ASTM E45-2010e1 6250 Standard Test Methods for Determining the Inclusion Content of Steel《钢中杂质含量的标准试验方法》.pdf

1、Designation: E45 101Standard 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. A number in

2、 parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1NOTEFor consistency, references to “Practice” E45 were editorially correct

3、ed to “Test Methods” E45 in February 2011.1. Scope1.1 These test methods cover a number of recognizedprocedures for determining the nonmetallic inclusion contentof wrought steel. Macroscopic methods include macroetch,fracture, step-down, and magnetic particle tests. Microscopicmethods include five g

4、enerally accepted systems of examina-tion. In these microscopic methods, inclusions are assigned toa category based on similarities in morphology, and notnecessarily on their chemical identity. Metallographic tech-niques that allow simple differentiation between morphologi-cally similar inclusions a

5、re briefly discussed. While the meth-ods are primarily intended for rating inclusions, constituentssuch as carbides, 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

6、 these methods; the methods will bedescribed in terms of their use on steels.1.2 These test methods cover procedures 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

7、a macroscopic or a microscopic method fordetermining the inclusion content, or combinations of the twomethods, may be 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 a

8、ny grade of steel.1.5 The values stated in SI units are to be regarded as thestandard. Values in parentheses are conversions 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 stan

9、dard 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:2E3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE381 Method of Macroetch Testing S

10、teel Bars, Billets,Blooms, and ForgingsE709 Guide for Magnetic Particle TestingE768 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 Practi

11、ce for Magnetic Particle TestingE1951 Guide for Calibrating Reticles and Light 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

12、Inspection ProcedureAMS 2301, Aircraft Quality Steel Cleanliness: MagneticParticle Inspection ProcedureAMS 2303, Aircraft Quality Steel Cleanliness: MartensiticCorrosion-Resistant Steels Magnetic Particle InspectionProcedureAMS 2304, Special Aircraft-Quality Steel Cleanliness:Magnetic Particle Inspe

13、ction Procedure2.4 ISO Standards:41These test methods are under the jurisdiction of ASTM Committee E04 onMetallography and is the direct responsibility of Subcommittee E04.09 on Inclu-sions.Current edition approved Feb. 23, 2011. Published December 2010. Originallyapproved in 1942. Last previous edi

14、tion approved in 2005 as E45 053. DOI:10.1520/E0045-10.2For referenced ASTM standards, visit the 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.3Avail

15、able from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West

16、Conshohocken, PA 19428-2959, United States.ISO 3763, Wrought SteelsMacroscopic Methods for As-sessing the Content of Nonmetallic InclusionsISO 4967, SteelDetermination of Content of NonmetallicInclusionsMicrographic Methods Using Standard Dia-grams2.5 ASTM Adjuncts:Inclusions in Steel Plates I-r and

17、 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 term inclusion count;since some methods of these test methods involve lengthmeasurements or conversions to numeri

18、cal 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 micro-structural feature.3.2.2 discontinuous stringerthree or more Type B or Cinclusions aligned in a plane para

19、llel 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 definitions of sulfide-, alumina-,and silicate-type inclusions, see Terminology E7. Globularoxide, in some methods refers

20、 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 ratinga method of measuring nonme-tallic inclusions based on the Swedish Jernkontoret procedures;Methods A and D

21、 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 direction or three or more Type B orC inclusions aligned in a plane parallel to the hot working axisand offset by

22、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 by one constituent in the microscope field.3.2.7 worst-field ratinga rating in which the specimen israted for each

23、 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 cover four macroscopic and fivemicroscopic test methods (manual and image analysis) fordescribing the inclusion con

24、tent of steel and procedures forexpressing test results.4.2 Inclusions are characterized by size, shape, concentra-tion, and distribution rather than chemical composition. Al-though compositions are not identified, Microscopic methodsplace inclusions into one of several composition-related cat-egori

