1、BSI Standards PublicationBS EN ISO 8044:2015Corrosion of metals and alloys Basic terms and definitionsBS EN ISO 8044:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 8044:2015.It supersedes BS EN ISO 8044:2000 which is withdrawn.BSI, as a member of CEN,
2、is obliged to publish EN ISO 8044 as aBritish Standard. However, attention is drawn to a specific part ofthe standard that the UK committee did not agree with.The Note 1 to Clause 4.13 and the definition in Clause 4.14 are con-sidered insufficiently accurate. Whilst the instant-off potential may app
3、roach the IR-drop corrected value it will normally be in error due to equalisation currents, uninterrupted currents and stray currents which have not been switched off. See BS EN 13509 AnnexF for the calculation of IR free potential. On-potentials will normallycontain significant IR-drop errors and
4、be more negative than instant-off, IR-drop corrected or IR free potentials.The UK participation in its preparation was entrusted to TechnicalCommittee ISE/NFE/8, Corrosion of metals and alloys.A list of organizations represented on this committee can beobtained on request to its secretary.This publi
5、cation does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 86254 0ICS 01.040.77; 77.060Compliance with a British Standard cannot confer im
6、munity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2015.Amendments/corrigenda issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8044 September 2015 ICS 77.06
7、0; 01.040.77 Supersedes EN ISO 8044:1999English Version Corrosion of metals and alloys - Basic terms and definitions (ISO 8044:2015) Corrosion des mtaux et alliages - Termes principaux et dfinitions (ISO 8044:2015) Korrosion von Metallen und Legierungen - Grundbegriffe (ISO 8044:2015) This European
8、Standard was approved by CEN on 13 May 2015. 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 references concerning
9、 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 versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its
10、 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, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, German
11、y, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR N
12、ORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8044:2015 EBS EN ISO 8044:2015EN ISO 8044:2015 (E) 3 European foreword This document (EN ISO 8044:2015
13、) 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. This European Standard shall be given the status of a national standard, either
14、 by publication of an identical text or by endorsement, at the latest by March 2016, and conflicting national standards shall be withdrawn at the latest by March 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CEN
15、ELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 8044:1999. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belg
16、ium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switze
17、rland, Turkey and the United Kingdom. Endorsement notice The text of ISO 8044:2015 has been approved by CEN as EN ISO 8044:2015 without any modification. BS EN ISO 8044:2015ISO 8044:2015(E/F)Contents PageForeword vIntroduction vi1 Scope . 12 General terms 13 Types of corrosion 34 Corrosion protectio
18、n 95 Corrosion testing .116 Electrochemical terms .126.1 The electrochemical cell 126.2 Reaction rates . 166.3 Passivation . 186.4 Electrochemical protection . 196.5 Electrochemical corrosion tests 20Bibliography .23 ISO 2015 All rights reserved/Tous droits rservs iiiBS EN ISO 8044:2015ISO 8044:2015
19、(E/F)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
20、 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 all mat
21、ters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This do
22、cument was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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 identifying any or all
23、such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and d
24、oes not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary infor
25、mationThe committee responsible for this document is ISO/TC 156, Corrosion of metals and alloys.This fourth edition cancels and replaces the third edition (ISO 8044:1999), which has been revised to include additional terms and definitions.iv ISO 2015 All rights reserved/Tous droits rservsBS EN ISO 8
26、044:2015ISO 8044:2015(E/F)IntroductionThe definitions in this International Standard have been drawn up with the objective of achieving a proper balance between precision and simplicity. The main objective of this International Standard is to provide definitions that can be understood to have the sa
27、me meaning by all concerned. Some corrosion terms in present use have developed through common usage and are not always logical. It has not, therefore, been possible to define certain terms in the form they are used in some countries. Because of the occasional conflicts between tradition and logic s
28、ome definitions inevitably represent a compromise.An example of this kind of conflict is the term “corrosion”. This has been used to mean the process, results of the process and damage caused by the process. In this International Standard corrosion is understood to mean the process. Any detectable r
29、esult of corrosion in any part of a corrosion system is termed “corrosion effect”. The term “corrosion damage” covers any impairment of the function of the technical system of which the metal and the environment form a part. Consequently the term “corrosion protection” implies that the important thi
30、ng is to avoid corrosion damage rather than to prevent corrosion, which in many cases is impossible and sometimes not necessary. ISO 2015 All rights reserved/Tous droits rservs vBS EN ISO 8044:2015BS EN ISO 8044:2015Corrosion of metals and alloys Basic terms and definitions1 ScopeThis International
