1、CEN ENu24503 93 m 3404589 0047104 b39 D EUROPEAN STANDARD i3N 24503 NORME EUROPENNE EUROPISCHE NORM April 1993 UM: 669.018.25 : 620.1 : 543.422.8 : 546.3 Descriptors: Powder metallurgy, hard metais, chemical analysis, metals, spectrophotometric analysis, X ray fluorescence spectrometry English versi
2、on Hardmetals - Determination of contents of metallic elements by X-ray fluorescence - Fusion method (IS0 4503 : 1978) Mtaux-durs - Dosage des lments mtalliques par fluorescence de rayons X - Mthode par fusion (IS0 4503 : 1978) Hartmetalle - Bestimmung des Gehaltes metallischer Elemente durch Rntgen
3、fluoreszenz in fester Lsung (IS0 4503 : 1978) This European Standard was approved by CEN on 1993-04-02. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
4、Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Centrai 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 u
5、nder the responsibility of a CEN member into its own language and notified to the Central Secretariat has 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, Nethe
6、rlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1993 Copyright reserved to CEN members Ref. No. EN 24503 : 1993
7、 E CEN ENS24503 93 m 3404589 0047305 575 m Page 2 EN 24503 : 1993 Foreword In 1992, IS0 4503 : 1978 Hurdmtals - Determination of contents of metallic elements by X-ray fluorescence - Fusm method was submitted to the CEN Primary Questionnaire procedure. Following the positive result of the CEN/CS Pro
8、posal IS0 4503 : 1978 was submitted to the CEN Formal Vote. The result of the Formal Vote was positive. This European Standard shall be given the status of national standard, either by publication of an identical text or by endorsement, at the latest by October 1993, and conflicting national standar
9、ds shail be withdrawn at the latest by October 1993. According to the Internal Regulations of CENKENELEC, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Port
10、ugal, Spain, Sweden, Switzerland, United Kingdom. CEN ENW4503 93 m 3404589 0047106 401 m Page 3 EN 24503 : 1993 Hardmetals - Determination of contents of metallic elements by X-ray fluorescence - Fusion method 1 SCOPE This International Standard specifies an X-ray fluorescence fusion method for the
11、determination of cobalt, chromium, iron, manganese, molybdenum, nickel, niobium, tantalum, titanium, tungsten, vanadium and zirconium contents of carbides and hardmetals. 2 FIELD OF APPLICATION The method is applicable to - carbides of niobium, tantalum, titanium, vanadium, tungsten and zirconium, -
12、 mixtures of these carbides and binder metals, - all grades of presintered or sintered hardmetals, produced from these carbides, with the element contents shown in table 1 Element Co Cr Fe Mn Mo Nb Ni Ta Ti V W Zr TABLE 1 Content, % (mim) min. 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.10 O .3 0.1 5 0.05
13、45 max. 3 PRINCIPLE Measurement of the intensity of the characteristic X-ray spectrum of the elements being determined. To eliminate the effects of particle size and inter-element effects, the test portion is dissolved in a suitable mixture of acids and converted to sulphates, or is directly oxidize
14、d. Either the sulphates or the oxides are then fused with a mixture of sodium tetraborate and a barium compound. 4 INTERFERING ELEMENTS The effect of interfering elements, such as line interference of titanium and tungsten on vanadium, shall be taken into account. 5 REAGENTS During the analysis, use
15、 only reagents of recognized analytical grade, and only distilled water or water of equivalent purity. 5.1 Barium peroxide, anhydrous, or barium carbonate, anhydrous. 5.2 Sodium tetraborate, anhydrous. To ensure freedom from water, heat the sodium tetraborate to approximately 400 “C. 5.3 Hydrofluori
16、c acid, p 1.12 g/ml. 5.4 Nitric acid, p 1.24 g/ml (nitric acid, p 1,42 g/ml, diluted 1 + 1). 5.5 Sulphuric acid,p 1,54 g/rnl (sulphuric acid, p 1,84 glml, diluted 1 + 1). 6 APPARATUS Ordinary laboratory apparatus and 6.1 X-ray spectrometer. 6.2 Furnaces for oxidation of the test portion at 700 to 90
17、0C and for preparation of the borate melt at approxi- mately 1 100 OC. 6.3 Platinum dishes, 50 to 100 ml. NOTE - Dishes of 95 % Pt + 5 % Au are to be preferred. 6.4 Plate, with polished surface, of platinum alloy, for example 85% Pt+10% Rh+5% Au or 95% Pt+5% AU. The plate shall be maintained at a su
18、rface temperature between 300 and 400 “C so that the borate disk (see 8.4) loosens easily and does not crack. CEN ENZYSO 93 rn LOLSM OOWLO 344 m Page 4 EN 24503 : 1993 , ? Element Co, Cr, Fe, Mn, Mo, Nb, Ni, Ti, V, Zr Ta, W Analytical line Ka1.2 La1 J 6.5 Brass rings or heat-resisting steel cylinder
