ASTM E1917-2002 Standard Test Method for Determination of Phosphorous in Nickel Ferronickel and Nickel Alloys by the Phosphovanadomolybdate Molecular Absorption Spectrometric Metho.pdf

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1、Designation: E 1917 02Standard Test Method forDetermination of Phosphorus in Nickel, Ferronickel, andNickel Alloys by the Phosphovanadomolybdate MolecularAbsorption Spectrometric Method1This standard is issued under the fixed designation E 1917; the number immediately following the designation indic

2、ates the year oforiginal adoption or, in the case of revision, the 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 determination

3、of phospho-rus in nickel, ferronickel, and nickel alloys in the 0.0007 %through 0.05 % range.1.2 Arsenic, chromium, hafnium, niobium, silicon, tanta-lum, titanium, and tungsten interfere, but the interference canbe avoided by complexation or volatilization (for Cr). Thelowest phosphorus content (0.0

4、007 %) can be reached only insamples with low contents of interfering elements.1.3 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 practices and dete

5、rmine the applica-bility of regulatory limitations prior to use. For specific hazardsassociated with the use of this practice see Practices E50.Refer to specific warning notes given throughout this testmethod.2. Referenced Documents2.1 ASTM Standards:2E50 Practices for Apparatus, Reagents, and Safet

6、y Precau-tions for Chemical Analysis of MetalsE 882 Guide for Accountability and Quality Control in theChemical Analysis LaboratoryE 1452 Practice for Preparation of Calibration Solutions forSpectrophotometric and for Spectroscopic Atomic Analy-sisE 1601 Practice for Conducting Interlaboratory Study

7、 toEvaluate the Performance of an Analytical Method2.2 ISO Standards:ISO 5725:1986 Precision of Test MethodsDeterminationof Repeatability and Reproducibility for a Standard TestMethod by Inter-laboratory Tests3ISO 11400:1992(E) Nickel, Ferronickel and NickelAlloysDetermination of Phosphorus ContentP

8、hosphovanadomolybdate Molecular Absorption Spectro-metric Method33. Summary of Test Method3.1 The sample is dissolved in a mixture of hydrochloricacid and nitric acid. The solution is evaporated to perchloricacid fumes and chromium is removed as volatile chromylchloride. Silicon and refractory eleme

9、nts are complexed withfluoride ions. The phosphorus is converted to phosphovanado-molybdic acid in a perchloric and nitric acid solution. Thephosphovanadomolybdic acid is extracted with 2-methyl-2-pentanone in the presence of citric acid to complex arsenic.Absorbance is measured at 355 nm.4. Signifi

10、cance and Use4.1 This test method is used for the analysis of nickel,ferronickel, and nickel base alloy samples by molecular ab-sorption spectrometry to check compliance with compositionalspecifications. It is assumed that all who use the procedure willbe trained analysts capable of performing commo

11、n laboratoryprocedures skillfully and safely. It is expected that the workwill be performed in a properly equipped laboratory and thatproper waste disposal procedures will be followed.Appropriatequality control practices must be followed, such as thosedescribed in Guide E 882.5. Apparatus5.1 Spectro

12、photometerCapable of measuring absorbanceat a wavelength of 355 nm.5.2 CellsTo fit spectrophotometer, having an optical pathof 1 cm.NOTE 1Cells having other dimensions can be used, provided suitableadjustments can be made in the amount of sample and reagents used.1This practice is under the jurisdic

13、tion of ASTM Committee E01 on AnalyticalChemistry of Metals, Ores and Related Materials and is the direct responsibility ofSubcommittee E01.08 on Nickel, Cobalt and High Temperature Alloys.Current edition approved Sept 10, 2002. Published June 2003. Originallyapproved in 1997. Last previous edition

14、approved in 1997 as E 1917-97.2For 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 to the standards Document Summary page onthe ASTM website.3Available from American Nation

15、al Standards Institute, 11 West 42nd Street,New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.3 Plastic separatory funnels, 250 mL capacity.6. Reagents6.1 Purity and Concentration of ReagentsThe purity andconcentra

