1、BRITISH STANDARD BS EN ISO 11306:1998 Corrosion of metals and alloys Guidelines for exposing and evaluating metals and alloys in surface sea water The European Standard EN ISO 11306:1998 has the status of a British Standard ICS 77.060BSEN ISO 11306:1998 This British Standard, having been prepared un
2、der the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board and comes intoeffect on 15April1998 BSI 04-1999 ISBN 0 580 29656 3 National foreword This British Standard reproduces verbatim EN ISO 11306:1998. It is identical with ISO11306:1998. The UK partic
3、ipation in its preparation was entrusted to Technical Committee ISE/NFE/8, Corrosion of metals and alloys, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change,
4、and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC standards
5、 normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the se
6、ction entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applicatio
7、n. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, page 2, the ISO title page, page ii, pages1to4 and abackcover. This standard has been upda
8、ted (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS EN ISO 11306:1998 BSI 04-1999 i Contents Page National foreword Inside front cover Foreword 2 Forew
9、ord ii Text of ISO 11306 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11306 February 1998 ICS Descriptors: See ISO document English version Corrosion of metals and alloys Guidelines for exposing and evaluating metals and alloys in surface sea water (ISO11306:1998) Corrosion de m
10、taux et alliages Lignes directrices pour lexposition et lvaluation des mtaux et alliages la surface de leau de mer (ISO 11306:1998) Korrosion von Metallen und Legierungen Richtlinien fr die Auslagerung von Metallen und Legierungen in oberflchennahem Meerwasser und fr die Auswertung (ISO11306:1998) T
11、his European Standard was approved by CEN on12 January1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical refere
12、nces concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member int
13、o its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Sp
14、ain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN n
15、ational Members. Ref. No. EN ISO 11306:1998 EEN ISO 11306:1998 BSI 04-1999 2 Foreword The text of the International Standard ISO11306:1998 has been prepared by Technical Committee ISO/TC156 “Corrosion of metals and alloys” in collaboration with Technical Committee CEN/TC262 “Metallic and other inorg
16、anic coatings”, the secretariat of which is held by DIN. 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 August1998, and conflicting national standards shall be withdrawn at the latest by August19
17、98. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
18、Portugal, Spain, Sweden, Switzerland and the UnitedKingdom. Endorsement notice The text of the International Standard ISO11306:1998 was approved by CEN as a European Standard without any modification. Contents Page Foreword 2 1 Scope 1 2 Normative references 1 3 Control specimens 1 4 Test sites 1 5
19、Exposure racks 1 6 Specimens 2 7 Preparation of specimens 2 8 Evaluation of test specimens 3 9 Test report 3EN ISO 11306:1998 ii BSI 04-1999 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prepa
20、ring International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in l
21、iaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publica
22、tion as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO11306 was prepared by Technical Committee ISO/TC156, Corrosion of metals and alloys. Descriptors: Metal products, alloys, corrosion, sea water corrosion, tests, corrosion
23、 tests, testing conditions, test specimens, rules (instructions).EN ISO 11306:1998 BSI 04-1999 1 1 Scope 1.1 This International Standard gives guidance on the conditions and procedures to be followed when conducting exposures of metals and alloys to surface sea water such that meaningful comparisons
24、 may be made for different locations. This International Standard applies to exposure areas from above water level which are wet for a significant period (splash and tidal zones) down to a depth at which the composition of the sea water is similar to that at the surface. 1.2 This practice gives guid
25、ance 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 are considered necessary to minimize the influence of these variable factors. 2 Normative references The fol
26、lowing standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are en
27、couraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 8407:1991, Corrosion of metals and alloys Removal of corrosion products from corrosion test specime
28、ns. ISO 11463:1995, Corrosion of metals and alloys Evaluation of pitting corrosion. 3 Control specimens It is prudent, because of the inherent variability in processing conditions, that control specimens be used in corrosion tests. Two kinds of control specimens are needed as follows. A specimen for
29、 which performance is well established in the given environment and which actually does corrode (for example, 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 pu
30、rpose of this specimen is to make sure that no unusual conditions, such as chemical pollution, were encountered during the test period. In the case of evaluations of aluminium alloys, care should be exercised in the location of these copper specimens (see6.2). 4 Test sites 4.1 Test sites shall be ch
31、osen at locations representative of natural seawater environments where the metals or alloys to be tested may be used. Ideally, a natural seawater test site shall be in a protected location where all necessary conditions required for such tests (splash, tidal and full immersion) may be encountered.
