BS EN ISO 12004-1-2008 Metallic materials - Sheet and strip - Determination of forminglimit ncurves - Part 1 Measurement and application of forminglimit ndiagrams in the press shop.pdf

1、BS EN ISO12004-1:2008ICS 77.040.10,NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDMetallic materials Sheet and strip Determination offorming-limit curvesPart 1: Measurement and applicationof forming-limit diagrams in the pressshop (ISO 12004-1:2008)This British

2、 Standardwas published underthe authority of theStandards Policy andStrategy Committee on 30November 2008 BSI 2008ISBN 978 0 580 57021 6Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 12004-1:2008National forewordThis British Standard is the UK implementation of EN ISO12004-1:20

3、08.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/NFE/4/2, Ductility testing.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

4、 are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 12004-1October 2008ICS 77.040.10English VersionMetallic materials - Sheet and strip - Determination of forming-limit curv

5、es - Part 1: Measurement and application of forming-limit diagrams in the press shop (ISO 12004-1:2008)Matriaux mtalliques - Tles et bandes - Dterminationdes courbes limites de formage - Partie 1: Mesurage etapplication des diagrammes limites de formage dans lesateliers demboutissage (ISO 12004-1:20

6、08)Metallische Werkstoffe - Bleche und Bnder - Bestimmungder Grenzformnderungskurve - Teil 1: Messung undAnwendung von Grenzformnderungsdiagrammen inStanzereien (ISO 12004-1:2008)This European Standard was approved by CEN on 12 October 2008.CEN members are bound to comply with the CEN/CENELEC Intern

7、al Regulations 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.

8、This European 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

9、the national 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, Switzerlan

10、d and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 12

11、004-1:2008: EBS EN ISO 12004-1:2008EN ISO 12004-1:2008 (E) 3 Foreword This document (EN ISO 12004-1:2008) has been prepared by Technical Committee ISO/TC 164 “Mechanical testing of metals“ in collaboration with Technical Committee ECISS/TC 1 “Steel - Mechanical testing” the secretariat of which is h

12、eld 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 April 2009, and conflicting national standards shall be withdrawn at the latest by April 2009. Attention is drawn to the possibility t

13、hat some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound

14、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, Swit

15、zerland and the United Kingdom. Endorsement notice The text of ISO 12004-1:2008 has been approved by CEN as a EN ISO 12004-1:2008 without any modification. BS EN ISO 12004-1:2008ISO 12004-1:2008(E) ISO 2008 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Symbols and abb

16、reviated terms . 1 3 Principle. 1 4 Test conditions . 2 5 Procedure 2 6 Interpretation of results 3 7 Test report . 3 Annex A (informative) Modification to forming-limit curves 5 Annex B (informative) Examples of grid patterns currently in use. 6 Bibliography . 8 BS EN ISO 12004-1:2008ISO 12004-1:20

17、08(E) iv ISO 2008 All rights reservedForeword ISO (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

18、interested in a subject for which a technical committee 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 Electrotech

19、nical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the 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 t

20、he technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by 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 right

21、s. ISO shall not be held responsible for identifying any or all such patent rights. ISO 12004-4 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 2, Ductility testing. This first edition of ISO 12004-1, together with ISO 12004-2, cancels and replaces ISO 1

22、2004:1997 which has been technically revised. ISO 12004 consists of the following parts, under the general title Metallic materials Sheet and strip Determination of forming-limit curves: Part 1: Measurement and application of forming-limit diagrams in the press shop Part 2: Determination of forming-

23、limit curves in the laboratory BS EN ISO 12004-1:2008ISO 12004-1:2008(E) ISO 2008 All rights reserved vIntroduction A forming-limit diagram (FLD) is a diagram containing measured major/minor strain points on a formed part. An FLD can distinguish between safe and necked, or failed, points. The transi

24、tion from safe to failed points is defined by the forming-limit curve (FLC). To determine the forming limit of materials, two different methods are possible. 1) Strain analysis of failed press shop components to determine component and process dependent FLCs: In the press shop, strain paths to reach

25、 these points are generally not known. Such an FLC depends on the material, the component and the chosen forming conditions. This method is described in this part of ISO 12004. 2) Determination of FLCs under well-defined laboratory conditions: For evaluating formability, one unique FLC for the defin

26、ed material is necessary. The determination of FLC has to be specific and it is necessary to use different linear strain paths. This method should be used for material characterization as described in ISO 12004-2. BS EN ISO 12004-1:2008BS EN ISO 12004-1:2008INTERNATIONAL STANDARD ISO 12004-1:2008(E)

27、 ISO 2008 All rights reserved 1Metallic materials Sheet and strip Determination of forming-limit curves Part 1: Measurement and application of forming-limit diagrams in the press shop 1 Scope This part of ISO 12004 provides guidelines for developing forming-limit diagrams and forming-limit curves fo

28、r metal sheets and strips of thicknesses from 0,3 mm to 4 mm. 2 Symbols and abbreviated terms The symbols used in forming-limit diagrams are specified in Table 1, and examples of grid patterns used are given in Annex B. Table 1 Symbols and definitions Symbol Definition Unit tol0l1l2e e1e2FLD FLC Thi

29、ckness of test piece Original gauge length of grid pattern Final length in major strain direction Final length at 90 to major strain direction Engineering strain Major engineering strain Minor engineering strain (90 to major) Forming-limit diagram Forming-limit curve mm mm mm mm % % % 3 Principle A

