1、BS EN ISO2740:2009ICS 77.040.10; 77.160NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDSintered metalmaterials, excludinghardmetals Tensiletest pieces (ISO2740:2009)This British Standardwas published underthe authority of theStandards Policy andStrategy Committe
2、e on 30November 2009. BSI 2009ISBN 978 0 580 62212 0Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 2740:2009National forewordThis British Standard is the UK implementation of EN ISO 2740:2009. Itsupersedes BS EN ISO 2740:2007 which is withdrawn.The UK participation in its prepa
3、ration was entrusted to TechnicalCommittee ISE/65, Sintered metal components.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct
4、application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 2740May 2009ICS 77.040.10; 77.160 Supersedes EN ISO 2740:2007 English VersionSintered metal materials, excluding hardmetals - Tensile testpieces (ISO 2740
5、:2009)Matriaux en mtal fritt, lexclusion des mtaux-durs -prouvettes pour essai de traction (ISO 2740:2009)Sintermetalle, ausgenommen Hartmetalle - Zugprobestbe(ISO 2740:2009)This European Standard was approved by CEN on 13 April 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regu
6、lations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This Eu
7、ropean Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the nat
8、ional standards bodies of Austria, Belgium, 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 U
9、nited Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 2740:2009:
10、EBS EN ISO 2740:2009EN ISO 2740:2009 (E) 3 Foreword This document (EN ISO 2740:2009) has been prepared by Technical Committee ISO/TC 119 “Powder metallurgy“ in collaboration with Technical Committee CEN/SS M11 “Powder metallurgy” the secretariat of which is held by CMC. This European Standard shall
11、be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2009, and conflicting national standards shall be withdrawn at the latest by November 2009. Attention is drawn to the possibility that some of the elements of this docu
12、ment may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 2740:2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are
13、bound to implement this European Standard: Austria, Belgium, 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
14、, Switzerland and the United Kingdom. Endorsement notice The text of ISO 2740:2009 has been approved by CEN as a EN ISO 2740:2009 without any modification. BS EN ISO 2740:2009ISO 2740:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references 1 3 Method of tes
15、ting.1 4 Manufacture of test pieces .1 5 Metal injection-moulded test pieces2 6 Machined test pieces.2 7 Identification of test pieces 3 BS EN ISO 2740:2009ISO 2740:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of n
16、ational 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 committee has been established has the right to be represented on that committee. Inter
17、national 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 electrotechnical standardization. International Standards are drafted in accordance with the
18、 rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to 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
19、 at least 75 % of the member bodies casting a vote. 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 rights. ISO 2740 was prepared by Technical Committee ISO/
20、TC 119, Powder metallurgy, Subcommittee SC 3, Sampling and testing methods for sintered metal materials (excluding hardmetals). This fifth edition cancels and replaces the fourth edition (ISO 2740:2007), of which it constitutes a minor revision. BS EN ISO 2740:2009INTERNATIONAL STANDARD ISO 2740:200
21、9(E) ISO 2009 All rights reserved 1Sintered metal materials, excluding hardmetals Tensile test pieces 1 Scope This International Standard is applicable to all sintered metals and alloys, excluding hardmetals. This International Standard specifies: the die cavity dimensions used for making tensile te
22、st pieces by pressing and sintering, and by Metal Injection Moulding (MIM) and sintering; the dimensions of tensile test pieces machined from sintered and powder forged materials. 2 Normative references The following referenced documents are indispensable for the application of this document. For da
23、ted references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 6892, Metallic materials Tensile testing at ambient temperature ISO 7500-1, Metallic materials Verification of static uniaxial testing machine
24、s Part 1: Tension/com-pression testing machines Verification and calibration of the force-measuring system 3 Method of testing 3.1 Test pieces shall be tested in accordance with ISO 6892, and the tensile test machine shall be calibrated to Class 1, in accordance with ISO 7500-1. 3.2 Data are to be r
25、eported for three or more test pieces. 4 Manufacture of test pieces 4.1 Pressed and sintered test pieces The tensile test pieces shall have thicknesses from 5 mm to 6,5 mm. A thickness tolerance of 1,5 mm accommodates varying apparent densities in metal powders. During testing, the thinner pieces ha
26、ve less grip slippage and are more likely to break near the centre of the gauge length. If necessary for measuring elongation, marks may be lightly scribed 25 mm apart and symmetrically about the centre line see Figures 1 a) and 2 a). Between the scribed marks, the thickness shall not vary by more t
27、han 0,04 mm. The gauge length shall be scribed in such a way that the tensile properties are not affected. BS EN ISO 2740:2009ISO 2740:2009(E) 2 ISO 2009 All rights reservedBecause of the possibility of creating microlaminations in the corners of test pieces compacted under laboratory conditions, re
28、presentative sintered test pieces shall be examined metallographically to show that there are no microlaminations longer than 0,25 mm. 4.2 Die specifications The dimensions of the two permitted die cavities are shown in Figures 1 b) and 2 b). The dies should prefe-rably be of hardmetal and their sur
29、face finish shall be such as to allow compression of the test pieces under normal conditions. Dies may include a small exit taper to facilitate ejection and to avoid cracks or microlaminations in the test pieces. A die cavity tapered 0,01 per side, to aid ejection, may be enlarged by 0,5 % for tooli