16、tion of common chemical reagents shall conform toPractices E50. The reagents should be free of or contain onlyminimal amounts (0.1 g/g) of phosphorus. Calibration solu-tions shall be prepared in accordance with Practice E 1452.6.1.1 Verify the absence of phosphorus in the reagents usingthe blank tes

17、t (9.6.1). Reagents giving high blank values areunsuitable and should not be used. The blank value for allreagents should be below 0.0005 % P calculated fora1gsample.6.2 Ammonium Metavanadate SolutionDissolve 2.5 g ofammonium metavanadate (NH4VO3) in water and dilute to 1 L.6.3 Citric Acid SolutionD

18、issolve 500 g citric acid mono-hydrate (C6H8O7H2O) in water and dilute to 1 L. Warm thesolution if necessary to facilitate dissolution.6.4 Fluoroboric Acid SolutionDisperse 75 g of boric acid(H3BO3) in 600 mLof hot water in a plastic beaker.Add 50 mLHF (40 %) and dilute to 1 L. Digest over medium he

19、at until theboric acid is dissolved. Store in plastic bottle. The solutionshould be gently heated if the boric acid forms crystals.NOTE 2Warning: HF and fluoroboric acid are extremely irritatingand corrosive to skin and mucous membranes, producing severe skinburns that are slow to heal. In case of c

20、ontact with skin, wash well withwater and seek medical advice. When using HF and fluoroboric acid,always wear appropriate safety gear, such as goggles and gloves.6.5 Hexaammonium Heptamolybdate SolutionDissolve15 g of hexaammonium heptamolybdate tetrahydrate(NH4)6Mo7O244H2O in warm water and dilute

21、to 100 mL.Prepare fresh solution each day. If high and unstable blankvalues appear, there might be a problem with the salt used. Insuch a case, switch to another lot.6.6 4-methyl-2-pentanonemethylisobutyl ketone.6.7 Phosphorus Stock Calibration Solution (1.000 g/L)Transfer 4.3942 g of potassium dihy

22、drogenorthophosphate(KH2PO4) (which has been previously dried at 110C toconstant weight and cooled in a desiccator) toa1Lvolumetricflask. Dissolve in water, dilute to the mark and mix.6.8 Phosphorus Calibration Solution (10 mg/L)Transfer10.0 mL of the phosphorus stock calibration solution toa1Lvolum

23、etric flask. Dilute to the mark with water and mix.6.9 Sodium Nitrite Solution (50 g/L)Dissolve 50 g ofsodium nitrite (NaNO2) in water and dilute to 1 L.7. Interlaboratory Studies (ILS)7.1 This test method was evaluated by a subcommitteewithin ISO Technical Committee 155 (ISO/TC 155/SC 4) onanalysis

24、 of nickel alloys, in accordance with ISO Standard5725. It was published as ISO Standard 11400. ILS test datawere not available for recalculation.8. Sampling and Sample Preparation8.1 The sampling shall be carried out by normal proceduresagreed upon between the parties, or in the event of a dispute,

25、in accordance with the relevant standard, if one is available.8.2 The laboratory sample is normally in the form ofmillings or drillings and no further preparation of the sample isnecessary.8.3 If it is suspected that the laboratory sample is contami-nated with oil or grease from the milling or drill

26、ing operation,it shall be cleaned by washing it with high purity acetone anddried in air.8.4 If the sample contains particles or pieces of widelyvarying sizes, the test sample should be obtained by riffling.9. Procedure9.1 Test Portion and Preparation of Test Solution:9.1.1 Weigh to the nearest 0.1

27、mg a test portion of thesample in accordance with Table 1.9.1.2 Transfer the test portion to a polytetrafluoroethylene(PTFE) beaker and add 5 mL of HNO3and then 5 mL of HCl.For samples with high contents of Nb, Si, Ta, or Hf, also add7 mL of HF. Cover the beaker with a PTFE cover and heatgently unti

