ASTM E45-2018a 1875 Standard Test Methods for Determining the Inclusion Content of Steel.pdf

1、Designation: E45 18aStandard Test Methods forDetermining the Inclusion Content of Steel1This standard is issued under the fixed designation E45; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in p

2、arentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 These test methods cover a number of recognizedprocedures for

3、determining the nonmetallic inclusion contentof wrought steel. Macroscopic methods include macroetch,fracture, step-down, and magnetic particle tests. Microscopicmethods include five generally accepted systems of examina-tion. In these microscopic methods, inclusions are assigned toa category based

4、on similarities in morphology, and notnecessarily on their chemical identity. Metallographic tech-niques that allow simple differentiation between morphologi-cally similar inclusions are briefly discussed. While the meth-ods are primarily intended for rating inclusions, constituentssuch as carbides,

5、 nitrides, carbonitrides, borides, and interme-tallic phases may be rated using some of the microscopicmethods. In some cases, alloys other than steels may be ratedusing one or more of these methods; the methods will bedescribed in terms of their use on steels.1.2 These test methods cover procedures

6、 to perform JK-typeinclusion ratings using automatic image analysis in accordancewith microscopic methods A and D.1.3 Depending on the type of steel and the propertiesrequired, either a macroscopic or a microscopic method fordetermining the inclusion content, or combinations of the twomethods, may b

7、e found most satisfactory.1.4 These test methods deal only with recommended testmethods and nothing in them should be construed as definingor establishing limits of acceptability for any grade of steel.1.5 The values stated in SI units are to be regarded as thestandard. Values in parentheses are con

8、versions and are ap-proximate.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-priate safety, health, and environmental practices and deter-mine the applicability of regul

9、atory 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 theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Or

10、ganization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE381 Method of Macroetch Testing Steel Bars, Billets,Blooms, and ForgingsE709 Guide for Magnetic Particle Testi

11、ngE768 Guide for Preparing and Evaluating Specimens forAutomatic Inclusion Assessment of SteelE1245 Practice for Determining the Inclusion or Second-Phase Constituent Content of Metals by Automatic ImageAnalysisE1444 Practice for Magnetic Particle TestingE1951 Guide for Calibrating Reticles and Ligh

12、t MicroscopeMagnifications2.2 SAE Standards:3J422, Recommended Practice for Determination of Inclu-sions in Steel2.3 Aerospace Material Specifications:3AMS 2300, Premium Aircraft-Quality Steel Cleanliness:Magnetic Particle Inspection ProcedureAMS 2301, Aircraft Quality Steel Cleanliness: MagneticPar

13、ticle Inspection ProcedureAMS 2303, Aircraft Quality Steel Cleanliness: MartensiticCorrosion-Resistant Steels Magnetic Particle InspectionProcedureAMS 2304, SpecialAircraft-Quality Steel Cleanliness: Mag-netic Particle Inspection Procedure1These test methods are under the jurisdiction of ASTM Commit

14、tee E04 onMetallography and is the direct responsibility of Subcommittee E04.09 on Inclu-sions.Current edition approved June 1, 2018. Published September 2018. Originallyapproved in 1942. Last previous edition approved in 2018 as E45 18. DOI:10.1520/E0045-18A.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.3Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sa

16、e.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of

17、 International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.12.4 ISO Standards:4ISO 3763, Wrought SteelsMacroscopic Methods for As-sessing the Content of Nonmetallic InclusionsISO 4967, SteelDetermination of Content of Nonme

18、tallicInclusionsMicrographic Methods Using Standard Dia-grams2.5 ASTM Adjuncts:Inclusions in Steel Plates I-A and II5Four Photomicrographs of Low Carbon Steel63. Terminology3.1 Definitions:3.1.1 For definitions of terms used in these test methods, seeTerminology E7.3.1.2 Terminology E7 includes the

19、term inclusion count;since some methods of these test methods involve lengthmeasurements or conversions to numerical representations oflengths or counts, or both, the term inclusion rating ispreferred.3.2 Definitions of Terms Specific to This Standard:3.2.1 aspect ratiothe length-to-width ratio of a

