BS EN ISO 9226-2012 Corrosion of metals and alloys Corrosivity of atmospheres Determination of corrosion rate of standard specimens for the evaluation of corrosivity《金属与合金的腐蚀 大气腐蚀性.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 9226:2012Corrosion of metals and alloys Corrosivity of atmospheres Determination of corrosionrate of standard specimens forthe evaluation of corrosivity(ISO 9226:2012)B

2、S EN ISO 9226:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 9226:2012.Together with BS EN ISO 9223:2011, BS EN ISO 9224:2011 and BS EN ISO 9225:2011, it supersedes BS EN 12500:2000 which is withdrawn.The UK participation in its preparation was entrust

3、ed to Technical Committee ISE/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 not purport to include all the necessary provisions of a contract. Users are responsible for its correct applica

4、tion. The British Standards Institution 2012. Published by BSI Standards Limited 2012ISBN 978 0 580 69031 0 ICS 77.060 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committ

5、ee on 29 February 2012.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 9226 February 2012 ICS 77.060 Supersedes EN 12500:2000English Version Corrosion of metals and alloys - Corrosivity of atmospheres - Determination of corrosion rate of

6、standard specimens for the evaluation of corrosivity (ISO 9226:2012) Corrosion des mtaux et alliages - Corrosivit des atmosphres - Dtermination de la vitesse de corrosion dprouvettes de rfrence pour lvaluation de la corrosivit (ISO 9226:2012) Korrosion von Metallen und Legierungen - Korrosivitt von

7、Atmosphren - Bestimmung der Korrosionsgeschwindigkeit von Standardproben zur Ermittlung der Korrosivitt (ISO 9226:2012) This European Standard was approved by CEN on 22 January 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving t

8、his European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official

9、 versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Aus

10、tria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United King

11、dom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 9226:2012: EBS

12、EN ISO 9226:2012EN ISO 9226:2012 (E) 3 Foreword This document (EN ISO 9226:2012) has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys“ in collaboration with Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which is held by BSI.

13、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 August 2012, and conflicting national standards shall be withdrawn at the latest by August 2012. Attention is drawn to the possibility that some of

14、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 rights. This document supersedes EN 12500:2000. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the fo

15、llowing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Sl

16、ovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 9226:2012 has been approved by CEN as a EN ISO 9226:2012 without any modification. BS EN ISO 9226:2012ISO 9226:2012(E) ISO 2012 All rights reserved iiiContents Page Foreword iv Introductio

17、n . v 1 Scope 1 2 Normative references 1 3 Principle . 1 4 Standard specimens . 2 5 Exposure of standard specimens 2 6 Expression of results 2 Annex A (informative) Chemical cleaning procedures for removal of corrosion products 4 Bibliography 5 BS EN ISO 9226:2012ISO 9226:2012(E) iv ISO 2012 All rig

18、hts reservedForeword ISO (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 f

19、or which a technical 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

20、 all matters 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 a

21、re circulated to 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

22、responsible for identifying any or all such patent rights. ISO 9226 was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys. This second edition cancels and replaces the first edition (ISO 9226:1992), which has been technically revised. In particular, the use of helix specimen

23、s as standard specimens is no longer prescribed and Annex A has been updated. BS EN ISO 9226:2012ISO 9226:2012(E) ISO 2012 All rights reserved vIntroduction The characterization of an atmospheric corrosion test site or of a service location with respect to its corrosivity can be accomplished by dete

24、rmining the corrosion rate of standard specimens exposed for one year to the atmosphere at the respective location (corrosivity determination). The standard specimens are flat plate specimens of the four standard structural materials: aluminium, copper, steel and zinc. This method represents an econ

25、omical way of evaluating corrosivity, taking into account all local environmental influences. BS EN ISO 9226:2012BS EN ISO 9226:2012INTERNATIONAL STANDARD ISO 9226:2012(E) ISO 2012 All rights reserved 1Corrosion of metals and alloys Corrosivity of atmospheres Determination of corrosion rate of stand

26、ard specimens for the evaluation of corrosivity WARNING Some of the procedures included in this International Standard entail the use of potentially hazardous chemicals. lt is emphasized that all appropriate safety precautions should be taken. 1 Scope This International Standard specifies methods wh

27、ich can be used for the determination of corrosion rate with standard specimens. The values obtained from the measurements (corrosion rates for the first year of exposure) are intended to be used as classification criteria for the evaluation of atmospheric corrosivity according to ISO 9223. They can

28、 also be used for informative evaluation of atmospheric corrosivity beyond the scope of ISO 9223. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest

29、 edition of the referenced document (including any amendments) applies. ISO 8407, Corrosion of metals and alloys Removal of corrosion products from corrosion test specimens ISO 8565, Metals and alloys Atmospheric corrosion testing General requirements ISO 9223, Corrosion of metals and alloys Corrosi

30、vity of atmospheres Classification, determination and estimation ISO 9224, Corrosion of metals and alloys Corrosivity of atmospheres Guiding values for the corrosivity categories 3 Principle The corrosivity of the exposure locations or of industrial installation sites is deduced from the corrosion r

31、ate, calculated from the loss of mass per unit area of standard specimens following the removal of corrosion products from the specimens after exposure periods of one year. In the case of alloys of iron, zinc and copper, mass loss is a proven measure of corrosion damage. In the case of aluminium all

