EN 10200-2012 en Chemical analysis of ferrous materials - Determination of boron in steels - Spectrophotometric method《黑色金属材料化学分析方法 用分光光度法测定钢中的硼含量》.pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 10200:2012Chemical analysis of ferrousmaterials Determinationof boron in steels Spectrophotometric methodBS EN 10200:2012 BRITISH STANDARDNational forewordThis British Stan

2、dard is the UK implementation of EN 10200:2012. It supersedes BS EN 10200:1992 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/102, Methods of Chemical Analysis for Iron and Steel. A list of organizations represented on this committee can be obtai

3、ned on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012ISBN 978 0 580 77390 7 ICS 77.040.30 Compliance w

4、ith a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2012.Amendments issued since publicationDate Text affectedBS EN 10200:2012EUROPEAN STANDARD NORME EUROPENNE EUROPI

5、SCHE NORM EN 10200 October 2012 ICS 77.040.30 Supersedes EN 10200:1991English Version Chemical analysis of ferrous materials - Determination of boron in steels - Spectrophotometric method Analyse chimique des matriaux ferreux - Dtermination du bore dans les aciers - Mthode spectrophotomtrique Chemis

6、che Analyse von Eisenwerkstoffen - Bestimmung von Bor in Stahl - Spektrophotometrisches Verfahren 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 for giving this European Standard t

7、he 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 three official versions (English, Fre

8、nch, 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 bodies of Austria, Belgium, Bulgaria

9、, 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, Spain, Sweden, Switzerland, Turkey

10、 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 CEN national Members. Ref. No. EN 102

11、00:2012: EBS EN 10200:2012EN 10200:2012 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Principle 54 Reagents .55 Apparatus .66 Sampling .87 Procedure .88 Expression of results . 119 Test report . 11Annex A (informative) Precision data . 13Bibliography . 15BS EN 10200

12、:2012EN 10200:2012 (E) 3 Foreword This document (EN 10200:2012) has been prepared by Technical Committee ECISS/TC 102 “Methods of chemical 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 publica

13、tion of an identical text or by endorsement, at the latest by April 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 other than those identifie

14、d above. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 10200:1991. Since the previous edition, no technical changes have been made, but the text has been editorially revised. According to the CEN/CENELEC Internal Regulatio

15、ns, 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, Italy,

16、 Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 10200:2012EN 10200:2012 (E) 4 Introduction The development of the method was carried out by a working group under French conveno

17、rship. The results of the inter-laboratory tests have shown that the determination of lower limit application of the method should be 0,000 4 % (m/m) boron, based on a relative deviation not exceeding 10 % within 66 % confidence limits. However, further work has shown that the method may be used for

18、 lower boron contents if a higher relative deviation is acceptable. BS EN 10200:2012EN 10200:2012 (E) 5 1 Scope This European Standard specifies a spectrophotometric method for the determination of boron in steels. The method is applicable to non-alloyed and alloyed steels with boron contents of 0,0

19、00 4 to 0,012 0 % (m/m). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docu

20、ment (including any amendments) applies. EN ISO 14284, Steel and iron Sampling and preparation of samples for the determination of chemical composition (ISO 14284) 3 Principle Dissolution of a test portion in hydrochloric and nitric acids. Decomposition of boron compounds (nitrides, etc.) with ortho

21、phosphoric and sulphuric acids at 290 C. Spectrophotometric measurement at a wavelength of 543 nm of the complex formed between boric acid and curcumin in buffered acetic medium. 4 Reagents During the analysis, use only reagents of recognised analytical grade and distilled water or water of equivale

22、nt purity. 4.1 Pure iron, free of boron or of known low boron content. 4.2. Crystalline sodium hypophosphite monohydrate (NaH2PO2.H2O). 4.3 Hydrochloric acid, HCl (20= 1,19 g/ml). 4.4 Nitric acid, HNO3(20= 1,40 g/ml). 4.5 Sulphuric acid, H2SO4(20= 1,84 g/ml). 4.6 Orthophosphoric acid, H3PO4(20= 1,71

