1、 STD-BSI BS EN IS0 7777-ENGL 2000 H 1624669 0835113 O13 E BRITISH STANDARD Metallic materials - Sheet and strip 3 mm thick or less - Reverse bend test The European Standard EN IS0 7799:2 has the status of a British Standard ICs 77.040.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMi“I3D BY COPYR
2、IGHT LAW 3s EN IS0 7799:2000 STDmBSI BS EN IS0 7799-ENGL 2000 = Lb24bbq 0635134 TST D BS EN IS0 77992000 been prepared under the direction of the Engineering Sector Commiuee, was published under the authority of the Standards Committee and comes into effect on 15 March 2000 Amd. No. O BSI 03-2000 IS
3、BN O 580 35870 4 National foreword Date Comments This British Standard is the English iangUage version of EN IS0 77W2. It is identical with IS0 7799 1985. The UK participation in its preparation was entrusted by Technical Committee ISE/NFE/4, Mechanical testing of metals, to Subcommittee ISE/NFE/4/2
4、, Ductility testing, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible intemationaYEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed - monitor related international and European deve
5、lopments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references Attention is dram to the fact that CEN and CENELEC Standards normally include an annex which lists nonnative references to internationai publ
6、ications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entited “International Standards Correspondence Index”, or by using the “Find” facility of the BSI
7、 Standards Electronic Catalogue. A British Standard does not purport to include ali the necessary provisions of a contract. Users of British Standarcis are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary
8、 of pages This document comprises a front cover, an inside front cover, the EN IS0 title page, the EN IS0 foreword page, the IS0 title page, the IS0 foreword page, pages 1 to 3 and a back cover. The BSI copynght notice displayed in this document indicates when the document was last issued. EUROPEAN
9、STANDARD NORME EUROPENNE EUROPISCHE NORM EN IS0 7799 January 2000 ICs 77.040.00 English version Metallic materials - Sheet and strip 3 mm thick or less - Reverse bend test (IS0 77993 985) MaiMaux mtalliques - Tle8 et feuillards dpaisseur infrieure ou gale 3 mm - Essai de pliage altem8 (IS0 Metallisc
10、he Werkstoffe - Bleche und Bnder mil einer Dicke unter 3 mm - Hin- und Herbiegeversuch (Is0 f799:1985) 7?99:1685) This European Sandard was approved by GEN on 12 November 1899. CEN members are bound to comply with lhe CENICENELEC Intemal Regulations which stipulate the conditions for ghg this Europe
11、an Standard he status of a national standard Wiaioul any aiteration. Up-to-date lists and bibliographical references concerning such national This European Standard exists in three official versions (English, French, Gem). A venion in any mr language made by handation under aie responsibiliy of a CE
12、N member into its own language and natified to the Central Secretarial has the same status as the offidal versions. may be obtained on application to the Central Secretariat or to any CEN member. CEN members are be national sandeirds bodies of Austria, Belgium. Czech Repubiic, Denmark. Finland, Fran
13、ce, Germany, Greece, Iceland, Ireland, itaiy, Luxembourg, Netherlands, Norway, Poriugai, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMiTEE FOR STANDARDIZATION COMITE EUROPEEN DE NORMALISATION EUROPISCHES KOMITEE FUR NORMUNG Q 2000 CEN All rights of exploitation in any form and by any
14、means resewed worldwide for CEN national Members. Ref. No. EN IS0 T7992CI E Foreword The text of the Intemational Standard from Technical Committee ISOiC 164 “Mechanical testing of metals“ of the Intemational Organization for Standardization (ISO) has been taken over as an European Standard by Techn
15、ical Committee ECISSTTC 1 “Steel - Mechanical testing“, the secretariat of which is held by AFNOR. 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 July 2000, and conflicting national standards sha
16、ll be withdrawn at the latest by July 2000. According to the CEWCENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland,
17、Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the Intemational Standard IS0 799:1985 has been approved by CEN as a European Standard without any modification. STDmBSI BS EN IS0 7799-ENGL 2000 W Lb24bb9 OB35117 7b9
18、EN IS0 7799:2000 International Standard 7799 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION*MEYHAPOHAR OPrAHHJAUHR il0 CTAHAAFTH3AUHH.ORGANISATION INTERNATIONALE DE NORMALISATION Metallic materials - Sheet and strip 3 mm thick or less - Reverse bend test Matriaux mtalliques - Tles et feuillards dpai
19、sseur infrieure ou gale i# 3 rnm - Essai de pliage altern First edition - 1985-10-01 UDC 669-415 : 620.177.6 Ref. No. ISO7799-1985 (E) Descriptors : metals, sheet metal. strips. tests, mechanical tests, reverse bend tests, test equipment. Price based on 3 pages STD-BSI BS EN IS0 7777-ENGL 2000 lh24h
20、b O3SlL bT5 m EN IS0 7799:2000 Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body intere
21、sted in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committe
