1、Designation: E363 09E363 16Standard 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
2、 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 These test methods cover the chemical analysis of chromium and ferrochromium having chemical compositions within thefollowing limit
3、s:Element Concentration, %Element Composition, %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 maxP
4、hosphorus 0.03 maxSilicon 12.00 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 PhotometricTest Method0.001 % to 0.005
5、10 20Arsenic by the Molybdenum Blue Spectropho-tometric Test Method0.001 % to 0.005 %10 20Lead by the Dithizone Photometric TestMethod0.001 % to 0.05 %21 31Lead by the Dithizone Spectrophotometric TestMethod0.001 % to 0.05 %21 31Chromium by the Sodium Peroxide Fusion-Titrimetric Test Method50 % to
6、75 %32 381.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1 These test methods are under the jurisdiction ofASTM Committee E01 on Analytical Chemistry for Metals, Ores, and Related Materials and are the direct responsibilit
7、yof Subcommittee E01.01 on Iron, Steel, and Ferroalloys.Current edition approved Oct. 1, 2009May 1, 2016. Published November 2009June 2016. Originally approved in 1970. Last previous edition approved in 20022009 asE363 83 (2002)E3631. 09. DOI: 10.1520/E0363-09.10.1520/E0363-16.This document is not a
8、n ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate.
9、In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States11.4 This standard does not purport to address all of the safety concer
10、ns, if any, associated with its use. It is the responsibilityof whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability ofregulatory limitations prior to use. Specific hazard statements are given in Section 6. and in special ”Warnin
11、g” paragraphsthroughout these test methods.2. Referenced Documents2.1 ASTM Standards:2A101 Specification for FerrochromiumA481 Specification for Chromium MetalE29 Practice for Using Significant Digits in Test Data to Determine Conformance with SpecificationsE32 Practices for Sampling Ferroalloys and
12、 Steel Additives for Determination of Chemical CompositionE50 Practices forApparatus, Reagents, and Safety Considerations for ChemicalAnalysis of Metals, Ores, and Related MaterialsE60 Practice for Analysis of Metals, Ores, and Related Materials by SpectrophotometryE135 Terminology Relating to Analy
13、tical Chemistry for Metals, Ores, and Related MaterialsE173 Practice for Conducting Interlaboratory Studies of Methods for Chemical Analysis of Metals (Withdrawn 1998)3E1601 Practice for Conducting an Interlaboratory Study to Evaluate the Performance of an Analytical Method3. Terminology3.1 For defi
14、nition of terms used in this test method, refer to Terminology E135.4. Significance and Use4.1 These test methods for the chemical analysis of metals and alloys chromium metal and ferrochromium alloy are primarilyintended to test such materials for compliance with compositional specifications such a
15、s SpecificationSpecifications A101 andA481. It is assumed that all who use these test methods will be trained analysts capable of performing common laboratoryprocedures skillfully and safely. It is expected that work will be performed in a properly equipped laboratory.5. Apparatus, Reagents, and Pho
16、tometricSpectrophotometric Practice5.1 Apparatus, standard solutions, and other reagents required for each determination are listed in separate sections precedingthe procedure. PhotometersSpectrophotometers shall conform to the requirements prescribed in Practice E60. .(Note 1)NOTE 1In these methods
17、 cells utilized to contain the reference material and sample solutions in spectrophotometers are referred to as “absorptioncells.” The radiant energy passed through the cells can be measured as absorbance or transmittance. These methods refer to absorbance measurements.Refer to Practices E60 for de
18、tails.5.2 PhotometricSpectrophotometric practices prescribed in these test methods shall conform to Practice E60.6. Hazards6.1 For precautions to be observed in the use of certain reagents in these test methods, refer to Practices E50.6.2 Specific hazard statements are given in 27.1, 27.527.6, and 3
19、6.2.7. Sampling7.1 For procedures for samplingto sample the material, and for particle size requirements of the sample for chemical analysis,sample, refer to Practices E32.8. Rounding Calculated Values8.1 Calculated values shall be rounded to the desired number of places as directed in the Rounding
20、Procedure of Practice E29.9. Interlaboratory Studies9.1 These test methods have been evaluated in accordance with Practice E173, unless otherwise noted in the precision and biassection. Practice E173 has been replaced by Practice E1601. The Reproducibility R2 corresponds to the Reproducibility Index
21、 Rof Practice E1601. The Repeatability R1 of Practice E173 corresponds to the Repeatability Index r of Practice E1601.ARSENIC BY THE MOLYBDENUM BLUE PHOTOMETRICSPECTROPHOTOMETRIC TEST METHOD10. Scope10.1 This test method covers the determination of arsenic in chromium and ferrochromium in concentrat
22、ionscompositions from0.001 % to 0.005 %.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved v
23、ersion of this historical standard is referenced on www.astm.org.E363 16211. Summary of Method11.1 Arsenic is first separated by distillation as the trivalent chloride.Ammonium molybdate is added to form arsenomolybdate,which is then reduced by hydrazine sulfate to form the molybdenum blue complex.
