1、February 2010 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).IC
2、S 77.160!$Gt“1573681www.din.deDDIN EN ISO 3907Hardmetals Determination of total carbon Gravimetric method (ISO 3907:2009)English translation of DIN EN ISO 3907:2010-02Hartmetalle Bestimmung des Gesamtkohlenstoff-Gehaltes Gravimetrisches Verfahren (ISO 3907:2009)Englische bersetzung von DIN EN ISO 39
3、07:2010-02Mtaux-durs Dosage du carbone total Mthode gravimtrique (ISO 3907:2009)Traduction anglaise de DIN EN ISO 3907:2010-02SupersedesDIN ISO 3907:1991-07www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 10 pages02.10 aDIN EN ISO 3907:2
4、010-02 2 National foreword This standard has been prepared by Technical Committee ISO/TC 119 “Powder metallurgy” (Secretariat: SIS, Sweden) in collaboration with Technical Committee CEN/SS M11 “Powder metallurgy” (Secretariat: CMC). The responsible German body involved in its preparation was the Nor
5、menausschuss Werkstofftechnologie (Technology of Materials Standards Committee), Working Committee NA 145-01-04 AA Probenahme und Prfverfahren fr Hartmetalle. Amendments This standard differs from DIN ISO 3907:1991-07 as follows: a) The standard has been editorially revised. b) Footnote 1 relating t
6、o the trade name of the product Ascarite has been updated. c) In the German version, national footnotes 2 and 3 have been deleted. Previous editions DIN ISO 3907: 1991-07 A comma is used as the decimal marker. EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 3907 October 2009 ICS 77.160 Supe
7、rsedes EN 23907:1993English Version Hardmetals - Determination of total carbon - Gravimetric method (ISO 3907:2009) Mtaux-durs - Dosage du carbone total - Mthode gravimtrique (ISO 3907:2009) Hartmetalle - Bestimmung des Gesamtkohlenstoff-Gehaltes - Gravimetrisches Verfahren (ISO 3907:2009) This Euro
8、pean Standard was approved by CEN on 29 September 2009. 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
9、 concerning such national standards may be obtained on application to the CEN 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
10、its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
11、Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2
12、009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 3907:2009: E2 DIN EN ISO 3907:2010-02 EN ISO 3907:2009 (E) Contents Page Foreword .3 1 Scope4 2 Principle .4 3 Reagents 4 4 Apparatus.5 5 Sampling 7 6 Procedure.7 6.1 General
13、.7 6.2 Test portion7 6.3 Blank test .7 6.4 Combustion7 6.5 Determination 7 7 Expression of results8 7.1 Calculation .8 7.2 Tolerances8 7.3 Final result .8 8 Test report8 Foreword 3 EN ISO 3907:2009 (E) DIN EN ISO 3907:2010-02 This European Standard shall be given the status of a national standard, e
14、ither by publication of an identical text or by endorsement, at the latest by April 2010, and conflicting national standards shall be withdrawn at the latest by April 2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/o
15、r CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 23907:1993. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Be
16、lgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement noti
17、ce The text of ISO 3907:2009 has been approved by CEN as a EN ISO 3907:2009 without any modification. This document (EN ISO 3907:2009) has been prepared by Technical Committee ISO/TC 119 “Powder metallurgy”. 1 Scope This International Standard specifies a gravimetric method for the determination of
18、the mass fraction of total carbon in carbides and hardmetals. This method is applicable to carbides of chromium, hafnium, molybdenum, niobium, tantalum, titanium, vanadium, tungsten and zirconium, mixtures of these carbides and binder metals, free of lubricant, all grade of presintered or sintered h
19、ardmetals, produced from these carbides, and having a mass fraction of total carbon exceeding 4 %. 2 Principle Oxidation of carbon to carbon dioxide at a high temperature in a stream of pure oxygen, with the addition of a flux, if necessary. Absorption of the carbon dioxide, carried by oxygen, by As
20、carite1)in a tared bulb. Determination of the increase in mass of the Ascarite1)which corresponds to the quantity of carbon dioxide formed. 22CO CO+ 22322NaOH CO Na CO H O+ + 3 Reagents During the analysis, use only reagents of recognized analytical grade, and only distilled water or water of equiva
21、lent purity. 3.1 Oxygen, with a limitation of carbon-containing impurities of u 0,6 ml of carbon per cubic metre of oxygen. 1) Ascarite is the trade name of a product supplied by Arthur H. Thomas Co. This information is given for the convenience of users of the International Standard and does not co
22、nstitute an endorsement by ISO of the product named. Equivalent products may be used if they can be shown to lead to the same results. 4 DIN EN ISO 3907:2010-02 EN ISO 3907:2009 (E) 3.2 Magnesium perchlorate, anhydrous. CAUTION To prevent the possibility of explosion, contact of this reagent with or
23、ganic materials must be avoided, especially when discarding it. 3.3 Flux, for example tin metal, copper metal or oxide, iron metal. 3.4 Ascarite1). 4 Apparatus Ordinary laboratory apparatus and the following. 4.1 Apparatus, consisting of an electric furnace with a combustion tube, a purification tra
24、in and a system to absorb carbon dioxide. If it is necessary to obtain oxygen of adequate purity, an oxygen purification train may also be used. Successive parts of the apparatus shall be joined together with connecting tubes forming an airtight seal. The apparatus is shown schematically in Figure 1