28、l the reaction ceases. Use a sandbath or other meansto avoid direct contact of the PTFE beaker with a metalhotplate surface. Add 10 mL of HClO4and, leaving a smallopening to release the vapors, evaporate to dense HClO4fumes.NOTE 3Nickel and some copper bearing nickel alloys, such as monel,will disso

29、lve more readily in HNO3(1+1).NOTE 4Warning: Fuming HClO4is a powerful oxidant and cancause explosions when in contact with organic materials. All evaporationsmust be carried out in the presence of HNO3and in a fume hood suitablefor use with HClO4.9.1.3 For samples containing less than 0.1 % chromiu

30、m,omit the next step and proceed directly to 9.3.9.2 Removal of Chromium:9.2.1 Continue fuming for 3 min. Cautiously begin addingHCl drop by drop to the fuming solution in the partly coveredbeaker until colored fumes are no longer liberated. Thenresume fuming to re-oxidize the remaining chromium. Re

31、peatthe treatment until no brown fumes appear when the HCl isadded. Cool to room temperature.9.3 Complexation:9.3.1 Add 25 mL HNO3(1+4) and 4 mL HF to the solutionand heat for 8 to 10 minutes until the precipitate is dissolved.NOTE 5It is important that the precipitated refractory oxides dissolvecom

32、pletely. If this does not happen, add another 2 mL HF and repeat theboiling. If the precipitate still remains undissolved, a new test sample ofa smaller weight must be taken for the analysis.9.3.2 Add 10 mL of sodium nitrite solution and boil thesolution for 10 minutes to reduce the residual dichrom

33、ate andexpel all nitrous fumes. Cautiously wash the beaker walls a fewtimes with water during boiling.TABLE 1 Weight of Test Portion of the SampleExpectedPhosphorusContent, %Weight of TestPortion, gMaximum concentration of the interferingelements, %As Hf Nb Ta Ti W0.0005 to 0.010 1.0 0.05 0.1 1 0.1

34、2 20.002 to 0.04 0.25 0.2 0.5 5 0.5 10 80.005 to 0.050 0.10 0.5 1.5 10 1 25 25E19170229.3.3 Add 40 mL of fluoroboric acid solution and rapidlycool the solution to between 20 and 30C, and proceedimmediately with the color development.NOTE 6The oxides might precipitate again if it required more than 1

35、0min to cool the solution.9.4 Color Development and Extraction:9.4.1 Add 10 mL of the ammonium metavanadate solutionand 15 mL of the hexaammonium heptamolybdate solution tothe cooled clear solution. Allow to stand at a temperaturebetween 18 and 25C for a minimum of 7 min, but not longerthan 15 min.9

36、.4.2 Transfer the solution to a 250 mL plastic separatoryfunnel that has been marked at the 100 mL level and, ifnecessary, make up to the mark with water.Add 10 mL of citricacid solution and immediately follow with 40 mL of 4-methyl-2-pentanone. Shake the funnel for 30 s.Allow the two layers tosepar

37、ate and discard the lower (aqueous) phase. Dry the insideof the stem of the separatory funnel with a small piece of filterpaper. Filter the organic layer through a dry filter paper into asmall dry beaker. Proceed immediately with the spectrometricmeasurement.9.5 Spectrometric Measurement:9.5.1 Ensur

38、e that the temperature of the solutions is constantto 61C. Measure the absorbance of the solution with aspectrophotometer at a wavelength of 355 nm. Use 4-methyl-2-pentanone as the reference and cells witha1cmoptical pathlength.9.6 Blank Test:9.6.1 Carry out a blank test in parallel with the determi

39、na-tion following the same procedure and using the same quanti-ties of reagents as in the determination, but omitting the testportion.9.7 Calibration:9.7.1 Transfer 0 mL, 2.5 mL, 5.0 mL, and 10.0 mL,respectively, of the phosphorus calibration solution to fourplastic beakers. The additions correspond

