1、Designation: E588 03 (Reapproved 2014)Standard Practice forDetection of Large Inclusions in Bearing Quality Steel bythe Ultrasonic Method1This standard is issued under the fixed designation E588; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、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. Scope1.1 This practice covers a procedure for the rating ofrectangular steel sections by immersion ult
3、rasonic 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 inc
4、lusions 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 as
5、 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 from
6、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 regulatory l
7、imitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E45 Test Methods for Determining the Inclusion Content ofSteelE214 Practice for Immersed Ultrasonic Testing by the Re-flection Method Using Pulsed Longitudinal Waves (With-drawn 2007)3E428 Practice for Fabrication and Control of Meta
8、l, Otherthan Aluminum, Reference Blocks Used in UltrasonicTestingE543 Specification for Agencies Performing NondestructiveTestingE1316 Terminology for Nondestructive Examinations2.2 ASNT Documents:SNT-TC-1A Recommended Practicefor Personnel Qualifi-cation and Certification in Nondestructive Testing4
9、ASNT-CP-189 Standard for Qualification and Certificationof Nondestructive Testing Personnel43. Terminology3.1 DefinitionsFor definitions of terms used in thispractice, see Terminology E1316.4. Basis of Application4.1 Agreements Between Using Parties In order for thispractice to be effectively used,
10、the following items requireagreement between the using parties.4.1.1 Evaluation of Nondestructive Testing Agencies Anagreement is required as to whether the nondestructive testingagency, as defined in Specification E543, must be formallyevaluated and qualified to perform the examination. If such ane
11、valuation is specified, a documented procedure such asSpecification E543 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 A
12、SNT CP-189, SNT-TC-1A, or a similardocument. The practice or standard used and its applicable1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.28 on Bearing Steels.Current edition approved Oc
13、t. 1, 2014. Published October 2014. Originallyapproved in 1976. Last previous edition approved in 2009 as E588 03(2009). DOI:10.1520/E0588-03R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、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 fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:
15、/www.asnt.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1revision shall be specified in the contractual agreement be-tween the using parties.4.1.3 Search Unit Performance TestsAnnex A1 definesthe minimum manufacturers specificati
16、ons for search units tobe used with this practice. The extent of testing and verificationof these parameters to be performed by the manufacturer shallbe specified in the contractual agreement between the usingparties.5. Summary of Practice5.1 The general technique used is immersion ultrasonictesting
17、 by the reflection method using pulsed longitudinalwaves such as described in Practice E214. Specific additionalrequirements for sample preparation, equipment operatingparameters and calibration, and expression of results aredelineated in this procedure. Special focused search unitshaving operating
18、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 infrequently occurring large incl
19、usions orclusters of small inclusions than eddy current, magneticparticle, microscopical, or macroscopic examination proce-dures.6.2 Limitation of Inclusion Size and TypeA limitation ofthe method is that it will not detect all inclusions. Inclusionchemistry, size, shape, location, and distribution m
20、ay 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 capabilities of the method. For
21、 steelwherein inclusion size, dispersion, and chemistry preventoptimum inclusion detection by ultrasonics, microscopicalmethods detailed in Test Methods E45 may be applied.7. Interference7.1 Reflections from Multiple InclusionsAn ultrasonic in-dication can represent the reflection from a single incl
22、usion;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 of different inclusio
23、n 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 test: ultrasonictest in
24、strument, 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 receiving electrical pulses
25、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 requirements delineated
26、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-1diameter ratio at a giv
27、en 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 % after1hofinstrumentwarm-u
28、p, 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 minimum of 80 mm ofthe s
29、weep 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 pulser shallnot be less than 500 pulses per
30、 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 characteristics to b
31、e 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 ultrasonicenergy is r
32、ecommended 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 of a12-in. or 12-mmd
33、iameter 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 affect the focal point
34、within thetest sample.)8.3.2 Search Unit CharacteristicsSearch units generallyemployed have the following frequency and focal length aspurchased:E588 03 (2014)2Frequency Focal Length in Water10 0.5 MHz 8.2 0.3 in. (208.3 7.6 mm)8.3.3 Beam SymmetryEach search unit should be rotatedon its ultrasonic b
35、eam 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 in indicat
36、ion amplitude in excess of 15 % during rotationshall not be considered satisfactory for the test. There are othermethods, such as optimum response over a precision anduniform taut wire, that have been found to be usable.8.3.4 PerformanceThe performance capabilities of allnew search units shall be ve
37、rified 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 Accessories An immersion tankwith associated scanning an
38、d 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 tank bridge and carriageass
39、emblies 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 fixturing permitting the mountin
40、g 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 agent has been added todispe
41、rse 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 is important that excessivet
42、hermal 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 been employed in conjunction w
43、ith ultrasonic instrumentsfor many years to determine the number of occurrences ofvarious amplitude indications. These include level counters,pulse counters, integrators, strip chart recorders, B-scanrecorders, C-scan recorders, memory oscilloscopes, and com-puter techniques. With pulse counters, bo
44、th 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 should be selected to provide
45、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 aminimum change in total counts o
46、f 10 % for each 10 %increase or decrease in amplitude setting. A maximum 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 must be either in the roll
47、ed 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 the purchaser.9.2 Specimen
48、 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 gateddepth. If special cons
49、ideration 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 may consist of normali
