ASTM E1085-1995(2004)e1 431 Standard Test Method for X-Ray Emission Spectrometric Analysis of Low-Alloy Steels.pdf

1、Designation: E 1085 95 (Reapproved 2004)1Standard Test Method forX-Ray Emission Spectrometric Analysis of Low-AlloySteels1This standard is issued under the fixed designation E 1085; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, t

2、he 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.1NOTEReference to the Research Report in Section 16 and the footnote were editorially removed in January 2009.1. Scope1

3、.1 This test method covers the wavelength dispersiveX-ray spectrometric analysis of low-alloy steels for the follow-ing elements:Element Concentration Range, %Nickel 0.04 to 3.0Chromium 0.04 to 2.5Manganese 0.04 to 2.5Silicon 0.06 to 1.5Molybdenum 0.005 to 1.5Copper 0.03 to 0.6Vanadium 0.012 to 0.6C

4、obalt 0.03 to 0.2Sulfur 0.009 to 0.1Niobium 0.002 to 0.1Phosphorus 0.010 to 0.08Calcium 0.001 to 0.0071.2 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 he

5、alth 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:2E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 305 Practice for Es

6、tablishing and Controlling AtomicEmission Spectrochemical Analytical CurvesE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE 1361 Guide for Correction of Interelement Effects inX-Ray Spectrometric AnalysisE 1622 Practice for Correction of Spectral Lin

7、e Overlap inWavelength-Dispersive X-Ray Spectrometry33. Terminology3.1 For definitions of terms used in this test method, refer toTerminology E 135.4. 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

8、 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 fixed time. Concentrations of theelemen

9、ts 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 sequential determinations of elements.5. Si

10、gnificance 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-duction delays. The analytical performan

11、ce 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 in order to enhance certain mechanica

12、l propertiesof steel. This test method is useful for determining the residualcalcium in the steel after such treatment.5.2.1 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

13、 ofdeterminations on freshly prepared surfaces will give someindication of the distribution of these inclusions.1This 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 I

14、ron, Steel, and Ferroalloys.Current edition approved Oct. 1, 2004. Published November 2004. Originallyapproved in 1987. Last previous edition approved in 2000 as E 1085 95 (2000).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org.

15、 For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, P

16、A 19428-2959, United States.6. Interferences6.1 Interelement or matrix effects may exist for some of theelements in 1.1. Mathematical corrections may be used to solvefor these effects. Various mathematical correction proceduresare commonly utilized. See Guide E 1361 and Practice E 1622.Any of these

17、procedures is acceptable that will achieveanalytical accuracy equivalent to that provided by this testmethod.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 th

18、e specimen to the extent that erratic 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,

19、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 shall be used.7.2 Excitation Source:7.2.1 X-Ray Tube Power Supply, providing a constant po-tential

20、or rectified power of sufficient energy to producesecondary radiation of the specimen for the elements specified.The generator may be equipped with a line voltage regulatorand current stabilizer.7.2.2 X-Ray Tubes, with targets of various high-purityelements, that are capable of continuous operation

21、at requiredpotentials and currents, and will excite the elements to bedetermined.7.2.2.1 For the determination of calcium only chromiumtarget tubes were tested. Other targets shall be tested prior touse.7.3 Spectrometer, designed for X-ray emission analysis, andequipped with specimen holders and a s

22、pecimen chamber. Thechamber 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 for the diffraction of the wavele

23、ngths ofinterest.7.3.2 Collimator, for limiting the characteristic X rays to aparallel bundle when flat crystals are used in the instrument.For curved crystal optics, a collimator is not necessary.7.3.3 Detectors, sealed or gas-flow proportional-type, scin-tillation counters, or equivalent.7.3.4 Vac

24、uum System, providing for the determination ofelements whose radiation is absorbed by air (for example,calcium, silicon, phosphorus, and sulfur). The system shallconsist of a vacuum pump, gage, and electrical controls toprovide automatic pumpdown of the optical path and maintaina controlled pressure

25、, usually 13 Pa (100 m Hg) or less,controlled to 6 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. Thes

26、ystem shall be equipped 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

27、 Institute of Standards and Technology4and 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

28、 standard testmethods. 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 a

