1、BRITISH STANDARD BS EN ISO 7539-7:2005 Corrosion of metals and alloys Stress corrosion testing Part 7: Method for slow strain rate testing The European Standard EN ISO 7539-7:2005 has the status of a British Standard ICS 77.060 BS EN ISO 7539-7:2005 This British Standard was published under the auth
2、ority of the Standards Policy and Strategy Committee on 21 February 2005 BSI 21 February 2005 ISBN 0 580 45476 2 National foreword This British Standard is the official English language version of EN ISO 7539-7:2005. It is identical with ISO 7539-7:2005. It supersedes BS EN ISO 7539-7:1995 which is
3、withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/NFE/8, Corrosion of metals and alloys, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standard
4、s which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This pu
5、blication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible internat
6、ional/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO
7、title page, the EN ISO foreword page, the ISO title page, pages ii and iii, a blank page, pages 1 to 7 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date Comments EUROPEAN STANDARD NORME
8、 EUROPENNE EUROPISCHE NORM EN ISO 7539-7 February 2005 ICS 77.060 Supersedes EN ISO 7539-7:1995 English version Corrosion of metals and alloys - Stress corrosion testing - Part 7: Method for slow strain rate testing (ISO 7539-7:2005) Corrosion des mtaux et alliages - Essais de corrosion sous contrai
9、nte - Partie 7: Mthode dessai faible vitesse de dformation (ISO 7539-7:2005) Korrosion von Metallen und Legierungen - Prfung der Spannungsrisskorrosion - Teil 7: Prfung mit langsamer Dehngeschwindigkeit (ISO 7539-7:2005) This European Standard was approved by CEN on 17 January 2005. CEN members are
10、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 obtained on application to th
11、e Central Secretariat 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 Central Secretariat has the same stat
12、us as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Sloveni
13、a, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN na
14、tional Members. Ref. No. EN ISO 7539-7:2005: E I NESO 57-93:72( 500E) 2 Foreword This document (EN ISO 7539-7:2005) 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 s
15、ecretariat 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 August 2005, and conflicting national standards shall be withdrawn at the latest by August 2005. This document s
16、upersedes EN ISO 7539-7:1995. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Icela
17、nd, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 7539-7:2005 has been approved by CEN as EN ISO 7539-7:2005 without any modifications. ENISO75397:2005
18、 Reference number ISO 7539-7:2005(E) OSI 5002INTERNATIONAL STANDARD ISO 7539-7 Second edition 2005-02-01 Corrosion of metals and alloys Stress corrosion testing Part 7: Method for slow strain rate testing Corrosion des mtaux et alliages Essais de corrosion sous contrainte Partie 7: Mthode dessai fai
19、ble vitesse de dformation ENISO75397:2005IS-9357 O7:(5002E) DPlcsid Fremia ihTs PDF file may ctnoian emdebt dedyfepcaes. In ccaocnadrw eith Aebods licensilop gnic,y this file mairp eb ynted iv roweb detu slahl ton ide ebtlnu deess the typefaces whice era hml era deddebicsnede to i dnanstlaled t noeh
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22、m ttneC ehlar Secrteiraat ta the serddaig sleb nevwo. ISO 5002 All irthgs erse.devr lnUeto sswrehise specified, on trap fo this lbupictaion maeb y cudorperro de tuilizi den yna form ro na ybm ynae,s lecetrinoc ro mecinahcal, inclidung tohpcoiypodna gn micrfoilm, wittuoh repmissii non writign from ie
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24、-9357 O7:(5002E) I SO 5002 All irthgs ersedevr iiiForeword 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
25、 member body 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 Internationa
26、l Electrotechnical 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
27、 adopted by the 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
28、 patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 7539-7 was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys. This second edition cancels and replaces the first edition (ISO 7539-7:1989), Clauses 1, 3, 4, 6, 7 and 8 of whi
29、ch have been technically revised. ISO 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 specime
30、ns Part 4: Preparation and use of uniaxially 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
31、 specimens to evaluate weldments Part 9: Preparation and use of pre-cracked specimens for tests under rising load or rising displacement ENISO75397:2005blank ENISO75397:2005INTENRATIONAL TSANDADR IS-9357 O7:(5002E)I SO 5002 All irthgs ersedevr 1Corrosion of metals and alloys Stress corrosion testing
32、 Part 7: Method for slow strain rate testing 1 Scope This part of ISO 7539 covers procedures for conducting slow strain rate tests for investigating susceptibility of a metal to stress corrosion cracking, including hydrogen-induced failure. The term “metal” as used in this part of ISO 7539 includes