23、g/ml). 4.7 Acetic acid free of aldehyde, CH3COOH (20= 1,05 g/ml). Test for absence of aldehyde: Place 20 ml of the acetic acid (4.7) to be tested and 1 ml of a 1 g/l solution of potassium permanganate (KMnO4) into a 50 ml beaker. In the absence of aldehyde, the initial violet colour of the potassium

24、 permanganate will persist; otherwise the solution will become brown, easily identifiable after 15 min. BS EN 10200:2012EN 10200:2012 (E) 6 4.8 Mixture of acetic and sulphuric acids. Add in small portions whilst cooling under water and swirling, a volume of sulphuric acid (4.5) to an equal volume of

25、 acetic acid (4.7). 4.9 Acetic buffer solution. Dissolve 225 g of ammonium acetate in 400 ml of water. Add 300 ml of acetic acid (4.7). Filter the solution obtained into a 1 000 ml polyethylene one-mark volumetric flask. Dilute to the mark with water and mix. 4.10 Sodium fluoride, 40 g/l solution. 4

26、.11 Boron, 100 mg/l standard solution. Dissolve 0,285 8 g of boric acid in water in a 500 ml one-mark volumetric flask. Dilute to the mark with water and mix. Store this solution in a polyethylene flask. 1 ml of this solution contains 0,1 mg of boron. 4.12 Boron, 2 mg/l standard solution. Transfer 2

27、0 ml of the boron standard solution (4.11) into a 1 000 ml one-mark volumetric flask. Dilute to the mark with water and mix. Store this solution in a polyethylene flask. 1 ml of this solution contains 2 g of boron. 4.13 Curcumin, 1,25 g/l acetic solution (prepared immediately before use). Dissolve 0

28、,125 g of curcumin in 60 ml of acetic acid (4.7) in a polyethylene or quartz vessel. Heat at 40 C in a water bath and stir with a magnetic stirrer. After dissolution, cool and transfer into a 100 ml polyethylene one-mark volumetric flask. Dilute to the mark with acetic acid (4.7) and mix. 5 Apparatu

29、s Glassware containing boron shall not be used and shall be replaced by polyethylene and quartz vessel rinsed with acetic acid (4.7), then with water and finally dried. 5.1 100 ml quartz beakers, with quartz covers (outside dimensions: 51 mm diameter and 70 mm height). 5.2 Aluminium alloy blocks, al

30、lowing a temperature of 290 C to be achieved and maintained in the test solutions throughout the fuming period. The block has holes designed to allow the location of the 100 ml quartz beakers and is heated by surface contact with a hotplate. NOTE Diagrams of these blocks are shown in Figures 1 and 2

31、. The dimensions of the holes should be adapted to the dimensions of the quartz beakers available. 5.3 50 ml polyethylene one-mark volumetric flasks. 5.4 100 ml polyethylene flasks. 5.5 Spectrophotometer, suitable for measuring absorbance at a wavelength of 543 nm, with 20 mm cells. BS EN 10200:2012

32、EN 10200:2012 (E) 7 Dimensions in millimetres NOTE Adapt the dimensions of the holes according to the dimensions of the beakers available. Figure 1 Example of circular aluminium alloy heating block BS EN 10200:2012EN 10200:2012 (E) 8 Dimensions in millimetres NOTE Adapt the dimensions of the holes a

33、ccording to the dimensions of the beakers available. Figure 2 Example of a rectangular aluminium alloy heating block 6 Sampling Sampling shall be carried out in accordance with EN ISO 14284 or an appropriate national standard for steel and iron. The chips thickness shall be smaller than 1 mm. 7 Proc

34、edure 7.1 Test portion Weigh, to the nearest 0,001 g, a test portion (m) as indicated below: m = 1 g 0,05 g for boron contents less than 0,006 %; m = 0,5 g 0,03 g for boron contents from 0,006 % to 0,012 %. NOTE For steel grades with nickel and cobalt total content greater than 30 %, do not take a t

35、est portion larger than 0,5 g. BS EN 10200:2012EN 10200:2012 (E) 9 7.2 Blank test Within each analytical series and in parallel with the analysis of the samples, carry out the analysis of pure iron test portions (4.1), having a mass corresponding to that of the test portions (see 7.1), following the