32、Unless the intent is to determine the corrosion due to pollution, the site shall have clean, uncontaminated sea water. Reference shall be made to tropical versus other conditions, and seasonal variations in temperature and in deposition of marine growth on the test panels with a defined “fouling sea
33、son”. Climatic and atmospheric characteristics may also be 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, these typically include water temperature, salin
34、ity, conductivity, pH, oxygen content, other compositional parameters (e.g.ammonia, hydrogen, sulfides, carbon dioxide, heavy metals) and tidal flow (velocity). The periodicity of measurement of water parameters will be a function of the length of exposure and the expected time variation in these pa
35、rameters. A mean value of the seawater conditions on a monthly basis is normal. 5 Exposure racks 5.1 Test racks shall be constructed of a material that will remain intact for the entire proposed period of exposure. Monel nickel-copper alloy400 (UNSNo.N04400) has been found to be an excellent materia
36、l for racks, but is not recommended for holding aluminium specimens. Coated aluminium racks(6061-T6 or5086-H32) also have given satisfactory service when used with strip insulators (such as polyethylene) and nylon bolts and nuts to mount the specimens. Nonmetallic racks may be used, provided that th
37、ey 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 leach out and affect corrosion of the test materials. 5.2 Specimens shall be mounted in the racks so that they are supported by porcelain
38、or plastic insulators and do not make electrical contact with each other or with the supporting racks. Rack charts shall be maintained showing the positions of all specimens and exposure data.EN ISO 11306:1998 2 BSI 04-1999 5.3 Spacing of the mounted specimens can be important, therefore it is desir
39、able to have sufficient space between surfaces of test specimens to ensure that adequate water flows between them and that with long exposures the accumulated 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, po
40、lyester or polypropylene rope depending on prevailing 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 the full effects of the sea water but free of galvanic contact with other specimens and w
41、ith minimal sedimentation of silt and debris on the specimen. 6 Specimens 6.1 When the material to be tested is in sheet form, a nominal specimen size of100mm by300mm is recommended. Specimens may be larger or smaller to suit a particular test. 6.2 If testing of materials in odd shapes (bolts, nuts,
42、 pipes, etc.) is desired, it is essential that a means of supporting them in the test racks be devised. It is important that the specimens be electrically insulated from their respective supports and from each other to prevent formation of galvanic corrosion cells unless this is part of the study. I
43、n some instances it is not sufficient to isolate specimens electrically to prevent corrosion of one material. For example, it is essential to exercise great care with aluminium specimens or racks so that they will not be contaminated by copper, which will cause accelerated corrosion of the aluminium
44、. A galvanic couple is not necessary to accelerate the corrosion of aluminium by copper. Copper or alloys containing copper physically located in the vicinity of aluminium may corrode sufficiently so that accelerated corrosion of the aluminium may be caused by copper deposition on the aluminium (see
45、clause3). 6.3 The total number of test specimens required shall be determined from a knowledge of the duration of the test and the planned removals of the specimens for intermediate evaluations. There is seldom reason to remove and evaluate specimens exposed less than6 months. For reliable results,
46、a sufficient number of replicate specimens should be used for removal at each exposure period. Triplicate specimens for each exposure period will usually satisfy this requirement. A suitable removal schedule might be0,5 y,1 y,2 y,5 y,10y and20y. In case of uncertainty as to an alloys corrosion resis
47、tance, shorter intervals might be appropriate and corrosion rate data may be used to establish more appropriate exposure periods. In addition, yearly inspections shall be made to ensure that the specimens are intact. 6.4 Unexposed replicate specimens shall be considered for use where comparisons of
48、exposed and unexposed material will be made such as for corrosion effects on mechanical properties or appearance. 7 Preparation of specimens 7.1 Specimens shall be marked in a manner that will ensure identification for the life of the test. One good method is to use a series of notches or drilled ho
49、les arranged according to some desired code. Another method is to attach a corrosion-resistant metal tag by means of an insulating cord and a suitably located hole. An example of materials that can be used for such tags are alloy625 (UNSNo.N06625), alloy C276 (UNS No.10276) or alloy400 (UNS No. N0400) (except for aluminium alloys) or titanium. Numbers stamped on relatively corrosion-resistant materials may be suitable for some tests.EN ISO 11306:1998 BSI 04-1999 3 7.2 Oil, grease and dirt shall be removed by degreasing with a solvent cleaner
