DIN EN 10071-2013 Chemical analysis of ferrous materials Determination of manganese in steels and irons Electrometric titration method German version EN 10071 2012《铁质材料的化学分析 钢和铁中锰含.pdf

《DIN EN 10071-2013 Chemical analysis of ferrous materials Determination of manganese in steels and irons Electrometric titration method German version EN 10071 2012《铁质材料的化学分析 钢和铁中锰含.pdf》由会员分享，可在线阅读，更多相关《DIN EN 10071-2013 Chemical analysis of ferrous materials Determination of manganese in steels and irons Electrometric titration method German version EN 10071 2012《铁质材料的化学分析 钢和铁中锰含.pdf（10页珍藏版）》请在麦多课文档分享上搜索。

1、January 2013 Translation by DIN-Sprachendienst.English price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS

2、 77.040.30!$LZ“1934155www.din.deDDIN EN 10071Chemical analysis of ferrous materials Determination of manganese in steels and irons Electrometric titration method;English version EN 10071:2012,English translation of DIN EN 10071:2013-01Chemische Analyse von Eisenwerkstoffen Bestimmung von Mangan in S

3、tahl und Eisen Elektrometrisches Titrierverfahren;Englische Fassung EN 10071:2012,Englische bersetzung von DIN EN 10071:2013-01Analyse chimique des matriaux ferreux Dtermination du manganse dans les aciers et les fontes Mthode par titrage lectromtrique;Version anglaise EN 10071:2012,Traduction angla

4、ise de DIN EN 10071:2013-01SupersedesDIN EN 10071:1990-04www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1012.12 DIN EN 10071:2013-01 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Tec

5、hnical Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel” (Secretariat: SIS, Sweden). The responsible German body involved in its preparation was the Normenausschuss Eisen und Stahl (Iron and Steel Standards Committee), Working Committee NA 021-00-30 AA Analysenverfahren. Amend

6、ments This standard differs from DIN EN 10071:1990-04 as follows: a) Clause 3 “Principle”: the third sentence has been reworded in order to correct the erroneous mention of “pyrophosphoric irons”. Previous editions DIN EN 10071: 1990-04 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 10071 Octo

7、ber 2012 ICS 77.040.30 Supersedes EN 10071:1989English Version Chemical analysis of ferrous materials - Determination of manganese in steels and irons - Electrometric titration method Analyse chimique des matriaux ferreux - Dtermination du manganse dans les aciers et les fontes - Mthode par titrage

8、lectromtrique Chemische Analyse von Eisenwerkstoffen - Bestimmung von Mangan in Stahl und Eisen - Elektrometrisches Titrierverfahren This European Standard was approved by CEN on 17 August 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions

9、for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in th

10、ree official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards b

11、odies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,

12、 Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CE

13、N national Members. Ref. No. EN 10071:2012: EEN 10071:2012 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Principle 44 Reagents .45 Apparatus .66 Sampling .67 Procedure .68 Expression of results 79 Test report 8DIN EN 10071:2013-01 EN 10071:2012 (E) 3 Foreword This document (EN 100

14、71:2012) has been prepared by Technical Committee ECISS/TC 102 “Methods of analysis for iron and steel”, the secretariat of which is held by SIS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by Ap

15、ril 2013, and conflicting national standards shall be withdrawn at the latest by April 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent r

16、ights. This document supersedes EN 10071:1989. In comparison with EN 10071:1989, the following significant technical change was made: Clause 3, Principle, rewording of the third sentence in order to correct the erroneous mention of “pyrophosphoric irons”. According to the CEN/CENELEC Internal Regula

17、tions, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Ita

18、ly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 10071:2013-01 EN 10071:2012 (E) 4 1 Scope This European Standard specifies an electrometric titration method for the determi

19、nation of manganese in steels and irons. The method is applicable to unalloyed, low alloy or alloyed steels and to irons with manganese contents greater than or equal to 0,5 % (m/m). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and

20、are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 648, Laboratory glassware Single-volume pipettes (ISO 648) EN ISO 1042, Laboratory glassware O

21、ne-mark volumetric flasks (ISO 1042) EN ISO 14284, Steel and iron Sampling and preparation of samples for the determination of chemical composition (ISO 14284) 3 Principle Dissolution of the test portion with appropriate acids, followed by a partial neutralisation of the acids with sodium hydrogen c

