1、Designation: E 1999 99 (Reapproved 2004)Standard Test Method forAnalysis of Cast Iron Using Optical Emission Spectrometry1This standard is issued under the fixed designation E 1999; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the optical emission spectro-metric analysis of cast iron by use of the point-to-p
3、lanetechnique for the following elements in the concentrationranges shown (Note 1):Concentration Ranges, %Elements Applicable Range, % Quantitative Range, %ACarbon 1.9 to 3.8 1.90 to 3.8Chromium 0 to 2.0 0.025 to 2.0Copper 0 to 0.75 0.015 to 0.75Manganese 0 to 1.8 0.03 to 1.8Molybdenum 0 to 1.2 0.01
4、 to 1.2Nickel 0 to 2.0 0.02 to 2.0Phosphorus 0 to 0.4 0.005 to 0.4Silicon 0 to 2.5 0.15 to 2.5Sulfur 0 to 0.08 0.01 to 0.08Tin 0 to 0.14 0.004 to 0.14Titanium 0 to 0.12 0.003 to 0.12Vanadium 0 to 0.22 0.008 to 0.22_AQuantitative range in accordance with Practice E 1601.NOTE 1The concentration ranges
5、 of the elements listed have beenestablished through cooperative testing of reference materials. Theseconcentration ranges can be extended by the use of suitable referencematerials.1.2 This test method covers analysis of specimens having adiameter adequate to overlap the bore of the spark standopeni
6、ng (to effect an argon seal). The specimen thicknessshould be sufficient to prevent overheating during excitation. Aheat sink backing may be used. The maximum thickness islimited only by the height that the stand will permit.1.3 This standard does not purport to address all of thesafety concerns, if
7、 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.2. Referenced Documents2.1 ASTM Standards:2E 135 Terminology Relating to Analytical Chemis
8、try forMetals, Ores, and Related MaterialsE 158 Practice for Fundamental Calculations to ConvertIntensities into Concentrations in Optical Emission Spec-trochemical AnalysisE 172 Practice for Describing and Specifying the ExcitationSource in Emission Spectrochemical AnalysisE 305 Practice for Establ
9、ishing and Controlling Spectro-chemical Analytical CurvesE 351 Test Methods for Chemical Analysis of Cast IronAll TypesE 406 Practice for Using Controlled Atmospheres in Spec-trochemical AnalysisE 826 Practice for Testing Homogeneity of Materials for theDevelopment of Reference MaterialsE 1019 Test
10、Methods for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel and in Iron, Nickel, andCobalt AlloysE 1059 Practice for Designating Shapes and Sizes of Non-graphite Counter Electrodes3E 1329 Practice for Verification and Use of Control Chartsin Spectrochemical Analysis3E 1601 Practice for
11、 Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE 1763 Guide for Interpretation and Use of Results fromInterlaboratory Testing of Chemical Analysis MethodsE 1806 Practice for Sampling Steel and Iron for Determi-nation of Chemical Composition2.2 Other Documents:
12、MNL 7 Manual on Presentation of Data and Control ChartAnalysis1This 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 approve
13、d Oct. 1, 2004. Published Nov. 2004. Originallyapproved in 1999. Last previous edition approved in 1999 as E 199999e1.2For 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 t
14、o 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.3. Terminology3.1 Definitions For definitions of terms used in this testmethod, refer to Terminology E 135.4. Summary of Test Me
15、thod4.1 The most sensitive lines for carbon, phosphorus, sulfurand tin lie in the ultraviolet region. The absorption of theradiation by air in this region is overcome by flushing the sparkchamber with argon or argon-hydrogen gas mixture and eitherevaluating all or portions of the spectrometer or fil
16、ling all orportions of the spectrometer with an inert gas. A capacitordischarge is produced between the flat, ground surface of thedisk specimen and a conically shaped electrode. The dischargeis terminated at a predetermined intensity of a selected ironline, or at a predetermined time, and the relat
17、ive radiantenergies of the analytical lines are recorded and converted toconcentration.5. Significance and Use5.1 The chemical composition of cast iron alloys must bedetermined accurately in order to insure the desired metallur-gical properties. This procedure is suitable for manufacturingcontrol an