20、 micro-structural feature.3.2.2 discontinuous stringerthree or more Type B or Cinclusions aligned in a plane parallel to the hot working axisand offset by no more than 15 m, with a separation of less than40 m (0.0016 in.) between any two nearest neighbor inclu-sions.3.2.3 inclusion typesfor definiti

21、ons of sulfide-, alumina-,and silicate-type inclusions, see Terminology E7. Globularoxide, in some methods refers to isolated, relatively nonde-formed inclusions with an aspect ratio not in excess of 2:1. Inother methods, oxides are divided into deformable and nonde-formable types.3.2.4 JK inclusion

22、 ratinga method of measuring nonme-tallic inclusions based on the Swedish Jernkontoret procedures;Methods A and D of these test methods are the principal JKrating methods, and Method E also uses the JK rating charts.3.2.5 stringeran individual inclusion that is highly elon-gated in the deformation d

23、irection or three or more Type B orC inclusions aligned in a plane parallel to the hot working axisand offset by no more than 15 m, with a separation of less than40 m (0.0016 in.) between any two nearest neighbor inclu-sions.3.2.6 threshold settingisolation of a range of gray levelvalues exhibited b

24、y one constituent in the microscope field.3.2.7 worst-field ratinga rating in which the specimen israted for each type of inclusion by assigning the value for thehighest severity rating observed of that inclusion type any-where on the specimen surface.4. Significance and Use4.1 These test methods co

25、ver four macroscopic and fivemicroscopic test methods (manual and image analysis) fordescribing the inclusion content of steel and procedures forexpressing test results.4.2 Inclusions are characterized by size, shape,concentration, and distribution rather than chemical composi-tion. Although composi

26、tions are not identified, Microscopicmethods place inclusions into one of several composition-related categories (sulfides, oxides, and silicatesthe last as atype of oxide). Paragraph 11.1.1 describes a metallographictechnique to facilitate inclusion discrimination. Only thoseinclusions present at t

27、he test surface can be detected.4.3 The macroscopic test methods evaluate larger surfaceareas than microscopic test methods and because examinationis visual or at low magnifications, these methods are best suitedfor detecting larger inclusions. Macroscopic methods are notsuitable for detecting inclu

28、sions smaller than about 0.40 mm(164 in.) in length and the methods do not discriminateinclusions by type.4.4 The microscopic test methods are employed to charac-terize inclusions that form as a result of deoxidation or due tolimited solubility in solid steel (indigenous inclusions). Asstated in 1.1

29、, these microscopic test methods rate inclusionseverities and types based on morphological type, that is, bysize, shape, concentration, and distribution, but not specificallyby composition.These inclusions are characterized by morpho-logical type, that is, by size, shape, concentration, anddistribut

30、ion, but not specifically by composition. The micro-scopic methods are not intended for assessing the content ofexogenous inclusions (those from entrapped slag or refracto-ries). In case of a dispute whether an inclusion is indigenous orexogenous, microanalytical techniques such as energy disper-siv

31、e X-ray spectroscopy (EDS) may be used to aid in deter-mining the nature of the inclusion. However, experience andknowledge of the casting process and production materials,such as deoxidation, desulfurization, and inclusion shapecontrol additives as well as refractory and furnace linercompositions m

32、ust be employed with the microanalyticalresults to determine if an inclusion is indigenous or exogenous4.5 Because the inclusion population within a given lot ofsteel varies with position, the lot must be statistically sampledin order to assess its inclusion content. The degree of samplingmust be ad

33、equate for the lot size and its specific characteristics.Materials with very low inclusion contents may be moreaccurately rated by automatic image analysis, which permitsmore precise microscopic ratings.4.6 Results of macroscopic and microscopic test methodsmay be used to qualify material for shipme

34、nt, but these testmethods do not provide guidelines for acceptance or rejectionpurposes. Qualification criteria for assessing the data devel-oped by these methods can be found in ASTM productstandards or may be described by purchaser-producer agree-ments. By agreements between producer and purchaser

35、, thesetest methods may be modified to count only certain inclusiontypes and thicknesses, or only those inclusions above a certain4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from ASTM International Headquar

