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 87.040!,y“9862958www.din.
2、deDDIN EN ISO 17872Paints and varnishes Guidelines for the introduction of scribe marks through coatings onmetallic panels for corrosion testing (ISO 17872:2007)English version of DIN EN ISO 17872:2007-06Beschichtungsstoffe Leitfaden zum Anbringen von Ritzen durch eine Beschichtung auf Metallplatten
3、 frKorrosionsprfungen (ISO 17872:2007)Englische Fassung DIN EN ISO 17872:2007-06www.beuth.deDocument comprises 16 pages 09.07DIN EN ISO 17872:2007-06 2 National foreword This standard falls within the responsibility of Technical Committee CEN/TC 139 “Paints and varnishes” (Secretariat: DIN, Germany)
4、. It is identical with International Standard ISO 17872 which was prepared by Technical Committee ISO/TC 35 “Paints and varnishes”, Subcommittee SC 9 “General test methods for paints and varnishes” (Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was the No
5、rmenausschuss Beschichtungsstoffe und Beschichtungen (Coatings and Coating Materials Standards Committee), Technical Committee NA 002-00-07 AA Allgemeine Prfverfahren fr Beschichtungsstoffe und Beschichtungen. Due to the large variety of scribing tools used tools that tear, cut, break or shave, with
6、 various geometries and widths it can hardly be expected that the results obtained are comparable. Because results are highly dependent on the operator, an automatic scribing machine should be used. It is extremely important to maintain the minimum width of the exposed mark so that it does not close
7、 up again. The type of scribe mark and scribing tool to be used should be agreed before testing to minimize variation (deviations). Whatever scribing tool is used, it is important to ascertain whether the necessary scribe mark depth has been achieved (e.g. to the zinc layer, to the steel substrate,
8、aluminium substrate). To see if the mark truly goes down to the steel, a test mark can be made and then the panel can be dipped in a copper sulphate solution. Copper forms a red deposit on steel, while zinc remains grey-black. The DIN Standards corresponding to the International Standards referred t
9、o in the bibliography of the EN are as follows: ISO 4623-1 DIN EN ISO 4623-1 ISO 4623-2 DIN EN ISO 4623-2 ISO 9227 DIN EN ISO 9227 ISO 11997-1 DIN EN ISO 11997-1 ISO 12944-6 DIN EN ISO 12944-6 National Annex NA (informative) Bibliography DIN EN ISO 4623-1, Paints and varnishes Determination of resis
10、tance to filiform corrosion Part 1: Steel substrate DIN EN ISO 4623-2, Paints and varnishes Determination of resistance to filiform corrosion Part 2: Aluminium substrates DIN EN ISO 9227, Corrosion tests in artificial atmospheres Salt spray tests DIN EN ISO 11997-1, Paints and varnishes Determinatio
11、n of resistance to cyclic corrosion conditions Part 1: Wet (salt fog)/dry/humidity DIN EN ISO 12944-6, Paints and varnishes Corrosion protection of steel structures by protective paint systems Part 6: Laboratory performance test EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 17872 March 20
12、07 ICS 87.040 English Version Paints and varnishes - Guidelines for the introduction of scribe marks through coatings on metallic panels for corrosion testing (ISO 17872:2007) Peintures et vernis - Lignes directrices pour la production de rayures au travers du revtement de panneaux mtalliques en vue
13、 des essais de corrosion (ISO 17872:2007) Beschichtungsstoffe - Leitfaden zum Anbringen von Ritzen durch eine Beschichtung auf Metallplatten fr Korrosionsprfungen (ISO 17872:2007) This European Standard was approved by CEN on 17 February 2007. CEN members are bound to comply with the CEN/CENELEC Int
14、ernal 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 me
15、mber. 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 mem
16、bers 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,
17、Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Re
18、f. No. EN ISO 17872:2007: EContents Page Foreword Introduction 1 Scope . 2 Scribe marks . 3 Apparatus 4 Test panels 5 Procedure 6 Shape verification of cross-section 7 Report Annex A (informative) Scribing tools . Annex B (informative) Determination of shape and dimensions of scribe marks made using
19、 2 EN ISO 17872:2007 (E)Bibliography . 345577 78 891214common scribing tools .Foreword This document (EN ISO 17872:2007) has been prepared by Technical Committee ISO/TC 35 “Paints and varnishes” in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes”, the secretariat of which is
