DIN EN ISO 7625-2013 Sintered metal materials excluding hardmetals - Preparation of samples for chemical analysis for determination of carbon content (ISO 7625 2012) German version.pdf

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1、March 2013 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).ICS 7

2、7.160!$v“1948397www.din.deDDIN EN ISO 7625Sintered metal materials, excluding hardmetals Preparation of samples for chemical analysis for determination ofcarbon content (ISO 7625:2012);English version EN ISO 7625:2012,English translation of DIN EN ISO 7625:2013-03Sintermetalle, ausgenommen Hartmetal

3、le Vorbereitung von Proben fr die chemische Analyse zur Bestimmung desKohlenstoffgehaltes (ISO 7625:2012);Englische Fassung EN ISO 7625:2012,Englische bersetzung von DIN EN ISO 7625:2013-03Matriaux mtalliques fritts, lexclusion des mtaux-durs Prparation des chantillons pour analyse chimique en vue d

4、u dosage du carbone(ISO 7625:2012);Version anglaise EN ISO 7625:2012,Traduction anglaise de DIN EN ISO 7625:2013-03SupersedesDIN EN ISO 7625:2010-08www.beuth.deDocument comprises 9 pagesIn case of doubt, the German-language original shall be considered authoritative.02.13 DIN EN ISO 7625:2013-03 2 A

5、 comma is used as the decimal marker. National foreword This document (EN ISO 7625;2012) has been prepared by Technical Committee ISO/TC 119 “Powder metallurgy” (Secretariat: SIS, Sweden) and has been adopted as European Standard by Technical Committee CEN/SS M11 “Powder metallurgy” (Secretariat: CM

6、C). The responsible German body involved in its preparation was the Normenausschuss Werkstofftechnologie (Technology of Materials Standards Committee), Working Committee NA 145-01-03 AA Probenahme und Prfverfahren fr Sintermetalle (ausgenommen Hartmetalle). The DIN Standard corresponding to the Inte

7、rnational Standard referred to in this document is as follows: ISO 2738 DIN EN ISO 2738 Amendments This standard differs from DIN EN ISO 7625:2010-08 as follows: a) Clause 6 “Precision“ has been revised; b) the standard has been editorially revised. Previous editions DIN ISO 7625: 1991-04 DIN EN ISO

8、 7625: 2010-08 National Annex NA (informative) Bibliography DIN EN ISO 2738, Sintered metal materials, excluding hardmetals Permeable sintered metal materials Determination of density, oil content and open porosity EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7625 November 2012 ICS 77.16

9、0 Supersedes EN ISO 7625:2010 English Version Sintered metal materials, excluding hardmetals Preparation of samples for chemical analysis for determination of carbon content (ISO 7625:2012) Matriaux mtalliques fritts, lexclusion des mtaux-durs Prparation des chantillons pour analyse chimique en vue

10、du dosage du carbone (ISO 7625:2012) Sintermetalle, ausgenommen Hartmetalle Vorbereitung von Proben fr die chemische Analyse zur Bestimmung des Kohlenstoffgehaltes (ISO 7625:2012) This European Standard was approved by CEN on 1 December 2012. CEN members are bound to comply with the CEN/CENELEC Inte

11、rnal 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 application to the CEN-CENELEC Management Centre or to any

12、 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 CEN-CENELEC Management Centre has the same status as the official ve

13、rsions. 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, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway

14、, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any

15、 form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 7625:2012: E Contents PageForeword .3 Introduction. 4 1 Scope . 5 2 Normative references . 5 3 Principle . 5 4 Materials 5 5 Procedure 6 5.1 RR of Rinterfering carbonaceous 6 5.2 Final preparation . 6 6 Precision 7 R

16、emoval2DIN EN ISO 7625:2013-03 EN ISO 7625:2012 (E) Foreword This document (EN ISO 7625:2012) has been prepared by Technical Committee ISO/TC 119 Powder metallurgy . This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement,

17、 at the latest by May 2013, and conflicting national standards shall be withdrawn at the latest by May 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or a

18、ll such patent rights. This document supersedes EN ISO 7625:2010. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Es

19、tonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice Th

20、e text of ISO 7625:2012 has been approved by CEN as a EN ISO 7625:2012 without any modification. 3DIN EN ISO 7625:2013-03 EN ISO 7625:2012 (E) “”IntroductionThe chemical analysis of sintered metal materials, excluding hardmetals, is carried out as it would be for solid metals, by using existing stan

21、dard methods. However, as these sintered materials very often contain carbonaceous constituents, the correct determination of carbon content (free or total) requires that certain precautions be taken when preparing the sample for analysis from components.Samples prepared in accordance with this Inte

22、rnational Standard may also be suitable for chemical analysis for other elements.4DIN EN ISO 7625:2013-03 EN ISO 7625:2012 (E) 1 ScopeThis International Standard specifies methods for preparing a sample from one or more sintered parts to be analysed for free or total carbon content. Combined carbon

