1、BRITISH STANDARD BS 6200-3.18.2: 1985 ISO629:1982 Sampling and analysis of iron, steel and other ferrous metals Part 3: Methods of analysis Section 3.18 Determination of manganese Subsection 3.18.2 Steel: spectrophotometric method ISO title: Steel and cast iron Determination of manganese content Spe
2、ctrophotometric method UDC 669.1:543.42.062:546.711BS6200-3.18.2:1985 This British Standard, having been prepared under the directionof the Iron and Steel Standards Committee, was published under the authority ofthe Board of BSI and comesintoeffecton 28February1985 BSI 11-1999 The following BSI refe
3、rences relate to the work on this standard: Committee reference ISM/18 Draft for approval84/39008 ISBN 0 580 14266 3 National foreword This Subsection of BS6200 has been prepared under the direction of the Iron and Steel Standards Committee. It is identical with ISO 629:1982 “Steel and cast iron Det
4、ermination of manganese content Spectrophotometric method” published by the International Organization for Standardization (ISO) and supersedes method2 for the determination of manganese in BSI Handbook No.19. Terminology and conventions. The text of the International Standard has been approved as s
5、uitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice t
6、o use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. Cross-reference. The Technical Committee has reviewed the provisions of ISO/R 377, to which reference is made in the te
7、xt, and has decided that they are acceptable for use in conjunction with this standard. At present there is no corresponding British Standard for ISO377-2, which is still at draft stage, but a related standard to ISO/R377 is BS1837 “Methods for the sampling of iron, steel, permanent magnet alloys an
8、d ferro-alloys”. Appropriate procedures from ISO377-2 will be incorporated in BS6200-2 “Methods of sampling and sample preparation”, which will be published in due course and which will supersede BS1837. A British Standard does not purport to include all the necessary provisions of a contract. Users
9、 of British Standards are responsible for their correct application. Compliance with 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, pagesi andii, pages1 to4, an inside back cover and a back
10、cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date of issue CommentsBS6200-3.18.2:1985 BSI 11-1999 i Contents Page National for
11、eword Inside front cover 1 Scope and field of application 1 2 Reference 1 3 Principle 1 4 Reagents 1 5 Apparatus 1 6 Sampling 1 7 Procedure 1 8 Expression of results 4 9 Test report 4 Table 1 Dilution guide for test solution 3 Table 2 Preparation guide for reference solution of manganese less than0,
12、05%(m/m) 3 Table 3 Preparation guide for reference solution of manganese between0,050 and4%(m/m) 3 Publication referred to Inside back coverii blankBS6200-3.18.2:1985 BSI 11-1999 1 1 Scope and field of application This International Standard specifies a spectrophotometric method for the determinatio
13、n of manganese in steel and cast iron. The method is applicable to products having manganese contents between0,001 and4%(m/m). 2 Reference ISO377-2, Selection and preparation of samples and test pieces of wrought steels Part2:Samples and test pieces in-tended for the determination of the chemical co
14、mposition 1) . 3 Principle Dissolution of a test portion in sulphuric-phosphoric acid mixture and nitric acid. Treatment of the test solution with perchloric acid. Formation of the permanganate ion by sodium periodate. Spectrophotometric measurement of the test solution at wavelength of about545nm.
15、4 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and only distilled water or water of equivalent purity. NOTEVerify by blank tests that relevant reagents are free from manganese. Wherever necessary, the results should be corrected accordingly.
