ASTM E363-2009 6875 Standard Test Methods for Chemical Analysis of Chromium and Ferrochromium《铬和铬铁合金的化学分析试验方法》.pdf

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1、Designation: E363 09Standard Test Methods forChemical Analysis of Chromium and Ferrochromium1This standard is issued under the fixed designation E363; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num

2、ber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover the chemical analysis ofchromium and ferrochromium having chemical compositionswithin the following limits:Elemen

3、t Concentration, %Aluminum 0.25 maxAntimony 0.005 maxArsenic 0.005 maxBismuth 0.005 maxBoron 0.005 maxCarbon 9.00 maxChromium 51.0 to 99.5Cobalt 0.10 maxColumbium 0.05 maxCopper 0.05 maxLead 0.005 maxManganese 0.75 maxMolybdenum 0.05 maxNickel 0.50 maxNitrogen 6.00 maxPhosphorus 0.03 maxSilicon 12.0

4、0 maxSilver 0.005 maxSulfur 0.07 maxTantalum 0.05 maxTin 0.005 maxTitanium 0.50 maxVanadium 0.50 maxZinc 0.005 maxZirconium 0.05 max1.2 The analytical procedures appear in the following order:SectionsArsenic by the Molybdenum Blue Photometric Test Method0.001 % to 0.005 %10-20Lead by the Dithizone P

5、hotometric Test Method0.001 % to 0.05 %21-31Chromium by the Sodium Peroxide Fusion-Titrimetric Test Method50 % to 75 %32-381.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of

6、thesafety concerns, if any, associated with its use. It is theresponsibility of whoever uses this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 6.2. Refe

7、renced Documents2.1 ASTM Standards:2A101 Specification for FerrochromiumA481 Specification for Chromium MetalE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE32 Practices for Sampling Ferroalloys and Steel Additivesfor Determination of Chemical Compo

8、sitionE50 Practices for Apparatus, Reagents, and Safety Consid-erations for Chemical Analysis of Metals, Ores, andRelated MaterialsE60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryE135 Terminology Relating to Analytical Chemistry forMetals, Ores, an

9、d Related MaterialsE173 Practice for Conducting Interlaboratory Studies ofMethods for Chemical Analysis of Metals3E1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical Method3. Terminology3.1 For definition of terms used in this test method, refer toTermi

10、nology E135.4. Significance and Use4.1 These test methods for the chemical analysis of metalsand alloys are primarily intended to test such materials forcompliance with compositional specifications such as Specifi-cation A101 and A481. It is assumed that all who use these testmethods will be trained

11、 analysts capable of performing com-mon laboratory procedures skillfully and safely. It is expectedthat work will be performed in a properly equipped laboratory.5. Apparatus, Reagents, and Photometric Practice5.1 Apparatus, standard solutions, and other reagents re-quired for each determination are

12、listed in separate sections1These test methods are under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and are the directresponsibility of Subcommittee E01.01 on Iron, Steel, and Ferroalloys.Current edition approved Oct. 1, 2009. Published Nove

13、mber 2009. Originallyapproved in 1970. Last previous edition approved in 2002 as E363 83 (2002)1.DOI: 10.1520/E0363-09.2For 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

14、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, PA 19428-2959, United States.preceding the procedure. Photome

15、ters shall conform to therequirements prescribed in Practice E60.5.2 Photometric practices prescribed in these test methodsshall conform to Practice E60.6. Hazards6.1 For precautions to be observed in the use of certainreagents in these test methods, refer to Practices E50.6.2 Specific hazard statem

16、ents are given in 27.1, 27.5, and36.2.7. Sampling7.1 For procedures for sampling the material, and forparticle size of the sample for chemical analysis, refer toPractices E32.8. Rounding Calculated Values8.1 Calculated values shall be rounded to the desired num-ber of places as directed in the Round

17、ing Procedure of PracticeE29.9. Interlaboratory Studies9.1 These test methods have been evaluated in accordancewith Practice E173, unless otherwise noted in the precision andbias section. Practice E173 has been replaced by PracticeE1601. The Reproducibility R2corresponds to the Reproduc-ibility Inde

18、x R of Practice E1601. The Repeatability R1ofPractice E173 corresponds to the Repeatability Index r ofPractice E1601.ARSENIC BY THE MOLYBDENUM BLUEPHOTOMETRIC TEST METHOD10. Scope10.1 This test method covers the determination of arsenic inchromium and ferrochromium in concentrations from 0.001 %to 0

19、.005 %.11. Summary of Method11.1 Arsenic is first separated by distillation as the trivalentchloride. Ammonium molybdate is added to form arsenomo-lybdate, which is then reduced by hydrazine sulfate to form themolybdenum blue complex. Photometric measurement is madeat approximately 850 nm.12. Concen

20、tration Range12.1 The recommended concentration range is 0.01 mg to0.15 mg of arsenic per 50 mL of solution using a 1-cm cell.NOTE 1This test method has been written for cells having a 1-cmlight path. Cells having other dimensions may be used, provided suitableadjustments can be made in the amount o