25、. 4.1.1 Source of oxygen (3.1), with a pressure-regulating valve. 4.1.2 Flow meter. 4.1.3 Electric furnace, capable of operation at up to 1 350 C, with a suitable device for temperature control. 4.1.4 Combustion tube, made of a non-porous refractory material. The internal diameter of the tube should
26、 be 18 mm to 30 mm and its length should be at least 650 mm, so that the ends of the tube do not reach a temperature higher than 60 C during the operation. 4.1.5 Boat, made of a refractory material, pretreated in an oxygen stream at the test temperature for 10 min or alternatively at 800 C to 1 000
27、C for 1 h. The boat shall be of suitable dimensions, for example of length 80 mm to 100 mm, width 12 mm to 14 mm and depth 8 mm to 9 mm. The pretreated boats shall be kept in a desiccator. The ground surfaces of the desiccator and its lid shall not be greased. 4.1.6 Plug of silica wool. 4.1.7 Drying
28、 bulb, containing anhydrous magnesium perchlorate (3.2). 4.1.8 Absorption bulbs, containing Ascarite1)(3.4) and a small amount of anhydrous magnesium perchlorate (3.2). An example of an absorption bulb is shown in Figure 2. 4.1.9 Additional absorption bulb, facing the opposite way to the absorption
29、bulb in 4.1.8 (see Figure 1, item reference 8) to avoid introduction of carbon dioxide and moisture from the air. 4.2 Hook, made from heat-resisting metal wire with a mass fraction of carbon less than 0,05 %. Its diameter should be approximately 3 mm and its length should be 500 mm to 600 mm. 5 EN I
30、SO 3907:2009 (E) DIN EN ISO 3907:2010-02 Key 1 source of oxygen 2 flow meter 3 electric furnace 4 combustion tube 5 boat 6 plug of silica wool 7 drying bulb 8 absorption bulbs 9 additional absorption bulb Figure 1 Apparatus Key 1 glass wool in stopper 2 anhydrous magnesium perchlorate (3.2) 3 Ascari
31、te1)(3.4), not too compressed 4 bottom layer of glass wool to protect inside of tube Figure 2 Absorption bulb 6 DIN EN ISO 3907:2010-02 EN ISO 3907:2009 (E) 5 Sampling 5.1 The sample shall be crushed to a powder in a mortar made of a material which does not alter the sample composition. The powder s
32、hall pass through a 180 m sieve. 5.2 The analysis shall be carried out on two or three test portions. 6 Procedure 6.1 General Check the temperature in the combustion zone (1 200 C to 1 350 C, and not less than 1 300 C if chromium carbide is present), the gastightness of the apparatus and the efficie
33、ncy of the oxygen purification. Pass oxygen through the apparatus for 10 min to 15 min at a rate of 300 cm3/min to 500 cm3/min depending on the diameter of the tube used. Then disconnect the absorption bulbs (see Figure 1, item reference 8), weigh them at ambient temperature and place them in positi
34、on again. 6.2 Test portion The mass of the test portion (m0) shall be such that it contains approximately 0,03 g of carbon, and shall be determined to the nearest 0,000 1 g. If necessary, add 0,2 g to 1 g of the flux (3.3) to the test portion. 6.3 Blank test Carry out the blank test by combustion (p
35、roceed as described in 6.4 and 6.5) in the presence of the quantity of flux used in the analysis, and carefully determine the increase in mass (m1) of the absorption bulbs. 6.4 Combustion Open the combustion tube at the oxygen inlet end and, using the hook (4.2), place the boat (see Figure 1, item r
36、eference 5) containing the test portion (6.2) in the centre of the heated zone of the tube. Quickly close the tube and immediately pass a stream of oxygen at a rate of 300 cm3/min to 500 cm3/min, depending on the diameter of the tube used. Continue to pass oxygen for 10 min to 20 min, so that the ca
37、rbon dioxide is completely removed from the combustion tube and the purifying bulb. 6.5 Determination Close the tap of the absorption bulbs (see Figure 1, item reference 8) and immediately remove the bulbs from the apparatus. After 5 min, weigh the bulbs to the nearest 0,000 1 g. It is recommended t
38、hat the fused mass in the boat be visually examined to verify that combustion has been completed. The increase in mass represents the carbon dioxide absorbed (m2). 7 EN ISO 3907:2009 (E) DIN EN ISO 3907:2010-02 7 Expression of results 7.1 Calculation The mass fraction of carbon, expressed as a perce
39、ntage, is given by the formula where m0is the mass, in grams (g), of the test portion; m1is the mass, in grams (g), of carbon dioxide obtained from the blank test; m2is the mass, in grams (g), of the carbon dioxide obtained from the combustion of the test portion; 27,29 is the carbon dioxide to carb
40、on conversion factor, multiplied by 100. 7.2 Tolerances The deviation between two or three independent determinations shall not exceed the values shown in Table 1. Table 1 Tolerances Total carbon mass fraction Range for two determinations Range for three determinations % % % from 4 to 10 0,05 0,06 o
41、ver 10 0,07 0,08 7.3 Final result Report the arithmetical mean of acceptable determinations rounded to the nearest 0,01 % (mass fraction). 8 Test report The test report shall include the following information: a) a reference to this International Standard; b) all details necessary for the identification of the test sample; c) the result obtained; d) all operations not specified in this International Standard, or regarded as optional; e) details of any occurrence which may have affected the result. 8 DIN EN ISO 3907:2010-02 EN ISO 3907:2009 (E) 01229,27mmm
