1、February 2009DEUTSCHE NORM English price group 9No 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 25.120.10; 77.040.10!$
2、UkU“1507250www.din.deDDIN EN ISO 12004-1Metallic materials Sheet and strip Determination of forming-limit curves Part 1: Measurement andapplication of forming-limit diagrams in the press shop(ISO 12004-1:2008)English version of DIN EN ISO 12004-1:2009-02Metallische Werkstoffe Bleche und Bnder Bestim
3、mung der Grenzformnderungskurve Teil 1: Messung und Anwendung vonGrenzformnderungsdiagrammen in Stanzereien (ISO 12004-1:2008)Englische Fassung DIN EN ISO 12004-1:2009-02www.beuth.deDocument comprises 14 pagesDIN EN ISO 12004-1:2009-02 2 National foreword This standard has been prepared by Technical
4、 Committee ISO/TC 164 “Mechanical testing of metals”, Subcommittee SC 2 “Ductility testing” (Secretariat: JISC, Japan) in collaboration with Technical Committee The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Tec
5、hnical Committee NA 062-01-42 AA Zug- und Duktilittsprfung fr Metalle. ECISS/TC 1 “Steel Mechanical testing” (Secretariat: AFNOR, France). EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 12004-1October 2008ICS 77.040.10English VersionMetallic materials - Sheet and strip - Determination of form
6、ing-limit curves - 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 (
7、ISO 12004-1:2008)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/
8、CENELEC Internal 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 a
9、ny CEN member.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.CE
10、N members are 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, Swed
11、en, Switzerland 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.
12、 No. EN ISO 12004-1:2008: EContents 2 DIN EN ISO 12004-1:2009-02 EN ISO 12004-1:2008 (E) Page Foreword .3 Introduction.4 1 Scope5 2 Symbols and abbreviated terms 5 3 Principle .5 4 Test conditions 6 5 Procedure.6 6 Interpretation of results 7 7 Test report7 Annex A (informative) Modification to form
13、ing-limit curves 9 Annex B (informative) Examples of grid patterns currently in use10 Bibliography12 Foreword 3 EN ISO 12004-1:2008 (E) DIN EN ISO 12004-1:2009-02 secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of
14、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 that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be h
15、eld 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 to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finla
16、nd, 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 12004-1:2008 has been approved by CEN as a EN
17、 ISO 12004-1:2008 without any modification. testing of metals” in collaboration with Technical Committee ECISS/TC 1 “Steel - Mechanical testing” the This document (EN ISO 12004-1:2008) has been prepared by Technical Committee ISO/TC 164 “Mechanical Introduction A forming-limit diagram (FLD) is a dia
18、gram containing measured major/minor strain points on a formed part. An FLD can distinguish between safe and necked, or failed, points. The transition from safe to failed points is defined by the forming-limit curve (FLC). To determine the forming limit of materials, two different methods are possib
19、le. 1) Strain analysis of failed press shop components to determine component and process dependent FLCs: In the press shop, strain paths to reach 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 t
20、his part of ISO 12004. 2) Determination of FLCs under well-defined laboratory conditions: For evaluating formability, one unique FLC for the defined 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
21、 for material characterization as described in ISO 12004-2. 4 DIN EN ISO 12004-1:2009-02 EN ISO 12004-1:2008 (E) 1 Scope This part of ISO 12004 provides guidelines for developing forming-limit diagrams and forming-limit curves for metal sheets and strips of thicknesses from 0,3 mm to 4 mm. 2 Symbols
22、 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 Thickness of test piece Original gauge length of grid pattern Final length
23、 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 pattern of precise gauge lengths of appropriate size is applied to the
24、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 determine the forming-limit under the imposed strain conditions. A number
25、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). 5 EN ISO 12004-1:2008 (E) DIN EN ISO 12004-1:2009-02 4 Test conditions 4.1 G
26、auge 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 before onset of necking. 4.3 In order to achieve this, any set of tooling employing a holding
27、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. Key X minor strain, in percent Y major strain, in percent Figure 1 Typical forming-limit
28、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. 6 DIN EN ISO 12004-1:2009-02 EN ISO 12004-1:2008 (E) 5.1.2 Apply a suitable grid pattern, that has been checked for accuracy o
29、f 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 that satisfies Clause 4 may be used to form the test piece, such as a universal tensile testing machine, a s
30、tamping 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 remote from the edge. A universal testing machine may be employed and forming limits established using a tens
31、ile 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 between the punch and the specimen shall be suitably lubricated using a standard product for the operation. A
32、 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 adjacent gauge lengths in the direction of e1that were originally in a straight line. Repeat until the three valu
33、es 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 to obtain three values within 10 %, form a new test piece and repeat the measurements. 5.1.9 Select one of t
34、he 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) 2020100llel= (2) 5.3 Make measurements on a sufficient number of test pieces to plot a forming-limit curve.
35、 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 X-axis. 6.2 Draw the forming-limit curve through the points of maximum e1strain (see Figure 1). 6.3 The effec
36、t 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 Test report 7.1 The test report shall include the following information: a) a reference to this part of ISO 120
37、04; 7 EN ISO 12004-1:2008 (E) DIN EN ISO 12004-1:2009-02 b) the identification of the test piece; c) the thickness of the test piece; d) the forming-limit curve (FLC) plotted on the forming-limit diagram (FLD) (as shown in Figure 1); e) the gauge length of the grid pattern used; f) lubrication condi
38、tions. 7.2 The test report may also include the following information: a) selected mechanical properties of the material tested; b) the chemical composition (percentage content of major elements) of the material tested; c) a description of the procedure used; d) the type of grid pattern used; e) det
39、ails of any deviation from the procedure specified (see, in particular, Annex A). 8 DIN EN ISO 12004-1:2009-02 EN ISO 12004-1:2008 (E) Annex A (informative) Modification to forming-limit curves To accommodate the variations experienced in the production of a given commercial product and to allow cor
40、rections to be made for known differences, such as the different behaviour of similar materials of different thicknesses when formed using the same tooling, or different strain-hardening characteristics, modifications have been proposed to the forming-limit curve. These modifications displace the cu
41、rve upwards for thicker materials and for materials with a higher strain hardening exponent (n-value) (see ISO 10275). Such modifications to FLCs have not been established as viable corrections and, if employed, shall be specifically noted in the test report. Figure 1 shows an example of an FLC. Def
42、ormed 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 material with a higher FLC should be used. 9 EN ISO 12004-1:2008 (E) DIN EN ISO 12004-1:2009-02 Annex B (informative) Examples of grid patterns current
43、ly 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 10 DIN EN ISO 12004-1:2009-02 EN ISO 12004-1:2008 (E) Figure B.4 Example of a circular grid pattern in squares Figure B.5 Example of a square grid pattern 11 EN ISO 12004-1:2008 (E) DIN EN ISO 12004-1:2009-02 Bibliography 1 ISO 10275, Metallic materials Sheet and strip Determination of tensile strain hardening exponent 12 DIN EN ISO 12004-1:2009-02 EN ISO 12004-1:2008 (E)