22、arbonate. Precipitation of the interfering cations with zinc oxide. Titration of Mn (II) with a potassium permanganate solution, in a pyrophosphoric medium at a pH of about 6,5. The oxidation-reduction reaction oxidation of Mn (II) to Mn (III) is controlled by an electrometric measurement. 4 Reagent

23、s During the analysis, use only reagents of recognised analytical grade. 4.1 Water, free from reducing compounds. For each 1 000 ml of water add 6 ml of sulphuric acid (20= 1,84 g/ml) and boil. Add a few crystals of sodium periodate and maintain the boiling for about 10 min. Cool and transfer into a

24、n appropriate vessel. 4.2 Zinc oxide, free from compounds which can reduce the permanganate ions. 4.3 Nitric acid solution, 1 + 1. Add 500 ml of nitric acid (20= 1,40 g/ml) to 500 ml of water (4.1). 4.4 Hydrochloric acid solution, 1 + 1. Add 500 ml of hydrochloric acid (20= 1,19 g/ml) to 500 ml of w

25、ater (4.1). DIN EN 10071:2013-01 EN 10071:2012 (E) 5 4.5 Aqua regia. Mix three volumes of hydrochloric acid (20= 1,19 g/ml) with one volume of nitric acid (20= 1,40 g/ml). 4.6 Sodium hydrogen carbonate, saturated solution at room temperature. NOTE The concentration of the saturated solution correspo

26、nds to about 100 g/l NaHCO3, in water (4.1). 4.7 Sodium pyrophosphate solution, 120 g/l. Dissolve 120 g of hydrated sodium pyrophosphate (Na4P2O7. 10 H2O) in a one-litre beaker with hot water (4.1). After cooling, transfer this solution into a 1 000 ml one-mark volumetric flask. Dilute to the mark w

27、ith water (4.1) and mix. NOTE The temperature shall not exceed 70 C. 4.8 Manganese standard solution, 0,500 g/l Mn. Weigh (1,4385 0,001) g of potassium permanganate (KMnO4) and transfer it into a 500 ml conical flask. Dissolve with 40 ml of hydrochloric acid (4.4) and then heat the solution until dr

28、yness. Add 5 ml of hydrochloric acid (4.4), 100 ml of water (4.1) and mix. Transfer the solution quantitatively into a 1 000 ml one-mark volumetric flask, cool, dilute to the mark with water (4.1) and mix. 1 ml of this solution contains 0,500 mg of Mn. 4.9 Potassium permanganate standard solution, a

29、bout 0,002 2 mol/l. 4.9.1 Preparation of the solution. Dissolve approximately 0,36 g of potassium permanganate with 1 000 ml of water (4.1) and allow the solution to stand out of the light, for at least two weeks. Filter through a glass wool or a sintered glass filter, transfer the filtrate into a b

30、rown glass bottle and mix. 4.9.2 Standardization of the solution. Transfer 350 ml of the sodium pyrophosphate solution (4.7) into a 600 ml beaker. With calibrated pipettes or a burette, add 30 ml of the manganese standard solution (4.8). Mix carefully and then add small amounts of nitric acid (4.3)

31、in order to set up the pH to about 6,5. NOTE The pH setting up can be controlled either by means of a pH-meter (5.2) or by means of a pH indicator paper (4.10). Titrate with the potassium permanganate standard solution (4.9) and determine the end point by means of an electrometric measurement. 4.9.3

32、 Calculation of the titre of the solution. The manganese concentration, 1C , of the potassium permanganate standard solution (4.9), expressed in mg/ml is given by the Formula (1): 1130 x 0,5000CV= (1) where DIN EN 10071:2013-01 EN 10071:2012 (E) 6 1V is the volume, expressed in millilitres, of the p

33、otassium permanganate standard solution (4.9) used for the titration. 4.10 pH indicator paper, range 5 to 7. 5 Apparatus All volumetric glassware shall be Class A and calibrated, in accordance with EN ISO 648 or EN ISO 1042 as appropriate. 5.1 Magnetic stirrer. 5.2 pH-meter, fitted with glass electr

34、ode and a calomel electrode. 5.3 Potentiometer, fitted with platinum electrode and a calomel electrode. 6 Sampling Sampling shall be carried out in accordance with EN ISO 14284 or an appropriate national standard for steel and iron. 7 Procedure 7.1 Test portion Weigh, to the nearest 0,001 g, 1,25 g

