1、Designation: E 1086 08Standard Test Method forAtomic Emission Vacuum Spectrometric Analysis ofStainless Steel by Point-to-Plane Excitation Technique1This standard is issued under the fixed designation E 1086; the number immediately following the designation indicates the year oforiginal adoption or,
2、 in the case 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 for the atomic emissionvacuum spectrometric analysis of
3、stainless steel in solid formby the point-to-plane excitation technique for the followingelements in the concentration ranges shown:Element Concentration Range, %Chromium 17.0 to 23.0Nickel 7.5 to 13.0Molybdenum 0.01 to 3.0Manganese 0.01 to 2.0Silicon 0.01 to 0.90Copper 0.01 to 0.30Carbon 0.005 to 0
4、.25Phosphorus 0.003 to 0.15Sulfur 0.003 to 0.0651.2 This test method is designed for the routine analysis ofchill-cast disks or inspection testing of stainless steel samplesthat have a flat surface of at least 13 mm (0.5 in.) in diameter.The samples must be sufficiently massive to prevent overheat-i
5、ng during the discharge and of a similar metallurgical condi-tion and composition as the reference materials.1.3 Analytical curves are plotted using the concentrationratio method as shown in Practice E 158. One or more of thereference materials must closely approximate the compositionof the specimen
6、. The technique of analyzing reference mate-rials along with unknowns and performing the indicatedmathematical corrections may also be used to correct forinterference effects and to compensate for errors resulting frominstrument drift.Avariety of such systems are commonly used.Any of these that will
7、 achieve analytical accuracy equivalent tothat reported for this test method are acceptable.1.4 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 health pract
8、ices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related MaterialsE 158 Practice for Fundamental Calculations to ConvertIntensities into Concentrations in Op
9、tical Emission Spec-trochemical Analysis4E 172 Practice for Describing and Specifying the ExcitationSource in Emission Spectrochemical Analysis4E 305 Practice for Establishing and Controlling AtomicEmission Spectrochemical Analytical CurvesE 406 Practice for Using Controlled Atmospheres in Spec-troc
10、hemical AnalysisE 876 Practice for Use of Statistics in the Evaluation ofSpectrometric Data4E 1060 Practice for Interlaboratory Testing of Spectro-chemical Methods of Analysis (Discontinued 1997) Re-placed by E 16014E 1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance o
11、f an Analytical MethodE 1806 Practice for Sampling Steel and Iron for Determi-nation of Chemical Composition3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology E 135.4. Summary of Test Method4.1 A controlled discharge is produced between the flatsurfac
12、e of the specimen and the counter electrode. The radiantenergy of selected analytical lines are converted into electricalenergies by photomultiplier tubes and stored on capacitors. Thedischarge is terminated at a predetermined level of accumu-lated radiant energy from the internal standard iron line
13、 or aftera fixed exposure time. At the end of the exposure period, the1This 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 editio
14、n approved Oct. 1, 2008. Published November 2008. Originallyapproved in 1985. Last previous edition approved in 2005 as E 1086 94 (2005).2Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: E02-1023.3For referenced ASTM standards, v
15、isit 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.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org
16、.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.charge on each capacitor is measured, and displayed orrecorded as a relative energy or concentration.5. Significance and Use5.1 The chemical composition of stainless steels must bedete
17、rmined accurately in order to ensure the desired metallur-gical properties. This procedure is suitable for manufacturingcontrol and inspection testing.6. Apparatus6.1 Sampling and Sample Preparation Equipment:6.1.1 Refer to Practice E 1806 for devices and practices tosample liquid and solid steel.6.