31、Standard defines terms relating to corrosion that are widely used in modern science and technology. In addition, some definitions are supplemented with short explanations.NOTE 1 Throughout the document IUPAC rules for electrode potential signs are applied. The term “metal” is also used to include al
32、loys and other metallic materials.NOTE 2 Terms and definitions related to inorganic surface treatment of metals are given in ISO 2080.NOTE 3 See also the ISO online browsing platform (OBP): www.iso.org/obp/ui/2 General terms2.1corrosionphysicochemical interaction between a metal and its environment
33、that results in changes in the properties of the metal, and which may lead to significant impairment of the function of the metal, the environment, or the technical system, of which these form a partNote 1 to entry: This interaction is often of an electrochemical nature.2.2corrosive agentcorrodentsu
34、bstance which when in contact with a given metal will cause corrosion (2.1)2.3corrosive environmentenvironment that contains one or more corrosive agents (2.2)2.4corrosion systemsystem consisting of one or more metals and those parts of the environment that influence corrosion (2.1)Note 1 to entry:
35、Parts of the environment may be, for example, coatings, surface layers or additional electrodes (6.1.2).2.5corrosion effectchange in any part of the corrosion system (2.4) caused by corrosion (2.1)2.6corrosion damagecorrosion effect (2.5) that causes impairment of the function of the metal, the envi
36、ronment or the technical system, of which these form a part2.7corrosion failurecorrosion damage (2.6) characterized by the total loss of function of the technical systemINTERNATIONAL STANDARD ISO 8044:2015(E/F) ISO 2015 All rights reserved/Tous droits rservs 1BS EN ISO 8044:2015ISO 8044:2015(E/F)2.8
37、corrosion productsubstance formed as a result of corrosion (2.1)2.9scalesolid layer of corrosion products (2.8)formed on a metal at high temperatureNote 1 to entry: The term “scale” is also used in some countries for deposits from supersaturated water.2.10rustvisible corrosion products (2.8) consist
38、ing mainly of hydrated iron oxides2.11corrosion depthdistance between a point on the surface of a metal affected by corrosion (2.1) and the original surface of the metal2.12corrosion ratecorrosion effect (2.5) on a metal per timeNote 1 to entry: The unit used to express the corrosion rate depends on
39、 the technical system and on the type of corrosion effect. Thus corrosion rate may be expressed as an increase in corrosion depth (2.11) per time, or the mass of metal turned into corrosion products (2.8) per area of surface and per time, etc. The corrosion effect may vary with time and may not be t
40、he same at all points of the corroding surface. Therefore, reports of corrosion rates should be accompanied by information on the type, time dependency and location of the corrosion effect.2.13corrosion resistanceability of a metal to maintain serviceability (2.16) in a given corrosion system (2.4)2
41、.14corrosivityability of an environment to cause corrosion (2.1) of a metal in a given corrosion system (2.4)2.15corrosion likelihoodqualitative and/or quantitative expression of the expected corrosion effects (2.5) in a defined corrosion system (2.4)2.16serviceability (with respect to corrosion)abi
42、lity of a corrosion system (2.4) to perform its specified functions without impairment due to corrosion (2.1)2.17durability (with respect to corrosion)ability of a corrosion system (2.4) to maintain serviceability (2.16) over a specified time when the specified requirements for use and maintenance h
43、ave been fulfilled2.18service life (with respect to corrosion)time during which a corrosion system (2.4) meets the requirements for serviceability (2.16)2.19critical humidityvalue of the relative humidity of an atmosphere above which there is a sharp increase in the corrosion rate (2.12) of a given
44、metal2 ISO 2015 All rights reserved/Tous droits rservsBS EN ISO 8044:2015ISO 8044:2015(E/F)2.20corrosion attackcorrosion effect (2.5) that is detrimental but has not progressed to the point of impairment of the function of the metal, the environment, or the technical system of which they form a part
45、2.21picklingremoval of oxides or other compounds from a metal surface by chemical or electrochemical action2.22pitting resistance equivalent numberPRENindication of the resistance of stainless steels and nickel-based alloys to pitting in the presence of chloride-containing waterNote 1 to entry: A wi
46、dely accepted formula for PREN is given byPREN Cr Mo WN=+()+ ()+ ()%,%,%33 05 16 . Note 2 to entry: The higher the PREN, the higher is the resistance to pitting corrosion.2.23trapmicro structural site at which the residence time for a hydrogen atom is long compared to the residence time in an inters
47、titial lattice site2.24time of wetnessperiod when a metallic surface is covered by adsorptive and/or liquid films of electrolyte to be capable of causing atmospheric corrosion2.25threshold stress (for stress corrosion cracking)tensile stress above which stress corrosion cracks initiate and grow, for
48、 the specified test conditions2.26threshold stress intensity factor for stress corrosion crackingKISCCstress intensity factor above which stress corrosion crack propagation is sustainedNote 1 to entry: The threshold stress intensity factor is a concept of linear elastic fracture mechanics (LEFM) and
49、 is applicable when the plastic zone size is large compared with the microstructure, the crack is sufficiently long, and a high constraint to plastic deformation prevails, i.e. under plane strain predominant conditions. For growing stress corrosion cracks, LEFM is not necessarily applicable in all detail but is adopted as a pragmatic tool that is commonly used.Note 2 to entry: Stress corrosion cracks may initiate at a surface or a surface defect and grow in the “short crack” regime at stress intensity factor levels below the apparent threshold s
