1、Designation: A751 14aStandard Test Methods, Practices, and Terminology forChemical Analysis of Steel Products1This standard is issued under the fixed designation A751; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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.INTRODUCTIONThese test methods, practices, and
3、terminology were prepared to answer the need for a singledocument that would include all aspects of obtaining and reporting the chemical analysis of steel,stainless steel, and related alloys. Such subjects as definitions of terms and product (check) analysisvariations (tolerances) required clarifica
4、tion. Requirements for sampling, meeting specified limits, andtreatment of data usually were not clearly established in product specifications.It is intended that these test methods, practices, and terminology will contain all requirements forthe determination of chemical composition of steel, stain
5、less steel, or related alloys so that productspecifications will need contain only special modifications and exceptions.1. Scope*1.1 These test methods, practices, and terminology coverdefinitions, reference methods, practices, and guides relating tothe chemical analysis of steel, stainless steel, a
6、nd relatedalloys. It includes both wet chemical and instrumental tech-niques.1.2 Directions are provided for handling chemicalrequirements, product analyses, residual elements, and refer-ence standards, and for the treatment and reporting of chemicalanalysis data.1.3 These test methods, practices, a
7、nd terminology applyonly to those product standards which include these testmethods, practices, and terminology, or parts thereof, as arequirement.1.4 In cases of conflict, the product specification require-ments shall take precedence over the requirements of these testmethods, practices, and termin
8、ology.1.5 Attention is directed to ISO/IEC 17025 when there maybe a need for information on criteria for evaluation of testinglaboratories.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
9、 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE50 Practices for Apparatus, Reagen
10、ts, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by SpectrophotometryE322 Test Method for Analysis of Low-Alloy Steels andCast Irons by Wavelength Dispersive X-Ray FluorescenceSpectrometryE350 Te
11、st Methods for Chemical Analysis of Carbon Steel,Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, andWrought IronE352 Test Methods for ChemicalAnalysis of Tool Steels andOther Similar Medium- and High-Alloy SteelsE353 Test Methods for Chemical Analysis of Stainless,Heat-Resisting, Maraging, an
12、d Other Similar Chromium-Nickel-Iron AlloysE354 Test Methods for Chemical Analysis of High-Temperature, Electrical, Magnetic, and Other Similar Iron,Nickel, and Cobalt Alloys1These test methods, practices, and terminology are under the jurisdiction ofASTM Committee A01 on Steel, Stainless Steel and
13、Related Alloys and are thedirect responsibility of Subcommittee A01.13 on Mechanical and Chemical Testingand Processing Methods of Steel Products and Processes.Current edition approved Oct. 1, 2014. Published October 2014. Originallyapproved in 1977. Last previous edition approved in 2014 as A751 14
14、. DOI:10.1520/A0751-14A.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.*A Summary of Changes section appears
15、 at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E415 Test Method for Analysis of Carbon and Low-AlloySteel by Spark Atomic Emission SpectrometryE548 Guide for General Criteria Used for Evaluating Labo-rator
16、y Competence (Withdrawn 2002)3E572 Test Method for Analysis of Stainless and Alloy Steelsby Wavelength Dispersive X-Ray Fluorescence Spectrom-etryE743 Guide for Spectrochemical Laboratory Quality Assur-ance (Withdrawn 1998)3E851 Practice for Evaluation of Spectrochemical Laborato-ries (Withdrawn 199
17、8)3E882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE1019 Test Methods for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel, Iron, Nickel, and CobaltAlloys by Various Combustion and Fusion TechniquesE1085 Test Method for Analysis of Low-Alloy Steels by
18、X-Ray Fluorescence SpectrometryE1086 Test Method forAnalysis ofAustenitic Stainless Steelby Spark Atomic Emission SpectrometryE1097 Guide for Determination of Various Elements byDirect Current Plasma Atomic Emission SpectrometryE1184 Practice for Determination of Elements by GraphiteFurnace Atomic A
19、bsorption SpectrometryE1282 Guide for Specifying the Chemical Compositions andSelecting Sampling Practices and Quantitative AnalysisMethods for Metals, Ores, and Related MaterialsE1329 Practice for Verification and Use of Control Charts inSpectrochemical AnalysisE1476 Guide for Metals Identification