24、Photometric Spectrophotometric absorbancemeasurement is made at approximately 850 nm.12. Concentration Range12.1 The recommended concentration range is 0.01 mg to 0.15 mg of arsenic per 50 mL of solution using a 1-cm cell.NOTE 2This test method has been written for cells having a 1-cm light path. Ce
25、lls having other dimensions may be used, provided suitableadjustments can be made in the amount of 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 their concentrationscompositions are u
26、nder the maximum limits shownin 1.1.15. Apparatus15.1 Distillation Apparatus, Fig. 1.15.2 Zirconium Crucibles, 30-mL capacity.16. Reagents16.1 Ammonium Bromide (NH4Br).16.2 Ammonium Molybdate Solution (10 g/L)Dissolve 2.5 g of ammonium heptamolybdate tetrahydrate (NH4)6-MoMo7O244H 4H2O) in 40 mL of
27、warm water. Add 128 mL of H2SO4 (1 + 3), dilute to 250 mL, and mix.16.3 Ammonium Molybdate-Hydrazine Sulfate SolutionDilute 100 mL of ammonium molybdate solution to 900 mL, add 10mL 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
28、 Standard Solution A (1 mL = 0.10 mg As)Transfer 0.1320 g of arsenic trioxide (As2O3) to a 1-L volumetricflask, dissolve in 100 mL of HCl, cool, dilute to volume, 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 = 0.10mg As) to
29、a 1-L volumetric fl ask, flask, dilute to volume, and mix.FIG. 1 Arsenic Distillation ApparatusE363 16316.6 Hydrazine Sulfate (NH2)2H2SO4).16.7 Hydrazine Sulfate Solution (1.5 g/L)Dissolve 1.5 g of hydrazine sulfate (NH2)2H2SO4) in water, dilute to 1 L, and mix.Do not use a solution that has stood m
30、ore than 1 day.16.8 Sodium Carbonate (Na2CO3).16.9 Sodium Peroxide (Na2O2).17. Preparation of Calibration Curve17.1 Calibration Solutions:17.1.1 Using pipets, transfer (1, 2, 5, 10, and 15) mL of arsenic Solution B (1 mL = 0.01 mgAs) to 125-mL Erlenmeyer fl asks.flasks.17.1.2 Add 10 mL of HNO3 and e
31、vaporate the solution to dryness on a hot plate. Bake for 30 min at 150 C to 180 C. Removefrom the hot plate. Add 45 mL of ammonium molybdate-hydrazine sulfate solution to each flask, warm gently to dissolve theresidue, and transfer the solution to a 50-mL volumetric fl ask. flask. Proceed as direct
32、ed in 17.3.17.2 Reference SolutionTransfer 10 mL of HNO3 to a 125-mL Erlenmeyer flask and proceed as directed in 17.1.2.17.3 Color DevelopmentHeat the flask in a boiling water bath for 15 min. Remove the flask, cool to room temperature, diluteto volume with ammonium molybdate-hydrazine sulfate solut
33、ion, and mix.17.4 Photometry:Spectrophotometry:17.4.1 Multiple-Cell PhotometerSpectrophotometerMeasure the cell correction using absorption cells with a 1-cm lightpath and a light band centered at approximately 850 nm. Using the test cell, take the photometric spectrophotometric absorbancereadings o
34、f the calibration solutions.17.4.2 Single-Cell PhotometerSpectrophotometerTransfer a suitable portion of the reference solution to an absorption cellwith a 1-cm light path and adjust the photometerspectrophotometer to the initial setting, using a light band centered atapproximately 850 nm. While mai
35、ntaining this adjustment, take the photometric spectrophotometric absorbance readings of thecalibration solutions.17.5 Calibration CurvePlot the net photometric spectrophotometric absorbance readings of the calibration solutions againstmilligrams of arsenic per 50 mLof solution. Follow the instrumen
36、t manufacturers instructions for generating the calibration curve.18. Procedure18.1 Test Solution:18.1.1 Select and weigh a sample to the nearest 0.2 mg in accordance with the following:as follows: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 sa
37、mple to a 30-mL zirconium crucible containing 10 g of Na2O2 and 1 g of Na2CO3 if ferrosilicon,ferrochromium, or 8 g of Na2O2 plus 2 g of Na2CO3 if siliconchromium metal.18.1.2 Mix thoroughly with a metal spatula. Fuse carefully over a free flame by holding the crucible with a pair of tongs andslowly
