1、BSI Standards PublicationBS EN ISO 4829-2:2016Steels Determinationof total silicon contents Reduced molybdosilicatespectrophotometric methodPart 2: Silicon contents between 0,01 %and 0,05 %BS EN ISO 4829-2:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO
2、4829-2:2016. It supersedes BS 6200-3.26.4:1989 which iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/102, Methods of Chemical Analysis for Iron and Steel.A list of organizations represented on this committee can beobtained on request to its secretary.This
3、publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 81554 6ICS 77.080.01Compliance with a British Standard cannot confer immun
4、ity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 4829-2 March 2016 ICS 77
5、.080.01 Supersedes EN 24829-2:1990English Version Steels - Determination of total silicon contents - Reduced molybdosilicate spectrophotometric method - Part 2: Silicon contents between 0,01 % and 0,05 % (ISO 4829-2:2016) Aciers - Dtermination du silicium total - Mthode spectrophotomtrique au silico
6、molybdate rduit - Partie 2: Teneurs en silicium comprises entre 0,01 % et 0,05 % (ISO 4829-2:2016) Stahl - Bestimmung des Gesamtsiliciumanteils - Spektrophotometrische Methode mit reduziertem Molybdatosilicat - Teil 2: Siliciumanteile zwischen 0,01 % und 0,05 % (ISO 4829-2:2016) This European Standa
7、rd was approved by CEN on 21 November 2015. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning
8、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, French, German). A version in any other language made by translation under the responsibility of a CEN member into its
9、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, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany
10、, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NOR
11、MUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 4829-2:2016 EBS EN ISO 4829-2:2016EN ISO 4829-2:2016 (E) 3 European foreword This document (EN ISO 4829-
12、2:2016) has been prepared by Technical Committee ISO/TC 17 “Steel” in collaboration with 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 publ
13、ication of an identical text or by endorsement, at the latest by September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CEN
14、ELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 24829-2:1990. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN-CENELEC Internal Regulatio
15、ns, the national standards organizations 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. Endorsement notice The text of ISO 4829-2:2016 has been approved by CEN as EN ISO 4829-2:2016 without any modification. BS EN ISO 4829
17、-2:2016ISO 4829-2:2016(E)Foreword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 36 Sampling 47 Procedure. 47.1 Test portion 47.2 Blank test . 47.3 Determination . 47.3.1 Dissolution of the test portion . 47.3.2 Treatment of insoluble residue . 47.3.3 Preparation of the
18、test solution 47.3.4 Development of the colour 57.3.5 Spectrophotometric measurements . 57.4 Establishment of the calibration curve 67.4.1 Preparation of the calibration solutions 67.4.2 Spectrophotometric measurements . 67.4.3 Plotting of the calibration curve . 68 Expression of results 68.1 Method
19、 of calculation 68.2 Precision . 79 Test report . 7Annex A (informative) Additional information on the interlaboratory test . 9Bibliography .10 ISO 2016 All rights reserved iiiContents PageBS EN ISO 4829-2:2016ISO 4829-2:2016(E)ForewordISO (the International Organization for Standardization) is a wo
20、rldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented o
21、n that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this
22、document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Dire
23、ctives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the develo
24、pment of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO sp
25、ecific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.The committee responsible for this document is ISO/TC 17, Steel, Subco
26、mmittee SC 1, Methods of determination of chemical composition.This second edition cancels and replaces the first edition (ISO 4829-2:1988), which has been technically revised.ISO 4829 consists of the following parts, under the general title Steels Determination of total silicon contents Reduced mol
27、ybdosilicate spectrophotometric method: Part 1: Silicon contents between 0,05 % and 1,0 % Part 2: Silicon contents between 0,01 % and 0,05 %iv ISO 2016 All rights reservedBS EN ISO 4829-2:2016INTERNATIONAL STANDARD ISO 4829-2:2016(E)Steels Determination of total silicon contents Reduced molybdosilic
28、ate spectrophotometric method Part 2: Silicon contents between 0,01 % and 0,05 %1 ScopeThis part of ISO 4829 specifies a spectrophotometric method for the determination of total silicon in steels using reduced molybdosilicate.The method is applicable to silicon contents between 0,01 % and 0,05 % (ma
29、ss fraction) in steels.2 Normative referencesThe 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 documen
30、t (including any amendments) applies.ISO 648, Laboratory glassware Single-volume pipettesISO 1042, Laboratory glassware One-mark volumetric flasksISO 3696, Water for analytical laboratory use Specification and test methodsISO 14284, Steel and iron Sampling and preparation of samples for the determin
31、ation of chemical composition3 PrincipleDissolution of a test portion in a hydrochloric/nitric acids mixture.Fusion of the acid-insoluble residue with sodium peroxide. Formation of the oxidized molybdosilicate (yellow) complex in weak acid solution.Selective reduction of the molybdosilicate complex
