1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationCorrosion of metals and alloys Procedures to determine and estimate runoff rates of metals from materials as a result of atmospheric corrosionBS ISO 17752:2012National forewordTh
2、is British standard is the UK implementation of ISO 17752:2012.The UK participation in its preparation was entrusted to Technical CommitteeISE/NFE/8, Corrosion of metals and alloys.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does
3、 not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012Published by BSI Standards Limited 2012 ISBN 978 0 580 67994 0 ICS 77.060 Compliance with a British Standard cannot confer immunity from legal
4、obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2012. Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS ISO 17752:2012 ISO 2012Corrosion of metals and alloys Procedures to determine and estim
5、ate runoff rates of metals from materials as a result of atmospheric corrosionCorrosion des mtaux et alliages Modes opratoires pour dterminer et valuer le taux dentranement par les eaux de ruissellement des mtaux prsents dans des matriaux soumis la corrosion atmosphriqueINTERNATIONAL STANDARDISO1775
6、2First edition2012-07-01Reference numberISO 17752:2012(E)BS ISO 17752:2012ISO 17752:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, elect
7、ronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb
8、 www.iso.orgPublished in SwitzerlandBS ISO 17752:2012ISO 17752:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope 12 Normative references . 13 Requirements for test specimens . 13.1 Types of specimen 13.2 Specimen preparation and handling 13.3 Marking of specimens
9、23.4 Number of specimens 23.5 Storage . 23.6 Specimen data records 24 Atmospheric-corrosion test sites . 34.1 Test site requirements 34.2 Test site locations and security . 34.3 Exposure frames . 35 Test site characterization 46 Operating conditions 47 Test procedure . 67.1 Duration of tests 67.2 Pe
10、riodic collection of runoff samples 67.3 Evaluation of results . 68 Test report . 7Annex A (informative) Conditions affecting estimation of runoff rates of metals from bare materials as a result of atmospheric corrosion in a particular application 8Bibliography . 11BS ISO 17752:2012ISO 17752:2012(E)
11、ForewordISO (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 technical committees. Each member body interested in a subject for which a te
12、chnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters
13、of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated t
14、o the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for
15、identifying any or all such patent rights.ISO 17752 was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys.iv ISO 2012 All rights reservedBS ISO 17752:2012ISO 17752:2012(E)IntroductionRunoff testing is carried out in order to obtain data on the release rates of metals of diff
16、erent materials under atmospheric exposure conditions. It involves exposure of specimens at a test site and, in addition, continuous collection of runoff water samples and is therefore more demanding than standardized corrosion tests.Standardized corrosion tests cannot be used for obtaining these da
17、ta since, on a long-term perspective, the runoff rate is always less than or equal to, and frequently much less than, the corrosion rate. The difference is the metal incorporated in the corrosion products. In contrast to standardized corrosion tests, runoff testing can be performed on real product s
18、urfaces or on any kind of surface-treated material, e.g. pure metals, alloys or different coatings (i.e. metallic coatings, metal-including organic coatings), as long as the history and surface finish and characteristics of the specimen are documented.The result of this field test is the metal relea
19、se rate to the collected rain water that has impinged the material surface. Further possible transformations of the metal in its different chemical forms and interactions with the environment are beyond the scope of this International Standard.Procedures to establish runoff rates can be carried out
20、either by determination (normative) based on exposure of specimens or by estimation (informative), taking into account the conditions in a particular application. ISO 2012 All rights reserved vBS ISO 17752:2012Corrosion of metals and alloys Procedures to determine and estimate runoff rates of metals
21、 from materials as a result of atmospheric corrosion1 ScopeThis International Standard specifies procedures to determine and estimate runoff rates of metals from metals, alloys and coatings under atmospheric conditions carried out in the open air.2 Normative referencesThe following referenced docume
22、nts are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 4221, Air quality Determination of mass concentration of sulphur dioxide in a
23、mbient air Thorin spectrophotometric methodISO 4226, Air quality General aspects Units of measurementISO 4543, Metallic and other non-organic coatings General rules for corrosion tests applicable for storage conditionsISO 8565, Metals and alloys Atmospheric corrosion testing General requirementsISO
24、9169, Air quality Definition and determination of performance characteristics of an automatic measuring systemISO 9225, Corrosion of metals and alloys Corrosivity of atmospheres Measurement of environmental parameters affecting corrosivity of atmospheresISO 9226, Corrosion of metals and alloys Corro
25、sivity of atmospheres Determination of corrosion rate of standard specimens for the evaluation of corrosivity3 Requirements for test specimens3.1 Types of specimenThe exposed surface area of the specimen should be of such a magnitude that it provides sufficient water runoff volumes to enable reprodu
26、cible results to be determined from the test, minimizing edge effects and any loss of runoff water. Rectangular specimens in the form of flat sheets shall be sized at least 100 mm 300 mm (300 cm2). The surface area of the specimens can be larger, provided that they can be accurately evaluated and al
27、l runoff water continuously collected. The specimen thickness shall be adequate to ensure that the specimens will endure the intended test period. A useful thickness is between 1 mm and 3 mm. The surface of the specimen tested should represent real products as closely as possible.3.2 Specimen prepar
28、ation and handlingBecause atmospheric corrosion and metal runoff tests may extend over many years, it is important to ensure that specimens are clearly identified and records of data (collected total runoff water volumes, pH, and measured total metal concentrations) are carefully kept.Surface damage