16、 4.1 Water, free from organic matter. Bring to the boil water acidified with10ml/l of sulphuric acid ( about1,83g/ml), add several crystals of sodium periodate (NaIO 4 ) and keep boiling for10min. 4.2 Pure iron, free from manganese. 4.3 Hydrochloric acid, about1,19g/ml. 4.4 Nitric acid, about1,40g/m
17、l. 4.5 Perchloric acid, about1,67g/ml. NOTEIt is also possible to use perchloric acid, about1,54g/ml.127ml of perchloric acid, about1,54g/ml is equivalent to100ml of perchloric acid, about1,67g/ml. 4.6 Perchloric acid, diluted1+499. 4.7 Sulphuric/phosphoric acid mixture To600ml of water add in the f
18、ollowing order, carefully and stirring at the same time,100ml of sulphuric acid ( about1,83g/ml) and150ml of phosphoric acid ( about1,71g/ml). Cool and dilute to1000ml with water. 4.8 Sodium periodate, 50g/l solution. 4.9 Manganese, standard solution 4.9.1 Stock solution Weigh, to the nearest0,001g,
19、2,877g of potassium permanganate, dissolve in500ml of water and add10ml sulphuric acid ( about1,83g/ml). Decolorize the solution with hydrogen peroxide about30%(m/m) or with a stream of sulphur dioxide. In the latter case, eliminate the excess of reagent by boiling. After cooling, transfer the solut
20、ion to a1000ml one-mark volumetric flask, dilute to the mark with water and mix. 1ml of this stock solution contains1,00mg of Mn. 4.9.2 Standard solution A Transfer100ml of the stock solution(4.9.1) to a1000ml one-mark volumetric flask and dilute to the mark with water and mix. 1ml of standard solut
21、ion A contains0,1mg of Mn. 4.9.3 Standard solution B Transfer250ml of the standard solution A(4.9.2) to a1000ml one-mark volumetric flask, dilute to the mark with water and mix. 1ml of standard solution B contains0,025mg of Mn. 5 Apparatus Ordinary laboratory apparatus and 5.1 Spectrophotometer 6 Sa
22、mpling Sampling shall be carried out in accordance with ISO377-2 or appropriate national standards for cast iron. 7 Procedure WARNING: Perchloric acid vapour may cause explosions in the presence of ammonia, nitrous fumes or organic material in general. 7.1 Test portion According to the presumed mang
23、anese content, weigh, to the nearest0,001g, the following mass(m) of the test portion: a) for Mn contents less than0,05%(m/m): m approximately2g; b) for Mn contents between0,05 and2%(m/m): m approximately1g; c) for Mn contents greater than2%(m/m): m approximately0,5g. 1) At present at the stage of d
24、raft. (Partial revision of ISO/R377:1964.)BS6200-3.18.2:1985 2 BSI 11-1999 7.2 Determination 7.2.1 Preparation of test solution Place the test portion(7.1) in a250ml conical flask, add50ml of the sulphuric/phosphoric acid mixture(4.7) and heat gently until effervescence ceases. When the attack is co
25、mplete, oxidize with a few drops of the nitric acid(4.4) and add20ml of the perchloric acid(4.5). Evaporate until white perchloric acid fumes are given off and keep at this temperature for10min. After cooling, take up with water, dilute to70 to80ml and boil. If necessary, filter and wash with the ho
26、t perchloric acid(4.6). Collect the filtrate in a100ml one-mark volumetric flask. Dilute to the mark with water and mix. This gives solution S 1 . NOTEFor samples that do not dissolve readily in the sulphuric/phosphoric acid mixture(4.7), add also10ml of the hydrochloric acid(4.3) and10ml of the nit
27、ric acid(4.4) to facilitate the dissolution. 7.2.2 Formation of coloured compound for test portion Introduce into a250ml conical flask the following quantities of solution S 1 , and reagents specified in Table 1, depending on the presumed manganese content. Bring to the boil, add10ml of the sodium p
28、eriodate solution(4.8), boil for2min and maintain at90 C for10min. Cool to ambient temperature. Transfer into a100ml volumetric flask, dilute to the mark with water(4.1) and mix. 7.2.3 Preparation of the compensation solution Take the same volumes of solution S 1 , water and sulphuric/phosphoric aci
29、d mixture(4.7) as for the formation of the coloured compound for the test portion(7.2.2). Add2 or3drops of the hydrochloric acid(4.3) and boil for several minutes. After cooling, transfer into a100ml one-mark volumetric flask, dilute to the mark with water and mix. 7.2.4 Spectrophotometric measureme
30、nt Carry out the spectrophotometric measurements on the test solution(7.2.2), using the spectrophotometer(5.1) at a wavelength about545nm, after having adjusted the instrument to zero absorbance against the compensation solution(7.2.3). 7.2.5 Establishment of calibration curve 7.2.5.1 Preparation of
31、 reference solutions 7.2.5.1.1 For manganese contents less than0,05%(m/m) Weigh, to the nearest0,001g,2,000g of the pure iron(4.2). Transfer into a series of six250ml conical flasks, add50ml of the sulphuric/phosphoric acid mixture(4.7) and heat gently until effervescence ceases. When the attack is