19、s or graphite cy1 i nders. NOTE - Instead of the plate (6.4) and brass rings (6.5). moulds of graphite or heat-resisting steel may be used. 6.6 Wet or dry grinding device. 7 SAMPLING 7.1 The sample shall be crushed in a mortar made of material which does not alter the sample composition. The crushed
20、 material shall pass a 2 mm sieve when using the acid solution method or a 0,18 mm sieve when using the oxidation method. 7.2 The analysis shall be carried out on two or three test portions. 8 PROCEDURE 8.1 Weigh, to the nearest 0,001 g, approximately 0,5 g of the test sample. NOTE - If the sample i
21、ncludes lubricant, a correction for the lubricant content must be applied. 8.2 Transform the test portion in a platinum dish by the preferred procedure of dissolution (8.2.1 ) or by oxidation (8.2.2). The oxidation procedure shall not be used if molybdenum may be present in quantities above 0,l % (m
22、/m). 8.2.1 Add 15 ml of the nitric acid (5.4) to the unoxidized or partially oxidized test portion, heat the dish moderately, add 2 ml of the hydrofluoric acid (5.3), drop by drop, and maintain the dish at moderate temperature. Following complete dissolution of the test portion, add 1 to 2 ml of the
23、 sulphuric acid (5.5). Take to dryness and heat at approximately 600 “C until no more SO, vapour is evolved. Cool. There is a possibility of transfer of molybdenum from one crucible to another, so care should be taken to avoid such transfer during the heating procedure. Therefore, do not heat sample
24、s with high and low molybdenum contents in the same furnace batch. 8.2.2 Oxidize the test portion in air in a furnace at 700 to 900C for about 1 h. If complete oxidation is achieved, continue as in 8.3. If complete oxidation is not achieved (as in the case of hardmetals with a high content of titani
25、um), continue as in 8.2.1. 8.3 Mix the test portion well with the fused buffer mixture consisting of 15 f 0,Ol g of the sodium tetraborate (5.2) and 41 0.01 g of the barium peroxide (5.1) or 4,5 f 0,Ol g of the barium carbonate (5.1), and heat the dish moderately until the contents are completely fu
26、sed and the reaction has subsided. Cover the dish with a lid. Dissolve the oxides by melting at approximately 1 100 OC for 10 to 15 min. Swirl the melt to obtain a homogeneous mass. 8.4 Pour the melt into the preheated ring (6.5) placed on the support plate (6.4) lying on a heating device at about 3
27、00 to 400 OC. Allow to cool until the disk loosens from the plate. Place the disk with the ring on an asbestos plate and allow it to cool to room temperature. 8.5 Grind the disk on the wet or dry grinding device (6.6) until an even and smooth surface is obtained. Immediately rinse and dry the surfac
28、e. NOTE - Final wet or dry grinding should be done on an abrasive paper N 220. Care must be taken to avoid contamination of one specimen by another from the abrasive paper, when dry grinding is used. 8.6 Analyse with the X-ray spectrometer. 9 X-RAY FLUORESCENCE ANALYSIS 9.1 All measuring parameters,
29、 including the target material of the X-ray tube, shall be chosen to obtain the optimal number of impulses. 9.2 The analytical lines shown in table 2 shall be used. NOTE - It is recommended that all elements be measured in the first order of reflexion by a LiF (200) crystal. For titanium, a pentaery
30、thritol crystal can be usad, with measurements in the second order. 9.3 Background corrections shall be made when necessary. 10 PREPARATION OF CALIBRATION CURVES The calibration curves shall be plotted on the basis of synthetically prepared samples with compositions as given in clause 2 and roughly
31、corresponding to the grades of hardmetals to be analysed. These samples shall be prepared by mixing accurately known amounts of metals or their suitable compounds. The mixture shall be analysed as des- cribed in 8.2 to 8.6. CEN ENx24503 93 3404589 0047308 284 Page 5 EN 24503 : 1993 Content % from 0.
32、05 to 0.4 over 0.4 to 30 over 30 to 95 11 EXPRESSION OF RESULTS Round to the nearest % 0,Ol o. 1 1 1 I .I Tolerances The deviations between two or three independent deter- minations shall not exceed the values shown in table 3. Range for two determinations % 0,w 0,20 0.30 0,4 1 .o Content % Range fo
33、r three determinations % 0.05 0.25 0.35 0.5 1.2 from 0,05 to 0.4 over 0.4 to 2 over 2 to 10 over 10 to 30 over 30 to 95 11.2 Final result Report the arithmetical mean of acceptable determinations rounded to the nearest value as shown in table 4. 12 TEST REPORT The test report shall include the follo
34、wing information : a) reference to this International Standard; b) all details necessary 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.