30、pattern of precise gauge lengths of appropriate size is applied to the flat surface of a metal sheet test piece, then the test piece is formed until fracture, and the percent change in the gauge length in the major direction and in the minor strain direction at 90 to this is measured in order to det

31、ermine the forming-limit under the imposed strain conditions. A number of repeated tests under varying strain conditions are carried out to provide data for the forming-limit curve (FLC) for the material when these limiting strains are plotted on the forming-limit diagram (FLD) (see Figure 1). BS EN

32、 ISO 12004-1:2008ISO 12004-1:2008(E) 2 ISO 2008 All rights reserved4 Test conditions 4.1 Gauge lengths in the range of 1,5 mm to 5,0 mm are recommended. The actual gauge lengths shall be known to within 2 %. 4.2 During the forming of test pieces, the strain in the critical area shall be uniform befo

33、re onset of necking. 4.3 In order to achieve this, any set of tooling employing a holding force and a deformation force may be used to develop the limiting strain condition. 4.4 The forming-limit curve shall be plotted on the forming-limit diagram. Figure 1 shows an example of a forming-limit curve.

34、 Key X minor strain, in percent Y major strain, in percent Figure 1 Typical forming-limit curve 5 Procedure 5.1 The recommended procedure for the determination of the forming limit is as follows. 5.1.1 Take a representative sample of the material to be evaluated. BS EN ISO 12004-1:2008ISO 12004-1:20

35、08(E) ISO 2008 All rights reserved 35.1.2 Apply a suitable grid pattern, that has been checked for accuracy of the initial gauge lengths, to the surface of a test piece in areas of the part to be formed which are known, or have been established by investigation, to be critical. 5.1.3 Any test device

36、 that satisfies Clause 4 may be used to form the test piece, such as a universal tensile testing machine, a stamping press, a cupping press, a hydraulic bulge machine and their combinations or any other equipment capable of clamping the test piece and applying a plastic deformation force in an area

37、remote from the edge. A universal testing machine may be employed and forming limits established using a tensile test. 5.1.4 Test pieces shall be tested while clamped around the whole of their periphery, or shall be cut into strips of varying widths to give a range of strain conditions. The surface

38、between the punch and the specimen shall be suitably lubricated using a standard product for the operation. A combination of polyethylene sheet and lubricant can be used. 5.1.5 Stop the test at the first occurrence of fracture. 5.1.6 Determine the strains e1and e2as follows. 5.1.7 Measure three adja

39、cent gauge lengths in the direction of e1that were originally in a straight line. Repeat until the three values obtained are the same to within 10 %. Record the average of these three values as l1. NOTE A more accurate method may be prescribed as mentioned in ISO 12004-2. 5.1.8 If it is not possible

40、 to obtain three values within 10 %, form a new test piece and repeat the measurements. 5.1.9 Select one of the gauge lengths measured in 5.1.7 and measure the gauge length at 90 to the original e1direction, and report this as l2. 5.2 Calculate the percent strains e1and e2as follows: 1010100llel= (1

41、) 2020100llel= (2) 5.3 Make measurements on a sufficient number of test pieces to plot a forming-limit curve. 6 Interpretation of results 6.1 Plot e1against e2on a forming-limit diagram. As shown in Figure 1, the major strain e1is plotted along the Y-axis and the minor strain e2is plotted along the

42、X-axis. 6.2 Draw the forming-limit curve through the points of maximum e1strain (see Figure 1). 6.3 The effect of a forming operation on a particular part may be estimated from the diagram by measuring the strains in critical areas and comparing the results with the curve for the material used. 7 Te

43、st report 7.1 The test report shall include the following information: a) a reference to this part of ISO 12004; BS EN ISO 12004-1:2008ISO 12004-1:2008(E) 4 ISO 2008 All rights reservedb) the identification of the test piece; c) the thickness of the test piece; d) the forming-limit curve (FLC) plott

44、ed on the forming-limit diagram (FLD) (as shown in Figure 1); e) the gauge length of the grid pattern used; f) lubrication conditions. 7.2 The test report may also include the following information: a) selected mechanical properties of the material tested; b) the chemical composition (percentage con

45、tent of major elements) of the material tested; c) a description of the procedure used; d) the type of grid pattern used; e) details of any deviation from the procedure specified (see, in particular, Annex A). BS EN ISO 12004-1:2008ISO 12004-1:2008(E) ISO 2008 All rights reserved 5Annex A (informati

46、ve) Modification to forming-limit curves To accommodate the variations experienced in the production of a given commercial product and to allow corrections to be made for known differences, such as the different behaviour of similar materials of different thicknesses when formed using the same tooli

47、ng, or different strain-hardening characteristics, modifications have been proposed to the forming-limit curve. These modifications displace the curve upwards for thicker materials and for materials with a higher strain hardening exponent (n-value) (see ISO 10275). Such modifications to FLCs have no

48、t been established as viable corrections and, if employed, shall be specifically noted in the test report. Figure 1 shows an example of an FLC. Deformed areas in a formed part which have strains lying above or close below, the FLC are likely to fail and should be examined to reduce strain, or a mate

49、rial with a higher FLC should be used. BS EN ISO 12004-1:2008ISO 12004-1:2008(E) 6 ISO 2008 All rights reservedAnnex B (informative) Examples of grid patterns currently in use Figure B.1 Examples of various types of circular grid patterns Figure B.2 Example of a circular grid pattern Figure B.3 Example of a circular grid pattern BS EN ISO 12004-1:2008ISO 12004-1:2008(E) ISO 2008 All rights reserved 7Figure B.4 Example of a circular grid pattern in squares Figure B.5 Example of a square gri