20、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 September 2007, and conflicting national standards shall be withdrawn at the latest by September 2007. According to the CEN/CENELEC Int
21、ernal 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, M
22、alta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 17872:2007 has been approved by CEN as EN ISO 17872:2007 without any modifications. 3 EN ISO 17872:2007 (E)Introduction Many International Stand
23、ards deal with corrosion testing, where scribe marks are introduced through a coating to a metallic substrate. However, the method of scribe-mark introduction (scribing pattern, tools, etc.) is not standardized across these standards. The main purposes of an intentionally inflicted damage in a coati
24、ng prior to corrosion testing are as follows: a) to simulate and to investigate how a specific type of damage behaves during exposure; b) to obtain an accelerated response during a corrosion test, e.g. at quality control during production; c) to investigate the general durability of a coating by obs
25、ervation of the rate of corrosion spread after exposure. Preliminary investigations have shown that several variants, both in terms of shape and dimensions, of scribing tools are used. This variation occurs both across countries and within countries. The effect of using different tools is the produc
26、tion of scribe marks with different cross-sectional shape, depth and exposed metal area. These differences will greatly affect test results obtained during corrosion tests, as the intention of introducing scribe marks into a coating system is such that oxygen and the electrolyte present during expos
27、ure testing can obtain access to a well-defined and active metal surface. The actual method used to introduce a scribe mark depends on the coating type and thickness. However, in all cases it is preferable if the cross-section is as smooth as possible, the metallic substrate is exposed evenly and no
28、 coating remains on the exposed substrate. Additionally, it is desirable that scribing methods are consistent across related International Standards. The scribing method greatly affects how the corrosion process occurs and the reproducibility when tests are repeated under the same conditions. In ord
29、er to obtain anticorrosive results with high accuracy and reproducibility, accurate and consistent scribing is required. 4 EN ISO 17872:2007 (E)1 Scope This International Standard describes methods of scribing coated steel or test-pieces for corrosion tests, where the coating system is applied at dr
30、y film thicknesses of less than 500 m. It is intended as a guideline only, being based on the results of a collaborative trial with no subsequent corrosion testing having been carried out to determine the suitability of the introduced scribe marks for such tests. This International Standard covers t
31、he scribing of metallic panels or test pieces made from steel, chemically treated steel, aluminium or aluminium alloy, and chemically treated aluminium. It does not cover the scribing of galvanized or electroplated metal or clad aluminium panels. 2 Scribe marks If not otherwise agreed or specified,
32、a scribe mark is made as an X-shape, T-shape or single-line, through the coating to the metal substrate according to the agreed conditions. Examples of X-shaped, T-shaped and a single-line scribe mark are given in Figure 1. Typically, the suitable length of the scribed lines is in the range of 50 mm
33、 to 70 mm, depending on the coating thickness and the expected amount of corrosion. The length of the scribe mark should be significantly more than the expected creep resulting from the corrosion test carried out. The width of the scribe mark can also affect the result of a corrosion test. The small
34、er the width, the stronger is the tendency for the exposed metal surface to be passivated by deposition of sparingly soluble corrosion products. It is therefore important to select a scribing tool which will provide a suitable scribe width for the corrosion test being carried out. The orientation of
35、 the scribed lines is often significant in terms of affecting corrosion test results. On panels with a slight inclination from the vertical, e.g. for salt-spray tests, more salt is collected in a horizontally exposed scribe mark. Also, a horizontally exposed scribe mark will generate an even salt di
