DIN EN ISO 9224-2012 Corrosion of metals and alloys - Corrosivity of atmospheres - Guiding values for the corrosivity categories (ISO 9224 2012) German version EN ISO 9224 2012《金属与.pdf

1、May 2012 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 77

2、.060!$|01“1891314www.din.deDDIN EN ISO 9224Corrosion of metals and alloys Corrosivity of atmospheres Guiding values for the corrosivity categories (ISO 9224:2012)English translation of DIN EN ISO 9224:2012-05Korrosion von Metallen und Legierungen Korrosivitt von Atmosphren Anhaltswerte fr die Korros

3、ivittskategorien (ISO 9224:2012)Englische bersetzung von DIN EN ISO 9224:2012-05Corrosion des mtaux et alliages Corrosivit des atmosphres Valeurs de rfrence relatives aux classes de corrosivit (ISO 9224:2012)Traduction anglaise de DIN EN ISO 9224:2012-05Together with DIN EN ISO9223:2012-05,DIN EN IS

4、O 9225:2012-05 andDIN EN ISO 9226:2012-05supersedesDIN EN 12500:2000-12www.beuth.deDocument comprises 19 pagesIn case of doubt, the German-language original shall be considered authoritative.04.12 DIN EN ISO 9224:2012-05 2 A comma is used as the decimal marker. National foreword This standard has be

5、en prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys” (Secretariat: SAC, China) and has been adopted as EN ISO 9224:2012 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” (Secretariat: BSI, United Kingdom) within the scope of the Agreement on technica

6、l cooperation between ISO and CEN (Vienna Agreement). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Committee NA 062-01-71 AA Korrosion und Korrosionsschutz. The DIN Standards corresponding to the Inter

7、national Standards referred to in this document are as follows: ISO 8044 DIN EN ISO 8044 ISO 9223 DIN EN ISO 9223 ISO 11303 DIN EN ISO 11303 ISO 14713-1 DIN EN ISO 14713-1 Amendments This standard differs from DIN EN 12500:2000-12 as follows: a) the specifications are now given in four standards (DI

8、N EN ISO 9223, DIN EN ISO 9224, DIN EN ISO 9225 and DIN EN ISO 9226); b) the specifications have been updated to reflect the current state of technology; c) the standard has been editorially revised. Previous editions DIN EN 12500: 2000-12 National Annex NA (informative) Bibliography DIN EN ISO 8044

9、, Corrosion of metals and alloys Basic terms and definitions DIN EN ISO 9223, Corrosion of metals and alloys Corrosivity of atmospheres Classification, determination and estimation DIN EN ISO 11303, Corrosion of metals and alloys Guidelines for selection of protection methods against atmospheric cor

10、rosion DIN EN ISO 14713-1, Zinc coatings Guidelines and recommendations for the protection against corrosion of iron and steel in structures Part 1: General principles of design and corrosion resistance EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 9224 February 2012 ICS 77.060 Supersedes

11、 EN 12500:2000English Version Corrosion of metals and alloys - Corrosivity of atmospheres - Guiding values for the corrosivity categories (ISO 9224:2012) Corrosion des mtaux et alliages - Corrosivit des atmosphres - Valeurs de rfrence relatives aux classes de corrosivit (ISO 9224:2012) Korrosion von

12、 Metallen und Legierungen - Korrosivitt von Atmosphren - Anhaltswerte fr die Korrosivittskategorien (ISO 9224:2012) 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 this

13、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 ver

14、sions (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 Austria

15、, 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 Kingdom.

16、 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 9224:2012: EContent

17、s Page Foreword 3Introduction 4 1 Scope . 5 2 Normative references . 5 3 Terms and definitions 5 4 Principle 6 5 Prediction of corrosion attack after extended exposure 6 6 Specific criteria for calculation of corrosion rates of structural metals . 7 6.1 Steels . 7 6.2 Zinc materials . 8 6.3 Copper a

18、lloys 8 6.4 Aluminium alloys 8 7 Long-term exposures . 8 Annex A (informative) Example of maximum corrosion attack after extended exposures for corrosivity categories 11 Annex B (informative) Average initial corrosion rates and average steady corrosion rates in intervals relative to classified corro

19、sivity categories . 13 Annex C (informative) Prediction of corrosion attack of steels with regard to steel composition . 14 Bibliography . 16 EN ISO 9224:2012 (E) DIN EN ISO 9224:2012-05 2Foreword This document (EN ISO 9224:2012) has been prepared by Technical Committee ISO/TC 156 “Corrosion of meta

20、ls and alloys“ in collaboration with 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

21、 August 2012, and conflicting national standards shall be withdrawn at the latest by August 2012. 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 pat

22、ent rights. This document supersedes EN 12500:2000. 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, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland

23、, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 9224:2012 has been approved by CEN as a

24、 EN ISO 9224:2012 without any modification. EN ISO 9224:2012 (E) DIN EN ISO 9224:2012-05 3 Introduction The “corrosivity category” established in ISO 9223 is a general term suitable for engineering purposes, which describes the corrosion properties of atmospheres based on current knowledge of atmosp

25、heric corrosion. Guiding values of corrosion attack can be used to predict the extent of corrosion attack in long-term exposures based on measurements of corrosion attack in the first-year exposure to the outdoor atmosphere in question. These values can also be used to determine conservative estimat

