DIN EN ISO 7539-1-2013 Corrosion of metals and alloys - Stress corrosion testing - Part 1 General guidance on testing procedures (ISO 7539-1 2012) German version EN ISO 7539-1 2012.pdf

1、April 2013Translation by DIN-Sprachendienst.English price group 13No 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 7

2、7.060!$G“1999336www.din.deDDIN EN ISO 7539-1Corrosion of metals and alloys Stress corrosion testing Part 1: General guidance on testing procedures (ISO 7539-1:2012);English version EN ISO 7539-1:2012,English translation of DIN EN ISO 7539-1:2013-04Korrosion der Metalle und Legierungen Prfung der Spa

3、nnungsrisskorrosion Teil 1: Allgemeiner Leitfaden fr Prfverfahren (ISO 7539-1:2012);Englische Fassung EN ISO 7539-1:2012,Englische bersetzung von DIN EN ISO 7539-1:2013-04Corrosion des mtaux et alliages Essais de corrosion sous contrainte Partie 1: Lignes directrices gnrales relatives aux mthodes de

4、ssai (ISO 7539-1:2012);Version anglaise EN ISO 7539-1:2012,Traduction anglaise de DIN EN ISO 7539-1:2013-04SupersedesDIN EN ISO 7539-1:1995-08www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document comprises 24 pages03.13 DIN EN ISO 7539-1:2013-04 2 A co

5、mma is used as the decimal marker. National foreword This document (EN ISO 7539-1:2012) has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys” (Secretariat: SAC, China) and has been adopted as EN ISO 7539-1:2012 by Technical Committee CEN/TC 262 “Metallic and other inor

6、ganic coatings” (Secretariat: BSI, United Kingdom) within the scope of the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Commit

7、tee NA 062-01-71 AA Korrosion und Korrosions-schutz. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 4287 DIN EN ISO 4287 ISO 7539-9 DIN EN ISO 7539-9 ISO 15324 DIN EN ISO 15324 Amendments This standard differs from DIN EN ISO 7539-1:19

8、95-08 as follows: a) specifications relating to the specimen preparation, test environment and test procedure have been brought in line with the state of the art; b) Annex A (informative) “Guide to selection of mechanical test method” has been added; c) the standard has been editorially revised. Pre

9、vious editions DIN EN ISO 7539-1: 1995-08 National Annex NA (informative) Bibliography DIN EN ISO 4287, Geometrical Product Specifications (GPS) Surface texture: Profile method Terms, definitions and surface texture parametersDIN EN ISO 7539-9, Corrosion of metals and alloys Stress corrosion testing

10、 Part 9: Preparation and use of precracked specimens for tests under constant load or constant displacement DIN EN ISO 15324, Corrosion of metals and alloys Evaluation of stress corrosion cracking by the drop evaporation test EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7539-1 December 2

11、012 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 sous contrainte - Partie 1: Lignes directrices gnrales relati

12、ves 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 December 2012. CEN members are bound to comply with the CEN/CENEL

13、EC 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 obtained on application to the CEN-CENELEC Management Centre or

14、 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-CENELEC Management Centre has the same status as the offi

15、cial 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, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,

16、 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 Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation

17、 in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 7539-1:2012: EContents Page Foreword . 3 1 Scope . 4 2 Terms and definitions 4 3 Background 5 4 Selection of test method . 6 5 Stressing systems 7 5.1 General 7 5.2 Constant total strain tests . 7 5.3 Constant

18、 load tests 8 5.4 Slow strain rate tests . 9 6 Environmental aspects 10 6.1 General 10 6.2 Temperature 10 6.3 Water chemistry . 10 6.4 Flow rate 12 6.5 Electrochemical aspects . 12 7 Time dependent issues . 13 7.1 General 13 7.2 Pitting and intergranular corrosion 13 7.3 Hydrogen uptake 13 8 Specime

19、n design and manufacture 14 8.1 General 14 8.2 Surface condition . 14 8.3 Area effects . 16 8.4 Pre-cracked test pieces . 16 8.5 Welds . 17 9 Stress corrosion test cells 17 10 Initiation of stress corrosion tests . 18 11 Assessment and treatment of results 18 Annex A (informative) Guide to selection

20、 of mechanical test method . 20 Bibliography 22 2DIN EN ISO 7539-1:2013-04EN ISO 7539-1:2012 (E) 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 ino

21、rganic 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 June 2013, and conflicting national standards shall be withdrawn at the latest by June 201

22、3. 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 patent rights. This document supersedes EN ISO 7539-1:1995. According to the CEN/CENELEC Internal

23、Regulations, the 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, Irelan

24、d, 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 7539-1:2012 has been approved by CEN as a EN ISO 7539-1:2012 without any modification. ”“I

25、SO 7539 consists 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 u

26、niaxially loaded 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 Pa

27、rt 9: Preparation 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 cracking 3DIN EN ISO 7539-1:2013-04 EN ISO 7539-1:2

28、012 (E) 1 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

29、 test 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

30、 to 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 i

31、s 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

32、 conditions. 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 t

33、he 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 labora

34、tory, 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).4DIN EN ISO 7539-1:2013-04EN ISO 7539-1:2012 (E) 2.5start of testtime when the stress is

35、applied or when the specimen is exposed to the test environment, whichever occurs later2.6crack initiation timeperiod 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

36、criterion of failure being the first appearance of cracking or the total separation of the test piece, or some 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

37、 failure in a representative environment at a constant displacement rate, the displacement rate being chosen to 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 failu

38、re occurs in a slow strain rate test expressed usually as the plastic strain to failure See ISO 7539-7.2.10average 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 speci

39、fied direction in the product from which it was prepared, e.g. the rolling direction in the plate3 Background3.1 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 th

40、e presence of stress, have also to be recognized.As far as this part of ISO 7539 is concerned, all phenomena involving 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

41、embrittlement by liquid metal and exfoliation corrosion.3.2 There exists a wide diversity of methods used for assessing 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

42、 mechanical and microstructural characteristics of the material and susceptibility or resistance to stress corrosion 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 co

43、rrosion in a given application, it is necessary to carry out simulation testing under all likely service exposure 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 guida

44、nce on likely service behaviour for given specific applications. However, these laboratory “standard tests” are only appropriate to service conditions where experience 5DIN EN ISO 7539-1:2013-04 EN ISO 7539-1:2012 (E) has shown an appropriate relationship, however empirical, to exist. The fact that

45、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 necessarily provide safe guidance if the exposure conditions are different. The

46、 use of a standard test beyond the point for which there is experience therefore requires validation.3.5 In the following clauses, attention is drawn particularly to the fact that the stress corrosion process can be extremely sensitive to small changes in exposure or test conditions. The user of mat

47、erials is responsible for selecting the conditions under which stress corrosion tests are performed and the fact that some tests are described in this part of ISO 7539 does not imply that these tests are the most appropriate ones for any given situation. The justification for describing these tests

48、in a standard is that they are in widespread use and have been proven as valid for specific or common equipment-environment systems. However, the responsibility for interpretation of the test results remains with the user of materials and it is in no way diminished by the existence of this standard.

49、3.6 In addition to specific parts of ISO 7539 to cover the most widely used methods, it is considered that this more general document, concerned with the selection of test details and the interpretation of results, is required.4 Selection of test method4.1 Before embarking on a programme of stress corrosion testing, a decision has to be made regarding which type of test is appropriate. Such a decision depends largely upon the purpose of