32、to a blue complex with ascorbic acid, after increasing the sulphuric acid concentration and adding oxalic acid to prevent the interference of phosphorus, arsenic and vanadium.Spectrophotometric measurement of the reduced blue complex at a wavelength of about 810 nm.4 ReagentsDuring the analysis, unl
33、ess otherwise specified, use only reagents of recognized analytical grade and only grade 2 water as specified in ISO 3696. Water demineralized by ion-exchange shall not be used as it may contain significant amounts of colloidal silica.Reagents supplied in glass bottles, once opened, might absorb moi
34、sture and become reactive to glassware. Alkaline reagents, e.g. sodium carbonate and sodium peroxide, are particularly susceptible. To avoid the risk of significant contamination arising from this source, it is recommended that only freshly opened bottles of all reagents be used for the preparation
35、of reagent solutions. ISO 2016 All rights reserved 1BS EN ISO 4829-2:2016ISO 4829-2:2016(E)To avoid adventitious contamination, the water shall be prepared, as required, for the specific purpose and collected in polypropylene containers for immediate use.All solutions shall be freshly prepared and s
36、tored in polypropylene or polytetrafluoroethylene containers.4.1 Pure iron, silicon content less than 2 g/g.4.2 Sodium peroxide, particle size less than 500 m.4.3 Sulphuric acid, approximately 1,84 g/ml, diluted 1 + 3.Add cautiously, while stirring, 250 ml of sulphuric acid, approximately 1,84 g/ml
37、to 600 ml of water. Cool, dilute to 1 l with water and mix.4.4 Sulphuric acid, approximately 1,84 g/ml, diluted 1 + 19.Add cautiously, while stirring, 50 ml of sulphuric acid, approximately 1,84 g/ml to 800 ml of water. Cool, dilute to 1 l with water and mix.4.5 Hydrochloric/nitric acids mixture.Add
38、 180 ml of hydrochloric acid, approximately 1,19 g/ml and 65 ml of nitric acid, approximately 1,40 g/ml, to 500 ml of water. Cool, dilute to 1 l with water and mix.4.6 Ascorbic acid, 20 g/l solution.This solution shall be freshly prepared.4.7 Oxalic acid, 50 g/l solution.Dissolve 5 g of oxalic acid
39、di-hydrate (C2H2O42H2O) in water, dilute to 100 ml with water and mix.4.8 Hydrogen peroxide, 60 g/l solution.Dilute 200 ml of hydrogen peroxide, 300 g/l, to 1 l with water and mix.4.9 Potassium permanganate, 22,5 g/l solution.This solution shall be filtered before use in order to remove the fine par
40、ticles of MnO2 that may be present in the solution, as they will interfere with the measurement.4.10 Sodium molybdate, 25 g/l solution.Dissolve 2,5 g of sodium molybdate di-hydrate (Na2MoO42H2O) in 50 ml of water and filter through a medium-texture filter paper.Immediately before use, add 15 ml of s
41、ulphuric acid (4.4), dilute to 100 ml with water and mix.4.11 Silicon standard solution, 1 g/l.Prepare a 1 g/l silicon standard solution by using one of the procedures described in 4.11.1 or 4.11.2.4.11.1 Preparation with silicaWeigh to the nearest 0,1 mg, 2,139 3 g of freshly calcined high-purity s
42、ilica ( 99,9 % SiO2) and transfer to a platinum crucible.2 ISO 2016 All rights reservedBS EN ISO 4829-2:2016ISO 4829-2:2016(E)The high-purity silica shall be calcined for 1 h at 1 100 C and cooled in a desiccator immediately before use.Mix thoroughly with 16 g of anhydrous sodium carbonate and fuse
43、at 1 050 C for 30 min. Extract the fusion product with 100 ml of water in a polypropylene or polytetrafluoroethylene beaker.NOTE Extraction of the fusion product might require gentle heating.Transfer the extract, which should contain no trace of residue, into a 1 000 ml one-mark volumetric flask, di
44、lute to the mark with water and mix. Transfer immediately into a well-stoppered polytetrafluoroethylene bottle for storage.1 ml of this standard solution contains 1 mg of silicon.4.11.2 Preparation with ammonium hexafluorosilicateDry several grams of ammonium hexafluorosilicate (NH4)2SiF6 for about
45、1 h at 105 C to 110 C in an oven and cool to room temperature in a desiccator.Weigh to the nearest 0,1 mg, 3,171 0 g of the dried product. Transfer it into a suitable plastic beaker and dissolve it in hot water (approximately 80 C).Allow to cool and transfer the solution quantitatively into a 500 ml
46、 polyethylene one-mark volumetric flask, dilute to the mark with water and mix.1 ml of this standard solution contains 1 mg of silicon.4.12 Silicon standard solution, 20 mg/l.Transfer 10,0 ml of one of the silicon standard solutions (4.11.1 or 4.11.2) into a 500 ml one-mark volumetric flask. Dilute
47、to the mark with water and mix. Transfer immediately to a well-stoppered polytetrafluoroethylene bottle for immediate use.1 ml of this standard solution contains 20 g of silicon.5 ApparatusOrdinary laboratory apparatus and the following shall be used.5.1 Beakers and lids, of polypropylene or polytet
48、rafluoroethylene.5.2 Zirconium crucibles, of 50 ml capacity.NOTE As alternative, vitreous carbon crucibles can be used. 5.3 Volumetric glasswareAll volumetric glassware shall be class A, in accordance with ISO 648 or ISO 1042, as appropriate.The use of glassware shall be restricted to a minimum of c
49、ontact time and borosilicate glass shall be used as far as possible.5.4 SpectrophotometerThe spectrophotometer shall be equipped to measure absorbance with a spectral bandwidth of 10 nm or less, at a wavelength of 810 nm, with suitable optical path length cells. Wavelength adjustment shall be accurate to 2 nm, as measured by the maximum absorption of a didymium filter at 803 nm, or other suitable calibration method. The absorption measurement for the solution of maximum absorbance shall have a repeatability, expressed
