1、Designation: E 363 83 (Reapproved 2003)e1Standard Test Methods forChemical Analysis of Chromium and Ferrochromium1This standard is issued under the fixed designation E 363; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f 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.e1NOTEWarnings were moved from notes to section text editorially December 20021. Scope1.1 These test methods cover the chemical
3、 analysis ofchromium and ferrochromium having chemical compositionswithin the following limits:Element 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 ma
4、xManganese 0.75 maxMolybdenum 0.05 maxNickel 0.50 maxNitrogen 6.00 maxPhosphorus 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:Section
5、sArsenic by the Molybdenum Blue Photometric Method 9-19Lead by the Dithizone Photometric Method 20-30Chromium by the Sodium Peroxide Fusion-Titrimetric Method 31-371.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of who
6、ever 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 5.2. Referenced Documents2.1 ASTM Standards:A 101 Specification for Ferrochromium2A 481 Spec
7、ification for Chromium Metal2E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications3E 32 Practices for Sampling Ferroalloys and Steel Additivesfor Determination of Chemical Composition4E 50 Practices for Apparatus, Reagents, and Safety Consid-erations of
8、Metals, Ores, and Related Materials4E 60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption Spectrometry4E 173 Practice for Conducting Interlaboratory Studies oftest methods for Chemical Analysis of Metals5E 360 Test Methods for Chemical Analysis of Silicon andFerros
9、ilicon4E 361 Test Methods for the Determination of Arsenic andLead in Ferromanganese43. Significance and Use3.1 These test methods for the chemical analysis of metalsand alloys are primarily intended to test such materials forcompliance with compositional specifications. It is assumedthat all who us
10、e these test methods will be trained analystscapable of performing common laboratory procedures skill-fully and safely. It is expected that work will be performed ina properly equipped laboratory.4. Apparatus, Reagents, and Photometric Practice4.1 Apparatus and reagents required for each determinati
11、onare listed in separate sections preceding the procedure. Theapparatus, standard solutions, and certain other reagents usedin more than one procedure are referred to by number and shallconform to the requirements prescribed in Practices E 50,except that photometers shall conform to the requirements
12、prescribed in Practice E 60.4.2 Photometric practices prescribed in these test methodsshall conform to Practice E 60.1These test methods are under the jurisdiction of ASTM Committee E01 onAnalytical Chemistry for Metals, Ores, and Related Materials and are the directresponsibility of Subcommittee E0
13、1.01 on Iron, Steel, and Ferroalloys.Current edition approved June 10, 2003. Published July 2003. Originallyapproved in 1970. Last previous edition approved in 2002 as E 363 83 (2002).2Annual Book of ASTM Standards, Vol 01.02.3Annual Book of ASTM Standards, Vol 14.02.4Annual Book of ASTM Standards,
14、Vol 03.05.5Discontinued. See 1997 Annual Book of ASTM Standards, Vol 03.06.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Safety Hazards5.1 For precautions to be observed in the use of certainreagents in these test methods, refer
15、 to Practices E 50.6. Sampling6.1 For procedures for sampling the material, and forparticle size of the sample for chemical analysis, refer toPractices E 32.7. Rounding Calculated Values7.1 Calculated values shall be rounded to the desired num-ber of places as directed in 6.4 to 6.6, Rounding Proced
16、ure, ofPractice E 29.8. Interlaboratory Studies8.1 These test methods have been evaluated in accordancewith Practice E 173, unless otherwise noted in the precisionand bias section.ARSENIC BY THE MOLYBDENUM BLUEPHOTOMETRIC METHOD9. Scope9.1 This method covers the determination of arsenic inchromium a
17、nd ferrochromium in concentrations from 0.001 to0.005 %.10. Summary of Method10.1 See Section 10 of Test Methods E 360.11. Concentration Range11.1 See Section 11 of Test Methods E 360.12. Stability of Color12.1 See Section 12 of Test Methods E 360.13. Interferences13.1 See Section 13 of Test Methods
18、 E 360.14. Apparatus14.1 See Section 14 of Test Methods E 360.15. Reagents15.1 Proceed as directed in 15.1 through 15.9 of TestMethods E 360.16. Preparation of Calibration Curve16.1 Proceed as directed in 16.1 through 16.5 of TestMethods E 360.17. Procedure17.1 Proceed as directed in 17.1 through 17
19、.4 of TestMethods E 360.18. Calculation18.1 Proceed as directed in Section 18 of Test MethodsE 360.19. Precision and Bias19.1 Nine laboratories cooperated in testing this method andobtained the data summarized in Table 1. Samples with arsenicconcentrations near the upper limit of the scope were nota
