1、BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Metallic powders Determination of flow rate by means of a calibrated funnel (Hall flowmeter) (ISO 4490:2018)BS EN ISO 4490:2018National forewordThis British Standard is the UK implementation of EN ISO 4490:2018. It supe
2、rsedes BS EN ISO 4490:2014, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee ISE/65, Sintered metal components.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include
3、 all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2018 Published by BSI Standards Limited 2018ISBN 978 0 580 90964 1ICS 77.160Compliance with a British Standard cannot confer immunity from legal obligations.This British
4、Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2018.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN ISO 4490:2018EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 4490May 2018ICS 77.160 Supersedes EN ISO
5、4490:2014EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGCEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2018 CEN Ref. No. EN ISO 4490:2018: EAll rights of exploitation in any form and by any means reserved worldwide for CEN national
6、 MembersMetallic powders - Determination of flow rate by means of a calibrated funnel (Hall flowmeter) (ISO 4490:2018)Poudres mtalliques - Dtermination du temps dcoulement au moyen dun entonnoir calibr (appareil de Hall) (ISO 4490:2018)Metallpulver - Bestimmung der Durchflussrate mit Hilfe eines kal
7、ibrierten Trichters (Hall flowmeter) (ISO 4490:2018)This European Standard was approved by CEN on 23 March 2018.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 alt
8、eration. 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 CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language mad
9、e 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 versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estoni
10、a, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.English VersionEN ISO
11、4490:2018 (E)European forewordThis document (EN ISO 4490:2018) 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, at the latest by November 2018
12、, and conflicting national standards shall be withdrawn at the latest by November 2018.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.This document s
13、upersedes EN ISO 4490:2014.According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republi
14、c of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.Endorsement noticeThe text of ISO 4490:2018 has been
15、approved by CEN as EN ISO 4490:2018 without any modification.iiBS EN ISO 4490:2018ISO 4490:2018Foreword iv1 Scope .12 Normative references 13 Terms and definitions .14 Principle 15 Apparatus .16 Calibration of the funnel. 36.1 Calibration by the manufacturer of the funnel 36.2 Calibration by the use
16、r of the funnel 37 Sampling 47.1 General . 47.2 Test sample weight 47.3 Test portion weight . 47.4 Number of test portions 48 Procedure.49 Expression of results 410 Precision . 511 Test report . 5Bibliography 7 ISO 2018 All rights reserved iiiContents PageBS EN ISO 4490:2018ISO 4490:2018ForewordISO
17、(the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical comm
18、ittee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrote
19、chnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafte
20、d in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that 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 right
21、s. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitut
22、e an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the
23、following URL: www.iso.org/iso/foreword.html.This document was prepared by Technical Committee ISO/TC 119, Powder metallurgy, Subcommittee SC 2, Sampling and testing methods for powders (including powders for hardmetals).This fifth edition, which cancels and replaces the fourth edition (ISO 4490:201
24、4), has been revised to include a precision statement together with some other minor clarifications.iv ISO 2018 All rights reservedBS EN ISO 4490:2018Metallic powders Determination of flow rate by means of a calibrated funnel (Hall flowmeter)1 ScopeThis document specifies a method for determining th
25、e flow rate of metallic powders, including powders for hard metals, by means of a calibrated funnel (Hall flowmeter).The method is applicable only to powders which flow freely through the specified test orifice.2 Normative referencesThere are no normative references in this document.3 Terms and defi
26、nitionsNo terms and definitions are listed in this document.ISO and IEC maintain terminological databases for use in standardization at the following addresses: ISO Online browsing platform: available at https:/www.iso.org/obp IEC Electropedia: available at http:/www.electropedia.org/4 PrincipleMeas
27、urement of the time required for 50 g of a metallic powder to flow through the orifice of a calibrated funnel of standardized dimensions.5 Apparatus5.1 Calibrated funnel, the dimensions of which are shown in Figure 1. The funnel shall be made of a non-magnetic, corrosion-resistant metallic material
28、with sufficient wall thickness and hardness to withstand distortion and excessive wear.5.2 Stand and horizontal vibration-free base, which shall support the funnel rigidly. An example is shown in Figure 2.5.3 Balance of sufficient capacity, capable of weighing the test portion to an accuracy of 0,05
29、 g.5.4 Timing device, capable of measuring the elapsed time to an accuracy of 0,1 s.5.5 Reference grit, a reference powder1)used for calibration of the funnel, shall be used.1) Material complying with 5.5 can be purchased as “Chinese emery grit” from ACuPowder International, LLC, 901 Lehigh Avenue,
30、Union, NJ 07083, USA. This information is given for the convenience of users of this document anddoes not constitute an endorsement by ISO of the company named above. Equivalent products may be used if theycan be shown to lead to the same results.INTERNATIONAL STANDARD ISO 4490:2018 ISO 2018 All rig
