on the content of largeinclusions or clusters of small inclusions for determining thesuitability of a steel lot for bearing applications. This practicein no manner defines or establishes limits of acceptability.1.2 For this document, large
4、inclusions are defined inultrasonic terms as those having a reflecting area equivalent toor larger than a164-in. diameter flat-bottom hole in a steelreference block of similar properties and thickness. In metal-lographic terms, large inclusions, defined in this way, are ofapproximately the same size
5、 as the smallest detectable sizesrevealed by the macroscopic methods of Test Methods E45.Insome cases, inclusions smaller than those described previouslycan be detected either individually or in clusters, depending ontheir type, chemical composition, orientation to the ultrasonicbeam and distance fr
6、om the sound entry surface of thespecimen.1.3 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 regulator
7、y limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E45 Test Methods for Determining the Inclusion Contentof SteelE 214 Practice for Immersed Ultrasonic Testing by theReflection Method Using Pulsed Longitudinal Waves3E 428 Practice for Fabrication and Control of Metal, Otherthan Al
8、uminum, Reference Blocks Used in UltrasonicTestingE 543 Specification for Agencies Performing Nondestruc-tive TestingE 1316 Terminology for Nondestructive Examinations2.2 ASNT Documents:SNT-TC-1A Recommended Practicefor Personnel Qualifi-cation and Certification in Nondestructive Testing4ASNT-CP-189
9、 STandard for Qualification and Certificationof Nondestructive Testing Personnel43. Terminology3.1 DefinitionsFor definitions of terms used in this prac-tice, see Terminology E 1316.4. Basis of Application4.1 Agreements Between Using PartiesIn order for thispractice to be effectively used, the follo
10、wing items requireagreement between the using parties.4.1.1 Evaluation of Nondestructive Testing AgenciesAnagreement is required as to whether the nondestructive testingagency, as defined in Specification E 543, must be formallyevaluated and qualified to perform the examination. If such anevaluation
11、 is specified, a documented procedure such asSpecification E 543 shall be used as the basis for evaluation.4.1.2 Personnel QualificationNondestructive testing(NDT) personnel shall be qualified in accordance with anationally recognized NDT personnel qualification practice orstandard such as ASNT CP-1
12、89, SNT-TC-1A, or a similardocument. The practice or standard used and its applicablerevision shall be specified in the contractual agreement be-tween the using parties.4.1.3 Search Unit Performance TestsAnnex A1 definesthe minimum manufacturers specifications for search units tobe used with this pr
13、actice. The extent of testing and verificationof these parameters to be performed by the manufacturer shallbe specified in the contractual agreement between the usingparties.1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct r
14、esponsibility of SubcommitteeA01.28 on Bearing Steels.Current edition approved April 1, 2009. Published April 2009. Originallyapproved in 1976. Last previous edition approved in 2003 as E 588 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at
15、serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from the American Society for Nondestructive Testing, 1711 A
16、rlin-gate Plaza, P.O. Box 28518, Columbus, OH 43228-0518.1*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. Summary of Practice5.1 The general technique used is immers
17、ion ultrasonictesting by the reflection method using pulsed longitudinalwaves such as described in Practice E 214. Specific additionalrequirements for sample preparation, equipment operatingparameters and calibration, and expression of results aredelineated in this procedure. Special focused search
18、unitshaving operating characteristics as defined in Annex A1 arerequired.6. Significance and Use6.1 Comparison with Other Inclusion Rating MethodsBecause the test is performed on a volumetric rather than asurface-examination basis, the ultrasonic method is inherentlybetter able to detect infrequentl
19、y occurring large inclusions orclusters of small inclusions than eddy current, magnetic par-ticle, microscopical, or macroscopic examination procedures.6.2 Limitation of Inclusion Size and TypeA limitation ofthe method is that it will not detect all inclusions. Inclusionchemistry, size, shape, locat