20、vailable for testing. The user is cautioned to verify, by the useof reference materials, if available, that the precision and biasof this method is adequate for the contemplated use.LEAD BY THE DITHIZONE PHOTOMETRICMETHOD20. Scope20.1 This method covers the determination of lead inchromium and ferro
21、chromium in concentrations from 0.001 to0.05 %.21. Summary of Method21.1 See Section 21 of Test Methods E 361.22. Concentration Range22.1 See Section 22 of Test Methods E 361.23. Stability of Color23.1 See Section 23 of Test Methods E 361.24. Interferences24.1 See Section 24 of Test Methods E 361.25
22、. Apparatus25.1 See Section 25 of Test Methods E 361.26. Reagents26.1 Proceed as directed in Section 26 of Test MethodsE 361.27. Preparation of Calibration Curve27.1 Proceed as directed in 27.1 through 27.5 of TestMethods E 361.28. Procedure28.1 Test Solution:28.1.1 Transfer a sample, selected in ac
23、cordance with 28.1.1of Test Methods E 361 and weighed to the nearest 0.1 mg, toa 250-mL beaker. Add 30 mL of HCl (1 + 1) and heat untildissolution is nearly complete. In the case of high-carbonferrochromium (4.00 to 9.00 % C), add 30 mL of HCl(concentrated) and several drops of HF, and heat until th
24、ereaction has subsided.28.1.2 Add several drops of HF (omit if added in precedingparagraph) plus 10 mL of HNO3and 10 mL of HClO4.Evaporate to heavy fumes of HClO4and fume until the volumeis reduced to approximately 5 mL. Add H2O2solution (1 + 9)TABLE 1 Statistical InformationArsenicFerroalloy Type A
25、rsenic Found, %Repeatability (R1,E 173)Reproduci-bility (R2, E 173)1. 70Cr-1Si-5C 0.0015 0.0001 0.0005E 363 83 (2003)e12dropwise until any precipitated manganese dioxide is dis-solved. Boil to remove excess H2O2and cool.28.1.3 Proceed as directed in 28.1.4 through 28.4 of Test testmethods E 361.29.
26、Calculation29.1 Proceed as directed in Section 29 of Test test methodsE 361.30. Precision and Bias30.1 Four laboratories cooperated in testing this method andobtained the results shown in Table 2. Samples with leadconcentrations near the upper limit of the scope were notavailable for testing. The us
27、er is cautioned to verify, by the useof reference materials, if available, that the precision and biasof this method is adequate for the comtemplated use.CHROMIUM BY THE SODIUM PEROXIDE FUSION-TITRIMETRIC METHOD31. Scope31.1 This method covers the determination of chromium inall carbon grades of fer
28、rochromium in concentrations from 50to 75 %.32. Summary of Method32.1 The sample is fused in sodium peroxide. After disso-lution of the melt in dilute sulfuric acid, chromium andmanganese are oxidized by ammonium peroxydisulfate withsilver nitrate as a catalyst. The permanganate ions are reducedwith
29、 hydrochloric acid and the chromate ions are reduced byadding an excess of standard ferrous ammonium sulfate salt.The excess ferrous ions are titrated with standard potassiumpermanganate solution.33. Interferences33.1 The elements ordinarily present do not interfere if theirconcentrations are under
30、the maximum limits shown in 1.1.34. Reagents34.1 Ammonium Peroxydisulfate (NH4)2S2O8).34.2 Ferrous Ammonium Sulfate SaltFine, well mixed,free flowing crystals of Fe (NH4)2(SO4)26H2O will be re-quired. Standardize as follows: Transfer 0.9806 g of NBSK2Cr2O7(equivalent to 200 mL of 0.1 N solution) to
31、a 600-mLbeaker. Add 300 mL of water, 30 mL of H2SO4(1 + 1), and 8.00g of the ferrous ammonium sulfate. Stir until completelydissolved. Add 6 drops of 1,10-phenanthroline indicator solu-tion, and using a 50-mL buret, titrate with 0.1 N KMnO4solution to the color change from red to green. Record the b
32、uretreading to the nearest 0.05 mL. Calculate the volume of 0.1 NK2Cr2O7solution equivalent to1gofferrous ammoniumsulfate as follows:A 5 200 1 B!/8 (1)where:A = millilitres of 0.1 N K2Cr2O7solution equivalent to 1 gof ferrous ammonium sulfate, andB = millilitres of 0.1 N KMnO4solution used.The salt
33、has proved to be stable for at least 1 week.34.3 Ferrous Ammonium Sulfate, Standard Solution (0.25N) (Note 1)Dissolve 89.6 g of Fe (NH4)2(SO4)26H2Oin500mL of cold H2SO4(5 + 95) and dilute to 1 litre withH2SO4(5 + 95). Use a solution that has been standardizedwithin the previous8hasfollows: Transfer
34、0.9806 g of NBSK2Cr2O7(equivalent to 200 mL of 0.1 N solution) to an 800-mLbeaker. Add 300 mL of water, 30 mL of H2SO4(1 + 1). Stiruntil completely dissolved, and add a slight excess of theferrous ammonium sulfate solution. Add 6 drops of 1,10-phenanthroline indicator solution and titrate with 0.1 N
