1、Designation: E572 12Standard Test Method forAnalysis of Stainless and Alloy Steels by WavelengthDispersive X-ray Fluorescence Spectrometry1This standard is issued under the fixed designation E572; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 of revision, 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 method2covers the analysis of stainless andalloy steels by wavelength dispersive X
3、-ray FluorescenceSpectrometry for the determination of the following elements:Element Range, Mass Fraction%Chromium 2.0 to 25.0Cobalt 0.03 to 0.40Copper 0.05 to 3.50Manganese 0.3 to 5.0Molybdenum 0.15 to 3.5Nickel 0.20 to 35.0Niobium 0.05 to 1.3Phosphorus 0.01 to 0.03Silicon 0.05 to 0.20Sulfur 0.02
4、to 0.30Titanium 0.002 to 0.04Vanadium 0.03 to 0.25NOTE 1Unless exceptions are noted, mass fraction ranges can beextended by the use of suitable reference materials.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the
5、 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:3E135 Terminology Relating to Analytical Chemistr
6、y forMetals, Ores, and Related MaterialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric AnalysisE1621 Guid
7、e 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-ray beam of high energy. Thesecondary X-rays pr
8、oduced are dispersed by means of crystalsand the count rates are measured by suitable detectors atselected wavelengths. The outputs of the detectors in voltagepulses are counted. Radiation measurements are made based onthe time required to reach a fixed number of counts, or on thetotal counts obtain
9、ed for a fixed time (generally expressed incounts per unit time). Mass fractions of the elements aredetermined by relating the measured radiation of unknownspecimens to analytical curves prepared using suitable refer-ence materials. Both simultaneous spectrometers containing afixed-channel monochrom
10、ator for each element and sequentialspectrometers using a goniometer monochromator can be usedfor measurement of the elements.5. Significance and Use5.1 This procedure is suitable for manufacturing control andfor verifying that the product meets specifications. It providesrapid, multi-element determ
11、inations with sufficient accuracy toassure product quality. The analytical performance data in-cluded may be used as a benchmark to determine if similarX-ray spectrometers provide equivalent precision andaccuracy, or if the performance of a particular spectrometer haschanged.5.2 It is expected that
12、this standard will be employed byanalysts knowledgeable in the field of X-ray fluorescencespectrometry and experienced in the use of the apparatusspecified in this standard.6. Interferences6.1 Interelement effects or matrix effects exist for some ofthe elements listed. Mathematical correction may be
13、 used to1This test method 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 Dec. 1, 2012. Published January 2013. Originallyapp
14、roved in 1976. Last previous edition approved in 2006 as E572 02a(2006)2.DOI: 10.1520/E0572-12.2Supporting data for this test method as determined by cooperative testing havebeen filed at ASTM International Headquarters as RR:E01-1118.3For referenced ASTM standards, visit the ASTM website, www.astm.
