1、June 2007DEUTSCHE NORM English price group 10No 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 25.160.10!,y$“9860159www.
2、din.deDDIN EN ISO 18594Resistance spot-, projection- and seam-welding Method for determining the transition resistance on aluminium and steelmaterial (ISO 18594:2007)English version of DIN EN ISO 18594:2007-06Widerstandspunkt-, Buckel- und Rollennahtschweien Verfahren fr das Bestimmen des bergangswi
3、derstands von Aluminium- undStahlwerkstoffen (ISO 18594:2007)Englische Fassung DIN EN ISO 18594:2007-06www.beuth.deDocument comprises 16 pages 09.07DIN EN ISO 18594:2007-06 2 National foreword This standard has been prepared by ISO/TC 44/SC 6 “Resistance welding” of ISO/TC 44 “Welding and allied pro
4、cesses” in collaboration with Technical Committee CEN/TC 121 “Welding” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Schweitechnik (Welding Standards Committee), Joint Committee NA 092-00-12 GA Widerstandsschweien (DVS AG V 3). The DIN S
5、tandard corresponding to the International Standard referred to in the EN is as follows: ISO 5821 DIN ISO 5821 National Annex NA (informative) Bibliography DIN ISO 5821, Resistance spot welding electrode caps EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 18594March 2007ICS 25.160.10English V
6、ersionResistance spot-, projection- and seam-welding - Method fordetermining the transition resistance on aluminium and steelmaterial (ISO 18594:2007)Soudage par rsistance par points, par bossage et lamolette - Mthode pour la dtermination de la rsistance detransition sur laluminium et sur lacier (IS
7、O 18594:2007)Widerstandspunkt-, Buckel- und Rollennahtschweien -Verfahren fr das Bestimmen des bergangswiderstandsvon Aluminium- und Stahlwerkstoffen (ISO 18594:2007)This European Standard was approved by CEN on 17 February 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulatio
8、ns 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.This Europea
9、n 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 the national
10、 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
11、 Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 18594:2007: EC
12、ontents Page Foreword 1 Scope . 2 Terms and definitions. 3 Basic principles 4 Measurement. 4.1 Measuring set-up 4.2 Measurement procedure 5 Test equipment . 6 7 Bibliography . 2 EN ISO 18594:2007 (E) . 3 4455589101112 14Test report .Formulae and abbreviations for calculating the transition resistanc
13、e . Annex A (informative) Test report Foreword This document (EN ISO 18594:2007) has been prepared by Technical Committee ISO/TC 44 “Welding and allied processes” in collaboration with Technical Committee CEN/TC 121 “Welding”, the secretariat of which is held by DIN. This European Standard shall be
14、given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2007, and conflicting national standards shall be withdrawn at the latest by September 2007. According to the CEN/CENELEC Internal Regulations, the national standards org
15、anizations 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,
16、Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 18594:2007 has been approved by CEN as EN ISO 18594:2007 without any modifications. 3 EN ISO 18594:2007 (E) 1 Scope This International Standard specifies the procedure and the experimental
17、set-up for determining the transition resistance of a single sheet or two overlapping sheets of aluminium or steel, with or without surface treatment, and with or without surface coating. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 contac
18、t resistance electric property of a contact area between two bodies which opposes and limits the passage through it of a steady current EXAMPLE The contacts between electrode/electrode, electrode/sheet and sheet/sheet. 2.2 bulk resistance ohmic resistance of an electrical conductor 2.3 total resista
19、nce R electrical resistance as measured between the sensing clamps (includes both bulk and contact resistances) See Figure 1 and Figure 2. 2.4 set-up resistance Rsresistance of the experimental set-up between the sensing clamps without metal sheet(s) between the electrodes, the two electrodes being
20、in direct contact See Figure 2 b), (R0+R1+R7). 2.5 transition resistance Rttotal resistance minus the set-up resistance 4 EN ISO 18594:2007 (E) 3 Basic principles Figure 1 shows schematically the resistances in the weld zone of the spot welding process. The contact resistances are not directly acces
21、sible to measurement. Key FEelectrode force 1 bulk resistance of top electrode, R12 contact resistance top electrode/upper sheet, R23 bulk resistance of upper sheet, R34 contact resistance sheet/sheet, R45 bulk resistance of lower sheet, R56 contact resistance lower sheet/bottom electrode, R67 bulk
22、resistance of bottom electrode, R7Figure 1 Resistance (schematic illustration) 4 Measurement 4.1 Measuring set-up Figure 2 a) shows schematically the experimental set-up for the determination of the transition resistance with one metal sheet between the electrodes. The total resistance is measured b