36、ters. Order Adjunct No.ADJE004502A. Original adjunct produced in 1983. Adjunct revised in 2011.6Available from ASTM International Headquarters. Order Adjunct No.ADJE004501. Original adjunct produced in 1983.E45 18a2severity level, or both. Also, by agreement, qualitative prac-tices may be used where

37、 only the highest severity ratings foreach inclusion type and thickness are defined or the number offields containing these highest severity ratings are tabulated.4.7 These test methods are intended for use on wroughtmetallic structures. While a minimum level of deformation isnot specified, the test

38、 methods are not suitable for use on caststructures or on lightly worked structures.4.8 Guidelines are provided to rate inclusions in steelstreated with rare earth additions or calcium-bearing com-pounds. When such steels are evaluated, the test report shoulddescribe the nature of the inclusions rat

39、ed according to eachinclusion category (A, B, C, D).4.9 In addition to the Test Methods E45 JK ratings, basic(such as used in Practice E1245) stereological measurements(for example, the volume fraction of sulfides and oxides, thenumber of sulfides or oxides per square millimeter, the spacingbetween

40、inclusions, and so forth) may be separately deter-mined and added to the test report, if desired for additionalinformation. This practice, however, does not address themeasurement of such parameters.MACROSCOPIC METHODS5. Macroscopical Test Methods Overview5.1 Summary:5.1.1 Macro-etch TestThe macro-e

41、tch test is used toindicate inclusion content and distribution, usually in the crosssection or transverse to the direction of rolling or forging. Insome instances, longitudinal sections are also examined. Testsare prepared by cutting and machining a section through thedesired area and etching with a

42、 suitable reagent. A solution ofone part hydrochloric acid and one part water at a temperatureof 71 to 82C (160 to 180F) is widely used. As the name ofthis test implies, the etched surface is examined visually or atlow magnification for inclusions. Details of this test areincluded in Method E381. Th

43、e nature of questionable indica-tions should be verified by microscopic examination or othermeans of inspection.5.1.1.1 Sulfides are revealed as pits when the standardetchant described in 5.1.1 is used.5.1.1.2 Only large oxides are revealed by this test method.5.1.2 Fracture TestThe fracture test is

44、 used to determinethe presence and location of inclusions as shown on thefracture of hardened slices approximately 9 to 13 mm (38 to12in.) thick. This test is used mostly for steels where it is possibleto obtain a hardness of approximately 60 HRC and a fracturegrain size of 7 or finer. Test specimen

45、s should not haveexcessive external indentations or notches that guide thefracture. It is desirable that fracture be in the longitudinaldirection approximately across the center of the slice. Thefractured surfaces are examined visually and at magnificationsup to approximately ten diameters, and the

46、length and distri-bution of inclusions is noted. Heat tinting, or blueing, willincrease visibility of oxide stringers. ISO 3763 provides a chartmethod for fracture surface inclusion ratings. In someinstances, indications as small as 0.40 mm (164 in.) in lengthare recorded.5.1.3 Step-Down MethodThe s

47、tep-down test method isused to determine the presence of inclusions on machinedsurfaces of rolled or forged steel. The test sample is machinedto specified diameters below the surface and surveyed forinclusions under good illumination with the unaided eye orwith low magnification. In some instances,

48、test samples aremachined to smaller diameters for further examination after theoriginal diameters are inspected. This test is essentially used todetermine the presence of inclusions 3 mm (18 in.) in lengthand longer.5.1.4 Magnetic Particle MethodThe magnetic particlemethod is a variation of the step

49、-down method for ferromag-netic materials in which the test sample is machined,magnetized, and magnetic powder is applied. Discontinuitiesas small as 0.40 mm (164 in.) in length create magnetic leakagefields that attract the magnetic powder, thereby outlining theinclusion. See Practice E1444 and Guide E709 on magneticparticle examinations for more details of the procedure. Referto Aerospace Materials Specifications AMS 2300, AMS 2301,AMS 2303, and AMS 2304.5.2 Advantages:5.2.1 These test methods facilitate the examination of speci-mens with large surface