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1、BRITISH STANDARD BS 6200-3.18.4: 1991 Sampling and analysis of iron, steel and other ferrous metals Part 3: Methods of analysis Section 3.18 Determination of manganese Subsection 3.18.4 Steel and cast iron: volumetric method Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2
2、006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 This British Standard, having been prepared under the direction of the Iron and Steel Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 29 November 1991 BSI 09-1999 The following BSI refer
3、ences relate to the work on this standard: Committee reference ISM/18 Draft for comment 91/35215 DC ISBN 0 580 19944 4 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Iron and Steel Standards Policy Committee (ISM/-) to Technical Committ
4、ee ISM/18, upon which the following bodies were represented: BCIRA British Steel Industry Department of Trade and Industry (Laboratory of the Government Chemist) Ferro Alloys and Metals Producers Association Ministry of Defence Amendments issued since publication Amd. No.DateComments Licensed Copy:
5、sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 BSI 09-1999i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Principle1 3Reagents1 4Apparatus1 5Sampling1 6Procedure1 7Calculation and expression of results2 8Te
6、st report3 Table 1 Precision data3 Table 2 Values for inter-laboratory agreement3 Publication(s) referred toInside back cover Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 ii BSI 09-1999 Foreword This Subsection of BS 6
7、200 has been prepared under the direction of the Iron and Steel Standards Policy Committee and supersedes method 1 for the determination of manganese in BSI Handbook No. 19, to which it is technically equivalent. BS 6200 is a multipart British Standard, covering all aspects of the sampling and analy
8、sis of iron, steel and other ferrous metals. A list of contents, together with general information, is given in Part 1. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with
9、 a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amen
10、dments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 BSI 09-19991 1 Scope This Subsection of BS 6200 describes a volumetric method f
11、or the determination of manganese in steel and cast iron. The method is applicable to manganese contents from 0.02 % (m/m) to 14 % (m/m). NOTEThe titles of the publications referred to in this Subsection of BS 6200 are listed on the inside back cover. 2 Principle From an oxidized sulfuric acid solut
12、ion of the sample, iron and chromium are separated with zinc oxide. Manganese is oxidized to permanganate with ammonium peroxodisulfate in the presence of a silver catalyst. Residual peroxodisulfate is destroyed by boiling and the determination completed by titration with diammonium iron(II) sulfate
13、 and potassium dichromate. 3 Reagents During the analysis, use only reagents of recognized analytical grade and only grade 3 water as specified in BS 3978. 3.1 Diammonium iron(II) sulfate, 40 g/L. Dissolve 40 g of diammonium iron (II) sulfate, (NH4)2SO4. FeSO4. 6H2O, in a mixture of 500 mL of water
14、and 20 mL of sulfuric acid, density = 1.84 g/mL, and cool. Transfer to a 1 L volumetric flask, dilute to the mark and mix. 3.2 Ammonium peroxodisulfate, 125 g/L solution. Dissolve 25 g of ammonium peroxodisulfate (NH4)2S2O8, in water, dilute to 200 mL and mix. 3.3 Hydrochloric acid, = 1.16 g/mL to 1
15、.18 g/mL. 3.4 Nitric acid, = 1.42 g/mL. 3.5 Phosphoric-sulfuric acid mixture. To 600 mL of water add cautiously 150 mL of orthophosphoric acid, = 1.75 g/mL, 150 mL of sulfuric acid, = 1.84 g/mL, and mix. Cool, dilute to 1 L and mix. 3.6 Potassium dichromate, standard solution. Dissolve 4.9035 g of p
16、otassium dichromate, K2Cr2O7, (previously dried to constant weight at 150 C) in approximately 500 mL of water. Cool, transfer to a 1 L volumetric flask, dilute to the mark and mix. 1 mL of this solution is equivalent to 1.1 mg of manganese. 3.7 Silver nitrate, 10 g/L solution. Dissolve 5 g of silver
17、 nitrate in water, dilute to 500 mL and mix. 3.8 Sodium N-phenylsulfanilate, preoxidized, (sodium diphenylaminesulfonate). Use pellets containing the equivalent of 1 mg of preoxidized sodium N-phenylsulfanilate, or a suitable solution containing the same equivalent of preoxidized sodium N-phenylsulf
18、anilate. 3.9 Sulfuric acid. To 400 mL of water add cautiously 150 mL of sulfuric acid, = 1.84 g/mL. Mix, cool, dilute to 1 L and mix. 3.10 Sulfurous acid. Pass sulfur dioxide gas into 100 mL of water until a saturated solution is obtained. 3.11 Zinc oxide suspension. Add 50 g of finely powdered zinc
