1、BS EN ISO3907:2009ICS77.160NOCOPYINGWITHOUTBSIPERMISSIONEXCEPTASPERMITTEDBY COPYRIGHTLAWBRITISH STANDARDHardmetals Determination of totalcarbon GravimetricmethodIncorporating corrigendumAugust 2015This British Standardwas publishedunderthe authority of theStandards PolicyandStrategy Committee on 30N
2、ovember2009.ISBN9780580914423BSENISO3907:2009NationalforewordThis BritishStandardisthe UK implementation of EN ISO 3907:2009.Itsupersedes BS EN 23907:1993which is withdrawn.The UK participation in its preparation was entrustedtoTechnicalCommittee ISE/65, Sintered metal components.Alist of organizati
3、onsrepresented on thiscommittee canbeobtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof acontract. Users areresponsible for itscorrect application.CompliancewithaBritishStandardcannotconferimmunityfromlegalobligations. The British Standard
4、s Institution 2015.Published by BSI Standards Limited 2015Amendments/corrigendaissuedsincepublicationDate Comments31 August 2015 Implementation of ISO correctedtext 15 February 2010. Missing equationin 7.1 addedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORMEN ISO 3907 October 2009 ICS 77.160 Supe
5、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 Europ
6、ean Standard was approved by CEN on 29 September 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations wh ich stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
7、concerning such nationalstandards 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 its
8、 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, Lithu
9、ania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN A
10、ll rights of exploitation in any form and by any means reserved worldwide for CEN national Members.Ref. No. EN ISO 3907:2009: EBS EN ISO 3907:2009EN ISO 3907:2009 (E)3 Foreword This document (EN ISO3907:2009) has been prepared by Technical Committee ISO/TC 119 “Powdermetallurgy“.This European Standa
11、rd shall be given the status ofa national standard, either by publication of an identical text or by endorsement, at the latestbyApril 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 docum
12、ent may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any orall such patent rights. This document supersedes EN 23907:1993.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound t
13、o implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, CzechRepublic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzer
14、land and the UnitedKingdom. Endorsement noticeThe text of ISO 3907:2009 has been approved by CEN as a EN ISO 3907:2009 without any modification.Reference numberISO 3907:2009(E)ISO 2009INTERNATIONAL STANDARD ISO3907Third edition2009-10-01Corrected version2010-02-15Hardmetals Determination of total ca
15、rbon Gravimetric method Mtaux-durs Dosage du carbone total Mthode gravimtrique ISO 3907:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded
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18、elating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including
19、photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in
20、 Switzerland ii ISO 2009 All rights reservedBS EN ISO 3907:2009ISO 3907:2009(E) ISO 2009 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards
21、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 on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take pa
22、rt in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to
23、prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility th
24、at 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. ISO 3907 was prepared by Technical Committee ISO/TC 119, Powder metallurgy, Subcommittee SC 4, Sampling and testing methods for hardmetal. Th
25、is third edition cancels and replaces the second edition (ISO 3907:1985), which has been technically revised. In this corrected version of ISO 3907:2009, the missing equation in 7.1 has been added. BS EN ISO 3907:2009INTERNATIONAL STANDARD ISO 3907:2009(E) ISO 2009 All rights reserved 1Hardmetals De
26、termination of total carbon Gravimetric method 1 Scope This International Standard specifies a gravimetric method for the determination of the mass fraction of total carbon in carbides and hardmetals. This method is applicable to carbides of chromium, hafnium, molybdenum, niobium, tantalum, titanium
27、, vanadium, tungsten and zirconium, mixtures of these carbides and binder metals, free of lubricant, all grade of presintered or sintered hardmetals, 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 te
28、mperature in a stream of pure oxygen, with the addition of a flux, if necessary. Absorption of the carbon dioxide, carried by oxygen, by Ascarite1)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
29、 Na CO H O+ + 3 Reagents During the analysis, use only reagents of recognized analytical grade, and only distilled water or water of equivalent 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 pr
30、oduct supplied by Arthur H. Thomas Co. This information is given for the convenience of users of the International Standard and does not constitute an endorsement by ISO of the product named. Equivalent products may be used if they can be shown to lead to the same results. BS EN ISO 3907:2009ISO 390
31、7:2009(E) 2 ISO 2009 All rights reserved3.2 Magnesium perchlorate, anhydrous. CAUTION To prevent the possibility of explosion, contact of this reagent with organic materials must be avoided, especially when discarding it. 3.3 Flux, for example tin metal, copper metal or oxide, iron metal. 3.4 Ascari
32、te1). 4 Apparatus Ordinary laboratory apparatus and the following. 4.1 Apparatus, consisting of an electric furnace with a combustion tube, a purification train and a system to absorb carbon dioxide. If it is necessary to obtain oxygen of adequate purity, an oxygen purification train may also be use
33、d. Successive parts of the apparatus shall be joined together with connecting tubes forming an airtight seal. The apparatus is shown schematically in Figure 1. 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 35
34、0 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 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 t
35、he 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 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 p
36、retreated 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 bulb, containing anhydrous magnesium perchlorate (3.2). 4.1.8 Absorption bulbs, containing Ascarite1)(3.4) and a small amount of anhydrous ma
37、gnesium 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 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-res
38、isting 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. BS EN ISO 3907:2009ISO 3907:2009(E) ISO 2009 All rights reserved 3Key 1 source of oxygen 2 flow meter 3 electric furnace 4 combustion tube 5 boat 6
39、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 Ascarite1)(3.4), not too compressed 4 bottom layer of glass wool to protect inside of tube Figure 2 Absorption bulb BS EN ISO 390
40、7:2009ISO 3907:2009(E) 4 ISO 2009 All rights reserved5 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 shall pass through a 180 m sieve. 5.2 The analysis shall be carried out on two or three test portions. 6
41、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 efficiency of the oxygen purification. Pass oxygen through the apparatus for 10 min to 15 min at a rate of 300
42、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 position again. 6.2 Test portion The mass of the test portion (m0) shall be such that it contains approximatel
43、y 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 (proceed as described in 6.4 and 6.5) in the presence of the quantity of flux used in the analysis, and ca
44、refully 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 reference 5) containing the test portion (6.2) in the centre of the heated zone of the tube. Quickly clos
45、e 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 carbon dioxide is completely removed from the combustion tube and the purifying bulb. 6.5 Determination Cl
46、ose 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 that the fused mass in the boat be visually examined to verify that combustion has been completed. The in
47、crease in mass represents the carbon dioxide absorbed (m2). BS EN ISO 3907:2009ISO 3907:2009(E) ISO 2009 All rights reserved 57 Expression of results 7.1 Calculation The mass fraction of carbon, expressed as a percentage, is given by the formula 21027,29mmmwhere m0is the mass, in grams (g), of the t
48、est 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 carbon conversion factor, multiplied by 100. 7.2 Tolerances The deviation betw
49、een 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 over 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 necessar
