SANS 10289-2008 Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates - Rating of test specimens and manufactured articles subjected to corr.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21508-8 SANS 10289:2008Edition 1ISO 10289:1999Edition 1SOUTH AFRICAN NATIONAL STANDARD Methods for corrosion testing of metallic and other

4、 inorganic coatings on metallic substrates Rating of test specimens and manufactured articles subjected to corrosion tests This national standard is the identical implementation of ISO 10289:1999 and is adopted with the permission of the International Organization for Standardization. Published by S

5、ABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 10289:2008 Edition 1 ISO 10289:1999 Edition 1 Table of changes Change No. Date Scope National foreword This South African standard was approved by Nati

6、onal Committee SABS TC 107, Metallic and other inorganic coatings, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in November 2008. INTERNATIONAL STANDARD IS0 10289 First edition 1999-1 0-1 5 Methods

7、 for corrosion testing of metallic and other inorganic coatings on metallic substrates - Rating of test specimens and manufactured articles subjected to corrosion tests Mthodes dessai de corrosion des revtements mtalliques et inorganiques sur substrats mtalliques - Cotation des prouvettes et des art

8、icles manufacturs soumis aux essais de corrosion Reference number IS0 10289:1999( E) SANS 10289:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .IS0 10289:1999(E) Contents Page 1 Scope . . . . . . . . . . . . 1 2 Terms and definitions . .

9、. , . . . 1 3 Principle . . . . . . . . 2 4 Types of defect . . . . . . . . . . . . . 2 5 Method of inspection . . . . . . . . . . . . . 3 6 Assignment of ratings . . . . . . . . . . . 3 7 Test report . . . . . . . . . . . . 5 Annex A (informative) Dot charts and colour photographs for coatings cath

10、odic to the basis metal . 7 Annex B (informative) Dot charts for coatings anodic to the basis metal . 17 Bibliography . . . . . . 22 O IS0 1999 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechan

11、ical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 CH-121 1 Genve 20 Switzerland Internet isoiso.ch Printed in Switzerland ii SANS 10289:2008This s tandard may only be used and printed by approv

12、ed subscription and freemailing clients of the SABS .O IS0 IS0 10289: 1999(E) Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS

13、0 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. IS0 collaborates c

14、losely 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 3. Draft International Standards adopted by the technical committees are circulat

15、ed to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 10289 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings, Subcommittee SC 7, Corrosion te

16、sts. This first edition cancels and replaces IS0 1462:1973, IS0 4540:1980 and IS0 8403:1991. Annexes A and B of this International Standard are for information only. iii SANS 10289:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .IS0 10289

17、:1999(E) O IS0 Introduction The rating method described in this International Standard recognizes that decorative and protective metallic and inorganic coatings on metallic substrates can be either anodic or cathodic to the substrate. In rating these coatings for the effects of corrosion, two evalua

18、tions shall be made: - the ability of the coating to protect the substrate from corrosion and thus prevent degradation of the base metal; - the ability of the coating to retain its integrity and thus maintain a satisfactory appearance. Although these functions overlap, they can be evaluated separate

19、ly in terms of: - a protection rating (Rp) relating to the corrosion of the basis metal; - an appearance rating (RA) relating to the deterioration of the coating. The protection rating (Rp) assigns a number representing the ability of the coating to protect the basis metal from corrosion. The appear

20、ance rating (RA) assigns a sequence of letters and numbers to the overall appearance of the specimen which includes all deterioration caused by the corrosion test or environment. NOTE 1 Imperfections on a panel or article before exposure testing should be noted and given due consideration when evalu

21、ating the results of the examination. Deliberate imperfections may also be introduced as part of a test programme. The coating system has to be known and reported if this rating system is applied. It is especially important to know, if possible, whether the coating is anodic or cathodic to the base

22、metal. NOTE 2 Determination of the anodic and cathodic corrosive mechanisms can be extremely difficult in some cases (chromated zinc on steel or multiple coatings). For the purposes of this document knowledge of these mechanisms is not necessary. iv SANS 10289:2008This s tandard may only be used and

23、 printed by approved subscription and freemailing clients of the SABS .INTERNATIONAL STANDARD O IS0 IS0 10289: 1999( E) Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates - Rating of test specimens and manufactured articles subjected to corrosion tests 1 Sc

24、ope This International Standard gives a method of evaluating the condition of decorative and protective metallic and inorganic coated panels or articles which have been exposed to corrosive environments for test or for other purposes. It is applicable to test panels or components exposed to natural

25、atmospheres, in mobile or static conditions, or subjected to accelerated tests. NOTE 1 This International Standard recognizes that the protection rating can be assessed objectively in accordance with clause 6. However, the assessment of appearance depends on many subjective factors (see 6.2). Exampl

26、es of such tests are given in the Bibliography. NOTE 2 The edges of test panels or components may be protected, e.g. by tape or wax (paraffin), if this is an agreed part of the test and is recorded in the test report. This is essential if the specimens are cut from larger pieces and have exposed unc

27、oated edges. 2 Terms and definitions 2.1 protection rating rating number (see Table 1) assigned to the ability of the coating to protect the basis metal from corrosion RP 2.2 protection defect defect used to assess the protection rating, including crater corrosion, pin-hole corrosion, corrosion stai

