DEUTSCHE NORM DIN EN ISO 10447 September 2007 D ICS 25.160.40 Supersedes DIN ISO 10447:1994-11 Resistance welding Peel and chisel testing of resistance spot and projection welds (ISO 10447:2006) English version of DIN EN ISO 10447:2007-09 Widerstandsschweißen Schäl-, Meißel- und Keilprüfung von Widerstandspunkt- und Buckelschweißverbindungen (ISO 10447:2006) Englische Fassung DIN EN ISO 10447:2007-09 No part of this standard may be reproduced without prior permission of DIN Deutsches Institut für Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, has the exclusive right of sale for German Standards (DIN-Normen). Document comprises 13 pages English price group 9 www.din.de www.beuth.de!$i3w" 11.07 1381652
DIN EN ISO 10447:2007-09 National foreword This standard has been prepared by the International Institute of Welding (IIW). The responsible German body involved in its preparation was the Normenausschuss Schweißtechnik (Welding Standards Committee), Joint Committee NA 092-00-12 AA Widerstandsschweißen (DVS AG V 3). The non-destructive chisel test cannot be used on very rigid joints (between thick plates or sheets, or between high-strength materials), where there is a high occurrence of partial plug failure and interface failure, because the welded joints are liable to be damaged. The DIN Standards corresponding to the International Standards referred to in the EN are as follows: ISO 14270 DIN EN ISO 14270 ISO 14329 DIN EN ISO 14329 Amendments This standard differs from DIN ISO 10447:1994-11 as follows: a) The previous edition of this standard also covered seam welds. The preferred test for this type of weld, the mechanized peel test, is now dealt with in DIN EN ISO 14270. Previous editions DIN ISO 10447: 1994-11 2 National Annex NA (informative) Bibliography DIN EN ISO 14270, Specimen dimensions and procedure for mechanized peel testing resistance spot, seam and embossed projection welds DIN EN ISO 14329, Resistance welding Destructive tests of welds Failure types and geometric measurements for resistance spot, seam and projection welds
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 10447 June 2007 ICS 25.160.40 English Version Resistance welding - Peel and chisel testing of resistance spot and projection welds (ISO 10447:2006) Soudage par résistance - Essais de déboutonnage au burin et de pelage appliqués aux soudures par résistance par points et par bossages (ISO 10447:2006) This European Standard was approved by CEN on 19 May 2007. Widerstandsschweißen - Schäl-, Meißel- und Keilprüfung von Widerstandspunkt- und Buckelschweißverbindungen (ISO 10447:2006) CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN 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, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 2007 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. B-1050 Brussels Ref. No. EN ISO 10447:2007: E
Foreword The text of ISO 10447:2006 has been prepared by IIW, International Institute of Welding, and has been taken over as EN ISO 10447:2007 by Technical Committee CEN/TC 121 Welding the secretariat of which is held by DIN. 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 December 2007, and conflicting national standards shall be withdrawn at the latest by December 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, 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. Endorsement notice The text of ISO 10447:2006 has been approved by CEN as a EN ISO 10447:2007 without any modification. 2
1 Scope This International Standard specifies the procedure and recommended tooling to be used for testing resistance spot and projection welds by means of peel and chisel tests. It applies to welds made in two or more sheets in the thickness range of 0,5 mm to 3,0 mm. The aim of these tests is to determine: weld size and failure type when the tests are used as destructive tests, and verification of welds when the tests are used as non-destructive tests. NOTE In the previous edition of this International Standard, seam welds were included. The preferred method of peel testing seam welds (mechanized peel testing) is now covered in ISO 14270. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 14270, Specimen dimensions and procedure for mechanized peel testing resistance spot, seam and embossed projection welds ISO 14329, Resistance welding Destructive tests of welds Failure types and geometric measurements for resistance spot, seam and projection welds 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 14329 and the following apply. 3.1 chisel test destructive or non-destructive test in which welds are tested by applying a predominantly tensile force that results in stresses primarily normal to the surface of the joint interface NOTE The force is applied using a chisel (see Figure 1). 3.2 peel test destructive test in which welds are tested by applying a peel force that results in stresses primarily normal to the surface of the joint interface NOTE The test can be accomplished either manually [see Figure 2 a)], or it can be mechanized using a tensile testing machine or other suitable mechanized equipment [see Figure 2 b)]. 3
a) Type 1 (Recessed chisel) 4 Test specimens b) Type 2 (One side testing) c) Type 3 (Both side testing) Figure 1 Chisel routine test on resistance spot and protection welded joints a) Manual peel test b) Mechanized peel test Figure 2 Peel routine test on resistance spot and protection welded joints When used for quality control in production, tests shall be conducted on actual components or specimens taken from actual components. When used for setting welding parameters, where it is not practicable to use actual components, separate welded test pieces may be used. The test pieces shall be produced from the same material as used for the component, and welded under conditions adapted to simulate and produce the same weld quality as observed in the component. The effects of different shunt or impedance conditions should be taken into account when producing the test pieces, by inserting sufficient material in the throat of the machine to approximate the magnetic effect of the work piece under production conditions. 4
5 Test procedure 5.1 Chisel test A chisel shall be used to separate the sheets adjacent to the weld under test. Typical chisel designs are shown in Figures 3 and 4. The chisel geometry should be chosen based on the work piece thickness and geometry, weld diameter, distance between welds, and whether the weld is to be destructively or non-destructively tested (see Table 1). a) Chisels for weld diameter < 8 mm b) Chisels for weld diameter < 13 mm Key 1 Burr to be removed from all corners Figure 3 Typical dimensions of chisels Dimensions in millimetres 5
