EN 24491-1-1993 en Metallic Powders - Determination of Oxygen Content by Reduction Methods - Part 1 General Guidelines《金属粉末 用还原法测定氧含量 第1部分 通则(ISO 4491-1-1989)》.pdf
《EN 24491-1-1993 en Metallic Powders - Determination of Oxygen Content by Reduction Methods - Part 1 General Guidelines《金属粉末 用还原法测定氧含量 第1部分 通则(ISO 4491-1-1989)》.pdf》由会员分享,可在线阅读,更多相关《EN 24491-1-1993 en Metallic Powders - Determination of Oxygen Content by Reduction Methods - Part 1 General Guidelines《金属粉末 用还原法测定氧含量 第1部分 通则(ISO 4491-1-1989)》.pdf(6页珍藏版)》请在麦多课文档分享上搜索。
1、CEN EN*F24491-1 93 3404589 004?7052 400 EUROPEAN STANDARD EN 24491-1 NORME EUROPENNE EUROPISCHE NORM April 1993 UDC 621.762 : 669-492.2 : 543.73 546.21 Descriptors: Powder metallurgy, metallic powder, chemical analysis, determination of content, oxygen, reduction method English version Metallic powd
2、ers - Determination of oxygen content by reduction methods - Part 1 : General guidelines (IS0 4491-1 : 1989) Poudres mtalliques - Dosage de l?oxygne par les mthodes de rduction - Partie 1: Directive gnrales (IS0 4491-1 : 1989) Metallpulver - Bestimmung des Sauerstoffgehaltes durch Reduktionsverfahre
3、n - Ri1 1: Allgemeine Hinweise (IS0 4491-1 : 1989) 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 alterat
4、ion. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application 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 translat
5、ion under 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,
6、Netherlands, 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 24491-1
7、 : 1993 E CEN EN+2449L-L 93 - 3404589 0047053 347 Page 2 EN 24491-1 : 1993 Foreword In 1992, IS0 24491-1: 1993 Metallic powders - Deterrnimtion of oxygen content bp reduction methods - Part 1: Geneml guidelines was submitted to the CEN Primary Questionnaire procedure. Following the positive result o
8、f the CEN/CS Proposal IS0 4491-1 : 1989 was submitted to the CEN 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 text or by endorsement, at the latest by October 1993, and conflict
9、ing national standards shall 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, Nethe
10、rlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. NOTE. The European references to international publications are given in annex ZA (normative). CEN EN+24491-1 93 = 3404589 O047054 283 W Page 3 EN 24491-1 : 1993 Introduction In powder metallurgy, the purity of the powders is a
11、n important parameter for the manufacture of sintered metals. Among the various impurities which may be present in a powder, oxygen plays a particular role as it is always present in any metal or alloy powder, and in amounts greater than those encountered in compact metals. Oxygen is mostly combined
12、 in the form of oxides which appear in the following ways: - Oxide film coatings on particle surfaces, spontaneously formed by oxidation of the metal by air or moisture during powder preparation and during handling and storage. - Oxide inclusions, being either oxides of the main metal remaining loca
13、lly unreduced during the production process (in the case of reduced powders), or other oxide impurities originating from the raw material and/or from the equipment (e.g. refractory ceramics from melting furnace in atomization processes). In practice, oxygen contents in metallic powders lie mostly in
14、 the range 0,l % (rn/m) to 1 % (m/rn). The determination of oxygen content can be made by means of many physical or chemical methods, for example a) specific methods, such as activation analysis or mass spectrometry, in which the element O is directly determined; b reduction methods, in which oxides
15、 present are, totally or partially, reduced by hydrogen or by carbon. Oxygen content is related, either to the loss of mass of the sample through reduction, or to the amount of water or CO/CO, produced by the reaction; c) separation methods, in which - either the oxide phase is selectively dissolved
16、 and determined chemically (for exaniple in copper powder, where copper oxide is dissolved by hydrochloric acid) ; - or the metal phase is selectively dissolved, and the insoluble residue (assumed to be oxide) is evaluated (for example in aluminium powder, aluminium is dissolved in bromine-methanol
17、reagent, leaving aluminium oxide). The present International Standard considers only reduction methods, as these are commonly used in laboratories for analysing a great variety of metal powders. Page 4 EN 24491-1 1993 Metallic powders - Determination of oxygen content by reduction methods - Part I :
18、 General guidelines 1 Scope This part of IS0 4491 is the first part of a series dealing with the determination of oxygen content in metallic powders by reduc- tion methods. It gives general guidance to these methods, and gives some recommendations for the correct interpretation of the results obtain
19、ed. The test methods are applicable generally to all powders of metals, alloys, carbides and mixtures thereof. The constituents of the powder shall be non-volatile under the conditions of test. The powder shall be free of lubricant or organic binder. However, there exist certain limitations which de
20、pend upon the nature of the analysed metal. These limitations are discussed in clause 4. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 4491. At the time of publication, the editions indicated were va
21、lid. All standards are subject to revision, and parties to agreements based on this part of IS0 4491 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standar
22、ds. IS0 4491-2 : 1989, Metallic powders - Determination of oxygen content by reduction methods - Part2: Loss of mass on hydrogen reduction (hydrogen lossl. IS0 4491-3 : 1989, Metaliic powders - Determination. of oxygen content by reduction methods - Part 3: Hydrogen- reducible oxygen. IS0 44914 : 19
23、89, Metaliic powders - Determination of oxygen content by reduction methods - Part 4: Total oxygen by reduction-extraction. 3 Sampling For sampling of the powder the procedures given in IS0 3954 : 1977, Powders for powder metallurgical purposes - Sam- pling, are recommended. The powder shall be test
24、ed in the as-received condition. Metallic powders are frequently reactive substances with respect to air and moisture. Therefore, particular attention shall be given to adequate conditions for handling and storage of the test sample. The test portion shall be taken immediately prior to the analysis.
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