1、October 2009DEUTSCHE NORM English price group 8No part of this standard 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 77.040.10; 77.160!$ZB3“
2、1553116www.din.deDDIN EN ISO 2740Sintered metal materials, excluding hardmetals Tensile test pieces (ISO 2740:2009)English version of DIN EN ISO 2740:2009-10Sintermetalle, ausgenommen Hartmetalle Zugprobestbe (ISO 2740:2009)Englische Fassung DIN EN ISO 2740:2009-10SupersedesDIN EN ISO 2740:2007-06ww
3、w.beuth.deDocument comprises 12 pagesDIN EN ISO 2740:2009-10 2 National foreword This standard has been prepared by Technical Committee ISO/TC 119 “Powder metallurgy” (Secretariat: SIS, Sweden) in collaboration with Technical Committee CEN/SS M11 “Powder metallurgy” (Secretariat: CMC). The responsib
4、le German body involved in its preparation was the Normenausschuss Werkstofftechnologie (Technology of Materials Standards Committee), Technical Committee NA 145-01-03 AA Probenahme und Prfverfahren fr Sintermetalle (ausgenommen Hartmetalle). The DIN Standards corresponding to the International Stan
5、dards referred to in clause 2 of this document are as follows: ISO 6892 DIN EN 10002-1 ISO 7500-1 DIN EN ISO 7500-1 Amendments This standard differs from DIN EN ISO 2740:2007-06 as follows: a) Figure 2a has been modified. b) The standard has been editorially revised. Previous editions DIN ISO 2740:
6、1991-05 DIN EN ISO 2740: 2001-04, 2007-06 National Annex NA (informative) Bibliography DIN EN 10002-1, Metallic materials Tensile testing Part 1: Method of testing at ambient temperature DIN EN ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compressio
7、n testing machines Verification and calibration of the force-measuring system 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 2740:2009)Matriaux
8、 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 Regulations which
9、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 European Standar
10、d 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 national standard
11、s 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 United Kingdom.
12、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: EEN ISO 2740:2
13、009 (E) 2 Contents Page Foreword .3 1 Scope4 2 Normative references4 3 Method of testing.4 4 Manufacture of test pieces .4 5 Metal injection-moulded test pieces5 6 Machined test pieces 5 7 Identification of test pieces 6 DIN EN ISO 2740:2009-10 EN ISO 2740:2009 (E) 3 Foreword This document (EN ISO 2
14、740:2009) 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 be given the status of a national standard, either by publication of an ide
15、ntical 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 document may be the subject of patent rights. CEN and/or CENELEC shall not be h
16、eld 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 bound to implement this European Standard: Austria, Belgium, Bulgaria, Cypr
17、us, 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 the United Kingdom. Endorsement notice The text of ISO 27
18、40:2009 has been approved by CEN as a EN ISO 2740:2009 without any modification. DIN EN ISO 2740:2009-10 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
19、 test 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
20、 dated 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 mach
21、ines 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 b
22、e reported 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
23、 have 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 mor
24、e than 0,04 mm. The gauge length shall be scribed in such a way that the tensile properties are not affected. EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 4Because of the possibility of creating microlaminations in the corners of test pieces compacted under laboratory conditions, representative sint
25、ered 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 surface finish shall
26、 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 tooling to be used for
27、 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-punch hold-down d
28、uring 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 for as-sintered tes
29、t 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 flat faces. Test
30、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 obtained with mach
31、ined 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 testing, the through-h
32、oles 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: a diameter of 0,
33、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 gate, manufacture
34、rs 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 75 mm impact bar.
35、 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 allow carburizin
36、g gases to enter. Final polishing shall be in the longitudinal direction (no circumferential scratch lines shall be visible). EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 5The test piece is gripped by a split collet, closely surrounding the 20 tapered region. During testing, the test piece is suppor
37、ted 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 piece is as-sintered or heat-treated.
38、 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 quenching, the usual sintered alloy ste
39、els 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 6892. When the diameter of the usefu
40、l 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 having two shoulders at each end be us
41、ed. 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 material; c) density of test piece; d
42、) 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 number of this International Standard
43、; 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. EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 6Dimensions in millimetres a) Test piece b) Die for compacting test pieces Figure 1 Test piece and
44、die for tensile testing Smooth grips EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 7Dimensions in millimetres a) Test piece b) Die for compacting test pieces Figure 2 Test piece and die for tensile testing Serrated grips EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 8Dimensions in millimetres aApplies
45、 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 tensile 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 EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 9Dimensions in millimetres Key 1 alternative end aCentering holes are acceptable. Figure 5 Machined tensile test piece EN ISO 2740:2009 (E) DIN EN ISO 2740:2009-10 10
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