23、is determined as the difference between total and free carbon. This standard covers the preparation of samples for the determination of carbon by a chemical method, i.e. combustion in oxygen and measurement of the carbon dioxide produced, in accordance with ISO 437. It does not cover the preparation

24、 of samples for carbon determination by physical methods, such as metallography or spectroscopy.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest ed

25、ition of the referenced document (including any amendments) applies.ISO 437, Steel and cast iron Determination of total carbon content Combustion gravimetric methodISO 2738, Sintered metal materials, excluding hardmetals Permeable sintered metal materials Determination of density, oil content, and o

26、pen porosity3 PrincipleEliminate any impregnated or surface carbon using the procedures in Clause 5. Prepare samples for analysis by fragmentation or machining, taking care not to lose any free carbon.4 MaterialsThis International Standard applies to parts in which carbon is uniformly distributed an

27、d present in the forms shown in Table 1. It does not apply to parts in which the carbon is not uniformly distributed throughout the part, including those parts with carburized or decarburized surfaces.In instances where the carbon is not uniformly distributed, for example a case-hardened part, the m

28、ethod of selecting the sample should be agreed upon between the supplier and the purchaser.The presence of carbonaceous materials in the pores or on the surface of the part to be analysed interferes with the determination of carbon, see Table 2.Table 1 Forms of carbon that can be determined by chemi

29、cal analysisForm of carbon Typical materials CommentsCombined carbon (as carbides or in solid solution)Carbon-containing steels and super-alloysDetermined as the difference between total and free carbonFree carbon Bronze and steel containing graph-ite; material impregnated with a graphite-containing

30、 liquidDetermined by combustion of the residue of selective dissolution of the metal in the sample.Total carbon Determined by direct combustion of the sample5DIN EN ISO 7625:2013-03 EN ISO 7625:2012 (E) Table 2 Origins of carbonaceous material and feasibility of carbon determination by chemical meth

31、odsCarbonaceous material Origin Feasibility1 Liquid or semi-liquid organic substances on the surface or in the poresSizing lubricant, quenching oil, impregnating lubricant, cutting fluid, greaseCarbon determination is possible only when these organic substances are totally eliminated by the method d

32、escribed in Clause 52 Waxes and wax-like substances Sizing lubricant, corrosion protec-tive3 Deposits of carbon on the parts Sintering, heat treatment4 Solid organic substances, for example, plastics materials on the surface or in the poresSealant material In general, it is not possible to elimi-nat

33、e these substances, and determi-nation of carbon is not possible5 Procedure5.1 Removal of interfering carbonaceous material5.1.1 GeneralCarbonaceous materials (see Table 2) that affect the carbon determination shall be removed from the part or parts to be analysed as specified in 5.1.2 and 5.1.3.5.1

34、.2 Impregnated organic substances in the pores or on the surface (see Cases 1 and 2 in Table 2) shall be removed by Soxhlet degreasing with an appropriate solvent, in accordance with ISO 2738. The solvent used shall be stated.NOTE When the impregnated liquid contains fine carbon particles, for examp

35、le colloidal graphite, it is possible that not all of these particles are removed by Soxhlet degreasing. In such a case, the determination of free carbon and total carbon is invalid. Nevertheless, the calculation of combined carbon is still valid if the free carbon and total carbon are determined on

36、 the same part or parts after degreasing.5.1.3 Surface deposits of carbon (see Case 3 in Table 2) shall be removed by mechanical treatment.5.2 Final preparationThe sample for analysis shall consist of small fragments of a size appropriate to the analysis method to be used, prepared by one of the fol

37、lowing methods: crushing in a mortar made of a material which does not alter the sample composition; drilling, milling or turning. Such machining shall be performed dry by using hardmetal or ceramic tools. Care shall be taken to avoid overheating, oxidation and contamination of the fragments. Where

38、drilling is used, the part shall be drilled through completely and the distribution of drilling holes shall be uniform over the whole surface of the part. If the part is too thick, the holes shall be drilled to the middle from both faces of the part.Where crushed or machined fragments contain fine p

39、articles (for example free graphite), care shall be taken not to lose these particles during handling.Where segregation is expected to be a problem, the entire sample should be analysed after being divided into a suitable number of test portions. The carbon content is then calculated as the average

40、of the results from each portion.In general, a sufficient quantity of fragments, representative of the part or parts, shall be prepared. The samples for analysis shall be kept in a container that is tightly sealed, in order to avoid contamination.6DIN EN ISO 7625:2013-03 EN ISO 7625:2012 (E) 6 Preci

41、sionWhen the degreasing is carried out according to ISO 2738 as stated in 5.1.2, the carbon content after oil removal can be considered suspect if the repeatability is greater than 5 % and the reproducibility is greater than 10 % at the 95 % confidence level.7DIN EN ISO 7625:2013-03 EN ISO 7625:2012 (E)