15、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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1solve for th
16、ese elements. Various mathematical correctionprocedures are commonly utilized. See Guides E1361 andE1621. Any of these procedures that achieves analyticalaccuracy equivalent to that provided by this test method isacceptable.7. Apparatus7.1 Specimen Preparation Equipment:7.1.1 Surface Grinder or Sand
17、er with Abrasive Belts orDisks, or Lathe, capable of providing a flat, uniform surface onthe reference materials and test specimens. Aluminum oxideand zirconium oxide belts and discs with a grit size of between60 and 180 have been found suitable.7.2 Excitation Source:7.2.1 X-ray Tube Power Supply, p
18、roviding a constant poten-tial or rectified power of sufficient energy to produce secondaryradiation from the specimen for the elements specified. Thegenerator may be equipped with a line voltage regulator andcurrent stabilizer.7.2.2 X-ray Tubes, with targets of various high-purity ele-ments that ar
19、e capable of continuous operation at requiredpotentials and currents and that will excite the elements to bedetermined.7.3 Spectrometer, designed for X-ray fluorescence analysisand equipped with specimen holders and a specimen chamber.The chamber shall contain a specimen spinner, and must beequipped
20、 for vacuum or helium-flushed operation for measure-ment of elements of atomic number 20 (calcium) and lower.7.3.1 Analyzing Crystals, flat or curved crystals with opti-mized capability for the diffraction of the wavelengths ofinterest. Synthetic multilayer structures can be used in place ofcrystals
21、.7.3.2 Collimators or Slits, for controlling the divergence ofthe characteristic X rays.7.3.3 Detectors, sealed and gas-flow proportional types,scintillation counters or equivalent. Some spectrometers mayallow for tandem use of two different detectors to increasesensitivity.7.3.4 Vacuum System, prov
22、iding for the determination ofelements whose radiation is absorbed by air (for example,silicon, phosphorus, and sulfur). The system shall consist of avacuum pump, gage, and electrical controls to provide auto-matic pump down of the optical path, and to maintain acontrolled pressure, usually 13 Pa (1
23、00 m Hg) or less,controlled to 6 3Pa(6 20 m Hg) or better. A helium-flushedsystem is an alternative to a vacuum system, and it must bedemonstrated to provide sufficient stability to achieve thedemonstrated repeatability performance of this standard.7.4 Measuring System, consisting of electronic circ
24、uits ca-pable of amplifying and integrating pulses received from thedetectors. For some measurements, a pulse height selector inconjunction with the detectors may be required to provide moreaccurate measurements. The system shall be equipped with anappropriate device.8. Reagents and Materials8.1 Det
25、ector 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 com-mercial and government sources.9.2 Reference Materials with matrices similar to those of thetest spe
26、cimens and containing varying amounts of the elementsto be determined may be used provided they have beenanalyzed in accordance with ASTM standard methods orsimilar procedures established by the certifying body. Thesereference materials shall be homogeneous and free of voids andporosity.9.3 The refe
27、rence materials shall cover the mass fractionranges of the elements being sought. A minimum of threereference materials shall be used for each element. A greaternumber of calibrants may be required if the analyst chooses toperform mathematical corrections for interelement effects. SeeGuide E1361.10.
28、 Hazards10.1 U.S Nuclear Regulatory Commission 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”4shall be observed at
29、allX-ray emission spectrometer installations in the U.S. It is alsorecommended that operating and maintenance personnel fol-low the guidelines of safe operating procedures given in similarhandbooks on radiation safety.10.2 Exposure to excessive quantities of high energy radia-tion such as those prod
30、uced 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 secondary or scattered radiation that might be present.The X-ray spectrometer should be operated in accordance withregulatio
31、ns governing the use of ionizing radiation. Duringmanufacturing, manufacturers of X-ray fluorescence spectrom-eters generally build into X-ray equipment appropriate shield-ing and safety interlocks that minimize the risk of excessiveradiation exposure to operators. Operators should not attemptto byp
32、ass or defeat these safety devices. Only authorizedpersonnel should service X-ray spectrometers.11. Preparation of Reference Materials and TestSpecimens11.1 The analyst must choose a measurement area ordiameter from the options built into the spectrometer. All testspecimens and reference materials m