26、es of corrosion attack based on environmental information or corrosivity category estimates as shown in ISO 9223. Corrosion attack estimates obtained by using the methods in this International Standard can be used to predict the useful life of metallic components and, in some cases, of metallic coat

27、ings exposed to outdoor atmospheres covered by ISO 9223. The corrosion attack results can also be used to determine whether or not protective measures, such as coatings, are required to achieve desired product lives. Other uses include the selection of construction materials for outdoor atmospheric

28、service. Guiding values of corrosion can be used as information for the selection of a protection method against atmospheric corrosion according to ISO 11303. The guiding values in this International Standard are based on a large number of exposures in many locations throughout the world. However, t

29、he procedure used in this International Standard cannot possibly cover all the situations in natural environments and service conditions which can occur. In particular, situations that result in significant changes in the environment can cause major increases or decreases in corrosion rates. Users o

30、f this International Standard are cautioned to consult with qualified experts in the field of outdoor atmospheric corrosion in cases where localized corrosion can be more important than general attack. The specific issues of galvanic (bi-metallic) corrosion, pitting corrosion, crevice corrosion, env

31、ironmental cracking and corrosion product wedging are not addressed in this International Standard. EN ISO 9224:2012 (E) DIN EN ISO 9224:2012-05 41 Scope This International Standard specifies guiding values of corrosion attack for metals and alloys exposed to natural outdoor atmospheres for exposure

32、s greater than one year. This International Standard is intended to be used in conjunction with ISO 9223. Guiding corrosion values for standard structural materials can be used for engineering calculations. The guiding corrosion values specify the technical content of each of the individual corrosiv

33、ity categories for these standard metals. Annex A provides examples of calculated maximum corrosion attack after extended exposure (up to 20 years) for six standardized corrosivity categories. Annex B provides presumed average initial and steady-state corrosion rates of standard metals in intervals

34、relative to six standardized corrosivity categories. Annex C provides the calculation procedure for corrosion attack of steels in regard to their composition. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only

35、the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 8044, Corrosion of metals and alloys Basic terms and definitions ISO 9223, Corrosion of metals and alloys Corrosivity of atmospheres Classification, determination

36、and estimation 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 8044 and the following apply. 3.1 guiding corrosion value corrosion rates, mass loss, penetration or other corrosion characteristics expressing the expected corrosive action of the atmosp

37、heric environment of a given corrosivity category towards standard metals 3.2 corrosion rate after extended exposure corrosion rate after exposures longer than one year EN ISO 9224:2012 (E) DIN EN ISO 9224:2012-05 5 3.3 average corrosion rate ravyearly corrosion rate calculated as an average value f

38、or the first 10 years of atmospheric exposure of a metal 3.4 steady-state corrosion rate rlinyearly corrosion rate derived from a long-term atmospheric exposure of a metal, not including the initial period NOTE For the purposes of this International Standard, the corrosion rate after 10 years of exp

39、osure is considered constant. 4 Principle The corrosion rate of metals and alloys exposed to natural outdoor atmospheres is not constant with exposure time. For most metals and alloys, it decreases with exposure time because of the accumulation of corrosion products on the surface of the metal expos

40、ed. The progress of attack on engineering metals and alloys is usually observed to be linear when the total damage is plotted against exposure time on logarithmic coordinates. This relationship indicates that the total attack, D, expressed either as mass loss per unit area or penetration depth, may

41、be given as: D = rcorrtb(1) where t is the exposure time, expressed in years; rcorris the corrosion rate experienced in the first year, expressed in grams per square metre per year g/(m2a) or micrometres per year (m/a), in accordance with ISO 9223; b is the metal-environment-specific time exponent,

42、usually less than 1. 5 Prediction of corrosion attack after extended exposure This procedure should be used in cases where the extent of corrosion attack in the first year is available or can be estimated by the procedures in ISO 9223, and the desire is to predict the extent of attack after an exten

43、ded exposure. The attack prediction is calculated by substituting the values in Equation (1). An appropriate b value is selected or calculated according to Clause 7. In cases where long-term metal loss data are available, use the b value from this data. In cases where the detailed composition of the

44、 metal is not known, select the B1 value from Table 2 for the metal or alloy in question. This is the b value to be used in Equation (1). The B1 values were taken as the average time exponents from regression analyses of the flat panel long-term results of the ISO CORRAG atmospheric exposure program

45、me1. NOTE It is necessary to distinguish between metal-environment-specific time exponent, b, in Equation (1), estimated from exposure data, and B1 and B2 values assumed or calculated from the ISO CORRAG programme as generalized b values. Table 3 contains values of the function tbfor time values up

46、to 100 years with the B1 exponents to simplify the calculations. However, it is possible for Equation (1) not to apply to exposures beyond 20 years (see Clause 7 below for a discussion of long-term exposures). EN ISO 9224:2012 (E) DIN EN ISO 9224:2012-05 6In cases where it is important to estimate a

47、 conservative upper limit of corrosion attack after an extended exposure, the b value used in Equation (1) should be increased to account for uncertainties in the data. One way to do this is to add two standard deviations to the average value to obtain a value at the upper 95 % confidence level. For

48、 the four metals shown in Table 2, the standard deviations of the b values1are: Carbon steel: 0,026 0 Zinc: 0,030 0 Copper: 0,029 5 Aluminium: 0,039 5 NOTE Estimation of a conservative upper limit of corrosion attack after an extended exposure is based on uncertainties in b. This estimation does not take into account uncertainties in rcorr, which