35、KMnO4solution to the color change from red to green.Calculate the volume of 0.1 N K2Cr2O7solution equivalent to1 mL of ferrous ammonium sulfate solution as follows:A 5 200 1 B!/C (2)where:A = millilitres of 0.1 N K2Cr2O7solution equivalent to 1mL of ferrous ammonium sulfate solution,B = millilitres
36、of 0.1 N KMnO4solution used, andC = millilitres of 0.25 N ferrous ammonium sulfate used.NOTE 1Ferrous ammonium sulfate salt is preferred to the standardferrous ammonium sulfate solution. If the ferrous ammonium sulfatesolution is used, it is necessary to add it by means of a calibrated 100-mLburet.3
37、4.4 1,10-Phenanthroline Ferrous Complex Indicator Solu-tion (0.025 M)Reagent No. 122.34.5 Potassium Permanganate Standard Solution (0.1 N)Reagent No. 13.34.6 Potassium Permanganate Solution (20 g/L)ReagentNo. 134.34.7 Silver Nitrate Solution (8 g/L)Reagent No. 133.35. Procedure35.1 Transfer a 0.50-g
38、 sample, weighed to the nearest 0.1mg, to a 30-mL iron crucible (Note 2). Add8gofdrysodiumperoxide (Na2O2) and mix thoroughly with a small stainlesssteel spatula. Clean the spatula after mixing by scraping on theinside edge of the crucible. Cover the mixture with anadditional 1 to2gofNa2O2.NOTE 2Cru
39、cibles made of ingot iron have a negligible blank andresist attack by the molten peroxide.35.2 Place the crucible on a wire gauze supported on atripod and heat with a Meker burner until the fusion has beeninitiated. Grasp the crucible with long handled tongs and fusecarefully by moving it around the
40、 edge of a free flame with agyratory motion while raising the temperature gradually toTABLE 2 Statistical InformationLeadFerroalloy Type Lead Found, %1. Electrolytic Cr Metal Lab A: 0.0020, 0.00200.0019, 0.0020Lab B: 0.0025, 0.00230.0020, 0.0011Lab C: 0.0020, 0.00210.0020, 0.0020Lab D: 0.0011, 0.000
41、9Average: 0.0019E 363 83 (2003)e13avoid spattering. When the contents are molten, swirl thecrucible to dissolve any unattacked particles of sample adher-ing to the bottom or sides. Finally, increase the temperatureuntil the crucible is bright red for 1 min. Cool the crucible toalmost room temperatur
42、e. (WarningUse proper safety prac-tices and equipment when performing sodium peroxide fu-sions.)35.3 Cover the crucible with a crucible cover, hold upright,and rap the bottom sharply on a piece of heavy metal to loosenthe cake. Transfer the cake to a dry, 800-mL beaker, add 300mL of water all at onc
43、e, and cover. Rinse and police thecrucible and cover and add the rinsings to the beaker. Add 60mL of H2SO4(1+1),5mLofH3PO4and 5 mL of HNO3, heatto boiling and boil for several minutes. Cool to 7080C, add5 mL of AgNO3solution,5gof(NH4)2S2O8, and 3 or 4 dropsof KMnO4solution (20 g/L). Boil for 10 min,
44、 add 5 mL of HCl(1 + 3), and boil for an additional 5 min after the KMnO4andany MnO2have completely disappeared. Cool to room tem-perature.35.4 Select and weigh a portion of the standard ferrousammonium sulfate salt (Note 3) to the nearest 0.1 mg inaccordance with the following:Chromium, % Ferrous A
45、mmonium Sulfate, g50 to 55 6.50055 to 60 7.00060 to 65 7.50065 to 70 8.00070 to 75 8.500Add the salt to the test solution and stir until it hascompletely dissolved. Add 6 drops of 1,10-phenanthrolineindicator solution and titrate with the KMnO4standard solutionto the color change from red to green.N
46、OTE 3A measured amount of the ferrous ammonium sulfate solu-tion, in excess of that required for the reduction, may be used instead ofthe salt, if desired (see Note 1).36. Calculation36.1 When ferrous ammonium sulfate salt is used, calculatethe percentage of chromium as follows:Chromium, % 5A 3 B! 2
47、 CD3 0.1734 (3)where:A = millilitres of 0.1 N K2Cr2O7solution equivalent to 1 gof ferrous ammonium sulfate (see 34.2),B = grams of ferrous ammonium sulfate used,C = millilitres of 0.1 N KMnO4solution required to titratethe excess ferrous ammonium sulfate, andD = grams of sample used.36.2 When ferrou
48、s ammonium sulfate solution is used,calculate the percentage of chromium as follows:Chromium, % 5A 3 B! 2 CD3 0.1734 (4)where:A = millilitres of 0.1 N K2Cr2O7solution equivalent to 1mL of ferrous ammonium sulfate solution (see 34.3),B = millilitres of ferrous ammonium sulfate solution used,C = milli
49、litres of 0.1 N KMnO4solution required to titratethe excess ferrous ammonium sulfate, andD = grams of sample used.37. Precision and Bias37.1 Nine laboratories cooperated in testing this method andobtained the data summarized in Table 3. Samples withchromium concentrations near the upper limit of the scopewere not available for testing. The user is cautioned to verify,by the use of reference materials, if available, that the precisionand bias of this method is adequate for the contemplated use.38. Keywords38.1 arsenic; chemical analysis; chromium; ferrochromium;l
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