EN ISO 11306:1998

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Korozija kovin in zlitin - Smernice za izpostavljanje in vrednotenje kovin in zlitin v površinski plasti morske vode (ISO 11306:1998)Korrosion von Metallen und Legierungen - Richtlinien für die Auslagerung von Metallen und Legierungen in oberflächennahem - Meerwasser und für die Auswertung (ISO 11306:1998)Corrosion de métaux et alliages - Lignes directrices pour l'exposition et l'évaluation des métaux et alliages a la surface de l'eau de mer (ISO 11306:1998)Corrosion of metals and alloys - Guidelines for exposing and evaluating metals and alloys in surface sea water (ISO 11306:1998)77.060Korozija kovinCorrosion of metalsICS:Ta slovenski standard je istoveten z:EN ISO 11306:1998SIST EN ISO 11306:1999en01-oktober-1999SIST EN ISO 11306:1999SLOVENSKI
STANDARD
AReference numberISO 11306:1998(E)INTERNATIONALSTANDARDISO11306First edition1998-02-15Corrosion of metals and alloys —Guidelines for exposing and evaluatingmetals and alloys in surface sea waterCorrosion des métaux et alliages — Lignes directrices pour l'expositionet l'évaluation des métaux et alliages à la surface de l'eau de merSIST EN ISO 11306:1999

ISO 11306:1998(E)©
ISO 1998All rights reserved. Unless otherwise specified, no part of this publication may be reproducedor utilized in any form or by any means, electronic or mechanical, including photocopying andmicrofilm, without permission in writing from the publisher.International Organization for StandardizationCase postale 56 · CH-1211 Genève 20 · SwitzerlandInternetcentral@iso.chX.400c=ch; a=400net; p=iso; o=isocs; s=centralPrinted in SwitzerlandiiForewordISO (the International Organization for Standardization) is a worldwidefederation of national standards bodies (ISO member bodies). The work ofpreparing International Standards is normally carried out through ISOtechnical committees. Each member body interested in a subject for whicha technical committee has been established has the right to be representedon that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISOcollaborates closely with the International Electrotechnical Commission(IEC) on all matters of electrotechnical standardization.Draft International Standards adopted by the technical committees arecirculated to the member bodies for voting. Publication as an InternationalStandard requires approval by at least 75 % of the member bodies castinga vote.International Standard ISO 11306 was prepared by Technical CommitteeISO/TC 156, Corrosion of metals and alloys.SIST EN ISO 11306:1999

INTERNATIONAL STANDARD
© ISOISO 11306:1998(E)1Corrosion of metals and alloys — Guidelines for exposingand evaluating metals and alloys in surface sea water1
Scope1.1
This International Standard gives guidance on the conditions and procedures to be followed when conductingexposures of metals and alloys to surface sea water such that meaningful comparisons may be made for differentlocations. This International Standard applies to exposure areas from above water level which are wet for asignificant period (splash and tidal zones) down to a depth at which the composition of the sea water is similar tothat at the surface.1.2
This practice gives guidance on procedures for the evaluation of the effects of sea water on metals and alloys.1.3
Because of the variability and complexity of sea water, exposures over a minimum period of one year areconsidered necessary to minimize the influence of these variable factors.2
Normative referencesThe following standards contain provisions which, through reference in this text, constitute provisions of thisInternational Standard. At the time of publication, the editions indicated were valid. All standards are subject torevision, and parties to agreements based on this International Standard are encouraged to investigate thepossibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintainregisters of currently valid International Standards.ISO 8407:1991, Corrosion of metals and alloys — Removal of corrosion products from corrosion test specimens.ISO 11463:1995, Corrosion of metals and alloys — Evaluation of pitting corrosion.3
Control specimensIt is prudent, because of the inherent variability in processing conditions, that control specimens be used incorrosion tests. Two kinds of control specimens are needed as follows.A specimen for which performance is well established in the given environment and which actually does corrode (forexample, mild steel). Its corrosion rate will help to determine the length of the test period.A specimen that is known to be normally resistant in the given environment (for example, copper). The purpose ofthis specimen is to make sure that no unusual conditions, such as chemical pollution, were encountered during thetest period. In the case of evaluations of aluminium alloys, care should be exercised in the location of these copperspecimens (see 6.2).SIST EN ISO 11306:1999

ISO 11306:1998(E)© ISO24
Test sites4.1
Test sites shall be chosen at locations representative of natural seawater environments where the metals oralloys to be tested may be used. Ideally, a natural seawater test site shall be in a protected location where allnecessary conditions required for such tests (splash, tidal and full immersion) may be encountered. Unless theintent is to determine the corrosion due to pollution, the site shall have clean, uncontaminated sea water. Referenceshall be made to tropical versus other conditions, and seasonal variations in temperature and in deposition ofmarine growth on the test panels with a defined “fouling season”. Climatic and atmospheric characteristics may alsobe important in selecting a site where tidal or splash and spray exposures may be conducted.4.2
Observations of critical water parameters shall be made and reported; depending on the experiment, thesetypically include water temperature, salinity, conductivity, pH, oxygen content, other compositional parameters (e.g.ammonia, hydrogen, sulfides, carbon dioxide, heavy metals) and tidal flow (velocity). The periodicity ofmeasurement of water parameters will be a function of the length of exposure and the expected time variation inthese parameters. A mean value of the seawater conditions on a monthly basis is normal.5
Exposure racks5.1
Test racks shall be constructed of a material that will remain intact for the entire proposed period of exposure.Monel nickel-copper alloy 400 (UNS No. N04400) has been found to be an excellent material for racks, but is notrecommended for holding aluminium specimens. Coated aluminium racks (6061-T6 or 5086-H32) also have givensatisfactory service when used with strip insulators (such as polyethylene) and nylon bolts and nuts to mount thespecimens. Nonmetallic racks may be used, provided that they have no effect on the corrosion of the specimens.Reinforced plastic racks may be used. Treated wood is not appropriate for test racks as the preservative may leachout and affect corrosion of the test materials.5.2
Specimens shall be mounted in the racks so that they are supported by porcelain or plastic insulators and donot make electrical contact with each other or with the supporting racks. Rack charts shall be maintained showingthe positions of all specimens and exposure data.5.3
Spacing of the mounted specimens can be important, therefore it is desirable to have sufficient space betweensurfaces of test specimens to ensure that adequate water flows between them and that with long exposures theaccumulated fouling will not block off the surface to the presence of the seawater environment.5.4
Racks may be suspended by such materials as nylon, polyester or polypropylene rope depending onprevailing conditions. Steel wire rope shall not be used.5.5
Exposure racks shall be suspended so that attached specimens will be oriented vertically and subjected to thefull effects of the sea water bu
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