18、d inspection testing.6. Interferences6.1 Interferences may vary with spectrometer design andexcitation characteristics. Direct spectral interferences may bepresent on one or more of the wavelengths listed in a method.Frequently, these interferences must be determined and propercorrections made by th
19、e use of various reference materials. Thecomposition of the sample being analyzed should matchclosely the composition of one or more of the referencematerials used to prepare and control the calibration curvewhich is employed. Alternatively, mathematical correctionsmay be used to solve for interelem
20、ent effects (refer to PracticeE 158). Various mathematical correction procedures are com-monly utilized. Any of these is acceptable, which will achieveanalytical accuracy equivalent to that provided by this testmethod.7. Apparatus7.1 When required, use sample preparation equipment asfollows:7.1.1 Sa
21、mple Mold, to produce graphite-free white chillediron samples that are homogeneous, free of voids or porosity inthe region to be excited, and representative of the material to beanalyzed. A chill-cast disk approximately 40 mm (112 in.) indiameter and 3 to 12-mm (18 to12-in.) thick is satisfactory. A
22、sample mold made from copper with a low oxygen content hasproven to be optimum for this purpose. Refer to PracticeE 1806 for iron sampling procedures.7.1.2 Surface Grinder or Sander with Abrasive Belts orDisks, capable of providing a flat, clean, uniform surface on thereference materials and specime
23、ns.7.2 Excitation Source, capable of providing sufficient en-ergy to sample the specimen and excite the analytes of interest.See Practice E 172. Any other excitation source whose perfor-mance has been proven to be equivalent may be used.7.3 Excitation Chamber, automatically flushed with argonor othe
24、r inert support gas. Gases and electrodes are describedin 8.1 and 8.2.NOTE 2Clean the excitation chamber when the counter electrode isreplaced. Clean the lens or protective window after approximately 200 to300 excitations, or at a statistically determined time based on intensityloss, to minimize tra
25、nsmission losses.7.4 Spectrometer, having sufficient resolving power andlinear dispersion to separate clearly the analytical lines fromother lines in the spectrum in the spectral region 170.0 to 500.0nm. The spectrometers used to test this method had a disper-sion of 0.3 to 0.6 nm/mm and a focal len
26、gth of 0.5 to 0.75 m.Spectral lines are listed in Table 1. The primary slit width is 15to 50 m. Secondary slit width is 15 to 200 m. Thespectrometer shall be provided with one or more of thefollowing:7.4.1 An air/gas inlet and a vacuum outlet. The spectrometershall be operated at a vacuum of 25 m of
27、 mercury or below.7.4.2 A gas inlet and a gas outlet.7.4.3 Sealed with nitrogen or other inert gas.TABLE 1 Analytical and Internal Standard Lines, PossibleInterferenceElement Wavelength, nm Reported PossibleInterferingElementsCarbon 193.093 A1, Mo, Cu, SChromium 267.716 Mo, S, Mn265.859Copper 211.20
28、9 Ni221.81327.4 Mo, P510.5 VManganese 293.306 Cr, Mo, WMolybdenum 202.03 Ni281.61 MnNickel 243.789 Mn231.604 Mn341.4352.45 MoPhosphorus 178.287 Cr, Mn, Mo, CuSilicon 212.411 Mo, Cu, Ni251.612288.16 Mo, CrSulfur 180.731 Mn, Cu, CrTin 189.989 Mn, Mo, FeTitanium 334.904 Cr337.2 Fe334.2Vanadium 310.23 N
29、i311.07IronA273.074271.4281.33360.89AInternal standard.E 1999 99 (2004)27.5 Measuring System, consisting of photomultipliers hav-ing individual voltage adjustment, capacitors on which theoutput of each photomultiplier is stored and an electronicsystem to measure voltages on the capacitors either dir
30、ectly orindirectly, and the necessary switching arrangements to pro-vide the desired sequence of operation.7.6 Readout Console, capable of indicating the ratio of theanalytical lines to the internal standard with sufficient precisionto produce the accuracy of analysis desired.7.7 Flushing System, co
31、nsisting of argon tanks or an argon-hydrogen gas mixture, a pressure regulator, and a gas flowme-ter. Automatic sequencing shall be provided to actuate the flowof argon or argon-hydrogen mixture at a given flow rate for agiven time interval and to start the excitation at the end of theflush period.