22、es are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 T799 was prepared by Technical Commi
23、ttee ISOITC 164, Mechanical testing of metals. It cancels and replaces IS0 Recommendation R 88-1959, of which it constitutes a technical revision. Metallic materials - Sheet and strip 3 mm thick or less - Reverse bend test Symbol Designation u Thickness of test piece r Radius of cylindrical supports
24、 h y Distance from top tangential plane of cylindrical supports to the bottom face of guide Distance from a plane defined by the axes of cylindrical supports and the nearest point of contact with the test piece Nb Number of reverse bends 1 Scope and field of application Unit mm rnm mm rnrn - This In
25、ternational Standard specifies the method for determin- ing the ability of sheet and strip from metallic materials 3 mm thick or less to undergo plastic deformation in reverse bending. This method can be applied to aluminium and its alloys only after previous agreement. 2 Principle The reverse bend
26、test consists of repeated bending through Wo, in opposite directions, of a rectangular test piece held at one end, each bend being over a cylindrical support of specified radius. 3 Symbols and designations Symbols and designations used in the reverse bend test are shown in figure 1 and specified in
27、table 1. Table 1 4 Testing equipment 4.1 General The testing machine shall be constructed so as to conform with the principles indicated in figure 1. Operating handle Pivoting axis of the bending Cylindrical supports A Grips with test piece Gripping faces arm and B Figure 1 1 STD.BSI BS EN IS0 7799-
28、ENGL ZOOU 1ib24bb9 0835120 253 = EN IS0 7799:ZOOO 4.2 Cylindrical supports and grips 4.2.1 The cylindrical supports and the grips shall be of suffi- cient hardness (to provide rigidity and/or resistance to abra- I sion t. 4.2.2 The radius r of the cylindrical supports shall be as specified in the re
29、levant International Standards. If not specified, the radius given in table 2 shall be used. Table 2 Values in millimetres Thickness of specimen Radius of cylindrical support U r u 2.5 mm, y = 3 mm.) 4.2.6 The distance h from the bottom of the guide to the top of the cylindrical supports shall be be
30、tween 25 and 50 mm. 4.3 Bending arm The distance of the pivoting axis of the bending arm from the top of the cylindrical supports shall be 1,0 mm for all sizes of supports. 5 lest piece 5.1 The thickness of the test piece shall be that of the sheet or strip from which the sample is taken, the surfac
31、es remaining intact. 5.2 The width of the machined test piece shall be between 20 and 25 mm. Strip material of a smaller width may be tested in the full width. 5.3 The test piece shall be prepared so that the effect of heating and mechanical strengthening is minimized. The sur- faces shall be free o
32、f cracks and marks, and the edges shall be free of burrs. 6 Procedure 6.1 In general, the test is carried out at ambient temperature between 10 and 35 OC. Tests carried out under controlled con- ditions shall be made at a temperature of 23 I 5 OC. 6.2 Clamp the lower end of the test piece between th
33、e grips in a position as shown in figure 1 with the upper end protruding through the guide slot. Then bend the test piece through 90 alterrltely in opposite directions. One bend consists of bending the free end of the test piece through Wo and return- ing it to its original position. Make the follow
34、ing bend in the op- posite direction as shown in figure 2. Do not interrupt the testing between successive bends. Figure 2 6.3 Bend at a uniform rate without shock and not exceeding one bend per second. If necessary, reduce the rate of bending to ensure that heat generated does not affect the result
35、 of the test. 6.4 To ensure continuous contact between the test piece and the blocks during the test, some form of constraint may be ap- plied. This may be in the form of a tensile stress not greater than 2 % of the value of the nominal tensile strength, unless otherwise specified in the rdevant sta
36、ndard. 6.5 Continue the test until the number of bends specified in the relevant standard is completed, or cracking visible without the use of magnifying aids is seen to occur. Alternatively, if specified in the relevant standard, continue the test until complete fracture of the test piece occurs. 6
37、.6 not be counted into the number of bends Nb. The bend during which failure of test piece occurs shall 2 STD-BSI BS EN IS0 7799-ENGL 2000 W lb2qbb9 OB35121 19T m EN IS0 7799:2000 7 Test report c) dimensions of the test piece; The test report shall include the following information : d) test conditi
38、ons (radius r of cylindrical supports, distance h, application of tensile stress if the case) ; e) fl results of the test. a) reference to this International Standard; b) data identih/ing the test piece (direction of the test piece axis relative to the product) : criterion for ending the test; 3 STD
39、-ES1 BS EN IS0 7799-ENGL 2000 lb24bb9 0835322 O26 = BS EN IS0 7799:2000 BSI 389 Chiswick High Road London w4 4AL BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the intemationa
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