1、BRITISH STANDARDBS EN ISO 11303:2008Corrosion of metals and alloys Guidelines for selection of protection methods against atmospheric corrosionICS 77.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g
2、40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN ISO 11303:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 11 December 2002 BSI 2008ISBN 978 0 580 60533 8National forewordThis British Standard is the UK implementation of EN ISO
3、11303:2008. It is identical with ISO 11303:2002. It supersedes BS ISO 11303:2002, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee ISE/NFE/8, Corrosion of metals and alloys.A list of organizations represented on this committee can be obtained on request
4、 to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate Comments30
5、 June 2008 This corrigendum renumbers BS ISO 11303:2002 as BS EN ISO 11303:2008EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 11303April 2008ICS 77.060English VersionCorrosion of metals and alloys - Guidelines for selection ofprotection methods against atmospheric corrosion (ISO11303:2002)Cor
6、rosion des mtaux et alliages - Lignes directrices pourle choix des mthodes de protection contre la corrosionatmosphrique (ISO 11303:2002)Korrosion von Metallen und Legierungen - Leitfaden zurAuswahl von Verfahren zum Schutz gegenberatmosphrischer Korrosion (ISO 11303:2002)This European Standard was
7、approved by CEN on 21 March 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationa
8、lstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notifi
9、ed to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
10、Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008 CEN All rights of exploitatio
11、n in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 11303:2008: EForeword The text of ISO 11303:2002 has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys” of the International Organization for Standardization (ISO) and has been tak
12、en over as EN ISO 11303:2008 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by Octo
13、ber 2008, and conflicting national standards shall be withdrawn at the latest by October 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent
14、 rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland
15、, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 11303:2002 has been approved by CEN as a EN ISO 11303:2008 without any modification. BS EN ISO 1130
16、3:20081Corrosion of metals and alloys Guidelines for selection of protection methods against atmospheric corrosion1 ScopeThis International Standard gives guidance on the selection of methods of protection against atmospheric corrosionof metals and alloys. It is applicable for technical equipment an
17、d products made of structural metals and used underatmospheric conditions. In a rational selection of protection methods, the corrosivity of the atmospheric environmentsis one of the important factors. These guidelines use the atmospheric corrosivity classification defined in ISO 9223.2 Normative re
18、ferencesThe following normative documents contain provisions which, through reference in this text, constitute provisions ofthis International Standard. For dated references, subsequent amendments to, or revisions of, any of thesepublications do not apply. However, parties to agreements based on thi
19、s International Standard are encouraged toinvestigate the possibility of applying the most recent editions of the normative documents indicated below. Forundated references, the latest edition of the normative document referred to applies. Members of ISO and IECmaintain registers of currently valid
20、International Standards.ISO 8044:1999, Corrosion of metals and alloys Basic terms and definitionsISO 9223:1992, Corrosion of metals and alloys Corrosivity of atmospheres ClassificationISO 9224:1992, Corrosion of metals and alloys Corrosivity of atmospheres Guiding values for the corrosivitycategorie
21、sISO 12944-2:1998, Paints and varnishes Corrosion protection of steel structures by protective paint systems Part 2: Classification of environments3 Terms and definitionsFor the purposes of this International Standard, the following terms and definitions apply.3.1 corrosion systemsystem consisting o
22、f one or more metals and those parts of environment that influence corrosionISO 80443.2 corrosion damagecorrosion effect that causes impairment of the function of the metal, the environment or the technical system of whichthese form a partISO 80443.3 corrosivityability of an environment to cause cor
23、rosion of a metal in a given corrosion systemISO 8044BS EN ISO 11303:200823.4 corrosion protectionmodification of a corrosion system so that corrosion damage is reducedISO 80443.5 serviceability (with respect to corrosion)ability of a system to perform its specified function(s) without impairment du
24、e to corrosionISO 80443.6 service life (with respect to corrosion)time during which a corrosion system meets the requirements for serviceabilityISO 80443.7 durability (with respect to corrosion)ability of a corrosion system to maintain serviceability over a specified time when the specified requirem
25、ents for useand maintenance have been fulfilledISO 80443.8 maintenancecomplex of activities, securing functions of a protection system during a planned service life3.9 atmospheremixture of gases, and normally also aerosols and particles, that surrounds a given objectISO 12944-24 Procedure for select
26、ion of a corrosion protection method4.1 GeneralIn general, protection against atmospheric corrosion can be achieved by the selection of suitable material, the designof the product with respect to protection against corrosion, by reducing the corrosivity of the environment and bycovering the product
27、with appropriate protective coatings.The selection of the appropriate corrosion protection method comprises several steps respecting characteristics ofthe product, its designed service life and other demands connected with its use, the corrosive environment and otherfactors outside the corrosion sys
28、tem e.g. cost. The relations are shown in Figure 1. The steps of the corrosionprotection selection defined in 4.2 to 4.6 are marked on this schematic diagram.4.2 Corrosion systemIn the sense of this International Standard, the corrosion system encompasses both the structural metallic elementand its
