1、Designation: E1085 16Standard Test Method forAnalysis of Low-Alloy Steels by Wavelength DispersiveX-Ray Fluorescence Spectrometry1This standard is issued under the fixed designation E1085; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revi
2、sion, 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 test method covers the wavelength dispersiveX-ray fluorescence analysis of low-alloy steels for
3、 the follow-ing elements:Element Mass FractionRange, %Calcium 0.001 to 0.007Chromium 0.04 to 2.5Cobalt 0.03 to 0.2Copper 0.03 to 0.6Manganese 0.04 to 2.5Molybdenum 0.005 to 1.5Nickel 0.04 to 3.0Niobium 0.002 to 0.1Phosphorus 0.010 to 0.08Silicon 0.06 to 1.5Sulfur 0.009 to 0.1Vanadium 0.012 to 0.6NOT
4、E 1Unless exceptions are noted, mass fraction ranges can beextended and additional elements can be included by the use of suitablereference materials and measurement conditions. Deviations from thepublished scope must be validated by experimental means. See GuideE2857 for information on validation o
5、ptions.1.2 The values stated in the International System of Units(SI) are to be regarded as standard. The values given inparentheses are mathematical conversions to other units thatare provided for information only, because they may used inolder software and laboratory procedures.1.3 This standard d
6、oes 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 limitations prior to use. Specific precau-tionary statement
7、s are given in Section 10.2. Referenced Documents2.1 ASTM Standards:2E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE691 Practice for Conducting an Interlaborato
8、ry Study toDetermine the Precision of a Test MethodE1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric AnalysisE1621 Guide for Elemental Analysis by Wavelength Disper-sive X-Ray Fluorescence SpectrometryE2857 Guide for Validating Analytical Methods3. Terminology3.1 For definitio
9、ns of terms used in this test method, refer toTerminology E135.4. Summary of Test Method4.1 The test specimen is finished to a clean uniform surfaceand then irradiated with a primary X-ray beam of high energy.The secondary X-rays produced are dispersed by means ofcrystals, and the intensities (also
10、called count rates) aremeasured by suitable detectors at selected wavelengths. Radia-tion measurements are made based on the time required toreach a fixed number of counts, or on the total counts obtainedfor a fixed time. Mass fractions of the elements are determinedby relating the measured intensit
11、ies from unknown specimensto analytical curves prepared with suitable reference materials.Either a fixed-channel, polychromator system or a sequential,wavelength dispersive monochromator system may be used toprovide simultaneous or sequential determinations of elements,respectively.1This test method
12、 is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is the directresponsibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.Current edition approved May 1, 2016. Published June 2016. Originallyapproved in 1987. Last previous
13、edition approved in 2009 as E1085 09. DOI:10.1520/E1085-16.2For 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.Co
14、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Significance and Use5.1 This test method is suitable for manufacturing controland for verifying that a product meets specifications. This testmethod provides rapid, multi-element determ
15、inations withsufficient accuracy to ensure product quality and to minimizeproduction delays. The analytical performance data may beused as a benchmark to determine if similar X-ray spectrom-eters provide equivalent precision and accuracy, or if theperformance of a particular X-ray spectrometer has c
16、hanged.5.2 Calcium is sometimes added to steel to affect inclusionshape to enhance certain mechanical properties of steel. Thistest method is useful for determining the residual calcium inthe steel after such treatment.5.2.1 Because calcium occurs primarily in inclusions, theprecision of this test m
17、ethod is a function of the distribution ofthe calcium-bearing inclusions in the steel. The variation ofdeterminations on freshly prepared surfaces will give someindication of the distribution of these inclusions.6. Interferences6.1 Interelement or matrix effects may exist for someelements in 1.1. Ma
18、thematical corrections may be used tocompensate for these effects. Various mathematical correctionprocedures are commonly utilized. See Guide E1361 andGuide E1621. Any of these procedures is acceptable that willachieve analytical accuracy equivalent to that provided by thistest method.6.2 Spectrosco
19、pic interferences or line overlaps may beobserved, if the energy resolution of the measurement condi-tions is insufficient. Mathematical corrections may be used tocalibrate the overlaps and perform corrections. See GuideE1621.6.3 Because trace amounts of calcium are being determinedwith this test me