36、stribution, whereas a diagonal, or more particularly a vertical, scribe mark tends to generate a gradient, with an increasing amount of salt along the lower edge of the scribe mark. An increased amount of salt usually leads to an increased corrosion rate, but on coated steel, high salt concentration
37、 might have an inhibiting effect on corrosion since the formed corrosion products are very dense. The cross-section of the scribe mark should be as uniform as possible along its entire length. The coating should be cut smoothly along the direction of the scribe mark. The cross-sectional shape of the
38、 scribe may be either “V” or “U” shaped, depending upon the tool used, and should be such that for a “V”-shaped cut a b c and for a “U”-shaped cut a b, with the width (b) of both “V” and “U” shapes such that b W 0,2 mm (see Figure 2 for an explanation of the symbols). Certain scribing tools may also
39、 produce a rectangular cross-section, where a, b and c are approximately equal. NOTE The shape, depth and uniformity of scribe marks resulting from the use of manual scribing tools will also depend on the operator carrying out the scribing procedure. To reduce this operator dependency, and hence var
40、iability in 5 EN ISO 17872:2007 (E)subsequent corrosion test results, automatic scribing machines may also be used to introduce scribe marks, provided they produce a scribe mark which penetrates to the substrate. Such machines are able to introduce rectangular shaped scribe marks, where the dimensio
41、ns a, b and c are approximately equal and each is greater than 0,5 mm. Dimensions in millimetresa) X-shape b) T-shape c) Single line Figure 1 Surface shape of scribe marks on coated panels 6 EN ISO 17872:2007 (E)a) “V”-shaped cut b) “U”-shaped cut Key 1 coating 2 substrate a width of scribe mark at
42、surface of coating b width of scribe mark at coating/substrate boundary c width of scribe mark at maximum penetration into substrate d penetration of scribe mark into substrate Figure 2 Cross-sectional shape of scribe mark through a coating 3 Apparatus 3.1 Scribing tool, see Annex A. 3.2 Metal rule,
43、 to aid the introduction of a straight scribe mark of the specified length. 3.3 Microscope, with 25 magnification lens (see Clause 6). 3.4 Magnification lens, 5 to 10 magnification, to visually ensure uniformity of the scribe and removal of debris (see Clause 5). 4 Test panels Use a coated panel (or
44、 test piece) appropriate for carrying out the corrosion-resistance test. 5 Procedure Ensure that the test panel is firmly secured while the scribe mark is being introduced to ensure uniform location and to prevent panel/tool slippage. Use the scribing tool to introduce the scribe mark through the co
45、ating to the metallic substrate. When scribing, use the metal rule to guide the scribing tool and use a continuous scribing action with uniform speed. Take care not to damage the surrounding coating whilst introducing the scribe mark. It is preferable that the scribe mark be introduced through the c
46、oating to the metal substrate in one smooth action. If this is not possible (see Annex B, Table B.2), it is recommended that actions should be repeated taking care to follow the cross-section of the previous actions. This should be recorded in the test report. An automated scribing machine may be us
47、ed to achieve penetration to the metal substrate in a single action. 7 EN ISO 17872:2007 (E)New scribing tools can be very sharp and it is recommended that they be conditioned prior to use on test-pieces by carrying out at least 10 scribes. The scribing tool can become blunt with use and therefore t
48、he blade/point should be regularly inspected and sharpened or replaced periodically. The edges of the scribe mark should be uniform and should completely penetrate the coating. Remove debris from the scribed mark. NOTE Ensuring uniformity of the scribe mark and complete removal of debris may be aide
49、d by viewing with a 5 to 10 magnification lens. 6 Shape verification of cross-section If shape verification of the scribe mark is required, use a microscope with 25 magnification lens (see Annex B). 7 Report A report of the procedure used for scribing should be prepared, including at least the following information: a) all information necessary for identification of the sample tested, including details of substrate material, and surface preparation prior to coating, and all details necessary to identify the coating