29、environment, i.e., the atmosphere in contact with it. The term atmosphere includes corrosive atmosphericcomponents (gases, aerosols, particles).BS EN ISO 11303:200834.3 Principal factor in selection of corrosion protection methodThe designed service life is the principal factor in the process of sel
30、ecting the protection method for structuralelements. Service life of a component or product is derived in relation to its most important functional property, e.g.thickness of an element, non-corroded surfaces, colour or gloss. If the service life cannot be attained because ofshorter life of the sele
31、cted optimum protection method, it shall be necessary to apply one or several maintenancecycles.NOTE References to the procedures described in clause 4.Figure 1 Procedure for the selection of a corrosion protection methodBS EN ISO 11303:200844.4 Further factors and demandsFurther factors to be taken
32、 into account in selecting the protection method are:a) application conditions, i.e. technical feasibility of applying the protection method;b) additional requirements derived from the use of the structural element to be protected, e.g. colour shade,mechanical or electrical properties, light reflect
33、ion.4.5 Considerations in the decision-making process4.5.1 GeneralWith respect to the component to be protected the main considerations are:a) its design (4.5.2);b) structural metals (4.5.3).With respect to the environment the main considerations are:c) active agent,e.g. gaseous pollution and partic
34、les (4.5.4);d) conditions of action, e.g. humidity, temperature, level and changes, etc. (4.5.4).4.5.2 DesignThe shape, size and other design factors of the structural element exert an important influence on the selection of theoptimum protection method. This cannot be described in a generalized for
35、m. The influence of the design shall alwaysbe considered individually.In the corrosion system the design of the structural element affects the severity of atmospheric effects on individualsurfaces, e.g. by different time of wetness, exposure categories or accumulation of corrodants.4.5.3 Structural
36、metalsThe most important structural metals are:a) carbon steel;b) low-alloy weathering steel;c) stainless steel;d) aluminium (and Al-alloys);e) copper (and Cu-alloys);f) zinc (and Zn-alloys).NOTE The sensitivity to atmospheric corrosion and characteristics of attack in these metals varies greatly.Th
37、e surface conditions of a basis metal, e.g. presence of corrosion products, salts and surface roughness, exert adecisive influence on the durability of the corrosion protection.4.5.4 Environmental conditionsMany factors influence the corrosivity of the atmosphere.ISO 9223 provides a means for classi
38、fying the corrosivity of atmospheres based on four standard metals (carbonsteel, zinc, copper and aluminium). The controlling factors are time of wetness and the deposition of chlorides andBS EN ISO 11303:20085sulfur dioxide (airborne corrodants). Other important factors of the environment are radia
39、tion from the sun andtemperature extremes.4.6 Further steps in the selection processIn general, the selection of a coating process may be limited by the design of the structural element (e.g. accessibilitymay limit use of a spray process and size may limit the use of a hot dip galvanizing process).T
40、he quality degree of the protection method should preferably be derived from the required service life. Durability ofthe selected protection system changes with the severity of the environment.If the selection of an optimum corrosion protection method for the given corrosion system does not lead tos
41、atisfactory results, it is possible to improve acceptability by changing the corrosion system (change of material ordesign of structural element, modification of environment).5 Significance of the corrosivity classification for selection of protection methodThe need for protective measures is based
42、on the application of corrosivity categories.The basis for deriving corrosivity categories is represented either by corrosion losses of standardized specimens offour basic structural metals (carbon steel, zinc, copper and aluminium) after a one year atmospheric exposure, or byyearly arithmetic means
43、 of the three most important environmental characteristics affecting atmospheric corrosion,i.e. time of wetness, deposition rate of sulfur dioxide and/or chlorides. The measured values are ranked into differentclassification categories and generalize certain ranges of environmental effects on those
44、metallic materials.Provided that similar corrosion mechanisms apply, the corrosivity categories yield useful information about thecorrosion behaviour of related alloys. The corrosivity categories are not applicable to stainless steels for which datashall be derived directly by taking the main factor
45、s of environment and the specific behaviour of these steels intoaccount.Corrosion losses determined after one year of exposure shall not be used for prediction of corrosion losses afterlonger periods because corrosion losses are not linear with time. However, these measurements can be used toestabli
46、sh the appropriate corrosion category. Then the corrosion losses after longer periods can be estimated fromthe guiding values outlined in ISO 9224.Structural elements include components differing from standardized surfaces used for specification of the corrosivitycategories. The orientation of the s
47、urface affects corrosion losses. The corrosivity information based on shelteredand indoor rooms may be helpful.6 Durability of the protection systemRequirements for the quality of protection systems become more stringent the higher the corrosivity category and thestricter the durability requirements
48、.The durability of a given protective system generally increases with its thickness within limits specific for that system.NOTE Detailed information for the selection of a protection system for a structural metal and its durability should be taken fromthe relevant specifications of the individual pr
49、otection method, e.g. for details of corrosion protection of steel structures byprotective paints systems see ISO 12944-1 to -8 and by metal coatings see ISO 14713.BS EN ISO 11303:20086Bibliography1 ISO 12944-1:1998, Paints and varnishes Corrosion protection of steel structures by protective paintsystems Part 1: General introduction2 ISO 12944-3:1998, Paints and varnishes Corrosion protection of steel structures by protective paintsystems Part 3: Design considerations3 ISO 12944-4:1998, Paints and varnishes Corrosion protection