21、f sample and reagents used.13. Stability of Color13.1 The color is stable for at least 2 h.14. Interferences14.1 The elements ordinarily present do not interfere if theirconcentrations are under the maximum limits shown in 1.1.15. Apparatus15.1 Distillation Apparatus, Fig. 1.FIG. 1 Arsenic Distillat

22、ion ApparatusE363 09215.2 Zirconium Crucibles, 30-mL capacity.16. Reagents16.1 Ammonium Bromide (NH4Br).16.2 Ammonium Molybdate Solution (10 g/L)Dissolve2.5 g of ammonium heptamolybdate tetrahydrate (NH4)6-Mo7O244H2O) in 40 mL of warm water. Add 128 mL ofH2SO4(1 + 3), dilute to 250 mL, and mix.16.3

23、Ammonium Molybdate-Hydrazine Sulfate SolutionDilute 100 mL of ammonium molybdate solution to 900 mL,add 10 mL of hydrazine sulfate solution, dilute to 1 L, and mix.Do not use a solution that has stood more than 1 h.16.4 Arsenic, Standard Solution A (1 mL = 0.10 mg As)Transfer 0.1320 g of arsenic tri

24、oxide (As2O3)toa1-Lvolumetric flask, dissolve in 100 mL of HCl, cool, dilute tovolume, and mix.16.5 Arsenic, Standard Solution B (1 mL = 0.01 mg As)Using a pipet, transfer 100 mL of arsenic solution A (1 mL =0.10 mg As) to a 1-L volumetric fl ask, dilute to volume, andmix.16.6 Hydrazine Sulfate (NH2

25、)2H2SO4).16.7 Hydrazine Sulfate Solution (1.5 g/L)Dissolve 1.5 gof hydrazine sulfate (NH2)2H2SO4) in water, dilute to 1 L,and mix. Do not use a solution that has stood more than 1 day.16.8 Sodium Carbonate (Na2CO3).16.9 Sodium Peroxide (Na2O2).17. Preparation of Calibration Curve17.1 Calibration Sol

26、utions:17.1.1 Using pipets, transfer (1, 2, 5, 10, and 15) mL ofarsenic Solution B (1 mL = 0.01 mgAs) to 125-mL Erlenmeyerfl asks.17.1.2 Add 10 mL of HNO3and evaporate the solution todryness on a hot plate. Bake for 30 min at 150 C to 180 C.Remove from the hot plate. Add 45 mL of ammoniummolybdate-h

27、ydrazine sulfate solution to each flask, warmgently to dissolve the residue, and transfer the solution to a50-mL volumetric fl ask. Proceed as directed in 17.3.17.2 Reference SolutionTransfer 10 mL of HNO3to a125-mL Erlenmeyer flask and proceed as directed in 17.1.2.17.3 Color DevelopmentHeat the fl

28、ask in a boiling waterbath for 15 min. Remove the flask, cool to room temperature,dilute to volume with ammonium molybdate-hydrazine sulfatesolution, and mix.17.4 Photometry:17.4.1 Multiple-Cell PhotometerMeasure the cell correc-tion using absorption cells with a 1-cm light path and a lightband cent

29、ered at approximately 850 nm. Using the test cell,take the photometric readings of the calibration solutions.17.4.2 Single-Cell PhotometerTransfer a suitable portionof the reference solution to an absorption cell with a 1-cm lightpath and adjust the photometer to the initial setting, using alight ba

30、nd centered at approximately 850 nm. While maintain-ing this adjustment, take the photometric readings of thecalibration solutions.17.5 Calibration CurvePlot the net photometric readingsof the calibration solutions against milligrams of arsenic per 50mL of solution.18. Procedure18.1 Test Solution:18

31、.1.1 Select and weigh a sample to the nearest 0.2 mg inaccordance with the following:As, % Sample Weight, g0.001 to 0.015 0.5000.01 to 0.04 0.2500.035 to 0.10 0.12518.1.1.1 Transfer the sample to a 30-mL zirconium cruciblecontaining 10 g of Na2O2and1gofNa2CO3if ferrosilicon, or8gofNa2O2plus2gofNa2CO

32、3if silicon metal.18.1.2 Mix thoroughly with a metal spatula. Fuse carefullyover a free flame by holding the crucible with a pair of tongsand slowly revolving it around the outer edge of the flame untilthe contents have melted down quietly; raise the temperaturegradually to avoid spattering. When th

33、e contents are molten,give the crucible a rotary motion to stir up any unattackedparticles of the alloy adhering to the bottom or sides. Finally,increase the temperature until the crucible is bright red for 1min. Cool the crucible to room temperature. Transfer thecrucible to an 800-mL beaker contain

34、ing 60 mL of H2SO4(1 +1) and 200 mL of water. Dissolve the melt; remove and rinsethe crucible.18.1.3 If manganese dioxide is present, add H2SO3drop-wise until the solution clears.18.1.4 Heat to boiling, and cool. While stirring vigorously,add NH4OH until the solution is alkaline to litmus, and thena

