ISO INTERNATIONAL STANDARD 9224 Second edition 2012-02-01 Corrosion of metals and alloys Corrosivity of atmospheres Guiding values for the corrosivity categories Corrosion des métaux et alliages - Corrosivite des atmospheres - Valeurs de réference relatives aux classes de corrosivite Reference number ISO 9224:2012(E) @ ISO 2012 py IHS under ted without license from IHS Not for Resale ISO 9224:2012(E) COPYRIGHTPROTECTEDDOCUMENT @ISO2012 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 mechanical, including photocopying and microfilm, without permission in writing from either isO at the address below or IsO's memberbody in the country of the requester. ISO copyright office Case postale 56 : CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @ ISO 2012 - All rights reserved y IHS unde Not for Resale ISO 9224:2012(E) Contents Page Foreword Introduction 1 Scope 2 Normative references. 3 Terms and definitions. 4 Principle ... 5 Prediction of corrosion attack after extended exposure. 6 Specific criteria for calculation of corrosion rates of structural metals... 6.1 Steels... 6.2 Zinc materials . 6.3 Copperalloys. 6.4 Aluminium alloys. 7 Long-term exposures. Annex A (informative) Example of maximum corrosion attack after extended exposures for corrosivity categories .... 7 Annex B (informative) Average initial corrosion rates and average steady corrosion rates in intervals relative to classified corrosivity categories... 9 Annex C (informative) Prediction of corrosion attack of steels with regard to steel composition .... 10 Bibliography. .12 Copyright International Organization for Standardizalon ghts reserved ili nse from IHS Not for Resale