29、nd Safety standards for ionizingradiation5shall be observed at all X-ray emission spectrometerinstallations. It is also recommended that operating and main-tenance personnel follow the guidelines of safe operatingprocedures given in current handbooks and publications fromthe National Institute of St

30、andards and Technology6,7and theU.S. Government Printing Office,8or similar handbooks onradiation 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 operating

31、and maintenance personnel.Safety regulations shall conform to applicable local, state, andfederal regulations. To meet local, state, and federal radiationstandards, periodic radiation surveys of the equipment for leaksand excessive scattered radiation shall be made by a qualifiedperson using an ioni

32、zation-chamber detector. The personal film4Office of Standard Reference Materials, National Institute of Standards andTechnology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070,http:/www.nist.gov.5ANSI/NBS Handbook 114, General Safety Standard for Installations UsingNon-Medical X-Ray

33、and Sealed Gamma-Ram Sources, available from AmericanNational Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY10036, http:/www.ansi.org.6NBS Handbook 76, Medical X-Ray Protection Up to Three Million Volts,available as NCRP33 from NCRPPublications, 7910 WoodmontAvenue, Suite 400,Be

34、thesda, Maryland 20814-3095, http:/www.ncrponline.org.7ANSI N43.2-1977/NBS Handbook 111, Radiation Safety for X-Ray Diffractionand Fluorescence Analysis, available from American National Standards Institute(ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.8Moore, T. M., and M

35、cDonald, D. J., Radiation Safety Recommendations forX-Ray Diffraction and Spectrographic Equipment, MORP 68-14, 1968, availablefrom National Technical Information Service (NTIS), 5285 Port Royal Rd.,Springfield, VA 22161, http:/www.ntis.gov.E 1085 95 (2004)12badge survey record, the radiation survey

36、 record, and anequipment maintenance record shall be available upon request.10.4 Special precautions for operators and maintenancepersonnel shall be posted at the equipment site.10.5 Radiation caution signs shall be posted near the X-rayequipment and at all entrances to the radiation area, consisten

37、twith 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 abras

38、ive sanding, select a grit size, and use that gritand size exclusively for all reference materials and testspecimens.11.2 Refinish the surface of the reference materials and testspecimens as needed to eliminate surface contamination.12. Preparation of Apparatus12.1 Prepare and operate the spectromet

39、er 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 a descrip-tion and specific details concerning the operation of a particular spectrom-eter, refer to the manufacturers

40、 manual.12.1.1 Start-upTurn on the power supply and electroniccircuits and allow sufficient time for instrument warm-up priorto taking measurements.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 X

41、-ray emission power supply in an individual laboratoryshall be reproduced for subsequent measurements.12.3 Proportional Counter Gas Flow When a gas-flowproportional counter is used, adjust flow of the P-10 gas inaccordance with the equipment manufacturers instructions.When changing P-10 tanks, the d

42、etectors should be adequatelyflushed with detector gas and adjusted before the instrument isused.12.4 Measurement ConditionsThe K-a lines for eachelement are used. The peak location, when using a scanningspectrometer, should be determined for each instrument.12.4.1 Crystals and DetectorsThe followin

43、g 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 PET, InSb FPMolybdenum L1, L2 ScCopper L1, L2 SP, Sc, FPVanadium L1, L2 SP, Sc, FPCobalt L1, L2 SP, Sc, FPSulfur Ge FPNiobium L1,

44、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 sufficient number ofcounts so that the precision of the analysis will not be affectedby the variation in the counting statistics. A

45、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 Analytical Curves)Using the conditions given in Section 12, measure a series ofreference materials that cover the required concentr

46、ationranges. 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 analytical curve for eachelement being determined (refer to Practice E 305).13.2 Standardization (Analytical Curve Adjustment)Usin

47、g a control reference material, check the calibration of theX-ray spectrometer at a frequency consistent with statisticalprocess control practice, or when the detector gas or majorcomponents have been changed. If the calibration checkindicates that the spectrometer has drifted, make appropriateadjus

48、tments in accordance with the instructions in the manu-facturers manual. Refer to Practice E 305 for frequency ofverification of standardization.14. Procedure14.1 Specimen LoadingOrient the reference materials andtest specimens in the specimen chamber so that the relationshipbetween the X-ray beam a

49、nd 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 used.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 specimens.14.4 Spectral InterferencesSome X-ray spectrometerswill n