Dimensions in millimetres Key 1 arbitrary value 6 a) Chisel of type 2-1 (for thickness u 2 mm) b) Chisel of type 2-2 (for thickness > 2 mm) Figure 4 Examples of dimensions of chisels for non-destructive test Chisel design Table 1 Selection of recommended chisels for chisel testing Test types (Destructive or non-destructive) Weld diameter D mm For testing Plate thickness t mm Figure 3 a) Both D < 8 Figure 3 b) Both D < 13 Figure 4 a) Non destructive t u 2,0 Figure 4 b) Non destructive t > 2,0
The slot in the chisels shown in Figure 3 is only necessary if the axis of the chisel is placed at the centre of the weld. Normally, the chisel is driven between the sheets manually by a hammer or a pneumatic tool. NOTE In chisel testing, the results can be influenced by the following factors: a) chisel shape dimensions and condition, b) hammer type mass and type of blow, c) test specimen sheet thickness, d) position of the weld in relation to the sheet and its edge, e) position of the chisel relative to the weld, and f) insertion depth of chisel. Before a chisel test is implemented in production for non-destructive testing, the effectiveness of this test shall be verified with destructive tests. The chisel test for non-destructive testing should be used with considerable caution, especially when used with high strength steels. Joint design and material thickness may also influence the results. For the destructive test, a chisel shall be driven between the sheets and adjacent to the weld until fracture occurs in or adjacent to the weld, or until severe deformation occurs. The aim of this test is to separate the sheets so that a weld plug or interfacial fracture occurs to allow weld size to be determined. In the case of a weld between three or more sheets, the test shall be made between each adjacent pair of sheets. For the non-destructive test, a chisel shall be driven between the sheets and adjacent to the weld until the material yields or bends near the weld. The aim of this test is to obtain an indication that a weld has been made without causing fracture to occur in or adjacent to the weld. In the case of a weld between three or more sheets, the test shall be made between each adjacent pair of sheets. If fracture has not occurred after testing, the components shall be restored to their original shape. 5.2 Peel test The peel test is a destructive test for determining weld size and fracture mode of a welded lap joint. The sheets near the weld shall be slowly peeled apart until all welds under test are completely fractured. A roller tool, pincers, pliers, vice, or mechanized equipment (see Figures 2 and 5) are typically used. If a roller tool is used, a diameter of 30 mm is recommended for sheet thicknesses up to 1 mm [see Figure 5 a)]. For testing using a vice and pliers, see Figure 5 b). For materials that are too thick or too strong to be tested manually, mechanized equipment is recommended (see ISO 14270). The applied force may be generated by means of a normal tensile testing machine or other suitable mechanized equipment. NOTE Fracture mode and plug size can vary depending on the direction of the applied force. Peel testing may be applied to test specimens cut from production components or welded test pieces. 7
Key 1 test piece 2 vice 3 weld 4 peeling direction 5 pliers 5.3 Measurement of weld size a) Example of peel testing using a vice and a roller b) Example using vice for peel tests Figure 5 Manual peel tests A destructive chisel test or peel test allows the measurement of the weld size and assessment of the failure type. In the case of mechanized testing, it may also be possible to measure the force at failure. Mechanized peel testing shall be performed in accordance with ISO 14270. The maximum and minimum diameters of the weld (d 1 and d 2 ) shall be measured to determine the weld size [see Figures 6 and 7 b)]. 8
Key 1 interfacial fracture a d = d p = (d 1 + d 2 )/2. b d = (d 1 + d 2 )/2 and d p = (d 2 + d 3 )/2. a) Symmetrical a b) Asymmetrical a c) Partial b Figure 6 Weld with plug failure 9
Key 1 jaws or knife-edged measuring tool 2 sheared nugget 3 corona bond zone 4 nugget 5 rough fracture zone a Diameter of the corona. b Diameter of the nugget. c d 1 or d 2. NOTE 1 a) Plug failure b) Interface failure Figure 7 Measuring weld diameter Precautions should be taken when measuring weld size, particularly when asymmetrical welds are evident. In the case of plug failure, fracture may occur away from the weld in the parent metal. If possible, this excess metal should be folded back or removed. If this is not possible, then only one dimension may be measured. Use a knife-edged gauge or measuring device, as indicated in Figure 7 a), for the measurement of weld diameters with plug failure. The average diameter of the weld, d, can be calculated from d 1 and d 2 as follows: 10 Weld diameter d = (d 1 + d 2 )/2 (1)
NOTE 2 When only one dimension is measured, it is considered to be the weld diameter, d. In the case of partial plug failure, the maximum and minimum plug diameters (d 2 and d 3 ) should also be measured and recorded. The average diameter of the plug, d p, can be calculated as follows: Plug diameter d p = (d 2 + d 3 )/2 for partial plug failure. (2) Depending upon the application, for asymmetric welds, the ratio between d 1 and d 2, shall be specified and included in the test report. NOTE 3 The strength of the weld may vary depending on the direction of the applied force when the weld shape is asymmetric. Weld diameter dimensions should be rounded down to the nearest 0,1 mm. In the case of an interface failure [see Figure 7 b)], the weld diameters (d 1 and d 2 ) should be measured using a pocket lens or magnifier with an incorporated scale to determine the edge of the interfacial fracture accurately. If a smooth pressure welded bond zone (corona bond) is present, only the rough fracture zone shall be measured. 6 Test report A test report shall include the following: a) reference to this International Standard; b) type of test (chisel or peel); c) description of test equipment; d) welding process (resistance spot or projection); e) welding equipment; f) welding parameters; g) material information; h) weld size (d 1, d 2, d 3, d, d p, as needed); i) ratio of maximum to minimum weld diameters for asymmetric welds, if required; j) failure mode (symmetrical, asymmetrical, partial, interfacial fracture); k) other data specified. 11