20、thod, exercise care not to contaminate thespecimen. Calcium in the grinding medium will contaminatethe specimen to the extent that erratic and incorrect results willbe obtained. Therefore, the grinding medium shall be analyzedfor calcium, and only materials that are free of calcium shall beused.7. A
21、pparatus7.1 Specimen Preparation Equipment:7.1.1 Surface Grinder or Sander with Abrasive Belts, Disks,or Lathe, capable of providing a flat, uniform surface on thereference materials and test specimens.7.1.1.1 When calcium is to be determined, 240-grit,calcium-free silicon carbide belts or disks sha
22、ll be used.7.2 Wavelength Dispersive Spectrometer, designed for X-rayfluorescence analysis, and equipped with specimen holders anda specimen chamber. The chamber may contain a specimenspinner, and must be equipped for vacuum or helium-flushedoperation for the determination of elements of atomic numb
23、er20 (calcium) or lower.7.2.1 X-Ray Tubes, with targets of various high-purityelements, that are capable of continuous operation at requiredpotentials and currents, and will excite the elements to bedetermined.7.2.1.1 For the determination of calcium, only chromiumtarget tubes were tested. Other tar
24、gets may be used providedthey produce data that meets the precision and bias in Section.7.2.2 Analyzing Crystals, flat or curved crystals with opti-mized capability for the diffraction of the wavelengths ofinterest.7.2.3 Collimator, for limiting the characteristic X-rays to aparallel bundle when fla
25、t crystals are used. Curved crystals donot require a collimator.7.2.4 Detectors, sealed or gas-flow proportional-type, scin-tillation counters, or equivalent.7.2.5 Vacuum System, providing for the determination ofelements whose radiation is absorbed by air, atomic number 20(calcium) or lower. The sy
26、stem shall consist of a vacuumpump, gage, and electrical controls to provide automaticpumpdown of the optical path and maintain a controlledpressure, usually 13 Pa (100 m Hg) or less, controlled to6 3Pa(6 20 m Hg).8. Reagents and Materials8.1 Detector Gas (P-10), consisting of a mixture of 90 %argon
27、 and 10 % methane, for use with gas-flow proportionalcounters only.9. Reference Materials9.1 Certified Reference Materials are available from na-tional metrology institutes, other government organizations,and commercial suppliers.9.2 Reference Materials with matrices similar to that of thetest speci
28、men and containing varying amounts of the elementsto be determined may be used provided they have beenchemically analyzed in using valid, independent test methods.These reference materials shall be homogeneous, and free ofvoids or porosity.9.3 The reference materials shall cover the mass fractionran
29、ges of the elements being sought. A minimum of threereference materials shall be used for each element. Whencorrection factors for matrix effects and spectroscopic interfer-ences are to be calculated from the empirical data as calibrationparameters, at least one additional reference material is need
30、edfor each correction parameter. Refer to Guide E1361 and GuideE1621.NOTE 2Calculation of correction factors for matrix effects andspectroscopic interferences from X-ray theory can be used to reduce thenumber of reference materials required for calibration.10. Hazards10.1 U.S Nuclear Regulatory Comm
31、ission Standards forionizing radiation as found in the Code of Federal Regulations10 CFR Part 19, “Notices, Instructions and Reports to Workers:Inspection and Investigations” and 10 CFR Part 20, ”Standardsfor Protection Against Radiation”3shall be observed at allX-ray emission spectrometer installat
32、ions in the U.S. It is also3Available from U.S. Government Printing Office, Superintendent ofDocuments, 732 N. Capitol St., NW, Washington, DC 20401-0001, http:/www.access.gpo.govE1085 162recommended that operating and maintenance personnel fol-low the guidelines of safe operating procedures given i
33、n similarhandbooks on radiation safety.10.2 Exposure to excessive quantities of high energy radia-tion such as those produced by X-ray spectrometers is injuriousto health. The operator should take appropriate actions to avoidexposing any part of their body, not only to primary X-rays, butalso to sec
34、ondary or scattered radiation that might be present.The X-ray spectrometer should be operated in accordance withregulations governing the use of ionizing radiation. Duringmanufacturing, manufacturers of X-ray fluorescence spectrom-eters generally build into X-ray equipment appropriate shield-ing and