28、n due to corrosion from the substrate, blisters and other defects that involve basis metal corrosion NOTE inspectors judgement may be required to decide whether a blister does or does not arise at the substrate-coating interface. Blisters on electroplated aluminium and zinc alloy die castings usuall

29、y signify base metal corrosion, but the 2.3 appearance rating rating number and symbols (see Table 2) assigned to describe the overall appearance of the specimen, including all defects caused by exposure RA 2.4 appearance defect defect that detracts from the appearance of the specimen (see Table 2)

30、1 SANS 10289:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .IS0 10289: 1 999( E) O IS0 2.5 performance rating combination of the protection rating number (Rp) followed by a slash mark followed by the appearance rating number (RA), i.e. R

31、dRA 2.6 coating system particular series of deposits including the thickness and type of layers in multilayer deposits and treatments which have been applied to the basis metal 2.7 significant surface part of the surface which is essential in the appearance or serviceability of the article and which

32、 is to be covered or is covered by the coating (see clause 5) 3 Principle This International Standard establishes a rating system for evaluating the deterioration of the coating and the basis metal due to corrosion. The rating method described in this International Standard is applied to evaluate th

33、e appearance of the coating, as well the extent of the corrosion on test panels or the significant surfaces of components which have been subjected to performance tests. The result of inspecting a surface, called the performance rating, is recorded as two separate ratings, the protection rating (Rp)

34、 and the appearance rating (RA). When recording the rating of a surface, the type(s) and severity of defect(s) contributing to the rating shall be noted if this information is required. This information is recorded using agreed symbols for the defects and the extent of these defects. When only the p

35、rotection rating (Rp) is required, it is permitted to omit the appearance rating (RA). However, in such a case, a written dash should follow the protection rating in order to indicate deliberate omission of the appearance rating . 4 Types of defect It is possible for defects to affect both the prote

36、ction rating (Rp) and the appearance rating (RA). In this rating system, the protection rating is a simple numerical rating while the appearance rating is permitted to include specific defects along with a numerical rating designating the intensity. A list of defects is given in Table 2. Additions m

37、ay also be made to the list, as appropriate, when recording specific defects. Defects include crater corrosion, pin-hole corrosion, general corrosion of the coating, corrosion products, blisters, and any other defect that involves the coating. Some defects, such as blisters, can be associated with t

38、he coating, the basis metal, the interface between the coating and the basis metal, or between layers in the coating. Other defects can have a small corrosion content but an appreciable affect on the appearance, e.g., staining, tarnishing, cracks, etc. Defects on the surface of the basis metal such

39、as scratches, porosity, non-conducting inclusions, roll and die marks, cold shuts and cracks can adversely affect the performance of coatings applied thereto, despite the observance of the best finishing practices. Such defects shall be reported and rated separately. Ensure that the coating system i

40、s reported, because the significance of certain defects can be dependent on whether the coating is anodic or cathodic to the basis metal. Note defects that develop on exposure, e.g. peeling or spalling of the coating, since this indicates possible improper preparation of the basis metal or improper

41、application of the coating. 2 SANS 10289:2008This s tandard may only be used and printed by approved subscription and freemailing clients of the SABS .O IS0 IS0 10289:1999(E) 5 Method of inspection Use drawings or suitably marked samples to indicate the significant surface. It may sometimes be neces

42、sary or appropriate to expose material which is defective in certain respects before carrying out environmental testing. In such cases, make an inspection and record the findings before the specimens are tested. If deliberate damage is applied to a surface, record the damage before the specimens are

43、 tested and so reported. If the specimen is purposely deformed, rate the deformed areas separately. Material may be inspected either on the exposure racks or in a more suitable location. Ensure that lighting during inspection is as uniform as possible; avoid direct reflection from sun or clouds, and

44、 use various angles of inspection to ensure that all defects are revealed. At the conclusion of the test, if the condition of the specimens allows, inspect them in the uncleaned condition. If dirt, salt deposits, etc., mask the defects and create difficulties with inspection, the surface may be spon

45、ged with a mild soap solution and then rinsed with water. However, exert no pressure during such cleaning in order to avoid accidentally upgrading the rating by, for example, cleaning off the corrosion products. Cleaning solutions should be compatible with the coatings and not cause any degradation

46、of the coating. In the case of intermediate, periodic inspections do not clean or otherwise disturb the specimens. Allow surfaces to dry before they are inspected. Defects to be noted and taken into account when rating surfaces include only those which can be seen by normal or corrected vision. NOTE

47、 1 Optical aids may be used subsequently to characterize defects, after initial detection. Edge defects, occurring within 5 mm of the edge of a specimen or tape/wax, may be noted in the report, but should not normally influence the numerical rating. Similarly, disregard contact and rack marks, mount

48、ing holes, etc. NOTE 2 Edge defects may be difficult to assess on deeply worked manufactured specimens, such as threads, bores etc. In these cases it may be necessary to obtain agreement between purchaser and supplier regarding the exact defective area to be reported. When the coating is anodic to t

49、he basis metal, white corrosion product developed from the edges of the specimen shall not constitute failure. Rubbing, polishing, chemical cleaning, etc., of the surface of the specimen may be used to facilitate study of the surface but confine it to the minimum practicable area, preferably not more than 100 mm2 on a surface of 100 mm x 150 mm. Note this area for subsequent ratings. 6 Assignment of ratings 6.1 Assignment of protection rating (Rp) The numerical rating system is based on the area of the substrate that exhibits corrosion, by the following formula: R,