18、1.2 Abrasive Grinder, a suitable belt grinder, horizontaldisk grinder, or similar grinding apparatus. The resultingsurface should be uniformly plane and free of defects. Thesemay be either wet or dry grinding devices. Grinding materialswith grit sizes ranging from 60 to 180 have been foundsatisfacto
19、ry.6.2 Excitation Source, with parameters capable of produc-ing a usable spectrum in accordance with 11.1 and PracticeE 172.6.3 Excitation Stand, suitable for mounting in optical align-ment, a flat surface of the specimen in opposition to a counterelectrode. The stand shall provide an atmosphere of
20、argon andmay be water cooled. Counter electrodes and argon aredescribed in 7.1 and 7.2.6.4 Spectrometer, having sufficient resolving power andlinear dispersion to separate clearly the analytical lines fromother lines in the spectrum of a specimen in the spectral region170.0 nm to 500.0 nm. Spectrome
21、ter characteristics for two ofthe instruments used in this test method are described as havingdispersion of 0.697 nm/mm (first order), and a focal length of1 m. Spectral lines are listed in Table 1.6.5 Measuring System, consisting of photomultiplier tubeshaving individual voltage adjustment, capacit
22、ors on which theoutput of each photomultiplier tube is stored and an electronicsystem to measure voltages on the capacitors either directly orindirectly, and the necessary switching arrangements to pro-vide the desired sequence of operation.6.6 Readout Console, capable of indicating the ratio of the
23、analytical lines to the internal standard with sufficient precisionto produce the accuracy of analysis desired.6.7 Vacuum Pump, capable of maintaining a vacuum of 25m Hg or less.6.8 Gas System, consisting of an argon supply with pressureand flow regulation.Automatic sequencing shall be provided toac
24、tuate the flow at a given rate for a specific time interval. Theflow rate may be manually or automatically controlled. Theargon system shall be in accordance with Practice E 406.NOTE 1It is not within the scope of this test method to prescribe alldetails of equipment to be used. Equipment varies amo
25、ng laboratories.7. Reagents and Materials7.1 Argon, either gaseous or liquid, must be of sufficientpurity to permit proper excitation of the analytical lines ofinterest. Argon of 99.998 % purity has been found satisfactory.Refer to Practice E 406.7.2 Counter Electrodes, can vary in diameter from 1.5
26、 mmto 6.5 mm (depending on the instrument manufacturer) andtypically are machined to a 90 or 120 angled tip. Silver orthoriated tungsten rods are typically used. Other material maybe used provided it can be shown experimentally that equiva-lent precision and accuracy are obtained.8. Reference Materi
27、als8.1 Certified Reference Materials are available from theNational Institute of Standards and Technology5and otherinternational certification agencies.8.2 Reference Materials with matrices similar to that of thetest specimen and containing varying amounts of the elementsto be determined may be used
28、 provided they have beenchemically analyzed in accordance with ASTM standard testmethods. These reference materials shall be homogeneous, andfree of voids or porosity.8.3 The reference materials shall cover the concentrationranges of the elements being sought. A minimum of threereference materials s
29、hall be used for each element.9. Preparation of Samples9.1 The specimens and reference materials must be preparedin the same manner. A specimen cut from a large samplesection must be of sufficient size and thickness for preparationand to properly fit the spectrometer stand.5Available from National I
30、nstitute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.TABLE 1 Analytical and Internal Standard LinesElement Wavelength, nmConcentration Switch OverPointsChromium 298.919Nickel 243.789227.021218.549216.910Molybdenum 202.030 1 %369.265Ma
31、nganese 293.306Silicon 251.612A288.158Copper 327.396 0.10 %Carbon 193.092Phosphorus 178.287ASulfur 180.731IronB271.441322.775ASilicon 251.612 can have a small but significant interference from molybde-num 251.611. Phosphorus 178.287 may show small but significant interferencesfrom unlisted lines or
32、background due to molybdenum, chromium, and manga-nese. Interference corrections will not be necessary if: separate silicon andphosphorus curves are used for 316 and 317 alloys; the manganese content variesonly between 0.7 % and 1.5 %; and the chromium concentration is held between17 % and 20 %.BEit
33、her iron line 271.441 or 322.775 with narrow entrance and exit slits to avoidinterference from manganese 322.809 can be used as internal standard with anyof the listed analytical lines. Iron 271.441 is not appropriate for tungsten tool steelsor super alloys with high cobalt because of interference f
34、rom cobalt 271.442.E10860829.2 Ensure the specimens are homogenous and free fromvoids and pits in the region to be excited. Grind the surfacewith an abrasive belt or disc. Refer to 6.1.2. Perform the finalgrind with a dry abrasive belt or disc.10. Preparation of Apparatus10.1 Follow the manufacturer