35、dd 3 mL to 5 mL in excess. Heat to boiling, remove from theheat, and allow the precipitate to settle. Filter on a coarse fi lterpaper and wash five times with hot water. Discard the filtrate.Remove the filter paper, carefully open it, and place it on theinside wall of the original 800-mL beaker. Was

36、h the precipitatefrom the paper using a fine stream of water. Pass 25 mL ofHNO3(1 + 1) over the paper, and wash well with water but donot exceed a total volume of 40 mL. Discard the paper. Warmgently until the precipitate dissolves.18.1.5 Transfer the solution to the distillation fl ask, add 1 gof N

37、H4Br and 0.75 g of hydrazine sulfate. Add 20 mL ofHNO3(1 + 1) to the receiving flask, and place the flask in an800-mL beaker containing cold water. Assemble the apparatus(Fig. 1), heat the distillation fl ask, and distill into the receivingflask.18.1.6 Distill until the volume is reduced to 10 mL or

38、 untiloxides of nitrogen are noted in the distillation flask. Removethe distillation flask from the heat source. Place the receivingflask on a hot plate and evaporate the solution to dryness. Bakefor 30 min at 150 C to 180 C. Add 45 mL of ammoniummolybdate-hydrazine sulfate solution to the fl ask, w

39、arm gentlyto dissolve the residue, and transfer the solution to a 50-mLvolumetric flask. Proceed as directed in 18.3.18.2 Reference SolutionCarry a reagent blank through theentire procedure using the same amounts of all reagents withthe sample omitted, for use as a reference solution.18.3 Color Deve

40、lopmentProceed as directed in 17.3.18.4 PhotometryTake the photometric reading of the testsolution as directed in 17.4.E363 09319. Calculation19.1 Convert the net photometric reading of the test solutionto milligrams of arsenic by means of the calibration curve.Calculate the percentage of arsenic as

41、 follows:Arsenic , % 5 A/B 3 10! (1)where:A = milligrams of arsenic found in 50 mL of final testsolution, andB = grams of sample represented in 50 mL of final testsolution.20. Precision and Bias20.1 Nine laboratories cooperated in testing this test methodand obtained the data summarized in Table 1.

42、Samples witharsenic concentrations near the upper limit of the scope werenot available for testing. The user is cautioned to verify, by theuse of reference materials, if available, that the precision andbias of this test method is adequate for the contemplated use.LEAD BY THE DITHIZONE PHOTOMETRIC T

43、ESTMETHOD21. Scope21.1 This test method covers the determination of lead inchromium and ferrochromium in concentrations from 0.001 %to 0.05 %.22. Summary of Test Method22.1 After dissolution of the sample, lead is precipitatedwith ammonium hydroxide. Interfering metals are complexedwith sodium citra

44、te and sodium cyanide, and the lead dithizonecomplex is extracted with chloroform. Photometric measure-ment is made at 520 nm.23. Concentration Range23.1 The recommended concentration range is from 0.001mg to 0.025 mg of lead per 10 mL of solution, using a 1-cmcell.NOTE 2This test method has been wr

45、itten for cells having a 1-cmlight path. Cells having other dimensions may be used, provided suitableadjustments can be made in the amounts of sample and reagents used.24. Stability of Color24.1 The color is quite stable if the solution is protectedagainst evaporation and decomposition of chloroform

46、. Becauseof the volatility of the solvent, it is advisable to make allreadings promptly. The color develops almost immediately.25. Interferences25.1 The elements ordinarily present do not interfere if theirconcentrations are under the maximum limits shown in 1.1.Ifmore than 0.005 % bismuth is presen

47、t, it must be removed asdirected in Note 4 in order to avoid high results for lead.26. Apparatus26.1 GlasswareUse only borosilicate beakers, covers, andfunnels. Wash all glassware with hot HNO3(1 + 1) and reservefor this determination only. Before using separatory funnels,rinse them with dithizone s

48、olution and then with water. Storeall reagents in glass-stoppered borosilicate bottles which havebeen previously washed with hot HNO3(1 + 1) and rinsed withdistilled water.26.2 pH MeterA pH meter for measurements to within60.10 pH units is required.27. Reagents27.1 Chloroform (CHCl3)(WarningChlorofo

49、rm ishighly toxic and is to be used in a well-ventilated hood.Consult the Material Safety Data Sheet or other source of dataprior to use. Refer to the Hazards Section of Practices E50.)27.2 Dithizone Solution (0.04 g/L in chloroform)Dissolve 0.02 g of dithizone (diphenylthiocarbazone) in 80 mLof CHCl3in a 500-mL conical separatory funnel, add 100 mLof cold water and 10 mL of NH4OH, stopper, and shakevigorously for 1 min to 2 min. Draw off the CHCl3layer anddiscard. Wash the aqueous layer with 5 mL of CHCl3anddiscard the latter. Add HCl (1 + 9)