33、ust have a flat surface ofgreater diameter than the chosen viewed area.4Available from the Nuclear Regulatory Commission, Public Document Room,Mail Stop:OWFN-1 F13, Washington, DC 20555, (800) 397-4209, or via email atPDR.Resourcenrc.gov, or via the website at www.nrc.gov.E572 12211.2 Prepare the re
34、ference materials and test specimens toprovide a clean, flat uniform surface to be exposed to theprimary X-ray beam One surface of a reference material maybe designated by the producer as the certified surface. Thesame surface preparation medium shall be used for all refer-ence materials and test sp
35、ecimens.11.3 As needed, refinish the surfaces of the referencematerials and test specimens to eliminate oxidation.12. Preparation of Apparatus12.1 Prepare and operate the spectrometer in accordancewith the manufacturers instructions.NOTE 2It is not within the scope of this test method to prescribemi
36、nute 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 power supply and electroniccircuits and allow sufficient time for instrument warm-up p
37、riorto taking measurements.12.2 Tube Power SupplyThe power supply conditionsshould be set according to the manufacturers recommenda-tions.12.2.1 The voltage and current established as optimum forthe X-ray tube power supply in an individual laboratory shallbe reproduced for subsequent measurements.12
38、.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 before the instrument is used. Afterchanging P
39、-10 tanks, check pulse height selector and gainsettings according to the manufacturers instructions.12.4 Measurement ConditionsThe K (K-L2,3) lines areused for all elements in this standard. When using a sequentialspectrometer, goniometer angle settings shall be calibratedaccording to the manufactur
40、ers guidelines.12.4.1 Crystals and DetectorsThe following crystals anddetector choices are used for the elements indicated:Element Crystal DetectorChromium L1, L2 FP, SP, ScCobalt L1, L2 FP, SP, ScCopper L1, L2 SP, FP, ScManganese L1, L2 FP, SP, ScMolybdenum L1, L2 Sc, SPNickel L1, L2 SP, FP, ScNiob
41、ium L1, L2 Sc, SPPhosphorus Ge FP, SPSilicon PET, InSb FP, SPSulfur Ge FP, SPTitanium L1, L2 FP, SPVanadium L1, L2 FP, SPL1 = LiF(200), L2 = LiF(220)FP = Flow Proportional, SP = Sealed Proportional, Sc = Scintillation12.4.2 Counting TimeCollect a sufficient number ofcounts so that the random nature
42、of X-ray emission andcounting does not significantly influence the repeatability ofthe measurements.Aminimum of 10 000 counts is required fora relative counting uncertainty of1%atalevel of one standarddeviation, and 40 000 counts is required for 0.5 % relativeuncertainty.13. Calibration and Standard
43、ization13.1 Calibration (Preparation of Analytical Curves)Using the conditions established in Section 12, measure aseries of reference materials that cover the required massfraction ranges. Use at least three reference materials for eachelement. Prepare an analytical curve for each element beingdete
44、rmined (refer to Guide E1621). For information on correc-tion of interelement effects in X-ray fluorescence, refer toGuide E1361. Information on correction of spectral lineoverlaps in wavelength dispersive X-ray spectrometry can befound in Guide E1621.13.2 Standardization (Analytical Curve Adjustmen
45、t)Usingcontrol reference materials, check the calibration of the X-rayspectrometer at a frequency consistent with the process controlpractice of the laboratory or when the detector gas or majorspectrometer components have been changed. If the calibrationcheck indicates that the spectrometer has drif
46、ted, make appro-priate adjustments according to the instructions in the manu-facturers manual. Refer to Guide E1621 for frequency ofverification of standardization.14. Procedure14.1 Specimen LoadingPlace each reference material ortest specimen in the appropriate specimen holding container. Ifthe spe
47、ctrometer is equipped with an automated loadingdevice, repeatability may be improved by loading and unload-ing all specimens from the same holder. The container shallhave a suitable opening to achieve the required precision in anacceptable amount of time. The holder must be equipped tokeep the speci
48、men from moving inside the holder.14.2 ExcitationExpose the specimen to primary X-rayradiation in accordance with Section 12.14.3 Radiation MeasurementsObtain and record thecounting rate for each element. Either fixed count or fixed timemodes may be used.14.4 Spectral InterferencesSome X-ray spectro
49、meterswill not completely resolve radiation from several elementcombinations (for example, molybdenum and sulfur; molyb-denum and phosphorus; and iron and cobalt). Therefore, caremust be exercised in the interpretation of count rates when bothelements are present. Mathematical calculations must be usedto correct for the interferences.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