30、ng to be used for repressing. The dies should be well supported with shrink rings, so as to minimize lateral expansion during compacting. Such a support decreases the possibility of cracking of the specimen at ejection. To reduce the incidence of cracks in the specimen, it is recommended to use top-
31、punch hold-down during ejection. The die in Figure 1 b) is recommended for as-sintered test pieces. Gripping is readily accomplished by sliding the 20 wedge faces of the test piece into matching pockets machined in the grips. Figure 1 a) shows the test piece. The die in Figure 2 b) is recommended fo
32、r as-sintered test pieces. The test piece is gripped on the raised serrations compacted on its gripping ends, to prevent slippage during testing. It is important for testing that the grips fit properly into the clevis. Alternatively, the test piece is compacted without serrations and gripped on the
33、flat faces. Test pieces made from the dies in Figure 1 b) or 2 b) are recommended for materials to be tested in the as-sintered condition. When testing relatively brittle, heat-treated materials, the constraint of the test pieces sharp corners can result in tensile values that are lower than those o
34、btained with machined tensile test pieces (see Figure 5). 5 Metal injection-moulded test pieces Figure 3 shows a larger diameter of the die cavity for Metal Injection Moulding (MIM) tensile test pieces of type A. Figure 4 shows a smaller die cavity for MIM tensile test pieces of type B. During testi
35、ng, the through-holes are intended to surround hardened steel pins. The pins are gripped in a clevis, and mounted on a testing machine in a self-aligning manner. The holes may optionally be drilled after sintering, rather than moulded with no draft permitted. These optional hole diameters should be:
36、 a diameter of 0,2506,5 mm+mm for a large bar or a diameter of 0,2504,77 mm+mm for a small bar, after sintering. The die dimensions assume about 17 % shrinkage during sintering, but variations in shrinkage are permitted. Either bar design may be used. Gauge marks may be scribed as noted in 4.1. The
37、gate, manufacturers identification and ejector location are optional, but shall not be in the gauge length Lcand not in the gripping area. 6 Machined test pieces 6.1 Figure 5 shows the dimensions of a machined button-head tensile test piece. This is conveniently machined from a standard 10 mm 10 mm
38、75 mm impact bar. The taper of 0,1 mm in the nominal diameters, over the gauge length, generally results in fracture occurring within the gauge region, even for relatively brittle materials. If a material is to be carburized after grinding, the surface pores in the gauge region shall be left open to
39、 allow carburizing gases to enter. Final polishing shall be in the longitudinal direction (no circumferential scratch lines shall be visible). BS EN ISO 2740:2009ISO 2740:2009(E) ISO 2009 All rights reserved 3The test piece is gripped by a split collet, closely surrounding the 20 tapered region. Dur
40、ing testing, the test piece is supported on the same taper. The test piece may have a 25 mm gauge length lightly scribed as in 4.1. This test piece is primarily recommended for testing materials in the heat-treated condition, where elongations at fracture may be 20 %, regardless of whether the test
41、piece is as-sintered or heat-treated. Some work-hardening occurs during machining, and if the test piece is tested in the sintered and machined condition, the work-hardening can lower elongation and raise yield strength. This is particularly true for stainless steels. During austenitizing and oil qu
42、enching, the usual sintered alloy steels may not fully harden to the centre of the machined test pieces. Such test pieces may be further qualified in the report, by indicating the hardness from the surface to the core. 6.2 Other cylindrical machined test pieces are possible and should conform to ISO
43、 6892. When the diameter of the useful part of the test pieces is less than 4 mm, its value shall be stated together with the fact that the results of the test may not be comparable with those obtained from test pieces of larger diameters. For sintered products, it is recommended that a test piece h
44、aving two shoulders at each end be used. The radius of the inner shoulder shall be between 1,5 mm and 2,5 mm (see Figure 5). 7 Identification of test pieces For the identification of test pieces, the following shall be stated: a) a reference to this International Standard, i.e. ISO 2740; b) type of
45、material; c) density of test piece; d) dimensions of test piece (thickness); e) when pressed and sintered test pieces are made according to 4.1, the nature of any finishing treatment and also, preferably, the material and the surface finish of the compacting tool; f) form of test piece, i.e. figure
46、number of this International Standard; g) die material, i.e. tool steel or hardmetal/carbide; h) whether as-sintered or heat-treated; i) hardness of test piece according to the heat treatment. BS EN ISO 2740:2009ISO 2740:2009(E) 4 ISO 2009 All rights reservedDimensions in millimetres a) Test piece b
47、) Die for compacting test pieces Figure 1 Test piece and die for tensile testing Smooth grips BS EN ISO 2740:2009ISO 2740:2009(E) ISO 2009 All rights reserved 5Dimensions in millimetres a) Test piece b) Die for compacting test pieces Figure 2 Test piece and die for tensile testing Serrated grips BS
48、EN ISO 2740:2009ISO 2740:2009(E) 6 ISO 2009 All rights reservedDimensions in millimetres aApplies to gauge length Lc. b c LcLdLtw R1R2D Type 0,1 0,1 0,2 0,2 0,5 0,1 0,5 0,5 0,1 A1 5,82 5,87 30,5 31,75 94 5,85 R 25 R 38 7,85 A2 3,8 3,85 30,5 27,5 85,5 3,85 R 23 R 23 6 Figure 3 Die cavity for MIM tens
49、ile test pieces of type A Dimensions in millimetres Key 1 mould-division plane Figure 4 Die cavity for MIM tensile test pieces of type B BS EN ISO 2740:2009ISO 2740:2009(E) ISO 2009 All rights reserved 7Dimensions in millimetres Key 1 alternative end aCentering holes are acceptable. Figure 5 Machined tensile test piece BS EN ISO2740:2009BSI GroupHeadquarters 389Chiswick High Road,London, W4 4AL, UKTel +44 (0)20 8996 9001Fax +44 (0)20 8996
