1、BRITISH STANDARD BS EN 24501:1994 ISO 4501:1978 Hardmetals Determination of titanium Photometricperoxide method The European Standard EN 24501:1994 has the status of a British Standard UDC 621.762:661.665.2:546.82:543.42BSEN24501:1994 This British Standard, having been prepared under the directionof
2、 the Iron and Steel Standards Policy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 15January1994 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference ISM/65 Announced in BSI News, January1993 ISBN 0 580 22157 1
3、Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denma
4、rk Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland
5、Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommi
6、ssionen i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN24501:1994 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 1 Scope 3 2
7、 Field of application 3 3 Principle 3 4 Interfering elements 3 5 Reagents 3 6 Apparatus 3 7 Sample preparation 3 8 Procedure 3 9 Elimination of interferences 4 10 Preparation of the calibration curve 4 11 Expression of results 4 12 Test report 5 National annex NA (informative) Committees responsible
8、 Inside back cover Table 1 3 Table 2 5BSEN24501:1994 ii BSI 12-1999 National foreword This British Standard has been prepared under the direction of the Iron and Steel Standards Policy Committee and is the English language version of EN24501:1993 Hardmetals Determination of titanium Photometric pero
9、xide method, published by the European Committee for Standardization (CEN). It is identical with ISO4501:1978, prepared by Technical Committee119 “Powder metallurgy” of the International Organization for Standardization (ISO) with the active participation of the UK. This British Standard supersedes
10、BS5600-4.12:1980 which is withdrawn. 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 a British Standard does not of itself confer immunity from legal obligations. Summ
11、ary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment tabl
12、e on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 24501 October 1993 UDC 621.762:661.665.2:546.82:543.42 Descriptors: Powder metallurgy, hard metals, chemical analysis, determination of content, titanium, spectrophotometric analysis English version Hardmetals Determina
13、tion of titanium Photometric peroxide method (ISO4501:1978) Mtaux durs Dtermination du titane Mthode photomtrique au peroxyde (ISO4501:1978) Hartmetalle Bestimmung des Titangehaltes Photometrische Wasserstoffsuperoxidmethode (ISO 4501:1978) This European Standard was approved by CEN on 1993-10-25. C
14、EN 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 such national standards may be obtained on ap
15、plication to the Central Secretariat 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 own language and notified to the Central Secretariat ha
16、s the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Stan
17、dardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1993 Copyright reserved to CEN members Ref. No. EN 24501:1993 EEN24501:1993 BSI 12-1999 2 Foreword On the proposal of the CEN Central Secretariat, the Technical Board de
18、cided to submit the International Standard: Hardmetals Determination of titanium Photometric peroxide method (ISO4501:1978) to the formal vote. The result of the formal vote was positive. This European Standard shall be given the status of a national standard, either by publication of an identical t
19、ext or by endorsement, at the latest by April1994, and conflicting national standards shall be withdrawn at the latest by April1994. In accordance with CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France,
20、 Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EN24501:1993 BSI 12-1999 3 1 Scope This International Standard specifies a photometric peroxide method for the determination of the titanium content of carbides and har
21、dmetals. 2 Field of application This method is applicable to carbide and binder metal powder mixtures, free of lubricant, all grades of presintered or sintered hardmetals, with a titanium content exceeding0,2% (m/m). 3 Principle Formation of a yellow complex of pertitanic acid. Determination of the
22、absorbance of the complex. 4 Interfering elements The effect of interfering elements which also form coloured complexes with hydrogen peroxide under the conditions specified, for example vanadium and molybdenum, shall be taken into account. A correction can be applied if the content is below5%(m/m)