31、hts reserved 1BS EN ISO 4490:2018ISO 4490:2018Dimensions in millimetresKey1 polished to Ra 0,4 maD =+25040,.Figure 1 Calibrated funnel (Hall flowmeter)2 ISO 2018 All rights reservedBS EN ISO 4490:2018ISO 4490:2018Figure 2 Arrangement of calibrated funnel and stand6 Calibration of the funnel6.1 Calib
32、ration by the manufacturer of the funnelThe manufacturer shall supply the flowmeter calibrated as follows.a) Dry the reference grit (5.5) in an open and clean glass jar at 110 C for 60 min in air.b) Cool the reference grit to room temperature in a desiccator.c) Weigh out 50 g 0,1 g of the reference
33、grit.d) Follow the procedure outlined in Clause 8.e) Repeat the procedure with the same 50 g mass of reference grit, until there are five determinations within 0,4 s.f) The average of these five determinations is stamped on the bottom of the funnel and the duration of flow shall be within 40,0 s 0,5
34、 s.6.2 Calibration by the user of the funnelIt is recommended that the users periodically verify whether a correction is needed or not. ISO 2018 All rights reserved 3BS EN ISO 4490:2018ISO 4490:2018The flow rate of the reference sample shall be determined by the above method. If the flow rate has ch
35、anged to be outside 40,0 s 0,5 s/50 g, a correction factor shall be used when measuring different powders. This correction factor is obtained by dividing 40,0 by the value obtained above.It is recommended that, before a correction factor is adopted, the cause of the change be investigated. If the fl
36、ow rate has decreased, it is probable that repeated use has burnished the orifice and a (new) correction factor is justified. An increase in flow rate may indicate a coating of soft powder on the orifice. This coating should be carefully removed and the calibration test repeated.It is recommended th
37、at the use of a funnel be discontinued after the duration of flow of the reference sample has decreased to less than 37 s.7 Sampling7.1 GeneralIn general, the powder shall be tested in the as-received condition. In certain cases, and after agreement between the supplier and user, the powder may be d
38、ried. However, if the powder is susceptible to oxidation, the drying shall take place in a vacuum or in inert gas. If the powder contains volatile substances, it shall not be dried.7.2 Test sample weightThe mass of the test sample shall be at least 200 g.7.3 Test portion weightImmediately before the
39、 test, weigh out a 50 g 0,1 g test portion.7.4 Number of test portionsThe determination shall be carried out on three test portions.8 Procedurea) Transfer the test portion to the funnel, keeping the discharge orifice properly closed, for example with a dry finger or a mechanical shutter. Take care t
40、hat the stem of the funnel is filled with powder.b) Start the timing device (5.4) when the orifice is opened and stop it at the instant when the last of the powder leaves the orifice.c) Record the elapsed time measured to the nearest 0,1 s.Alternatively, the orifice can be kept open when the test po
41、rtion is transferred to the funnel, with the rest of the procedure being the same.If the powder does not begin to flow when the orifice is opened, one slight tap on the funnel to start the flow is permitted. If this has no effect, or if the flow stops during the test, the powder is considered to pos
42、sess no flowability according to the test method described in this document.9 Expression of resultsCalculate the arithmetic mean of the results of the three determinations and report the value in seconds per 50 g, rounded to the nearest second. If a correction factor (see 6.2) is used, the average s
43、hall be multiplied by this correction factor.4 ISO 2018 All rights reservedBS EN ISO 4490:2018ISO 4490:201810 PrecisionThree iron powders, see Table 1, were included in the inter-laboratory study to develop this precision statement.Table 1 Types of powders included in the inter laboratory studyType
44、of powderPlain atomized iron powderPlain sponge iron powderStainless steel powderIn Table 2 the repeatability and reproducibility are presented as one standard deviation.Table 2 Repeatability and reproducibility as standard deviationsTested powderLevel Average flow time sRepeatability (sr) Standard
45、deviation sReproducibility (sR) Standard deviation sPlain atomized iron powder 25 0,4 1,1Plain sponge iron powder 33 0,3 1,1Stainless steel powder 32 0,2 1,2The difference between two test results found on identical test material by one operator using the same apparatus within the shortest feasible
46、time interval will exceed the repeatability limit (r), see Table 3, on average not more than once in 20 cases in the normal and correct operation of the method.Test results on identical test material reported by two laboratories will differ by more than the reproducibility limit (R), see Table 3, on
47、 average not more than once in 20 cases in the normal and correct operation of the method.Table 3 Repeatability and reproducibility, difference between two tests at 95 % probability levelTested powderLevel Average flow time sRepeatability (r) Limit sReproducibility (R) Limit sPlain atomized iron pow
48、der 25 1,1 3,1Plain sponge iron powder 33 0,7 3,0Stainless steel powder 32 0,6 3,2The accuracy data were determined from an experiment organized and analysed in accordance with ISO 5725-21in 2014 involving 14 laboratories and three levels. Data from two of the laboratories contained outliers for the
49、 stainless steel powder. These data points were excluded in the calculations of the precision statement.The repeatability and reproducibility are valid for powders similar to the powders evaluated for the precision statement. Other types of metal powders, with properties different from the evaluated powders, may have repeatability and reproducibility that are different from what is reported in this precision statement.11 Test reportThe test report shall include the following information:a) a reference to this document (i.e