20、, Grade Verification,and SortingE1806 Practice for Sampling Steel and Iron for Determina-tion of Chemical Composition2.2 ISO Standards:4ISO/IEC 17025 General Requirements for the Competenceof Testing and Calibration Laboratories3. Terminology3.1 Definitions:3.1.1 Pertaining to Analyses:3.1.1.1 cast
21、or heat (formerly ladle) analysis, napplies tochemical analyses representative of a heat of steel as reportedto the purchaser and determined by analyzing a test sample,preferably obtained during the pouring of the steel, for theelements designated in a specification.3.1.1.2 product, check, or verifi
22、cation analysis, na chemi-cal analysis of the semifinished or finished product, usually forthe purpose of determining conformance to the specificationrequirements. The range of the specified composition appli-cable to product analysis is normally greater than that appli-cable to heat analysis in ord
23、er to take into account deviationsassociated with analytical reproducibility (Note 1) and theheterogeneity of the steel.NOTE 1All of the chemical analysis procedures referenced in thesetest methods include precision statements with reproducibility data, withthe exception of Test Methods E50.3.1.1.3
24、product analysis tolerances (Note 2), na permis-sible variation over the maximum limit or under the minimumlimit of a specified element and applicable only to productanalyses, not cast or heat analyses.NOTE 2The term “analysis tolerance” is often misunderstood. It doesnot apply to cast or heat analy
25、ses determined to show conformance tospecified chemical limits. It applies only to product analysis and becomesmeaningful only when the heat analysis of an element falls close to one ofthe specified limits. For example, stainless steel UNS 30400 limits forchromium are 18.00 to 20.00 %. A heat that t
26、he producer reported as18.01 % chromium may be found to show 17.80 % chromium by a userperforming a product analysis. If the product analysis tolerance for such achromium level is 0.20 %, the product analysis of 17.80 % chromiumwould be acceptable. A product analysis of 17.79 % would not beacceptabl
27、e.3.1.1.4 proprietary analytical method, na non-standardanalytical method, not published by ASTM, utilizing referencestandards traceable to the National Institute of Standards andTechnology (NIST) (when available) or other sources refer-enced in Section 10.3.1.1.5 referee analysis, nperformed using
28、ASTM meth-ods listed in 9.1.1, NIST reference standards or methods, andreference standards agreed upon between parties. The selectionof a laboratory to perform the referee analysis shall be a matterof agreement between the supplier and the purchaser.3.1.1.6 certified reference material, na specimen
29、of mate-rial specially prepared, analyzed, and certified for chemicalcontent under the jurisdiction of a recognized standardizingagency or group, such as the NIST, for use by analyticallaboratories as an accurate basis for comparison. Referencesamples should bear sufficient resemblance to the materi
30、al tobe analyzed so that no significant differences are required inprocedures or corrections (for example, for interferences orinter-element effects).3.1.1.7 working reference materials, nreference materialsused for routine analytical control and traceable to NISTstandards and other recognized stand
31、ards when appropriatestandards are available.3.1.2 Pertaining to Elements:3.1.2.1 intentionally added unspecified element, nan ele-ment added in controlled amounts at the option of the producerto obtain desirable characteristics.3.1.2.2 residual element, na specified or unspecifiedelement, not inten
32、tionally added, originating in raw materials,refractories, or air.3.1.2.3 specified element, nan element controlled to aspecified range, maximum or minimum, in accordance with therequirements of the product specification.3.1.2.4 trace element, na residual element that may occurin very low concentrat
33、ions, generally less than 0.01 %.4. Concerning Specification of Chemical CompositionRequirements4.1 It is recommended that Guide E1282 be consulted as aguide for specifying the chemical compositions for steels.3The last approved version of this historical standard is referenced onwww.astm.org.4Avail
34、able from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.A751 14a24.2 The recommended practice for specifying chemicalcomposition limits is to limit the number of significant figuresfor each element so that the number of figures to the