23、of each. 5 Reagents During the analysis, use only reagents of recognized analytical grade, and only distilled water or water of equivalent purity. 5.1 Ammonium hydrogen fluoride 5.2 Ammonium sulphate 5.3 Sodium disulphite 5.4 High-purity titanium metal or titanium dioxide, analysed for all impuritie
24、s exceeding0,01% (m/m) each. 5.5 Citric acid solution, 30% (m/m). 5.6 Perchloric acid, 1,54 or1,67g/ml. 5.7 Sulphuric acid, 1,84g/ml. 5.8 Sulphuric acid, 1,54g/ml (sulphuric acid, 1,84g/ml, diluted1+1). 5.9 Hydrogen peroxide, 30% (m/m). 5.10 Hydrofluoric acid, 1,12g/ml. 5.11 Nitric acid, 1,40g/ml. 6
25、 Apparatus Ordinary laboratory apparatus and 6.1 Spectrophotometer or filter photometer 7 Sample preparation 7.1 The sample shall be crushed to a powder in a mortar made of a material which does not alter the sample composition. The powder shall pass a0,18mm sieve. 7.2 The analysis shall be carried
26、out on two or three test portions. 8 Procedure 8.1 Preparation Select the mass of the test portion, the volume of the volumetric flask and the cell length in accordance withTable 1. Table 1 NOTEApproximately17mg of titanium in250ml of final solution gives unit absorbance with a10mm cell. 8.2 Test po
27、rtion Weigh, to the nearest0,0001g, 0,1or0,2g of the test sample. 8.3 Attack Transfer the test portion into a100to200ml conical flask or a250ml beaker. Add5g of the ammonium sulphate (5.2) and10ml of the sulphuric acid (5.7). Cover the beaker or flask with a watch glass. Heat near the boiling point
28、until complete dissolution is achieved. Alternative dissolution method: Transfer the test portion into a platinum dish. Add10ml of water and 5ml of the hydrofluoric acid (5.10). Cover the dish with a polypropylene or platinum cover. Heat to approximately80 C. Add the nitric acid(5.11) drop by drop u
29、ntil solution is complete. Cool. Add10ml of the sulphuric acid(5.7) and5g of the ammonium sulphate(5.2). Heat until fumes (SO 3 ) are observed. Cool. If any unattacked particles or carbonaceous matter are left, cool to below100 C, and cautiously add1ml of the perchloric acid (5.6). Heat to fume off
30、the perchloric acid then cool to room temperature. CAUTION When using perchloric acid avoid contact with organic matter. Titanium content Test portion mass Flask volume Cell length % (m/m) g ml mm 0,2 to 4 0,2 250 20 2 to 8 0,2 250 10 5 to 15 0,2 500 10 10 to 30 0,1 500 10EN24501:1993 4 BSI 12-1999
31、8.4 Preparation of the solution for analysis Add, in small portions, 1ml of the hydrogen peroxide (5.9), mixing by shaking. Add, in small portions, 30ml of the citric acid solution (5.5), while mixing. Add40ml of water. 8.4.1 Using a 250 ml volumetric flask Transfer the solution into the volumetric
32、flask, rinsing copiously with water. Add25ml of the sulphuric acid (5.8), fill nearly to the mark and mix. Cool. Add1ml of the hydrogen peroxide (5.9), mix, make up to volume and mix again. 8.4.2 Using a 500 ml volumetric flask Transfer the solution into the volumetric flask, rinsing copiously with
33、water. Add30ml of the citric acid solution (5.5) and50ml of the sulphuric acid(5.8), fill nearly to the mark and mix. Cool. Add2ml of the hydrogen peroxide (5.9), mix, make up to volume, and mix again. 8.5 Compensating solution Transfer approximately30ml of the coloured solution (8.4) into a50ml bea
34、ker. Add approximately0,2g of the sodium disulphite (5.3) to decolorize the solution. If necessary, repeat the addition of sodium disulphite. 8.6 Determination of absorbance Choose appropriate cells. Measure the absorbance of the coloured and the compensating solutions at a wavelength of420nm using
35、the same cell or a matched pair of cells. 9 Elimination of interferences 9.1 Vanadium Transfer30ml of the coloured solution (8.4) into a50ml beaker and add approximately0,1g of the ammonium hydrogen fluoride (5.1), which destroys the coloured titanium complex. Wait for3min. The colour left is due to
36、 vanadium. Measure the absorbance, and subtract it from the absorbance due to titanium plus vanadium. 9.2 Molybdenum The colour of the molybdenum peroxide complex is weak. It cannot be compensated for chemically but a correction can be calculated from the molybdenum content. 1% of molybdenum in the
37、sample corresponds to approximately0,08% of titanium at420nm, but the correction should be determined with the spectrophotometer used. 10 Preparation of the calibration curve 10.1 Standard titanium solution The standard titanium solution can be prepared from titanium metal or titanium dioxide. 10.1.