35、of the test sample. 7.2 Determination 7.2.1 Dissolution of the test portion 7.2.1.1 Unalloyed and low alloyed steels and irons Transfer the test portion (7.1) into a 500 ml conical flask and dissolve it with 30 ml of nitric acid solution (4.3). 7.2.1.2 Alloyed steels Transfer the test portion (7.1)

36、into a 500 ml conical flask and start the dissolution by adding 20 ml of hydrochloric acid solution (4.4). NOTE Larger volumes of hydrochloric acid solution (4.4) can be necessary. Oxidise with 10 ml of nitric acid solution (4.3) or with 15 ml of aqua regia (4.5). 7.2.2 Preparation of the test solut

37、ion Heat the test solution (7.2.1) until boiling, in order to expel nitrogen oxides. Cool and add water until about 80 ml. Whilst stirring slowly add, 80 ml of the sodium hydrogen carbonate solution (4.6). NOTE 1 The addition of the sodium hydrogen carbonate solution (4.6) will partially neutralise

38、the acids added for the sample dissolution. This will minimise the zinc amount that can be dissolved during the hydroxides precipitation with zinc oxide. DIN EN 10071:2013-01 EN 10071:2012 (E) 7 NOTE 2 Before the zinc oxide addition, the solution needs to be perfectly limpid. The precipitate that ca

39、n appear during the addition of the sodium hydrogen carbonate solution (4.6) will lead to a manganese loss. Consequently, if the test solution is not perfectly limpid, the precipitate needs to be dissolved by adding a minimum amount of nitric acid solution (4.3) and then boiling until the nitrogen o

40、xides have been expelled. In all cases, boil the solution once again and add about 5 g of zinc oxide (4.2), whilst stirring vigorously. Transfer the solution and the precipitate into a 250 ml volumetric flask, cool, dilute to the mark with water (4.1) and mix. Filter the solution through a dry, flut

41、ed filter paper and collect the filtrate in an appropriate dry vessel, after having rejected the first fractions of the filtrate (a few millilitres). 7.2.3 Titration Transfer 350 ml of the sodium pyrophosphate solution (4.7) into a 600 ml beaker. According to the expected manganese content of the sa

42、mple, add the aliquot portion of the filtrate (7.2.2) specified in Table 1, whilst continuously and vigorously stirring by means of a magnetic stirrer (5.1), in order to avoid the precipitation of zinc phosphate. Table 1 Aliquot portion of the filtrate Expected manganese content of sample % Aliquot

43、portion of the filtrate (7.2.2) ml Dilution ratio (D) 0,5 Mn 4 100,0 2,54 Mn 8 50,0 5,0 8 Mn 20,0 12,5 Adjust the pH to approximately 6,5 by adding nitric acid solution (4.3). This setting up is controlled either by means of a pH-meter (5.2) or by means of a pH indicator paper (4.10). Titrate with t

44、he potassium permanganate standard solution (4.9). Follow the progress of the titration by an electrometric measurement as for example, by means of a potentiometer (5.3). Let 2V be the volume, expressed in millilitres, of the potassium permanganate standard solution (4.9) used for the titration. NOT

45、E In presence of an excess of pyrophosphate, the pH of the test solution after the addition of the aliquot portion of the filtrate (7.2.2) is greater than 6,5. The adjustment of the pH value is therefore carried out by addition of an acid solution: this will avoid the formation of precipitates diffi

46、cult to redissolve, which can happen when the pH value has to be increased by addition of an alkaline solution. 8 Expression of results The manganese mass fraction (wMn), in percent (%), is given by the Formula (2): wMnm x 10D x C x 12V= (2) where DIN EN 10071:2013-01 EN 10071:2012 (E) 8 2V is the v

47、olume in millilitres, of the potassium permanganate standard solution (4.9) used for the titration; 1C is the manganese concentration of the potassium permanganate standard solution (4.9), expressed in mg/ml; D is the dilution ratio (see Table 1); m is the mass, in grams, of the test portion (7.1).

48、9 Test report The test report shall contain the following information: a) identification of the test sample; b) method used; c) results; d) any unusual characteristics noted during the determination; e) any operation not included in this European Standard or in the document to which reference is made or regarded as optional; f) date of the test and/or date of preparation or signature of the test report; g) signature of the responsible person. DIN EN 10071:2013-01