23、y means of the voltage/potential drop between the two sensing clamps. Either one or two specimens are placed between the electrodes, the electrode force is applied and a rectified current from an external source is allowed to flow through the test pieces via the electrodes. The voltage drop between
24、the sensing clamps is measured and the total resistance calculated using Ohms law: URI= (1) 5 EN ISO 18594:2007 (E) where R is the total resistance, in ohms; U is the voltage, in volts; I is the current, in amperes. The resistance of the experimental set-up, or set-up resistance, is obtained by meas
25、uring the voltage drop between the sensing clamps without any test pieces between the electrodes see Figure 2 b). The set-up resistance comprises the bulk resistance of the electrodes between the sensing clamps and the contact resistance between the electrodes. In the case of single metal sheet meas
26、urements, the total resistance consists of the bulk resistances of the top and bottom electrodes between the sensing clamps (R1, R7), the contact resistances (R2, R6) and the bulk resistance of the sheet (R3) see Figure 2 c). The total resistance, in the case of two-sheet measurements, consists of t
27、he bulk resistances of the top and bottom electrodes between the sensing clamps (R1, R7), the contact resistances (R2, R4, R6) and bulk resistances of the two-sheets (R3, R5) see Figure 2 d). 6 EN ISO 18594:2007 (E) Key 1 electrode 4 d.c. current source 2 sheet FEelectrode force 3 voltmeter I curren
28、t a) Set-up for determining the transition resistance Key FEelectrode force I current R0contact resistance R1; R7bulk resistance Key FEelectrode force I current R1; R3; R7; bulk resistance R2; R6contact resistance Key FEelectrode force I current R1; R3; R5; R7bulk resistance R2; R4; R6contact resist
29、ance b) Measurement of the set-up resistance c) Single-sheet measurement d) Two-sheet measurement Figure 2 Experimental set-up for determining the transition resistance 7 EN ISO 18594:2007 (E) 4.2 Measurement procedure 4.2.1 Preparatory steps Test pieces, e.g. of a size 50 mm 100 mm, are taken from
30、each material to be investigated. Surface conditions which do not correspond to production conditions in the measurement area (e.g. dirt, scratches, fingerprints) are not permitted. Normal surface conditions (e.g. oiled, phosphated, conversion coated) shall be documented in the test report. In the c
31、ase of two-sheet measurements, the specimens shall be flat. Burrs are not admissible at the sheet-to-sheet interface. Before starting the test, both the measuring set-up and the sheet material shall be at ambient conditions. In the case of two-sheet measurements, it is recommended that the upper and
32、 lower surfaces of each metal sheet are marked with “A” and “B” respectively. It is further recommended that test runs with the following combinations are carried out: A-B/B-A, B-A/A-B, and A-B/A-B. During a single test series, the surface position of the test pieces shall not be changed. 4.2.2 Dete
33、rmination of the set-up resistance The experimental set-up is used as shown in Figure 2. The set-up resistance shall be measured, as described under 4.1, after the electrodes are brought together. The electrode speed shall not exceed 15 mm/s at contact, and the dynamic electrode force shall not exce
34、ed the set force. The set-up resistance shall be measured before and after each test series. For this purpose, the electrodes shall be prepared using emery paper with a grain size of 1 200, first the top electrode and then the bottom one. Any dust shall be removed using a clean, dry tissue or micro-
35、fibre cloth. The electrodes are then brought together and the set-up resistance measured as described above. Since the set-up resistance can change during a test series due to pick-up on the working faces, the set-up resistance values shall be determined both before and after each test series. The s
36、et-up resistance for the test series is the mean value of the two measurements. 4.2.3 Measuring the total resistance A minimum of seven measurements shall be carried out at different locations on each test piece (see 4.2.1). In order to make the seven measurements on each test series, the specimen s
37、hall be positioned between the electrodes and the electrode force applied. After the nominal value of the electrode force is reached, the d.c. power source is switched on and the voltage drop measured after an elapsed time of (15 1) s. The location of the measuring points shall be selected such that
38、 the distance centre-to-centre and centre-to-specimen edge is greater than, or equal to, 15 mm (see Figure 3). 8 EN ISO 18594:2007 (E) Dimensions in millimetres Figure 3 Example for the location of the measuring points The test pieces shall be positioned perpendicular to the axis of the electrodes.