19、 oxide to 200 mL of water and stir or shake until a smooth cream is obtained. The suspension should be stirred immediately before use, and also between additions during use. 4 Apparatus 4.1 Ordinary laboratory apparatus 4.2 Filter papers. Medium fast qualitative 24 cm fluted filter papers. NOTEWhatm
20、an No. 2 V or equivalent have been found satisfactory. 4.3 Volumetric glassware, in accordance with class A of BS 846, BS 1583 or BS 1792, as appropriate. 5 Sampling Carry out sampling in accordance with BS 1837. NOTEBS 6200-2, which will supersede BS 1837, is currently in preparation. On its public
21、ation this Subsection will be amended to include sampling in accordance with BS 6200-2. 6 Procedure 6.1 Test portion Weigh, to the nearest 0.001 g, a test portion of 2.2 g. When the manganese content exceeds 2.75 % (m/m), reduce the mass of the test portion so that the manganese content of the final
22、 solution (see 6.2.3) does not exceed 30 mg. 6.2 Determination 6.2.1 Preparation of the test solution Place the test portion in a 650 mL conical beaker. Add 70 mL of sulfuric acid (3.9), cover the beaker and heat until solvent action ceases. If dissolution is incomplete, for example in the case of h
23、igh nickel stainless steel or heat-resisting steel, make additions of both hydrochloric acid (3.3) and nitric acid (3.4) to facilitate solution. If initial acid attack leaves large residues of acid-resistant carbide, for example with certain types of high carbon chromium steels, evaporate the sulfur
24、ic acid solution until fumes appear. Cool, redissolve in water, oxidize with nitric acid (3.4), and proceed to 6.2.2. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 2 BSI 09-1999 Oxidize with nitric acid (3.4) but do NOT
25、 oxidize stainless steel types until solution is complete unless hydrochloric acid is already present or is added to the solution. Evaporate until fumes appear, then cool. If hydrochloric acid has been added to facilitate solution, dissolve the salts in water, and repeat the evaporation to fumes. Ad
26、d 150 mL of water, five drops of sulfurous acid (3.10) and heat until soluble salts are dissolved. Cool to room temperature. If substantial amounts of tungstic acid or graphite are present at this stage, filter through a paper-pulp pad, wash with a small amount of cold sulfuric acid (3.9) and discar
27、d the residue. 6.2.2 Separation of iron and chromium Add zinc oxide suspension (3.11) approximately 5 mL at a time, mixing thoroughly after each addition, until the solution is neutralized and a faint permanent precipitate of iron-group hydroxides is obtained. Then make a final addition of 10 mL of
28、zinc oxide suspension (3.11) to complete the precipitation, indicated by a definite change from a clear dark-coloured solution to a turbid brown solution due to the precipitation of hydroxides. The addition of the 10 mL excess of zinc oxide suspension causes the brown precipitate to assume a slightl
29、y milky white appearance. Add 35 mL of silver nitrate solution (3.7), mix thoroughly, transfer to a 500 mL volumetric flask, and dilute to the graduation mark. Make a correction for the volume occupied by the precipitated hydroxides and the excess of zinc oxide by adding 2.5 mL of water per 1 g of t
30、est portion plus an allowance of 0.5 mL for the zinc oxide present, e.g. for a 2.2 g test portion the addition would be 5.5 + 0.5 = 6 mL. Mix thoroughly and allow to stand for 5 min. Take an aliquot by filtration through a dry medium fast texture 24 cm fluted filter paper (4.2) into a 250 mL volumet
31、ric flask. Rinse the flask with the first few millilitres of filtrate before collecting the aliquot. 6.2.3 Oxidation and titration of manganese Transfer the aliquot to a 650 mL conical beaker and add 60 mL of phosphoric-sulfuric acid mixture (3.5). Add a few glass beads, heat to boiling, add cautiou
32、sly 20 mL of ammonium peroxodisulfate (3.2), boil the solution for precisely 15 min, and cool rapidly to room temperature. Titrate with diammonium iron(II) sulfate solution (3.1) until an excess of at least 2 mL is present. Add preoxidized sodium N-phenylsulfanilate indicator (3.8) and titrate with
33、potassium dichromate solution (3.6) until one drop produces a deep violet coloured end point. Record the volumes of titrants used. 6.2.4 Standardization of diammonium iron(II) sulfate solution Transfer 60 mL of phosphoric-sulfuric acid mixture (3.5) to a 650 mL conical beaker, dilute to 300 mL and a
34、dd preoxidized sodium N-phenylsulfanilate indicator (3.8). Add three drops of diammonium iron(II) sulfate solution (3.1) and then add potassium dichromate solution (3.6) until one drop produces a deep violet colour. By means of a pipette or burette, add exactly 25 mL of diammonium iron(II) sulfate s
