1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 7539-1:2012Corrosion of metals and alloys Stress corrosion testingPart 1: General guidance on testing proceduresCopyright European Committee for Standardization Provide
2、d by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 7539-1:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 7539-1:2012.It supersedes BS EN ISO 7539-1:1995 which is withdrawn.The UK
3、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 publication does not purport to include all the necessaryprovisions of a contract. User
4、s are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013 ISBN 978 0 580 71187 9 ICS 77.060 Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of th
5、eStandards Policy and Strategy Committee on 31 January 2013. Amendments issued since publicationDate Text affectedCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EUROPEAN STANDAR
6、D NORME EUROPENNE EUROPISCHE NORM EN ISO 7539-1 December 2012 ICS 77.060 Supersedes EN ISO 7539-1:1995English Version Corrosion of metals and alloys - Stress corrosion testing - Part 1: General guidance on testing procedures (ISO 7539-1:2012) Corrosion des mtaux et alliages - Essais de corrosion sou
7、s contrainte - Partie 1: Lignes directrices gnrales relatives aux mthodes dessai (ISO 7539-1:2012) Korrosion der Metalle und Legierungen - Prfung der Spannungsrisskorrosion - Teil 1: Allgemeiner Leitfaden fr Prfverfahren (ISO/FDIS 7539-1:2012) This European Standard was approved by CEN on 18 Decembe
8、r 2012. 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 such national standards may be obtai
9、ned 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 own language and notified to the CEN
10、-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, Germany, Greece, Hungary, Iceland, Ireland,
11、 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 NORMUNG Management Centre: Avenue Marn
12、ix 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 7539-1:2012: ECopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permit
13、ted without license from IHS-,-,-BS EN ISO 7539-1:2012EN ISO 7539-1:2012 (E) 3 Foreword This document (EN ISO 7539-1:2012) 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”
14、 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 June 2013, and conflicting national standards shall be withdrawn at the latest by June 2013. Attention is
15、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 patent rights. This document supersedes EN ISO 7539-1:1995. According to the CEN/CENELEC Internal Regulations, the
16、 national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia
17、, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 7539-1:2012 has been approved by CEN as a EN ISO 7539-1:2012 without any modification. Copyright European
18、Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 7539-1:2012ISO 7539-1:2012(E) ISO 2012 All rights reserved iiiContents PageForeword iv1 Scope . 12 Terms and definitions . 13 Background 24
19、 Selection of test method . 35 Stressing systems . 45.1 General . 45.2 Constant total strain tests 45.3 Constant load tests 55.4 Slow strain rate tests . 66 Environmental aspects . 76.1 General . 76.2 Temperature 76.3 Water chemistry 76.4 Flow rate . 96.5 Electrochemical aspects 97 Time dependent is
20、sues .107.1 General 107.2 Pitting and intergranular corrosion . 107.3 Hydrogen uptake 108 Specimen design and manufacture 118.1 General 118.2 Surface condition . 118.3 Area effects 138.4 Pre-cracked test pieces . 138.5 Welds 149 Stress corrosion test cells .1410 Initiation of stress corrosion tests
21、1511 Assessment and treatment of results 15Annex A (informative) Guide to selection of mechanical test method .18Bibliography .20Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-B
22、S EN ISO 7539-1:2012ISO 7539-1:2012(E)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
23、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 liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotech
24、nical Commission (IEC) on 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
25、 technical committees are 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.