39、No relative movement between the electrode working faces and the specimen surface, e.g. vibration, rotation or sliding, is permitted. The total resistance of the test series is the mean value of a minimum of seven measurements. Since the contact resistance on a sheet or a component can vary from loc
40、ation to location, it is recommended that for representative results at least five test pieces are taken from different locations. 4.2.4 Determining the transition resistance The transition resistance of a test series is the difference between the total resistance and the set-up resistance of the te
41、st series. The mean value, the standard deviation and the coefficient of variation shall be calculated in accordance with Clause 6 see Equations (6), (7) and (8), using the results of at least five test pieces. 5 Test equipment The mechanical system shall have a high stiffness in order to minimise a
42、 sliding of the electrode working faces. The eccentricity of the electrode axes shall not exceed 0,1 mm. The distance between the introduction of the current and the sensing clamps shall be greater than 15 mm. If electrode caps are used, the sensing clamps shall be applied to the electrodes. Instead
43、 of the separate d.c. power source and the digital voltmeter, a precision resistance meter may also be used. For details of the test equipment and set-up conditions to be used see Table 1. 9 EN ISO 18594:2007 (E) Table 1 Test equipment and set-up conditions Measuring and testing equipment Aluminium
44、Steel Force-generating system set-up force maximum error 5 kN to 7,5 kNa 5 % 3,5 kN 5 % Electrodes material diameter radius CuCrZr or CuCr W 20 mm 150 mm to 300 mmaCuCrZr or CuCr W 16 mm 40 mm to 50 mmad.c. power sourceb set-up current maximum ripple maximum error (reading value) e.g. 10 A, 100 A 0,
45、5 % 1 % Digital voltmeterb sensitivity maximum error of display u 1 V 1,0 % and 1 digit (Micro-)Ohm meter measuring current sensitivity e.g. 10 A, 100 A u 0,1 aData to be used shall be specified. bThe minimum resolution of the combination d.c. power source and digital voltmeter shall be W 0,1 . 6 Fo
46、rmulae and abbreviations for calculating the transition resistance The set-up resistance, Rs, expressed in ohms, is calculated as follows: ssURI= (2) where I is the measured current, in amperes; Usis the set-up voltage, in volts, and calculated as follows: sv sns()2UUU+= (3) where Usvis the voltage
47、drop between the sensing clamps on the electrodes due to the set-up resistance before test series, in volts; Usnis the voltage drop between the sensing clamps on the electrodes due to the set-up resistance after test series, in volts. 10 EN ISO 18594:2007 (E) The mean value of the voltage drop in a
48、test series, ,U expressed in volts, is calculated as follows: 1234567()nUUUUUUU UUn+ += (4) where U1,., Unis the voltage drop between the sensing clamps on the electrodes during a test series. The transition resistance, Rt, expressed in ohms, is calculated as follows: tsUR RI= (5) The mean value of
49、the transition resistance, t,R expressed in ohms, is calculated as follows: tt11niiR Rn=(6) where Rtiis the transition resistance at measuring point i, in ohms. The standard deviation, s, expressed in ohms, is calculated as follows: 2tt11()(1)niisRRn=(7) The coefficient of variation, V, expressed as a percentage, is calculated as follows: t100sVR=(8) 7 Test report The test report(s) shall provide information regarding the following: test results; date of test; referen