20、ion, and distribution may limit theability of the method to provide indications distinct from thosegenerated by the surrounding metallurgical structure. Therecommended practice is only meaningfully applicable toexamination of steel wherein the inclusion size and type arewithin the detection capabili
21、ties of the method. For steelwherein inclusion size, dispersion, and chemistry preventoptimum inclusion detection by ultrasonics, microscopicalmethods detailed in Test Methods E45may be applied.7. Interference7.1 Reflections from Multiple InclusionsAn ultrasonicindication can represent the reflectio
22、n from a single inclusion;however, it typically represents the vector summation ofreflections from clusters of small inclusions contained within avolume of a few cubic millimetres.7.2 Response as a Function of Inclusion TypeThe indi-vidual inclusion reflections can have different amplitudesbecause o
23、f different inclusion characteristics. In addition, theindividual reflections may have different phase characteristicswhen arriving at the search unit if the travel distances aredifferent.8. Apparatus8.1 Equipment RequiredAn equipment system with thefollowing components is needed to conduct this tes
24、t: ultrasonictest instrument, search unit, a means of recording signals ofvarious amplitudes, a system reference block, instrumentcalibration block, and an immersion tank with suitable scan-ning accessories.8.2 Ultrasonic InstrumentThe ultrasonic instrument shallbe capable of generating and receivin
25、g electrical pulses of10-MHz frequency at levels compatible with the test require-ments. It shall have both an A-scan presentation and an analogor digital output. It shall be the ultrasonic instrument manu-facturers responsibility that instruments supplied for use withthis test meet the minimum requ
26、irements delineated in thisrecommended practice.8.2.1 Receiver CharacteristicsThe center frequency shallbe 10 6 0.5 MHz. The bandpass of the receiver shall be at least1.3 MHz (3 dB points).8.2.2 Dynamic RangeThe dynamic range of the instru-ment shall permit detection of steel balls with a 16-to-1dia
27、meter ratio at a given sensitivity. Balls shall be placed inwater at the focal point of the search unit. Each size ball withinthis range shall give a significantly different amplitude ofindication.8.2.3 StabilityThe signal amplitude of a usable full-scaleindication shall not vary more than 5 % after
28、1hofinstrumentwarm-up, and preferably by less than 2 % (4-h test with airtemperature being held to 61.2C over a temperature range of17.5 to 25.5C).8.2.4 Sweep Length and LinearitySweep length of oscil-loscope presentation shall be capable of being adjusted torepresent 1 mm = 1.27 mm of steel. A mini
29、mum of 80 mm ofthe sweep display shall be linear to within 5 % of full scale.The signal amplitude of an indication from a target shall notvary more than 64 % over the gated portion of the sweepemployed in calibration and testing.8.2.5 Repetition RateThe repetition rate of the pulsershall not be less
30、 than 500 pulses per second.8.3 Search UnitsUltrasonic search units for this test shallbe spherically focused immersion-type units. Uniform perfor-mance characteristics of search units are critical for obtainingreproducible test measurements. (See Annex A1, which delin-eates search unit performance
31、characteristics to be met bysearch unit manufacturers.) Performance characteristics ofsearch units requiring consideration are: the uniformity of focaldistance in water, center frequency, frequency spectrum, lensradius, width of field, and beam symmetry.8.3.1 Focal LengthA focused beam of radiated u
32、ltrasonicenergy is recommended to provide lateral resolution of smalldefects and to improve testing sensitivity in the region near thefocal point. The focal length of a search unit is defined in thisdiscussion as the distance in water, on the search unit axis,between the search unit and the surface
33、of a12-in. or 12-mmdiameter ball target at which the highest reflection amplitudeindication is obtained. Different focal length transducers maybe used to obtain optimum response at selected distances belowthe test sample surface. (Variation of search unit-to-specimensurface water path would also aff
34、ect the focal point within thetest sample.)8.3.2 Search Unit CharacteristicsSearch units generallyemployed have the following frequency and focal length aspurchased:Frequency Focal Length in Water10 6 0.5 MHz 8.2 6 0.3 in. (208.3 6 7.6 mm)8.3.3 Beam SymmetryEach search unit should be rotatedon its u
35、ltrasonic beam axis (not necessarily geometric axis)until a particular circumferential orientation is found whichgives a maximum severity, or count, from the system referenceblock. This search unit orientation shall be identified andemployed in subsequent tests. Search units that exhibit varia-tions
