1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58marks through coatings on metallic panels for corrosion testingThe European Standard EN ISO 17872:2
2、007 has the status of a British StandardICS 87.040Paints and varnishes Guidelines for the introduction of scribe BRITISH STANDARDBS EN ISO 17872:2007BS EN ISO 17872:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 September 2007 BSI 200
3、7ISBN 978 0 580 54203 9Amendments issued since publicationAmd. No. Date CommentsCompliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of EN ISO 17872:2007.The UK participation in its preparation was entrusted
4、to Technical Committee STI/10, Test methods for paints.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.EUROPEAN
5、 STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 17872March 2007ICS 87.040English VersionPaints and varnishes - Guidelines for the introduction of scribemarks through coatings on metallic panels for corrosion testing(ISO 17872:2007)Peintures et vernis - Lignes directrices pour la productionde rayures a
6、u travers du revtement de panneauxmtalliques en vue des essais de corrosion (ISO17872:2007)Beschichtungsstoffe - Leitfaden zum Anbringen von Ritzendurch eine Beschichtung auf Metallplatten frKorrosionsprfungen (ISO 17872:2007)This European Standard was approved by CEN on 17 February 2007.CEN members
7、 are bound to comply with the CEN/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
8、 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same
9、 status as theofficial 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,Romani
10、a, Slovakia, Slovenia, Spain, Sweden, Switzerland and United 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 reservedworld
11、wide for CEN national Members.Ref. No. EN ISO 17872:2007: EForeword 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 held by DIN. This E
12、uropean 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 Internal Regulations,
13、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,
14、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. EN ISO 17872:2007Reference numberISO 17872:2007(E)INTERNATIONAL STANDARD ISO178
15、72First edition2007-03-01Paints and varnishes Guidelines for the introduction of scribe marks through coatings on metallic panels for corrosion testing Peintures et vernis Lignes directrices pour la production de rayures au travers du revtement de panneaux mtalliques en vue des essais de corrosion E
16、N ISO 17872:2007ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Scribe marks . 1 3 Apparatus 3 4 Test panels 3 5 Procedure 3 6 Shape verification of cross-section 4 7 Report 4 Annex A (informative) Scribing tools . 5 Annex B (informative) Determination of shape and dimensions of scribe
17、marks made using common scribing tools 8 Bibliography . 10 EN ISO 17872:2007iv Foreword 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 I
18、SO technical committees. Each member body 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
19、closely with the International Electrotechnical 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.
20、Draft International Standards adopted by the 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 d
21、ocument may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 17872 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9, General test methods for paints and varnishes. EN ISO 17872:2007vIntroductio
22、n Many International Standards 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 i
23、nflicted damage in a coating 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 dura
24、bility of a coating by observation 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 dif
25、ferent tools is the production 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 electr
26、olyte present during exposure 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 substrat
27、e is exposed evenly and no 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 t
28、he same conditions. In order to obtain anticorrosive results with high accuracy and reproducibility, accurate and consistent scribing is required. EN ISO 17872:2007blank1Paints and varnishes Guidelines for the introduction of scribe marks through coatings on metallic panels for corrosion testing 1 S
29、cope This International Standard describes methods of scribing coated steel or test-pieces for corrosion tests, where the coating system is applied at dry 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 c
30、orrosion testing having been carried out to determine the suitability of the introduced scribe marks for such tests. This International Standard covers the scribing of metallic panels or test pieces made from steel, chemically treated steel, aluminium or aluminium alloy, and chemically treated alumi
31、nium. It does not cover the scribing of galvanized or electroplated metal or clad aluminium panels. 2 Scribe marks If not otherwise agreed or specified, 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. Example
32、s 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 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
33、 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 smaller the width, the stronger is the tendency for the exposed metal surface to be passivated by deposition of sparingly soluble corrosion products. It
34、 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 the scribed lines is often significant in terms of affecting corrosion test results. On panels with a slight inclination from the vertical, e.g. f
35、or salt-spray tests, more salt is collected in a horizontally exposed scribe mark. Also, a horizontally exposed scribe mark will generate an even salt distribution, whereas a diagonal, or more particularly a vertical, scribe mark tends to generate a gradient, with an increasing amount of salt along
36、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 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
37、 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 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
38、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 produce a rectangular cross-section, where a, b and c are approximately equal. NOTE The shape, depth and uniformity of scribe marks resulting from
39、 the use of manual scribing tools will also depend on the operator carrying out the scribing procedure. To reduce this operator dependency, and hence variability in EN ISO 17872:20072 subsequent corrosion test results, automatic scribing machines may also be used to introduce scribe marks, provided
40、they produce a scribe mark which penetrates to the substrate. Such machines are able to introduce rectangular shaped scribe marks, where the dimensions 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 s
41、hape of scribe marks on coated panels EN ISO 17872:20073a) “V”-shaped cut b) “U”-shaped cut Key 1 coating 2 substrate a width of scribe mark at 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
42、 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, 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 len
43、s, 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 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 b
44、eing introduced to ensure uniform location and to prevent panel/tool slippage. Use the scribing tool to introduce the scribe mark through the coating 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
45、care not to damage the surrounding coating whilst introducing the scribe mark. It is preferable that the scribe mark be introduced through the coating 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 taki
46、ng care to follow the cross-section of the previous actions. This should be recorded in the test report. An automated scribing machine may be used to achieve penetration to the metal substrate in a single action. EN ISO 17872:20074 New scribing tools can be very sharp and it is recommended that they
47、 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 the blade/point should be regularly inspected and sharpened or replaced periodically. The edges of the scribe mark should be uniform and should completely penetr
48、ate the coating. Remove debris from the scribed mark. NOTE Ensuring uniformity of the scribe mark and complete removal of debris may be aided 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 wit
49、h 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 system tested; b) a reference to this International Standard (ISO 17872:2007); c) a reference to the International Standard by which the scribed pane
