1、Designation: E1085 09Standard Test Method forAnalysis of Low-Alloy Steels by X-Ray FluorescenceSpectrometry1This standard is issued under the fixed designation E1085; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 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 the follow-ing elemen
3、ts:Element Concentration Range, %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 0.61.2 The values stated in
4、 inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
5、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 statements are given in Section 10.2. Referenced Documents2.1 ASTM Standards:2E135 Terminology Rela
6、ting to Analytical Chemistry forMetals, Ores, and Related MaterialsE305 Practice for Establishing and Controlling AtomicEmission Spectrochemical Analytical CurvesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1361 Guide for Correction of Interelement
7、 Effects inX-Ray Spectrometric AnalysisE1621 Guide for X-Ray Emission Spectrometric Analysis3. Terminology3.1 For definitions 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 an X
8、-ray beam of high energy. Thesecondary X-rays produced are dispersed by means of crystals,and the intensities are measured by suitable detectors atselected wavelengths. Radiation measurements are made basedon the time required to reach a fixed number of counts, or onthe total counts obtained for a f
9、ixed time. Concentrations of theelements are determined by relating the measured radiation ofunknown specimens to analytical curves prepared with suitablereference materials. Either a fixed-channel, polychromatorsystem or a sequential, monochromator system may be used toprovide simultaneous or seque
10、ntial determinations of elements.5. Significance and Use5.1 This procedure is suitable for manufacturing control andfor verifying that the product meets specifications. This testmethod provides rapid, multielement determinations with suf-ficient accuracy to ensure product quality and minimize pro-du
11、ction delays. The analytical performance data may be usedas a benchmark to determine if similar X-ray spectrometersprovide equivalent precision and accuracy, or if the perfor-mance of a particular X-ray spectrometer has changed.5.2 Calcium is sometimes added to steel to effect inclusionshape control
12、 in order to enhance certain mechanical propertiesof steel. This test method is useful for determining the residualcalcium in the steel after such treatment.1This test method is under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and is the dir
13、ectresponsibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.Current edition approved Oct. 1, 2009. Published December 2009. Originallyapproved in 1987. Last previous edition approved in 2004 as E1085 95 (2004).DOI: 10.1520/E1085-09.2For referenced ASTM standards, visit the ASTM website,
14、 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5
15、.2.1 Because calcium occurs primarily in inclusions, theprecision of this test method 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. Inter
16、ferences6.1 Interelement or matrix effects may exist for some of theelements in 1.1. Mathematical corrections may be used tocompensate for these effects. Various mathematical correctionprocedures are commonly utilized. See Guide E1361 andPractice E1621. Any of these procedures is acceptable that wil
17、lachieve analytical accuracy equivalent to that provided by thistest method.6.2 Because trace amounts of calcium are being determinedwith this test method, exercise care not to contaminate thespecimen. The presence of calcium in the grinding mediumwill contaminate the specimen to the extent that err
18、atic andincorrect results will be obtained. Therefore, the grindingmedium shall be analyzed for calcium and only those materialsthat are free of calcium shall be used.7. Apparatus7.1 Specimen Preparation Equipment:7.1.1 Surface Grinder or Sander With Abrasive Belts, Disks,or Lathe, capable of provid
19、ing 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 shall be used.7.2 Excitation Source:7.2.1 X-Ray Tube Power Supply, providing a constant po-tential or rectified power of sufficient
20、energy to producesecondary radiation from the specimen for the elements speci-fied. The generator may be equipped with a line voltageregulator and current stabilizer.7.2.2 X-Ray Tubes, with targets of various high-purityelements, that are capable of continuous operation at requiredpotentials and cur
21、rents, and will excite the elements to bedetermined.7.2.2.1 For the determination of calcium only chromiumtarget tubes were tested. Other targets may be used providedthey produce data that meets the precision and bias in Section16.7.3 Spectrometer, designed for X-ray fluorescence analysis,and equipp
22、ed with specimen holders and a specimen chamber.The chamber may contain a specimen spinner, and must beequipped for vacuum or helium-flushed operation for thedetermination of elements of atomic number 20 (calcium) orlower.7.3.1 Analyzing Crystals, flat or curved crystals with opti-mized capability f
23、or the diffraction of the wavelengths ofinterest.7.3.2 Collimator, for limiting the characteristic X rays to aparallel bundle when flat crystals are used. Curved crystals donot require a collimator.7.3.3 Detectors, sealed or gas-flow proportional-type, scin-tillation counters, or equivalent.7.3.4 Va
24、cuum System, providing for the determination ofelements whose radiation is absorbed by air, atomic number 20(calcium) or lower. The system shall consist of a vacuumpump, gage, and electrical controls to provide automaticpumpdown of the optical path and maintain a controlledpressure, usually 13 Pa (1
25、00 m Hg) or less, controlled to6 3Pa(6 20 m Hg).7.4 Measuring System, consisting of electronic circuits ca-pable of amplifying and integrating pulses received from thedetectors. For some measurements, pulse height analyzers maybe required to provide more accurate measurements. Thesystem shall be equ
26、ipped with an appropriate recording device.8. Reagents and Materials8.1 Detector Gas (P-10), consisting of a mixture of 90 %argon and 10 % methane, for use with gas-flow proportionalcounters only.9. Reference Materials9.1 Certified Reference Materials are available from theNational Institute of Stan