36、 in indication amplitude in excess of 15 % during rotationshall not be considered satisfactory for the test. There are otherE 588 03 (2009)2methods, such as optimum response over a precision anduniform taut wire, that have been found to be usable.8.3.4 PerformanceThe performance capabilities of alln
37、ew search units shall be verified by an actual test on thesystem reference block. The data obtained for new search unitsshould be compared with that obtained for other search unitshaving the same specifications and tested under identicalconditions.8.4 Immersion Tank and AccessoriesAn immersion tankw
38、ith associated scanning and indexing facilities shall be used.8.4.1 Search Unit AngulationThe tank shall be providedwith a manipulator capable of continuously angulating thesearch unit in two vertical mutually perpendicular planespermitting the required normalization.8.4.2 Scanning and IndexingThe t
39、ank bridge and carriageassemblies shall provide X-Y motion to the search unit. Thescanning shall be parallel or perpendicular (depending on theprocedure) to the test specimen axis and the indexing shall beperpendicular to the scanning.8.4.3 Test Specimen MountingThe tank shall be providedwith fixtur
40、ing permitting the mounting of the entry surface ofthe test specimen parallel to the bridge travel so that thedistance between search unit and specimen remains constantwithin 6164 in. (0.4 mm).8.4.4 Couplant:8.4.4.1 The inspection solution shall consist of tap ordistilled water to which a wetting ag
41、ent has been added todisperse air bubbles. The pH of the water shall be maintainedwithin 712 to 812 . Rust preventives may also be added. Allchemical additives shall be held within concentrations that donot adversely affect test performance. Water temperature mustbe held between 19.5 and 25.5C. It i
42、s important that excessivethermal gradients do not exist between the search unit and thecalibration standards.8.4.4.2 A means of circulating the immersion inspectionsolution shall be employed, when necessary, to dissipatethermal gradients.8.5 Readout EquipmentVarious types of instrumentationhave bee
43、n employed in conjunction with ultrasonic instrumentsfor many years to determine the number of occurrences ofvarious amplitude indications. These include level counters,pulse counters, integrators, strip chart recorders, B-scan re-corders, C-scan recorders, memory oscilloscopes, and com-puter techni
44、ques. With pulse counters, both repetition rate andscanning speed must be held within a 5 % tolerance and,preferably, 2 %.8.6 System Reference BlockA system reference block(defined dimensionally in Section 9.2) is required for initialadjustments and operational testing of the equipment. Thissample s
45、hould be selected to provide reflection signals at allcounting levels. Depth distribution of inclusions in the selectedreference block should make its response characteristics rela-tively insensitive to minor focal length variations betweendifferent search units. The reference block should give amin
46、imum change in total counts of 10 % for each 10 %increase or decrease in amplitude setting.Amaximum of 30 %change in count for each 10 % change in amplitude settingshould not be exceeded. It should be suitably protected fromcorrosion to assure its longevity.9. Test Specimens9.1 GeneralTest specimens
47、 must be either in the rolled orforged condition. If forged, upset forging is prohibited in orderto maintain the rolling direction. Care should be taken not tooverheat the forging to avoid spurious ultrasonic indications.Specimen location and frequency shall be as agreed uponbetween the supplier and
48、 the purchaser.9.2 Specimen Size and ShapeSpecimens shall have aminimum cross-sectional dimension after preparation of 312 in.(88.9 mm). The area scanned shall be sufficient to permittesting of a minimum of 25 in.3(410 cm3) of the specimen. Thetested volume equals the scanned area multiplied by the
49、gateddepth. If special consideration is given, thinner samples may betested.9.3 Entry Surface FinishThe test surface through whichthe sound enters the specimen shall be machined and ground.This finish in any direction over the surface shall be preferably10 to 80 in. (0.25 to 2.0 m). Final material removal mayrequire a dressed grinding wheel to avoid spurious, near-surface indications. All four sides are to be ground.9.4 Heat TreatmentThermal conditioning of the speci-mens is required to minimize acoustic anomalies. Typical heattreatment ma
