ISO INTERNATIONAL STANDARD 21746 First edition 2019-04 Composites and metal assemblies Galvanic corrosion tests of carbon fibre reinforced plastics (CFRPs) related bonded or fastened structures in artificial atmospheres Salt spray tests Assemblages composites et meétal - Essais de corrosion galvanique des structures en plastiques renforcés de fibres de carbone (CFRP) jointes ou fixees en atmospheres artificielles - Essais au brouillard salin Reference number ISO 21746:2019(E) rso @ IS0 2019 IS0 21746:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below or Iso's member body in the country of the requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2019 - All rights reserved IS0 21746:2019(E) Contents Page Foreword ..iv Introduction ..V 1 Scope. ..1 2 Normative references ..1 3 Terms and definitions 4 Test solutions .2 4.1 Preparation of the sodium chloride solution .2 4.2 pHadjustment .3 4.2.1 pH of the salt solution .3 4.2.2 Neutral salt spray test (NSS) .3 4.2.3 Acetic acid salt spray test (AASS) 3 4.2.4 Copper-accelerated acetic acid salt spray test (CASS) .3 4.3 Filtration. .3 5 Apparatus .4 6 Method for evaluating cabinet corrosivity ..5 6.1 General .5 6.2 Reference specimens .5 6.3 Arrangement of the reference specimens .6 6.4 Durationoftests .6 6.5 Determination of mass loss (mass per area) ..6 6.6 Satisfactory performance of cabinet .6 7 Test specimens. .7 8 Arrangement of the test specimens .1 9 Operating conditions ..8 10 Durationoftests ..8 11 Treatment of specimens after test .9 11.1 General .9 11.2 Non-organic coated specimens: metallic and/or inorganic coated. 9 11.3 Organic coated specimens. .9 11.3.1 Scribed organic coated specimens .9 11.3.2 Organic coated but not scribed specimens ..9 12 Evaluation of results .9 13 Test report .10 Annex A (informative) Example schematic diagram of one possible design of spray cabinet for galvanic corrosion test with means for optional treating fog exhaust and drain. .11 Annex B (informative) Compiementary method for evaiuating gaivanic corrosion test cabinet corrosivity using zinc reference specimens .13 Annex C (normative) Preparation of galvanic corrosion test panels with organic coatings .15 Annex D (normative) Required supplementary information for testing galvanic corrosion test panels with organic coatings. .16 Annex E (informative) Recommended specimen geometries - Salt spray tests to metal and CFRP assemblies. .17 Bibliography .19 @ IS0 2019 - All rights reserved ii