40、 to 0 mg, 0.025 mg,0.050 mg, and 0.100 mg of phosphorus. Proceed as directed in9.1.2-9.5.1, but do not add any test portions.9.7.2 Subtract the absorbance of the “zero” solution fromthat of each solution containing phosphorus, and plot theabsorbance against the weight, in milligrams, of phosphorusad

41、ded.9.8 Number of Determinations:9.8.1 Carry out the determinations at least in duplicate.10. Calculation10.1 Correct the absorbance reading of the test solution bysubtracting the absorbance reading in the blank test. Convertthe net absorbance of the test solution into mg of phosphorusby means of th

42、e calibration graph.10.2 Calculate the percentage by weight of phosphorus inthe test sample using the formula:% P 5 A/10B (1)where:A = the weight, in mg, of phosphorus found in the testportion, andB = the weight, on g, of the test portion.11. Test Reports11.1 Report the following information:11.1.1

43、The reference to the method used.11.1.2 The results of the analysis.11.1.3 The number of independent replications.11.1.4 Any unusual feature noted during the analysis.11.1.5 Any omission, addition, or deviation from this testmethod.12. Precision and Bias412.1 PrecisionEight laboratories cooperated i

44、n the testingof this test method using samples described in Table 2 andTable 3 and obtained statistical information summarized inTable 4.12.2 BiasNo information on the accuracy of this testmethod is known because only one accepted reference standardwas used in the ILS. The user of this test method i

45、s encouraged4Supporting data are available from ASTM International Headquarters. RequestRR:E011021.TABLE 2 Nominal Composition of Nickel and Ferro-nickelSamples, %Test Material P As Cr Fe Si NiNi #1 0.00005 - - 0.01 - balanceNi #2 0.0008 - - balance - balanceFe-Ni #1 0.01 0.001 0.5 balance 0.5 25Fe-

46、Ni #2 0.01 0.1 4.5 balance 5 25Fe-Ni #3 0.045 0.001 0.5 balance 0.6 25Fe-Ni #4 0.045 0.1 4.5 balance 5 25TABLE 3 Nominal Composition of Nickel Alloy Samples, %Sample P Co Cr Cu Fe Mo Ni Nb W4D-7 0.01 - - 32 1 - 65 - -4D-8 0.01 - 21 - 4 9 62 3 -4D-9 0.02 - 19 - 19 3 53 5 -4D-10 0.02 - 20 - 46 - 31 -

47、-4D-11 0.01 - 21 - 20 8 47 - -4D-12A0.005 42 21 - 2 4 20 4 4AStandard Reference alloy BAM 328-1, certified at 0.005 % P was used assample 4D-12.TABLE 4 Results of Statistical AnalysisTestMaterialAMean,%Repeatability SD(Sr, ISO 5725)BReproducibilitySD (SR,ISO5725)CReproducibility(R, ISO 5725)DRrel %N

48、i #2 0.00091 0.00007 0.00012 0.0004 444D-12E0.0054 0.0001 0.0008 0.0022 404D-8 0.0089 0.0009 0.0015 0.0050 56FeNi #1 0.0100 0.0004 0.0002 0.0014 14FeNi #2 0.0100 0.0004 - 0.0012 124D-7 0.0120 0.0007 0.0007 0.0026 214D-11 0.0135 0.0006 0.0008 0.0027 204D-9 0.0148 0.0008 0.0006 0.0028 184D-10 0.0185 0

49、.0003 0.0007 0.0022 11FeNi #4 0.0425 0.0010 0.0010 0.0038 8.9FeNi #3 0.0437 0.0014 0.0021 0.0068 15AMaterial Compositions are summarized in Table 2 and Table 3.BEquivalent to minimum standard deviation, sM, (Practice E 1601).CEquivalent to reproducibility standard deviation, sR, (Practice E 1601).DEquivalent to reproducibility index, R, (Practice E 1601).EStandard Reference alloy BAM 328-1, certified at 0.005 % P was used assample 4D-12.E1917023to employ accepted reference materials, if available, to deter-mine the accuracy of this test method as it appl