32、complete, oxidize with a few drops of the nitric acid(4.4) and add20ml of the perchloric acid(4.5). Evaporate until white perchloric acid fumes are given off and keep at this temperature for10min. After cooling, take up with water, dilute to70 to80ml and boil. If necessary, filter and wash with the
33、hot perchloric acid(4.6). Collect the filtrate in a100ml one-mark volumetric flask. After cooling, dilute to the mark with water and mix. This gives solution S 2 . Introduce into a series of six250ml conical flasks the quantities of manganese standard solutionB(4.9.3) specified in Table 2. Dilute th
34、e above volumes to25ml with water, add40,0ml of solution S 2and5ml of the sulphuric/phosphoric acid mixture(4.7). Continue in accordance with sub-clause7.2.2, beginning at “Bring to the boil.”. 7.2.5.1.2 For manganese contents between0,05 and4%(m/m) Weigh, to the nearest0,001g, approximately1g of th
35、e pure iron(4.2). Transfer into a250ml conical flask, add50ml of the sulphuric/phosphoric acid mixture(4.7) and heat gently until effervescence ceases. When the attack is complete, oxidize with a few drops of the nitric acid(4.4) and add20ml of the perchloric acid(4.5). Evaporate until white perchlo
36、ric acid fumes are given off and keep at this temperature for10min. After cooling, take up with water, dilute to70 to80ml and boil. If necessary, filter and wash with the hot perchloric acid(4.6). Collect the filtrate in a100ml conical flask. After cooling, dilute to the mark with water and mix. Thi
37、s gives solution S 3 . Introduce into a series of six250ml conical flasks the quantities of manganese standard solutionA(4.9.2) specified in Table 3. Dilute the above volumes to25ml with water, add10ml of solution S 3and20ml of the sulphuric/phosphoric acid mixture(4.7). Continue in accordance with
38、sub-clause7.2.2, beginning at “Bring to the boil.”.BS6200-3.18.2:1985 BSI 11-1999 3 7.2.5.2 Spectrophotometric measurements Carry out the spectrophotometric measurements on the reference solutions(7.2.5.1.1 and7.2.5.1.2), using the spectrophotometer(5.1) at a wavelength about545nm, after having adju
39、sted the instrument to zero absorbance against the reference solution“0”. 7.2.5.3 Plotting of calibration curve or calculating of angular coefficient of the straight line Plot the absorbance against the known mass of manganese, in milligrams, in100ml of reference solution. Calculate the angular coef
40、ficient (a), the mass, in milligrams, of manganese in100ml by absorbance per optical pathlength of1cm, from the slope of the calibration curve if it is a straight line. Table 1 Dilution guide for test solution Table 2 Preparation guide for reference solution of manganese less than0,05% (m/m) Table 3
41、 Preparation guide for reference solution of manganese between0,050 and4%(m/m) Presumed Mn content Mass of original test portion Volume of solution S 1 Mass of equivalent test portion Volume of water added Volume of sulphuric/phosphoric acid mixture(4.7) added %(m/m) g ml g ml ml Less than0,05 0,05
42、to0,50 0,10 to1,00 0,20 to2,00 0,40 to4,00 2 1 1 1 0,5 40,0 40,0 20,0 10,0 10,0 0,80 0,40 0,20 0,10 0,05 10 10 20 25 25 5 5 15 20 20 1 2 3 4 5 6 Flask Introduce 0 2,0 5,0 10,0 15,0 20,0 ml of standard solution B(4.9.3) containing 0 0,050 0,125 0,250 0,375 0,500 mg of manganese corresponding to for a
43、 test portion of a test volume of 2g 40ml 0 0,006 0,016 0,031 0,047 0,063 %(m/m) of manganese 1 2 3 4 5 6 Flask Introduce 0 2,0 5,0 10,0 15,0 20,0 ml of standard solution A(4.9.2) containing 0 0,20 0,50 1,00 1,50 2,00 mg of manganese corresponding to for a test portion of a test volume of 1g 40ml 20
44、ml 10ml 0 0 0 0,050 0,100 0,200 0,125 0,250 0,500 0,250 0,500 1,000 0,375 0,750 1,500 0,500 1,000 2,000 %(m/m) of manganese 0,5g 10ml 0 0,400 1,000 2,000 3,000 4,000BS6200-3.18.2:1985 4 BSI 11-1999 8 Expression of results The manganese (Mn) content, as a percentage by mass, is obtained in accordance
45、 with the calibration curve or calculated from the formula where a is the angular coefficient, in D is the absorbance of the test solution corrected with the absorbance of its compensating solution(7.2.5.3); d is the optical pathlength, in centimetres, used for the measurement(7.2.4 or7.2.5.2); V is
46、 the volume, in millilitre, of the test solution used for the determination(7.2.2); m is the mass, in grams, of the test portion(7.1). 9 Test report The test report shall include the following particulars: a) the method used by reference to this International Standard; b) the results, and the form i
47、n which they are expressed; c) any unusual features noted during the determination; d) any operation not specified in this International Standard, or any optional operations which may have influenced the result. Mn%(m/m) = = a D d - 100 V - 1 m - 1 10 3 - 100 aD 10 dV m - mg Mn/100 ml absorbance/cm
48、-BS6200-3.18.2:1985 BSI 11-1999 Publication referred to Seenational foreword.BS 6200-3.18.2: 1985 ISO629:1982 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards
49、in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would info