25、es (sulfides, oxides, and silicatesthe last as a type ofoxide). Paragraph 12.2.1 describes a metallographic techniqueto facilitate inclusion discrimination. Only those inclusionspresent at the test surface can be detected.4.3 The macroscopic test methods evaluate larger surfaceareas than microscopic

26、 test methods and because examinationis visual or at low magnifications, these methods are best suitedfor detecting larger inclusions. Macroscopic methods are notsuitable for detecting inclusions smaller than about 0.40 mm(164 in.) in length and the methods do not discriminateinclusions by type.4.4

27、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, these microscopic test methods rate inclusionseverities and types based on morphological type, that is, bysi

28、ze, shape, concentration, and distribution, but not specificallyby composition. These inclusions are characterized by morpho-logical type, that is, by size, shape, concentration, and distri-bution, but not specifically by composition. The microscopicmethods are not intended for assessing the content

29、 of exog-enous inclusions (those from entrapped slag or refractories). Incase of a dispute whether an inclusion is indigenous orexogenous, microanalytical techniques such as energy disper-sive X-ray spectroscopy (EDS) may be used to aid in deter-mining the nature of the inclusion. However, experienc

30、e andknowledge of the casting process and production materials,such as deoxidation, desulfurization, and inclusion shapecontrol additives as well as refractory and furnace linercompositions must be employed with the microanalyticalresults to determine if an inclusion is indigenous or exogenous4.5 Be

31、cause 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 adequate for the lot size and its specific characteristics.Materials with very low inclusion contents may be mo

32、reaccurately 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 shipment, but these testmethods do not provide guidelines for acceptance or rejectionpurposes. Qualification criter

33、ia 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, thesetest methods may be modified to count only certain inclusiontypes and thicknesses, or only those inclu

34、sions above a certainseverity level, or both. Also, by agreement, qualitative prac-tices may be used where only the highest severity ratings foreach inclusion type and thickness are defined or the number offields containing these highest severity ratings are tabulated.5Available from ASTM Internatio

35、nal Headquarters. Order Adjunct No.ADJE004502. Original adjunct produced in 19836Available from ASTM International Headquarters. Order Adjunct No.ADJE004501. Original adjunct produced in 1983E4510124.7 These test methods are intended for use on wroughtmetallic structures. While a minimum level of de

36、formation isnot specified, the test 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 shoulddescri

37、be the nature of the inclusions rated 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 squ

38、are millimeter, the spacingbetween 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 Summa

39、ry:5.1.1 Macro-etch TestThe macro-etch 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

40、 thedesired area and etching with a 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

41、test areincluded in Method E381. The 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.

42、2 Fracture TestThe fracture test is 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 fracturegrai

43、n size of 7 or finer. Test specimens 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 ap

44、proximately ten diameters, and the 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 some in-stances, indications as small as 0.40 mm (164 in.) in length ar

45、erecorded.5.1.3 Step-Down MethodThe step-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 l

46、ow magnification. In some instances, 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 part

47、iclemethod is a variation of the step-down method for ferromag-netic materials in which the test sample is machined, magne-tized, and magnetic powder is applied. Discontinuities as smallas 0.40 mm (164 in.) in length create magnetic leakage fieldsthat attract the magnetic powder, thereby outlining t

48、he inclu-sion. See Practice E1444 and Guide E709 on magnetic particleexaminations for more details of the procedure. Refer toAerospace 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 surfac

49、e areas. The larger inclusions in steel,which are the main concern in most cases, are not uniformlydistributed and the spaces between them are relatively large, sothat the chances of revealing them are better when largerspecimens are examined.5.2.2 Specimens for macroscopic examination may bequickly prepared by machining and grinding.Ahighly polishedsurface is not necessary. The macroscopic methods are suffi-ciently sensitive to reveal the larger inclusions.5.3 Disadvantages:5.3.1 These test methods do not distinguish among thedifferent inclusion shap