33、alloys. Slow strain rate tests are adaptable for testing a wide variety of product forms, including plate, rod, wire, sheet and tubes, as well as composites of these and parts joined by welding. Notched specimens may be used, as well as initially plain specimens. The principal advantage of the test
34、is the rapidity with which susceptibility to stress corrosion cracking of a particular metal/environment combination can be assessed. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies
35、. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 7539-1:1987, Corrosion of metals and alloys Stress corrosion testing Part 1: General guidance on testing procedures ISO 7539-4:1989, Corrosion of metals and alloys Stress corrosion testing
36、 Part 4: Preparation and use of uniaxially loaded tension specimens ISO 7539-6:2003, Corrosion of metal and alloys Stress corrosion testing Part 6: Preparation and use of pre-cracked specimens for tests under constant load or constant displacement 3 Terms and definitions For the purposes of this doc
37、ument, the terms and definitions given in ISO 7539-1 and the following apply. 3.1 creep time-dependent mechanical deformation of a specimen after application of the initial load 3.2 elongation to fracture ratio, of the increase in gauge length which has occurred during a test, to the original gauge
38、length, expressed as a percentage ENISO75397:2005IS-9357 O7:(5002E) 2 I SO 5002 All irthgs ersedevr3.3 maximum load maximum value of the load achieved during a test taken to total failure or, in the case of composite materials, the load corresponding to failure of one element 3.4 nominal stress-elon
39、gation curves plot of the nominal stress calculated from the instantaneous applied load and the original cross-sectional area of a specimen, against the elongation of the gauge length at the time of the load measurement 3.5 plastic strain to failure estimated plastic contribution to the total strain
40、 to failure determined by subtracting the elastic strain at failure from the total strain at failure 3.6 reduction of area ratio of the maximum decrease in cross-sectional area which has occurred during a test, to the original cross- sectional area, expressed as a percentage 3.7 strain rate initial
41、rate of increase in gauge length of an initially plain tensile specimen 4 Principle 4.1 The test consists of subjecting a specimen to increasing strain whilst exposed to a specified environment with a view to determining stress corrosion susceptibility by reference to one or more of the parameters e
42、numerated in Clause 7. 4.2 Corrosive environments may cause a deterioration of the properties of stressed materials beyond those observed with the same combination of environment and material when the latter is not subjected to slow dynamic strain. This enhanced deterioration, usually due to the ini
43、tiation and growth of cracks, may be expressed in a number of different ways for the purpose of assessing stress corrosion susceptibility. 4.3 Tests may be conducted in tension or in bending, on initially plain or notched specimens. The most important characteristic of the test is the relatively slo
44、w strain rate generated at the region of crack initiation or growth in the metal, hence the preference for such tests being referred to as slow strain rate tests. 5 Specimens 5.1 A variety of specimen shapes and sizes can be used, but those most commonly utilized are described in ISO 7539-4 and ISO
45、7539-6. 5.2 The remarks in the aforementioned documents concerning specimen design, preparation and gripping are equally applicable to specimens for slow strain rate tests. 6 Procedure 6.1 The equipment required for slow strain rate testing consists of a device that permits a selection of deflection
46、 rates whilst being powerful enough to cope with the loads generated. Deflection rates that have been used most frequently in testing initially plain specimens are in the range 10 3s 1to 10 7s 1 . 6.2 Notched specimens may be used when it is desired to restrict cracking to a particular location, e.g
47、. when testing the heat-affected zone associated with a weld or whenever a given piece of material exhibits a ENISO75397:2005IS-9357 O7:(5002E) I SO 5002 All irthgs ersedevr 3range of mechanical properties that would be likely to promote different strain rates in different parts of a specimen. Notch
48、ed specimens may also be used to restrict load requirements, where bending, as opposed to tensile loading, may offer further advantages. 6.3 For initially plain specimens, especially with a waisted gauge length, the strain rate at the outset of the test is readily defined, but once cracks are initia
49、ted and have grown to some extent in such specimens, straining is likely to be concentrated in the material in the vicinity of the crack tip and may not be the same as the initial strain rate. Rigorous solutions for the strain rate at notches are not yet available, but it is likely that the effective strain rates will be higher than those for the same displacement rates applied to plain specime