35、s instructions for verifyingthe optical alignment of the entrance slit and programming theappropriate wavelengths (Table 1).11. Excitation and Exposure11.1 Electrical ParametersTwo different types of sourceswere employed in the testing of this test method.11.1.1 Directional Self-Initiating Capacitor
36、 DischargeSource:Capacitance, F 0.015Inductance, L1, H 310Inductance, L2,H 20Resistance, V residualPotential, V 13 500Peak Current, A 90First Valley Current, A 60Current pulse duration, s 120Number of discharges/s 24011.1.1.1 Exposure Conditions:Flush, s 7 Argon Flow 0.42 m3/hPreburn, s 20 Argon Flo
37、w 0.42 m3/hIntegration, s 20 Argon Flow 0.42 m3/h11.1.2 Triggered Capacitor Discharge Source:Preburn ExposurePulse Output:Capacitance, F (d-c charged) 7.5 2.5Inductance, H 50 50Resistance, V residual residualPotential, V 950 950Peak Current, A 275 100Current pulse duration, s 250 130Number of discha
38、rges/s 120 120Trigger:Capacitance (d-c charged), F 1.2 .Inductance, H residual .Resistance, V residual .Potential, V 425 .11.1.2.1 Exposure Conditions:Flush, s 2 Argon Flow 0.56 m3/hPreburn, s 10 Argon Flow 0.56 m3/hExposure, s 10 or 15 Argon Flow 0.56 m3/h12. Calibration, Standardization, and Verif
39、ication12.1 CalibrationUsing the conditions given in 11.1, ex-cite each calibrant and standardant two to four times andbracket these with similar excitations of any verifiers.Averifiermay be used as a calibrant even though it is burned only as averifier. There shall be at least three calibrants for
40、eachelement, spanning the required concentration range. If thespectrometer system and software permits, repeat with differ-ent random sequences at least four times. Follow the procedurefor the concentration-ratio method in accordance with PracticeE 158. Using the averages of the data for each point,
41、 determineanalytical curves in accordance with Practice E 305.12.2 StandardizationFollowing the manufacturers rec-ommendations, standardize on an initial setup or anytime thatit is known or suspected that readings have shifted. Make thenecessary corrections either by adjusting the controls on therea
42、dout or by applying arithmetic corrections. Standardizationwill be done anytime verification indicates that readings havegone out of statistical control.12.3 VerificationAnalyze verifiers in replicate to confirmthat they read within expected confidence interval, in accor-dance with 12.4.12.3.1 Each
43、laboratory should determine the frequency ofverification necessary based on statistical analysis. Typically,every 4 to 8 hours is practical and adequate (or if theinstrument has been idle for more than 1 hour). If the resultsare not within the control limits established in 12.4, perform astandardiza
44、tion and then repeat verification. Repeat standard-ization as necessary so verifications are within control limits orinvestigate further for instrument problems.12.4 The confidence interval will be established from ob-servations of the repeatability of the verifiers and determiningthe confidence int
45、erval for some acceptable confidence level inaccordance with Practice E 876 or by establishing the upperand lower limit of a control chart in accordance with ASTMManual MNL7A.6The latter is the preferable approach since italso monitors the consistency of the statistics of the measure-ments and provi
46、des a way of maintaining a record of perfor-mance.13. Procedure for Excitation and Radiation Measurement13.1 Produce and record the spectra using the conditions in11.1.13.2 Replicate ExcitationMake duplicate excitations ofeach specimen and report the average. Place the freshlysurfaced specimen on th
47、e excitation stand in a manner to effecta gas-tight seal and adequate argon flushing. Position thespecimen so there will be a uniform pattern of excitationsaround its face. For example, a disk-shaped specimen shouldhave a ring of excitation marks around its outer edge andapproximately 6 mm (0.25 in.
48、) from the edge. Avoid the centerof cast specimens because of possible quench cracks andsegregation. Make a good electrical ground. Cool the specimenafter two excitations to prevent overheating, if required.Examine the specimen after each excitation to evaluate thequality of excitation. Cracks, void
49、s, pits, moisture, or inclu-sions will limit the sampling and the accuracy of a determina-tion. Successive excitations shall be sufficiently separated sothat the discharge patterns do not overlap.14. Calculation of Results14.1 Average the readings obtained for each specimen. Ifthe readout is not in direct concentration units, use this value toobtain the concentrations from the curves, or related scalevalues and concentration by reference to a table that has beenpreviously prepared.6MNL 7A Manual on Presentation of Data and Control Chart Analysis, ASTMManual Seri
