ISO INTERNATIONAL STANDARD 4628-8 Second edition 2012-11-01 Paints and varnishes Evaluation of degradation of coatings Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 8: Assessment of degree of delamination and corrosion around a scribe or other artificial defect Peintures et vernis Evaluation de la dégradation des revetements Désignation de la quantite et de la dimension des défauts, et de I'intensite des changements uniformes d'aspect - Partie 8: Evaluation du degré de décollement et de corrosion autour d'une rayure ou d'un autre défaut artificiel Reference number ISO 4628-8:2012(E) LSO @ ISO 2012 ISO4628-8:2012(E) 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 IsO Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEc Directives, Part 2. The main task of technical committees is to prepare International Standards. 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. rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 4628-8 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9 General test methods for paints and varnishes. This second edition cancels and replaces the first edition (IsO 4628-8:2005). For this revision a) of pictorial standards; b) artificial defects with shape other than a linear scribe mark are introduced. IsO 4628 consists of the following parts, under the general title Paints and varnishes — Evaluation of degradation Part 1: General introduction and designation system Part 2: Assessment of degree of blistering Part 3: Assessment of degree of rusting Part 4: Assessment of degree of cracking Part 5: Assessment of degree of flaking Part 6: Assessment of degree of chalking by tape method -Part 7: Assessment of degree of chalking by velvet method Part 8: Assessment of degree of delamination and corrosion around a scribe or other artificial defect Part 10: Assessment of degree of filiform corrosion @ ISO 2012 - All rights reserved ili ISO 4628-8:2012(E) Introduction IsO 4628-1[1] defines a system for designating the quantity and size of defects and the intensity of uniform changes, for example yellowing. As far as possible, already existing evaluation schemes have been used as the basis. After exposure of a coated test panel with a scribe or other artificial defect in a corrosive environment, one, or a combination of both of, the following phenomena can occur around the scribe or other artificial defect: 一 delamination; corrosion. Delamination and corrosion around the scribe or other artificial defect are evaluated separately to provide more detailed information about the performance of a coating system in corrosive environments. around the scribe or other artificial defect may be carried out using optical image processing. Rating of other defects is described in other parts of iSO 4628. iv @ ISO 2012 -All rights reserved