32、Means of changing the flow rate of argon orargon-hydrogen mixture shall be provided. The flushing systemshall be in accordance with Practice E 406.7.8 Vacuum Pump, if required, capable of maintaining avacuum of 25 m Hg.NOTE 3A pump with a displacement of at least 0.23 m3/min (8 ft3/min) is usually a
33、dequate.8. Reagents and Materials8.1 Inert gas, argon, nitrogen, and hydrogen, as required,must be of sufficient purity to permit proper excitation of theanalytical lines of interest in the excitation chamber or lighttransmittance in the spectrometer chamber. Use in accordancewith Practice E 406.8.2
34、 Counter ElectrodesA silver or thoriated tungsten rodof 2 to 6-mm diameter ground to a 30 to 90 included angleconical tip, which conforms to Practice E 1059, has been foundsatisfactory.NOTE 4A black deposit may build up on the tip of the electrode, thusreducing the overall intensity of the spectral
35、radiation. The number ofacceptable excitations on an electrode varies from one instrument toanother and should be determined in each laboratory. With a thoriatedtungsten electrode, it has been reported that a hundred or more excitationsusually can be made before replacement. Cleaning electrodes afte
36、r eachburn significantly reduces this buildup and gives more consistent results.9. Reference Materials9.1 Certified Reference Materials, used as calibrants, forchill-cast iron alloys are available commercially.9.2 Other Calibrants, shall be chemically analyzed testspecimens taken from production hea
37、ts. They shall cover theconcentration ranges of the elements to be determined and shallinclude all of the specific types of alloys being analyzed. Thesecalibrants shall be homogeneous and free of voids and porosity.The metallurgical history of the calibrants should be similar tothat of the specimens
38、 being analyzed. Refer to Test MethodsE 351 and E 1019 or other nationally accepted test methods forchemical analysis of iron base alloys. Refer to Practice E 826for information on homogeneity testing of reference materials.9.2.1 In selecting calibrants, use caution with compositionsthat are unusual
39、. One element may influence adversely theradiant energy of another element or its uniformity of distri-bution within the material. Tests should be made to determineif interrelations exist between elements in the calibrants. Tocompensate for interelement effects, it is suggested that thecalibrants ap
40、proximate the composition of the material to betested.10. Preparation of Calibrants and Specimens10.1 Cast graphite-free specimens from molten metal into asuitable mold and cool. The molten metal must be at a highenough temperature for all carbon to be in solution. Prepare thesurface to be analyzed
41、on a suitable belt or disk grinder.Prepare the surface of the specimens and reference materials ina similar manner. All specimens must be moisture-free forproper excitation in the argon atmosphere.NOTE 5Specimen porosity is undesirable because it leads to the“diffuse-type” rather than the desired “c
42、oncentrated-type” discharge. Thespecimen surface should be kept clean because the specimen is theelectron emitter, and electron emission is inhibited by oily, dirty surfaces.NOTE 6Reference materials and specimens shall be refinished dry ona belt or disc sander before being re-excited on the same ar
43、ea.11. Excitation and Exposure11.1 Operate the spectrometer according to the manufactur-ers instructions.NOTE 7When parameters are established, maintain them carefully.The variation of the power supply voltage shall not exceed 65 % andpreferably should be held within 62%.11.1.1 An example of excitat
44、ion parameters for a highenergy undirectional spark source is listed below:Preburn ExposureCapacitance, F 10 10Inductance, H 20 20Resistance, V 04.4Potential, V 550 350Number of discharges/s 120 6011.2 Exposure Conditions (Note 8)An example of expo-sure parameters is listed below:Preflush period, s
45、2 to 10Preburn period, s 5 to 20Exposure period, s 5 to 20Argon Flow (Note 9)ft3/h L/minFlush 5 to 45 2.5 to 25Preburn 5 to 45 2.5 to 25Exposure 5 to 30 2.5 to 15NOTE 8Select preburn and exposure periods after a study of volati-zation rates during specimen excitation. Once established, maintain thep
46、arameters consistently.NOTE 9A high-purity argon atmosphere is required for the analyticalgap. Molecular gas impurities, nitrogen, oxygen, hydrocarbons, or watervapor, either in the gas system or from improperly prepared specimensshould be minimized.11.3 Electrode System For conventional capacitor d
47、is-charge excitation systems, the specimen, electrically negative,serves as one electrode. The opposite electrode is a thoriatedtungsten or silver rod, the tip of which has been sharpened toa 30 to 90 included angle cone. Usea3to6-mm (0.125 to0.25-in.) gap. Once a gap size is selected, maintain a co
48、nsistentgap. Center the analytical gap on the optical axes of thespectrometer. Condition a fresh counter electrode with 2 to 6excitations using the conditions given in 11.1 and 11.2.E 1999 99 (2004)312. Preparation of Apparatus12.1 Prepare the spectrometer in accordance with the manu-facturers instr
49、uctions. Program the spectrometer to accommo-date the internal standard lines and one of the analytical linesfor each element listed in Table 1.NOTE 10It is not within the scope of this test method to prescribe alldetails of equipment to be used. Equipment varies between laboratories.NOTE 11The lines listed in Table 1 have been proven satisfactory forthe elements and concentration ranges described in the scope. Otherinternal standard and analytical lines may be used provided that it can beshown experimentally that equivalent precision and ac