27、dards and Technology3and otherinternational certification agencies.9.2 Reference Materials with matrices similar to that of thetest specimen and containing varying amounts of the elementsto be determined may be used provided they have beenchemically analyzed in accordance with ASTM standard testmeth
28、ods. These reference materials shall be homogeneous, andfree of voids or porosity.9.3 The reference materials shall cover the concentrationranges of the elements being sought. A minimum of threereference materials shall be used for each element.10. Hazards10.1 Occupational Health and Safety standard
29、s for ionizingradiation (1)4shall be observed at all X-ray fluorescencespectrometer installations. It is also recommended that operat-ing and maintenance personnel follow the guidelines of safeoperating procedures given in current handbooks and publica-tions from the National Council on Radiation Pr
30、otection andMeasurements (2-4) and the U.S. Government Printing Office(5), or similar handbooks on radiation safety.10.2 X-ray equipment shall be used only under the guidanceand supervision of a responsible, qualified person.10.3 Monitoring Devices, either film badges or dosimetersmay be worn by all
31、 operating and maintenance personnel.Safety regulations shall conform to applicable local, state, andfederal regulations. Follow all local, state, and federal radiationstandards and regulations related to (1) periodic radiationsurveys of the equipment for leaks or excessive scatteredradiation, or bo
32、th; (2) personal film badge survey records; (3)radiation survey records; and (4) equipment maintenancerecords.10.4 Special precautions for operators and maintenancepersonnel shall be posted at the equipment site.3Office of Standard Reference Materials, National Institute of Standards andTechnology (
33、NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070,http:/www.nist.gov.4The boldface numbers in parentheses refer to a list of references at the end ofthis standard.E1085 09210.5 Radiation caution signs shall be posted near the X-rayequipment and at all entrances to the radiation area, con
34、sistentwith state and federal regulations.10.6 Fail-safe “X-Ray On” warning lights shall be used onthe equipment.11. Preparation of Reference Materials and TestSpecimens11.1 Prepare the reference materials and test specimens toprovide a clean, flat uniform surface to be exposed to the X-raybeam. For
35、 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 between 60 and 180 have been foundsuitable.11.2 Refinish the surface of the reference materials and testspe
36、cimens as needed to eliminate surface contamination.12. Preparation of Apparatus12.1 Prepare and operate the spectrometer in accordancewith the manufacturers instructions.NOTE 1It is not within the scope of this test method to prescribeminute details relative to the preparation of the apparatus. For
37、 a descrip-tion and specific details concerning the operation of a particular spectrom-eter, refer to the manufacturers manual.12.1.1 Start-upTurn on the power supply and electroniccircuits and allow sufficient time for instrument stabilizationprior to taking measurements.12.2 Tube Power SupplyAdjus
38、t the voltage of the powersupply to produce optimum conditions.12.2.1 The voltage and current established as optimum forthe X-ray fluorescence power supply in an individual labora-tory shall be reproduced for subsequent measurements.12.3 Proportional Counter Gas FlowWhen a gas-flowproportional count
39、er is used, adjust 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 Measurement ConditionsThe K-a lines for eachelement are used. The pe
40、ak location, when using a scanningspectrometer, should be optimized for each instrument.12.4.1 Crystals and DetectorsThe following crystals anddetectors are used for the elements indicated:Element CrystalADetectorANickel L1, L2 SP, Sc, FPChromium L1, L2 SP, Sc, FPManganese L1, L2 SP, Sc, FPSilicon P
41、ET, InSb FPMolybdenum L1, L2 ScCopper L1, L2 SP, Sc, FPVanadium L1, L2 SP, Sc, FPCobalt L1, L2 SP, Sc, FPSulfur Ge FPNiobium L1, L2 ScPhosphorus Ge FPCalcium L1 FP_AL1 = LiF(200), L2 = LiF(220), SP = Sealed Proportional, Sc = Scintillation, andFP = Flow Proportional.12.4.2 Counting TimeCollect a suf
42、ficient number ofcounts so that the precision of the analysis will not be affectedby the variation in the counting statistics. A minimum of10 000 counts is required for 1 % precision of the countingstatistics and 40 000 for 0.5 %.13. Calibration and Standardization13.1 Calibration (Preparation of An
43、alytical Curves)Using the conditions given in Section 12, measure a series ofreference materials that cover the required concentrationranges. Use at least three reference materials for each element.Measure the reference materials at least two different times oneach of two separate days. Prepare an a
44、nalytical curve for eachelement being determined (refer to Practice E305).13.2 Standardization (Drift Correction)Using a controlreference material, check the calibration of the X-ray spec-trometer at a frequency consistent with statistical processcontrol practice, or when the detector gas or major c
45、omponentshave been changed. If the calibration check indicates that drifthas occurred, make appropriate adjustments in accordance withthe instructions in the manufacturers manual. Refer to PracticeE305 for frequency of verification of standardization.14. Procedure14.1 Specimen LoadingOrient the refe
46、rence 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 when a spinner is use
47、d.14.2 ExcitationExpose the specimen to primary X radia-tion in accordance with Section 12.14.3 Radiation MeasurementsObtain and record thecounting rate measurement for each element. Either fixed countor fixed time modes may be used. Obtain at least the prede-termined minimum counts for all specimen
48、s.14.4 Spectral InterferencesSome X-ray spectrometerswill not completely resolve radiation from several elementalcombinations (for example, molybdenum and sulfur; molyb-denum and phosphorus; iron and cobalt). Therefore, exercisecare in the interpretation of intensities when both elements arepresent.
49、 Use mathematical calculations to correct for suchinterferences. See Practice E1621.14.5 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 radiation measurements for the test specimenan
