ISO INTERNATIONAL STANDARD 28706-1 First edition 2008-12-01 Vitreous and porcelain enamels Determination of resistance to chemical corrosion- Part 1: Determination of resistance to chemical corrosionbyacidsatroomtemperature Emaux vitrifies-Determination de la resistance a la corrosion chimique Partie1:Determinationdela resistanceala corrosion chimiqueparles acidesatemperatureambiante Reference number ISO 28706-1:2008(E) ISO ISO2008 ISO28706-1:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation COPYRIGHTPROTECTEDDOCUMENT ISO2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, IsO's member body in the country of the requester. ISO copyright office Casepostale56.CH-1211Geneva20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii ISo2008-Allrights reserved ISO28706-1:2008(E) Contents Page Foreword. iv Introduction. 1 Scope, 2 Normativereferences. 3 Principle... 4 Reagents 5 Materials and apparatus. 6 Testspecimens. 7 Procedure... 7.1 Attack by the test solution.. 7.2 8 Classificationof results 9 Citric acid testat roomtemperature. 9.1 Test solution.... 9.2 Testtime 9.3 Testreport 10 Sulfuric acid test at room temperature.... 10.1 Test solution.. 10.2 Test time... 10.3 Test report... 11 Other test solutions at room temperature... 11.1 Test solution.. 11.2 Testtime.. 11.3 Test report. @ ISO 2008 - All rights reserved ili ISO28706-1:2008(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies non-governmental, in liaison with IsO, also take part in the work.Iso collaborates closely with the InternationalElectrotechnicalCommission(iEC)onallmattersofelectrotechnicalstandardization International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. The main task of technical committees is toprepare International Standards.Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an rights. isO shall not be held responsible for identifying any or all such patent rights. ISO28706-1waspreparedbytheEuropeanCommitteeforStandardization(CEN)(asEN14483-1)andwas adopted,underaspecial“fast-trackprocedure,byTechnicalCommitteeIsO/TC1o7,Metallicandother ItcancelsandreplacesISO2722:1997andiSO8290:1998,whichhavebeentechnicallyrevised. Iso28706 consists of the followingparts,underthe general titleVitreous and porcelain enamels Determinationofresistancetochemicalcorrosion: Part1:Determinationofresistanceto chemicalcorrosionbyacidsat roomtemperature Part 2:Determination of resistance to chemical corrosion by boiling acids, boiling neutral liquids and/or theirvapours Part3:Determinationofresistancetochemicalcorrosionbyalkalineliquidsusingahexagonalvessel Part4:Determination of resistance tochemical corrosionbyalkaline liquidsusinga cylindricalvessel Part5:Determinationofresistancetochemicalcorrosioninclosedsystems iv ISO2008-Allrights reserved ISO28706-1:2008(E) Introduction Corrosion of vitreous and porcelain enamels by aqueous solutionsis a dissolution process.The main component of the enamel, SiO2,forms a three-dimensional silica network.After hydrolysis, it decomposes and forms silicic acid or silicates. These are released into the attacking medium. Other components, mainly metal oxides, are hydrolysed as well and form the corresponding hydrated metal ions or hydroxides. All corrosion