38、1 Standard titanium solution from titanium metal Weigh approximately250mg of the titanium metal(5.4) and transfer it into a200ml conical flask. Add30ml of water and20ml of the sulphuric acid (5.8). Cover the flask. Warm gently and keep the volume constant by adding water until all metal has dissolve
39、d. Cool. Add approximately1ml of the hydrogen peroxide (5.9) to oxidize the titanium. Evaporate the water by heating to fumes. Cool. Add10g of the ammonium sulphate (5.2) and heat gently until deposits on the walls of the flask have dissolved. Cool. Add about50ml of water. Transfer into a250ml volum
40、etric flask and add25ml of the sulphuric acid (5.8). Cool. Make up to volume with water and mix. Calculate the titanium content in grams of Ti per litre. 10.1.2 Standard titanium solution from titanium dioxide Weigh a quantity of the titanium dioxide (5.4) calculated to contain approximately250mg of
41、 titanium and transfer it into a200ml conical flask. Add10g of the ammonium sulphate (5.2) and10ml of the sulphuric acid (5.7). Cover the flask. Heat to near boiling until a clear solution is obtained. Cool. Add, in small portions,1ml of the hydrogen peroxide (5.9), mixing by shaking. Add about50ml
42、of water. Transfer into a250ml volumetric flask and add25ml of the sulphuric acid (5.8). Cool. Make up to volume with water and mix. Calculate the titanium content in grams of Ti per litre. 10.2 Calibration Determine the slope of the absorbance-titanium curve,i.e.the absorbance for1,0mg of titanium
43、per250ml of solution, for example as follows: Into four conical flasks transfer5g of the ammonium sulphate (5.2) and 10ml of the sulphuric acid (5.7). Add separately to three of the flasks5,0, 10,0and15,0ml of the standard titanium solution (10.1). Use the remaining flask for the blank test. Continu
44、e as in8.4 to 8.6. 11 Expression of results 11.1 Calculation The titanium content, expressed as a percentage by mass, is given by the formula where A is the absorbance attributable to the titanium in the hardmetal; a is the absorbance when the concentration is1mg of titanium per250ml with a10mm cell
45、;EN24501:1993 BSI 12-1999 5 m is the mass, in milligrams, of the test portion; V is the volume, in millilitres, of the coloured solution; L is the cell length, in millimetres. The result shall be rounded to the nearest0,01%. 11.2 Tolerances The deviations between two or three independent determinati
46、ons shall not exceed the values shown inTable 2. Table 2 11.3 Final results Report the arithmetical mean of acceptable determinations rounded to the nearest0,1%. 12 Test report The test report shall include the following information: a) reference to this International Standard; b) all details necess
47、ary for identification of the test sample; c) the result obtained; d) all operations not specified by this International Standard, or regarded as optional; e) details of any occurrence which may have affected the result. Titanium content Range for two determinations Range for three determinations %
48、% % from 0,2 to 5 0,10 0,12 over 5 to 8 0,15 0,18 over 8 to 15 0,20 0,25 over 15 0,30 0,356 blankBSEN24501:1994 BSI 12-1999 National annex NA (informative) Committees responsible The United Kingdom participation in the preparation of this European Standard was entrusted by the Iron and Steel Standar
49、ds Policy Committee (ISM/-) to Technical Committee ISM/65, upon which the following bodies were represented: British Hardmetal Association Federation of British Engineers (Test Manufacturers) Society of Motor Manufacturers and Traders Ltd.BS EN 24501:1994 ISO 4501:1978 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 in Europe and at the international level. It is incorporated by