35、 safety interlocks that minimize the risk of excessiveradiation exposure to operators. Operators should not attemptto bypass or defeat these safety devices. Only authorizedpersonnel should service X-ray spectrometers.11. Preparation of Reference Materials and TestSpecimens11.1 Prepare the reference
36、materials and test specimens toprovide a clean, flat uniform surface to be exposed to the X-raybeam. For abrasive sanding, select a grit size, and use that gritand size exclusively for all reference materials and testspecimens. Aluminum oxide and zirconium oxide belts anddiscs with a grit size of be
37、tween 60 and 180 have been foundsuitable.11.2 Refinish the surfaces of the reference materials and testspecimens as needed to eliminate surface contamination.12. Preparation of Apparatus12.1 Prepare and operate the spectrometer in accordancewith the manufacturers instructions.NOTE 3It is not within
38、the scope of this test method to prescribeminute details relative to the preparation of the apparatus. For a descrip-tion and specific details concerning the operation of a particularspectrometer, refer to the manufacturers manual.12.1.1 Start-upTurn on the spectrometer and allow suffi-cient time fo
39、r instrument stabilization prior to taking measure-ments.12.2 Tube Power SupplyAdjust the voltage of the powersupply to produce optimum conditions.12.2.1 The voltage and current established as optimum forthe power supply in an individual laboratory shall be repro-duced for subsequent measurements.12
40、.3 Proportional Counter Gas FlowWhen a gas-flowproportional counter is used, adjust the flow of the P-10 gas inaccordance with the equipment manufacturers instructions.When changing P-10 tanks, the detectors should be adequatelyflushed with detector gas and adjusted before the instrument isused.12.4
41、 Measurement ConditionsThe K-L2,3(K) line ismeasured for each element. The peak location, when using ascanning spectrometer, should be optimized for each instru-ment.12.4.1 Crystals and DetectorsThe following crystals anddetectors used for the elements are listed below. In somespectrometers, multipl
42、e detectors may be used simultaneously.Element Crystal DetectorANickel LiF(200), LiF(220) SP, FP, ScChromium LiF(200), LiF(220) FP, SP, ScManganese LiF(200), LiF(220) FP, SP, ScSilicon PET, InSb FPMolybdenum LiF(200), LiF(220) Sc, SPCopper LiF(200), LiF(220) SP, FP, ScVanadium LiF(200), LiF(220) FP,
43、 SP, ScCobalt LiF(200), LiF(220) FP, SP, ScSulfur Ge FPNiobium LiF(200), LiF(220) Sc, SPPhosphorus Ge FPCalcium LiF(200) FPASP = Sealed Proportional, Sc = Scintillation, and FP = Flow Proportional.12.4.2 Counting TimeCollect a sufficient number ofcounts so that the repeatability of the analysis will
44、 not beaffected by variance in X-ray counting. A minimum of 10 000counts is required for 1 % relative standard uncertainty and 40000 counts for 0.5 %.13. Calibration and Standardization13.1 Calibration (Preparation of Analytical Curves)Using the conditions given in Section 12, measure a series ofref
45、erence materials that cover the mass fraction ranges ofinterest. Prepare an analytical curve for each element beingdetermined. Refer to Guide E1361 and Guide E1621.13.2 Standardization (Drift Correction)Using a controlreference material, check the calibration of the X-ray spec-trometer at a frequenc
46、y consistent with statistical processcontrol practice, or when the detector gas or major componentshave been changed. If the calibration check indicates that drifthas occurred, make appropriate adjustments in accordance withthe instructions in the manufacturers manual.14. Procedure14.1 Specimen Load
47、ingOrient the reference materials andtest specimens in the specimen chamber so that the relationshipbetween the X-ray beam and the grinding striations is the samefor all measurements. This is an essential requirement if thespectrometer is not equipped with a specimen spinner, but isnot necessary whe
48、n a spinner is used.14.2 ExcitationExpose the specimen to primary X-rays inaccordance with Section 12.14.3 Radiation MeasurementsObtain the count rate mea-surement for each element. Either fixed count or fixed timemodes may be used. Obtain at least the predetermined mini-mum counts for all specimens
49、.14.4 Replicate MeasurementsMake a single measurementon each test specimen. The performance of an X-ray spectrom-eter is not improved significantly by making multiple measure-ments on the same surface of the specimen. Confidence in theaccuracy of analysis will improve by making multiple mea-surements on freshly prepared surfaces of the same specimenor by analyzing more than one specimen.15. Calculation of Results15.1 Using the count rates measured for the test specimenand the appropriate analytical curves, determine the massfractions of the elements.E1085 16
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