32、oys, mass loss is a valid measure of corrosion. This International Standard describes only evaluation by mass loss and not corrosion penetration. Corrosion rates for the first year of exposure may be used for the calculation of corrosion rates for long-term exposures in accordance with ISO 9224. BS

33、EN ISO 9226:2012ISO 9226:2012(E) 2 ISO 2012 All rights reserved4 Standard specimens The specimens are rectangular plates with dimensions of preferably 100 mm 150 mm, but at least 50 mm 100 mm, and a thickness of approximately 1 mm. The materials used to prepare the standard specimens are of current

34、fabrication, i.e. steel: unalloyed carbon steel (Cu 0,03 % to 0,10 %, P 0,07 %) zinc: 98,5 % min. copper: 99,5 % min. aluminium: 99,5 % min. Prior to exposure, all specimens shall be solvent degreased. The sample shall be free from oil and grease; in order to achieve this, it may be necessary to use

35、 different solvents in successive steps. Steel specimens with visible rust stains or corrosion products on their surfaces shall be polished with 120 grit abrasive paper prior to degreasing to remove these visible corrosion products. The cleaning of metal specimens by sand blasting can result in a su

36、rface that is more prone to corrosion and is therefore not recommended for the cleaning of the standard specimens for corrosivity classification in accordance with ISO 9223. Copper, zinc and aluminium specimens shall not be used if visible corrosion products are present before exposure. NOTE For det

37、ails on the quality of recommended metallic materials, see the Bibliography. 5 Exposure of standard specimens The exposure of the weighed and marked standard specimens shall be carried out in accordance with the specifications of ISO 8565. Three specimens of each metal shall be exposed for one year,

38、 starting at the beginning of the worst corrosive period of the year (e.g. spring or autumn). After exposure, the corrosion products formed on specimens shall be removed in accordance with the specifications of ISO 8407 and reweighed to the nearest 0,1 mg. The cleaning procedure shall be repeated se

39、veral times in equal cleaning cycles. NOTE For procedures suitable for chemical cleaning, see Annex A. 6 Expression of results The corrosion rate, rcorr, for each metal, expressed as a mass loss per unit area over time, is given by Equation (1): corrmrA t(1) where rcorris the corrosion rate, express

40、ed in grams per square metre per year g/(m2 a); m is the mass loss, expressed in grams (g); A is the surface area, expressed in square metres (m2); t is the exposure time, expressed in years (a). BS EN ISO 9226:2012ISO 9226:2012(E) ISO 2012 All rights reserved 3The corrosion rate can also be express

41、ed as a thickness reduction rate given by Equation (2): corrmrA t (2) where rcorris the corrosion rate, expressed in micrometres per year (m/a); is the density of the metal (Fe: 7,86 g/cm3; Zn: 7,14 g/cm3; Cu: 8,96 g/cm3; Al: 2,70 g/cm3); m is the mass loss, expressed in grams (g); A is the surface

42、area, expressed in square metres (m2); t is the exposure time, expressed in years (a). The test report shall give all single values and their mean values. Any possible anomalies detected before, during and after exposure, which can have an influence of the mean result, shall be specified. BS EN ISO

43、9226:2012ISO 9226:2012(E) 4 ISO 2012 All rights reservedAnnex A (informative) Chemical cleaning procedures for removal of corrosion products WARNING When working with dangerous substances (such as chromium trioxide), all necessary safety precautions shall be taken. Material Chemical Time Temperature

44、 Remarks Steel 500 ml of hydrochloric acid (HCl, 1,19 g/ml) 3,5 g hexamethylene tetramine Distilled water to make up to 1 000 ml 10 min 20 C to 25 C An increased number of pickling intervals or longer times may be required in certain circumstances. Zinc 250 g glycine (NH2CH2COOH) Distilled water to

45、make up to 1 000 ml (saturated solution) 1 min to 10 min 20 C to 25 C Copper 50 g of amidosulfonic acid (sulfamic acid) Distilled water to make up to 1 000 ml 5 min to 10 min 20 C to 25 C Aluminium 50 ml of phosphoric acid (H3PO4, 1,69 g/ml)20 g of chromium trioxide (CrO3) Distilled water to make up

46、 to 1 000 ml 5 min to 10 min 80 C If corrosion products remain, follow the procedure below. Aluminium Nitric acid (HNO3, 1,42 g/ml) 1 min to 5 min 20 C to 25 C To avoid reactions that can result in excessive removal of basis metal, remove extraneous deposits and bulky corrosion products. BS EN ISO 9

47、226:2012ISO 9226:2012(E) ISO 2012 All rights reserved 5Bibliography 1 EN 485-1, Aluminium and aluminium alloys Sheet, strip and plate Part 1: Technical conditions for inspection and delivery 2 EN 485-2, Aluminium and aluminium alloys Sheet, strip and plate Part 2: Mechanical properties 3 EN 1179, Zi

48、nc and zinc alloys Primary zinc 4 EN 1652, Copper and copper alloys Plate, sheet, strip and circles for general purposes 5 EN 10130, Cold rolled low carbon steel flat products for cold forming Technical delivery conditions This page deliberately left blankThis page deliberately left blankBSI is the

49、independent national body responsible for preparing British Standards and other standards-related publications, information and services. It presents the UK view on standards in Europe and at the international level. BSI is incorporated by Royal Charter. British Standards and other standardisation products are published by BSI Standards Limited.British Standards Institution (BSI)raising standards worldwideBSI389 Chiswick High Road Londo