38、 revolving it around the outer edge of the flame until the contents have melted down quietly; completely melted; raise thetemperature gradually to avoid spattering. When the contents are molten, give the crucible a rotary motion to stir up any unattackedparticles of the alloy adhering to the bottom
39、or sides. Finally, increase the temperature until the crucible is bright red for 1 min.Cool the crucible to room temperature. Transfer the crucible to an 800-mL beaker containing 60 mL of H2SO4 (1 + 1) and 200mL of water. Dissolve the melt; remove and rinse the crucible.18.1.3 If manganese dioxide i
40、s present, add H2SO34 drop-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 then add 3mLto 5 mLin excess. Heat to boiling, remove from the heat, and allow the precipitate to settle. Filter on a coarse
41、fi lter filter paperand wash five times with hot water. Discard the filtrate. Remove the filter paper, carefully open it, and place it on the inside wallof the original 800-mL beaker. Wash the precipitate from the paper using a fine stream of water. Pass 25 mL of HNO3 (1 + 1)over the paper, and wash
42、 well with water but do not exceed a total volume of 40 mL. Discard the paper. Warm gently until theprecipitate dissolves.18.1.5 Transfer the solution to the distillation fl ask, flask, add 1 g of NH4Br and 0.75 g of hydrazine sulfate. Add 20 mL ofHNO3 (1 + 1) to the receiving flask, and place the f
43、lask in an 800-mL beaker containing cold water. Assemble the apparatus (Fig.1), heat the distillation fl ask, flask, and distill into the receiving flask.18.1.6 Distill until the volume is reduced to 10 mL or until oxides of nitrogen are noted in the distillation flask. Remove thedistillation flask
44、from the heat source. Place the receiving flask on a hot plate and evaporate the solution to dryness. Bake for 30min at 150 C to 180 C. Add 45 mL of ammonium molybdate-hydrazine sulfate solution to the fl ask, flask, warm gently todissolve the residue, and transfer the solution to a 50-mL volumetric
45、 flask. Proceed as directed in 18.3.E363 16418.2 Reference SolutionCarry a reagent blank through the entire procedure using the same amounts of all reagents with thesample omitted, for use as a referenceomitted. Proceed as directed in 18.3solution18.3 Color DevelopmentProceed as directed in 17.3.18.
46、4 PhotometrySpectrophotometryTake the photometric spectrophotometric absorbance reading of the test solution asdirected in 17.4.19. Calculation19.1 Convert the net photometric spectrophotometric absorbance reading of the test solution to milligrams of arsenic by meansof the calibration curve. Calcul
47、ate the percentage of arsenic as follows:Arsenic ,%5A/B 310! (1)where:A = milligrams of arsenic found in 50 mL of final test solution, andB = grams of sample represented in 50 mL of final test solution.20. Precision and Bias20.1 Nine laboratories cooperated in testing this test method and obtained t
48、he data summarized in Table 1. Samples with arsenicconcentrationscompositions near the upper limit of the scope were not available for testing. The user is cautioned to verify, by theuse of reference materials, if available, that the precision and bias of this test method is adequate for the contemp
49、lated use.LEAD BY THE DITHIZONE PHOTOMETRICSPECTROPHOTOMETRIC TEST METHOD21. Scope21.1 This test method covers the determination of lead in chromium and ferrochromium in concentrationscompositions from0.001 % to 0.05 %.22. Summary of Test Method22.1 After dissolution of the sample, lead is precipitated with ammoniumNH4 hydroxide. OH. Interfering metals are complexedwith sodium citrate and sodium cyanide, and the lead dithizone complex is extracted with chloroform. PhotometricSpectrophotometric absorbance measurement is mad
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