ASTM E45-2005e1 Standard Test Methods for Determining the Inclusion Content of Steel《测定钢中杂质含量的标准试验方法》.pdf

1、Designation: E 45 05e1Standard Test Methods forDetermining the Inclusion Content of Steel1This standard is issued under the fixed designation E 45; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number

2、 in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.e1NOTETable 1 was editorially corrected in February 2007.1. Scope1.1 Th

3、ese 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 generally accepted systems of examina-tion. In these micr

4、oscopic 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 are briefly discussed. While the meth-ods are primarily i

5、ntended 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 these methods; the methods will bedescribed in terms of

6、 their use on steels.1.2 This practice covers 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 a macroscopic or a microscopic method fordetermining the inc

7、lusion 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 any grade of steel.1.5 The values stated in SI units are to b

8、e 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 standard to establish appro-priate safety and health practices a

9、nd determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 96 Test Method for Water and Sediment in Crude Oil byCentrifuge Method (Field Procedure)E3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating to MetallographyE 38

10、1 Method of Macroetch Testing Steel Bars, Billets,Blooms, and ForgingsE 709 Guide for Magnetic Particle ExaminationE 768 Practice for Preparing and Evaluating Specimens forAutomatic Inclusion Assessment of SteelE 1245 Practice for Determining Inclusion or Second-PhaseConstituent Content of Metals by

11、 Automatic Image Analy-sisE 1444 Practice for Magnetic Particle ExaminationE 1951 Guide for Calibrating Reticles and Light Micro-scope Magnifications2.2 SAE Standards:3J422, Recommended Practice for Determination of Inclu-sions in Steel2.3 Aerospace Material Specifications:3AMS 2300, Premium Aircraf

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

13、lity Steel Cleanliness:Magnetic Particle Inspection Procedure2.4 ISO Standards:4ISO 3763, Wrought SteelsMacroscopic Methods for As-sessing the Content of Nonmetallic Inclusions1These test methods are under the jurisdiction of ASTM Committee E04 onMetallography and is the direct responsibility of Sub

14、committee E04.09 on Inclu-sions.Current edition approved Nov. 1, 2005. Published December 2005. Originallyapproved in 1942. Last previous edition approved in 2002 as E 45 97 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.or

15、g. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4

16、th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ISO 4967, SteelDetermination of Content of NonmetallicInclusionsMicrographic Methods Using Standard Dia-grams2.5 ASTM Adjuncts:Inclusions in Steel Plates I-

17、r and II5Four Photomicrographs of Low Carbon Steel63. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice, 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 E 7. Globularoxide, in some methods refer

20、s 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

21、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 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 eac

23、h 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 co

24、ntent 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-egor

25、ies (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 microscopi

26、c 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). Theseinclusions are characterized by morphological type, that is, bysize, shape, concentration, and distribution, but not sp

28、ecificallyby composition. The microscopic methods are not intended forassessing the content of exogenous inclusions (those fromentrapped slag or refractories).4.5 Because the inclusion population within a given lot ofsteel varies with position, the lot must be statistically sampledin order to assess

29、 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 moreaccurately rated by automatic image analysis, which permitsmore precise microscopic ratings.4.6 Results of macroscopic and microscopi

30、c test methodsmay be used to qualify material for shipment, 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 a

31、gree-ments. By agreements between producer and purchaser, thispractice may be modified to count only certain inclusion typesand thicknesses, or only those inclusions above a certainseverity level, or both. Also, by agreement, qualitative prac-tices may be used where only the highest severity ratings

32、 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 methods are not suitable for use

33、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 rated according to eachinclusion cate

34、gory (A, B, C, D).4.9 In addition to the Practice E 45 JK ratings, basic (suchas used in Practice E 1245) stereological measurements (forexample, the volume fraction of sulfides and oxides, thenumber of sulfides or oxides per square millimeter, the spacingbetween inclusions, and so forth) may be sep

35、arately deter-mined and added to the test report, if desired for additionalinformation. This practice, however, does not address themeasurement of such parameters.5Available from ASTM Headquarters. Order ADJE004502.6Available from ASTM Headquarters. Order ADJE004501.E4505e12MACROSCOPIC METHODS5. Mac

36、roscopical Test Methods Overview5.1 Summary: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 b

37、y cutting and machining a section through 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 magni

38、fication for inclusions. Details of this test areincluded in Method E 381. 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 ox

39、ides are revealed by this test method.5.1.2 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

40、of approximately 60 HRC and a fracturegrain 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 exami

41、ned visually and at magnificationsup to approximately 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

42、as small as 0.40 mm (164 in.) in length arerecorded.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

43、illumination with the unaided eye orwith low 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

44、 Magnetic Particle MethodThe magnetic particlemethod 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 attrac

45、t the magnetic powder, thereby outlining the inclu-sion. See Practice E 1444 and Guide E 709 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

46、 examination of speci-mens with large surface 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 Specime

47、ns 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 sha

48、pes.5.3.2 They are not suitable for the detection of smallglobular inclusions or of chains of very fine elongated inclu-sions.5.3.3 The magnetic particle method can lead to incorrectinterpretation of microstructural features such as streaks ofretained austenite, microsegregation, or carbides in cert

49、ainalloys; this is particularly likely if high magnetization currentsare employed.MICROSCOPIC METHODS6. Microscopic Test Methods Overview6.1 Microscopic methods are used to characterize the size,distribution, number, and type of inclusions on a polishedspecimen surface. This may be done by examining the speci-men with a light microscope and reporting the types ofinclusions encountered, accompanied by a few representativephotomicrographs. This method, however, does not lend itselfto a uniform reporting style. Therefore, standard referencecharts depicting a s