35、right of thedecimal point conforms to the following:ChemicalConcentration:Maximum Number of Figuresto the Right of the Decimal Point:Up to 0.010 %, incl. 0.XXXX or may be expressed as ppmOver 0.010 % to 0.10 %, incl. 0.XXXOver 0.10 % to 3.0 %, incl. 0.XXOver 3.0 % 0.X4.3 For those cases in which the
36、 composition range spanseither 0.10 % or 3.0 %, the number of figures to the right of thedecimal is to be determined by that indicated by the upperlimit.4.4 Technical considerations may dictate the employment ofless than the number of figures to the right of the decimal aspreviously recommended.NOTE
37、 3The recommendations should be employed to reduce thenumber of significant figures, such as from 18.00 % to 18.0 %, but asignificant figure should never be added unless there is a technical reasonfor so doing.5. Cast or Heat Analysis5.1 The producer shall perform analyses for those elementsspecifie
38、d in the material specification. The results of suchanalyses shall conform to the requirements specified in thematerial specification.5.1.1 For multiple heats, either individual heat or castanalysis, or an average heat or cast analysis, shall be reported.If significant variations in heat or cast siz
39、e are involved, aweighted average heat or cast analysis, based on the relativequantity of metal in each heat or cast, shall be reported.5.1.2 For consumable electrode remelted material, a heat isdefined as all the ingots remelted by the same process from aprimary heat. The heat analysis shall be obt
40、ained from oneremelted ingot, or the product of one remelted ingot, from eachprimary melt. If this heat analysis does not meet the heatanalysis requirements of the specification, one sample from theproduct of each remelted ingot shall be analyzed, and theanalyses shall meet the heat analysis require
41、ments.5.2 If the test samples taken for the heat analysis are lost,inadequate, or not representative of the heat, a product analysisof the semifinished or finished product may be used to establishthe heat analysis.5.2.1 If a product analysis is made to establish the heatanalysis, the product analysi
42、s shall meet the specified limits forheat analysis and the product analysis tolerances described inSection 6 do not apply.6. Product Analysis Requirements6.1 For product analysis, the range of the specified chemicalcomposition is normally greater (designated product analysistolerances) than that app
43、licable to heat analyses to take intoaccount deviations associated with analytical reproducibilityand the heterogeneity of the steel. If several determinations ofany element in the heat are made, they may not vary bothabove and below the specified range.6.2 Product analysis tolerances may not be use
44、d to deter-mine conformance to the specified heat or cast analysis unlesspermitted by the individual material specification.6.3 Product analysis tolerances, where available, are givenin the individual material specifications or in the generalrequirement specifications.7. Unspecified Elements (Note 4
45、)7.1 Reporting analyses of unspecified elements is permitted.NOTE 4All commercial metals contain small amounts of variouselements in addition to those which are specified. It is neither practical nornecessary to specify limits for every unspecified element that might bepresent, despite the fact that
46、 the presence of many of these elements isoften routinely determined by the producer.7.2 Analysis limits shall be established for specific elementsrather than groups of elements such as “all others,” “rareearths,” and “balance.”8. Sampling8.1 Cast or Heat Analyses:8.1.1 Samples shall be taken, insof
47、ar as possible, during thecasting of a heat, at a time which, in the producers judgment,best represents the composition of the cast.8.1.2 In case the heat analysis samples or analyses are lostor inadequate, or when it is evident that the sample does nottruly represent the heat, representative sample
48、s may be takenfrom the semifinished or finished product, in which case suchsamples may be analyzed to satisfy the specified requirements.The analysis shall meet the specified limits for heat analysis.8.2 Check, Product, or Verification AnalysesUnless other-wise specified, the latest revision of Prac
49、tice E1806 shall beused as a guide for sampling.9. Test Methods9.1 This section lists some test methods that have beenfound acceptable for chemical analysis of steels.9.1.1 The following ASTM wet chemical test methods havebeen found acceptable as referee test methods and as a base forstandardizing instrumental analysis techniques:TestMethods: General Description:E350 basic wet chemical procedure for steelsE352 wet chemical procedure for tool steelsE353 wet chemical procedure for stainless steelsE354 wet chemical procedure for high nickel steelsE1019 determination o