29、 shall be avoided. All specimens, in particular coated materials, shall be free from surface damage. To minimize surface contamination and to ensure surface uniformity, the uncoated specimens should INTERNATIONAL STANDARD ISO 17752:2012(E) ISO 2012 All rights reserved 1BS ISO 17752:2012ISO 17752:201
30、2(E)be cleaned prior to exposure, if possible, depending on the material. A convenient procedure is degreasing in acetone and isopropylic alcohol. Abrasion is not recommended since such a surface is not representative for real product conditions and can largely influence the extent of released metal
31、s. Fingerprints during specimen handling can influence the results and shall be avoided by using cotton gloves and by handling the specimens at the edges.The reverse side of each specimen shall be covered by an adhesive tape and the cut-edges shall be sealed with lacquer (metal-free) or wax in order
32、 to avoid metal release from these parts of the specimen. Sealing of cut-edges is primarily essential for coated materials.A specimen holder without a metal specimen made of an inert material with the same area should be exposed in parallel to continuously collect impinging rainwater for background
33、deposition rates of the metals of interest.3.3 Marking of specimensMark the specimens in such a way that no confusion during the exposure is possible. It is recommended to mark both the sample holder and the specimen.This can be accomplished by notching (which shall be on the back side of the specim
34、en). Other marking procedures may be used, provided that the requirements of legibility and durability are met. The area affected by marking shall be minimized. Any method of identification used on the specimens shall not influence, or otherwise interfere with, the results of the test; this is parti
35、cularly important where notching is used to identify coated specimens. All notching on coated specimens shall be made prior to coating.3.4 Number of specimensFor each type of material, one specimen is sufficient as long as the surface area is equal to or exceeds 300 cm2(see 3.1).3.5 StorageThe time
36、period between specimen preparation and start of exposure should be kept as short as possible to minimize any corrosive effects induced on the specimen during storage. Such effects can influence runoff results, in particular for specimens releasing very low concentrations of metals. The recommended
37、time between specimen preparation and start of exposure is one week, in particular for bare metal and alloy surfaces.Since runoff tests can be conducted on any kind of surface, it is essential to document the storage time and storage conditions prior to testing. If the specimens are to be analysed f
38、or corrosion products and surface morphology after exposure termination, the recommended maximum time between the end of exposure and surface evaluation is two weeks to ensure no changes in surface characteristics and to avoid further oxidation. Naturally this period shall be kept as short as possib
39、le, in particular for short-term exposures.During storage of the test specimens before exposure, care shall be taken to avoid mechanical damage and contact with other specimens. A room with controlled temperature and relative humidity of 50 % or less shall be used for storage purposes. Particularly
40、sensitive specimens shall be stored in a desiccator or sealed in plastic bags with a desiccant. (See ISO 4543.)3.6 Specimen data recordsFor each series of test specimens, record the data that are needed for the assessment of the runoff effects (see Clause 8). These records shall include the followin
41、g:a) in the case of bare metals or alloys: chemical composition including main and minor alloying elements; exposure geometry and surface area; surface finish characteristics (e.g. surface roughness profile, etc.);2 ISO 2012 All rights reservedBS ISO 17752:2012ISO 17752:2012(E) specimen history (e.g
42、. storage conditions, pretreatments, surface ageing).b) in the case of coatings or other product surfaces, in addition: specification of the basis metal (substrate), if available; specification of the coating application method(s); specification of the coating material(s), chemical composition; coat
43、ing thickness.NOTE 1 The composition can vary from point to point on the specimen, as can the morphology of coating exposed to the test.NOTE 2 Visual and photographic records of the specimen conditions prior to and during testing can be made.4 Atmospheric-corrosion test sites4.1 Test site requiremen
44、tsThe atmospheric-corrosion test site shall provide facilities for open-air exposure, i.e. direct exposure to all atmospheric conditions and atmospheric contaminants (see ISO 8565).Test sites shall be selected so that the testing area will normally be exposed to the full effects of the weather. The
45、presence of buildings, structures, trees and certain geographical features (rivers, lakes, hills or hollows) might cause unintended shelter of exposure to wind, sources of pollution or sunlight.Unless the effects from man-made or natural features are to be an intended part of the exposure programme,
46、 such features in the vicinity of the test site, that could influence the results of the test, should be avoided; otherwise their presence shall be reported. Similarly, the presence of low-growing shrubs and other plants may affect the temperature and humidity distribution over a given test site. Th
47、erefore these shall be absent or controlled to a maximum height of 0,2 m or by placing test frames on well-drained ground or on gravel, concrete or paved foundations.4.2 Test site locations and securityThe exposure site shall be selected so that it represents uniform conditions of some atmospheric s
48、ite with specific characteristics, for example, a rural, urban, marine or industrial environment. If possible, it shall be located at or near a site where on-going meteorological and environmental measurements of temperature, humidity, rainfall characteristics (rainfall quantity, rain intensity), ga
49、seous and/or particle contaminants are performed, for instance by environmental or health organizations. Near-point sources of emission of corrosive substances shall be avoided. Ideally, the test site shall be fenced or in other ways protected from damage caused by the public or by animals and from growing plants reaching the specimens.4.3 Exposure framesThe function of the exposure frames is to maintain the test specimen securely in position without undergoing significant deterioration or infl