36、 same procedure and using the same quantities of all the reagents. The absorbance of the blank test solution (bA ) and that of the corresponding blank compensating solution (bcA ) are thus obtained. 7.3 Determination 7.3.1 Preparation of the test solution Place the test portion (7.1) in a 100 ml qua

37、rtz beaker and add 10 ml hydrochloric acid (4.3) and 5 ml of nitric acid (4.4). Cover the beaker with a quartz cover and leave it at ambient temperature in order to avoid possible loss of boron at higher temperatures. Wait until dissolution is complete or until the end of the effervescence for sampl

38、es which are difficult to dissolve. Then add carefully 10 ml of orthophosphoric acid (4.6) and 5 ml of sulphuric acid (4.5). Heat to copious white sulphuric fumes, swirling from time to time in order to recover any particles attached to the sides of the beaker. Place the beaker in a hole of the alum

39、inium alloy block (5.2) and place the block on a heat source allowing a temperature of 290 C to be obtained in the solutions. Maintain the heating for 30 min, taking care to replace the quartz cover after the appearance of white fumes. NOTE The temperature of 290 C 5 C is obtained by calibration of

40、the heat source by means of a thermometer, graduated from 0 to 350 C, immersed in a beaker identical to those used for the test and containing the same amounts of the dissolution reagents. Remove the beaker from the heat source and allow to cool. Dilute the syrupy solution with 30 ml of water. Warm

41、whilst stirring. Remove from the heat source. Then add carefully 5 ml of hydrochloric acid (4.3) and bring to the boil. Add 3 g of sodium hypophosphite (4.2). Allow to boil gently for 15 min. Remove from the heat source and allow to cool. Transfer the solution quantitatively into a 50 ml polyethylen

42、e one-mark volumetric flask. Dilute to the mark with water and mix. 7.3.2 Formation of the coloured complex Transfer 1,0 ml of the test solution obtained in accordance with 7.3.1 into a 100 ml polyethylene flask (5.4) previously cleaned and dried. Add into the flask, whilst swirling in a circular mo

43、vement to avoid contact with the stopper, the following volumes of reagents: 6,0 ml of the mixture of acetic and sulphuric acids (4.8), avoiding contact of the pipette with the neck and sides of the flask; mix; 6,0 ml of the curcumin acetic solution (4.13); stopper the flask and mix. Allow to stand

44、for 2 h 30 min for complete development of the colour. Then add: 1,0 ml of orthophosphoric acid (4.6) to stabilise the colour. Shake and allow to stand for 30 min; 30,0 ml of the acetic buffer solution (4.9). The solution turns orange. Stopper and shake. Allow to stand for exactly 15 min. BS EN 1020

45、0:2012EN 10200:2012 (E) 10 7.3.3 Compensating solution Transfer 1,0 ml of the test solution obtained in accordance with 7.3.1 into a 100 ml polyethylene flask (5.4) previously cleaned and dried. Add 0,2 ml of sodium fluoride solution (4.10) to the bottom of the flask. Carefully swirl the small volum

46、e of solution. Allow to stand for 1 h. Continue as in 7.3.2. from “Add into the flask, whilst swirling in a circular movement“. 7.3.4 Spectrophotometric measurements NOTE In order to carry out the spectrophotometric measurements on all the solutions whilst waiting exactly 15 min after the addition o

47、f the acetic buffer solution, it is advisable to divide them into a series of 6 measurements, i.e. 12 flasks. In fact, for long series of measurements where the waiting time cannot be strictly adhered to, the formation of a cloudiness in the solutions may be observed and consequently erroneous resul

48、ts obtained. After adjusting the spectrophotometer to zero absorbance with water, carry out spectrophotometric measurements of the test solution (7.3.2) and the corresponding compensating solution (7.3.3) at a wavelength of 543 nm in cells of 20 mm optical path length. The absorbance of the test sol

49、ution ( A) and that of the compensating solution (cA ) are thus obtained. 7.4 Preparation of the calibration 7.4.1 Preparation of the calibration solutions Weigh 1,000 g portions of iron (4.1) into a series of six 100 ml quartz beakers and using calibrated pipettes add the volumes of the boron standard solution (4.12) indicated in Table 1. Table 1 Composition of the calibration solutions Volume of boron standard solution (4.12) ml Corresponding mass of boron mg Corresponding boron content