35、olution (3.1) and titrate with potassium dichromate solution (3.6) until one drop produces a deep violet end point. Record the volume of potassium dichromate solution (3.6) used between the two endpoints. 7 Calculation and expression of results 7.1 Calculation Calculate the factor F of the diammoniu
36、m iron(II) sulfate solution (3.1) from the equation: F = Vf/25 where Vf is the volume, of potassium dichromate standard solution (3.6) used in 6.2.4 in the titration between the two end points (in mL). NOTE1 mL of potassium dichromate solution (3.6) is equivalent to 1.1 mg of manganese. Calculate th
37、e manganese content Mn expressed as a percentage by mass from the equation: where V1is the volume of diammonium iron(II) sulfate solution (3.1) used in 6.2.3 (in mL); V2is the volume of potassium dichromate solution (3.6) used in 6.2.3 (in mL); mis the mass of the test portion in 6.1 (in g). Mn 0.22
38、0 F V1V2() m - -= Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 BSI 09-19993 7.2 Precision 7.2.1 Precision data A planned trial of this method was carried out by 9 to 10 laboratories on each of 12 samples. The mean resu
39、lts for each laboratory given in the original report1) have been examined statistically to obtain values for between-laboratory agreement. In the absence of individual results it is not possible to calculate repeatability, r, or reproducibility, R, as defined in BS 5497-1. From the reported results,
40、 for probability P = 95 %, the statistical limits (2.83s) for agreement between laboratory means have been calculated and are given in Table 1. The difference between the mean results of two laboratories found on identical test material will exceed the P = 95 % agreement level not more that once in
41、20 cases, on average, in the normal and correct operation of the method. Table 1 Precision data 7.2.2 Regression data Statistical analysis of the results showed a logarithmic relationship between manganese content and the value of the standard deviation of the laboratory means summarized by the equa
42、tion: log s = 0.3204 log Mn % 1.8192 correlation 0.831 The predicted values for the statistical limits for agreement between two laboratories at P = 95 % calculated from the equation are given in Table 2. Table 2 Values for inter-laboratory agreement (2.83s, P = 95 %) 8 Test report The test report s
43、hall include the following information: a) all information necessary for the identification of the sample, the laboratory and the date of analysis; b) the method used, by reference to this Subsection of BS 6200; c) the results, and the form in which they are expresed; d) any unusual features noted d
44、uring the determination; e) any operation not specified in this British Standard or any optional operation which may have influenced the results. 1) Methods of Analysis Committee. The determination of silicon and manganese in iron and steel. Metallurgia, October 1948, 347-352. Type of steel or alloy
45、Manganese content Between-laboratory agreement 2.83s 80 % Ni, 20 % Cr alloy % (m/m) 0.1120.016 25 % Co magnet alloy0.1290.026 18 % W, 4 % Cr, 1 % V steel0.2820.042 1.5 % C, 14 % Cr, 2.5 % Co steel0.4000.035 14 % Cr, 0.1 % Zr steel0.4670.028 18 % Cr, 8 % Ni, 1.5 % Ti, 1 % Al0.6440.029 35 % Co magnet
46、alloy0.6950.025 25 % Cr, 20 % Ni steel0.9370.040 0.5 % Si basic iron1.090.058 2.5 % Si haematite iron1.420.057 18 % Cr, 8 % Ni, 1.5 % Mn steel1.540.062 18 % Cr, 9 % Mn steel9.200.077 13.5 % Mn steel (four laboratories)13.450.36 Manganese95 % inter-laboratory agreement % (m/m) 0.10 0.20 0.5 1.0 2.0 5
47、.0 10.0 0.021 0.026 0.034 0.043 0.054 0.072 0.090 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 blank Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 15:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6200-3.18.4:1991 BSI 09-1
48、999 Publication(s) referred to BS 846, Specification for burettes. BS 1583, Specification for one-mark pipettes. BS 1792, Specification for one-mark volumetric flasks. BS 1837, Methods for the sampling of iron, steel, permanent magnet alloys and ferro-alloys. BS 3978, Specification for water for lab
49、oratory use. BS 5497, Precision of test methods. BS 5497-1, Guide for the determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. BS 6200, Sampling and analysis of iron, steel and other ferrous metals. BS 6200-1, Introduction and contents2). BS 6200-2, Methods of sampling and sample preparation3). BSI Handbook No. 19, Methods for the sampling and analysis of iron, steel and other ferrous metals2). 2) Referred to in the foreword only. 3) In preparatio
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