26、ISO shall not be held responsible for identifying any or all such patent rights.ISO 7539-1 was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys.This second edition cancels and replaces the first edition (ISO 7539-1:1987), which has been technically revised.ISO 7539 consists
27、 of the following parts, under the general title Corrosion of metals and alloys Stress corrosion testing: Part 1: General guidance on testing procedures Part 2: Preparation and use of bent-beam specimens Part 3: Preparation and use of U-bend specimens Part 4: Preparation and use of uniaxially loaded
28、 tension specimens Part 5: Preparation and use of C-ring specimens Part 6: Preparation and use of pre-cracked specimens for tests under constant load or constant displacement Part 7: Method for slow strain rate testing Part 8: Preparation and use of specimens to evaluate weldments Part 9: Preparatio
29、n and use of pre-cracked specimens for tests under rising load or rising displacement Part 10: Reverse U-bend method Part 11: Guidelines for testing the resistance of metals and alloys to hydrogen embrittlement and hydrogen-assisted crackingiv ISO 2012 All rights reservedCopyright European Committee
30、 for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 7539-1:2012INTERNATIONAL STANDARD ISO 7539-1:2012(E)Corrosion of metals and alloys Stress corrosion testing Part 1: General guidance on testing proc
31、edures1 Scope1.1 This part of ISO 7539 describes the general considerations that apply when designing and conducting tests to assess susceptibility of metals to stress corrosion.1.2 This part of ISO 7539 also gives some general guidance on the selection of test methods.NOTE 1 Particular methods of t
32、est are not treated in detail in this part of ISO 7539. These are described in the additional parts of ISO 7539.NOTE 2 This part of ISO 7539 is applicable to cathodic protection conditions.2 Terms and definitions2.1stress corrosionprocess involving conjoint corrosion and straining of the metal due t
33、o applied or residual stress2.2threshold stressstress corrosion stress above which stress corrosion cracks initiate and grow, for the specified test conditions2.3threshold stress intensity factorKISCCstress corrosion cracking stress intensity factor above which stress corrosion crack propagation is
34、sustainedNote 1 to entry: The threshold stress intensity factor is a concept of linear elastic fracture mechanics (LEFM) and is applicable when the plastic zone size is large compared with the microstructure and a high constraint to plastic deformation prevails; i.e. under plain strain-predominant c
35、onditions. For growing stress corrosion cracks, LEFM is not necessarily applicable in 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 levels below the
36、 apparent threshold stress intensity factor. However, LEFM is not applicable in the short crack regime and sustained propagation of these cracks requires that the threshold stress intensity factor be exceeded.2.4test environmenteither a service environment, or an environment produced in the laborato
37、ry, to which the test specimen is exposed and which is maintained constant or varied in an agreed mannerNote 1 to entry: In the case of stress corrosion, the environment is often quite specific (see Clause 6). ISO 2012 All rights reserved 1Copyright European Committee for Standardization Provided by
38、 IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 7539-1:2012ISO 7539-1:2012(E)2.5start of testtime when the stress is applied or when the specimen is exposed to the test environment, whichever occurs later2.6crack initiation time
39、period from the start of a test to the time when a crack is detectable by the means employed2.7time to failureperiod elapsing between the start of a test and the occurrence of failure, the criterion of failure being the first appearance of cracking or the total separation of the test piece, or some
40、agreed intermediate condition2.8slow strain rate testtest for evaluating the susceptibility of a metal to stress corrosion cracking that most commonly involves pulling a tensile specimen to failure in a representative environment at a constant displacement rate, the displacement rate being chosen to
41、 generate nominal strain rates usually in the range 105s1to 108s1Note 1 to entry: Slow strain rate testing may also be applied to specimens in bend.2.9strain to failurestrain at which failure occurs in a slow strain rate test expressed usually as the plastic strain to failure See ISO 7539-7.2.10aver
42、age crack velocitymaximum depth of crack(s) due to stress corrosion, divided by the test time2.11orientationdirection of applied tensile stress of a test specimen with respect to some specified direction in the product from which it was prepared, e.g. the rolling direction in the plate3 Background3.
43、1 Although it is generally agreed that cracking is the usual result of stress corrosion, other manifestations such as intergranular corrosion or elongated fissures, which are enhanced by the presence of stress, have also to be recognized.As far as this part of ISO 7539 is concerned, all phenomena in
44、volving metal dissolution or the action of hydrogen introduced into the metal as the result of simultaneous effects of a corrosive environment and a tensile stress are included, except for embrittlement by liquid metal and exfoliation corrosion.3.2 There exists a wide diversity of methods used for a
45、ssessing the stress corrosion properties of metals. Each has its own particular advantage in certain situations.3.3 Stress corrosion cracking depends on both the exposure conditions and the mechanical and microstructural characteristics of the material and susceptibility or resistance to stress corr
46、osion can only be defined in that context. Thus, for example, there is no intrinsic threshold stress intensity factor for a material.3.4 Ideally, in order to establish the risk of stress corrosion in a given application, it is necessary to carry out simulation testing under all likely service exposu
47、re conditions. In practice, this is difficult, if not impossible, and rarely achieved, but a number of “standard tests” have been found as a result of experience to provide reasonable guidance on likely service behaviour for given specific applications. However, these laboratory “standard tests” are
48、 only appropriate to service conditions where experience 2 ISO 2012 All rights reservedCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 7539-1:2012ISO 7539-1:2012(E)has
49、shown an appropriate relationship, however empirical, to exist. The fact that a given alloy passes or does not pass a test previously found useful in relation to another alloy may or may not be significant and a test that discriminates correctly between alloys used for a given application will not necessari
