1、August 2008DEUTSCHE NORM English price group 12No part of this standard 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 77.060!$QNS“1464348www.
2、din.deDDIN EN ISO 7539-8Corrosion of metals and alloys Stress corrosion testing Part 8: Preparation and use of specimens to evaluate weldments(ISO 7539-8:2000)English version of DIN EN ISO 7539-8:2008-08Korrosion der Metalle und Legierungen Prfung der Spannungsrisskorrosion Teil 8: Vorbereitung und
3、Anwendung von Proben zur Bewertung vonSchweiverbindungen (ISO 7539-8:2000)Englische Fassung DIN EN ISO 7539-8:2008-08www.beuth.deDocument comprises 23 pagesDIN EN ISO 7539-8:2008-08 2 National foreword This standard has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys”
4、 (Secretariat: GOST R (Russian Federation). Based on the results of the unique acceptance procedure, ISO 7539-8:2000 has been adopted by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” (Secretariat: BSI, United Kingdom) as a European Standard. The responsible German body invol
5、ved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Technical Committee NA 062-01-71 AA Korrosion und Korrosions-schutz. The DIN Standards corresponding to the International Standards referred to in clause 2 of the EN are as follows: ISO 857-1 DIN I
6、SO 857-11)ISO 7539-2 DIN EN ISO 7539-2 ISO 7539-3 DIN EN ISO 7539-3 ISO 7539-4 DIN EN ISO 7539-4 ISO 7539-5 DIN EN ISO 7539-5 ISO 7539-6 DIN EN ISO 7539-6 ISO 7539-7 DIN EN ISO 7539-7 National Annex NA (informative) Bibliography DIN 1910-100, Welding and allied processes Vocabulary Part 100: Metal w
7、elding processes with additions to DIN EN 14610:2005 DIN EN 14610, Welding and allied processes Definitions of metal welding processes DIN EN ISO 7539-2, Corrosion of metals and alloys Stress corrosion testing Part 2: Preparation and use of bent-beam specimen DIN EN ISO 7539-3, Corrosion of metals a
8、nd alloys Stress corrosion testing Part 3: Preparation and use of U-bend specimens DIN EN ISO 7539-4, Corrosion of metals and alloys Stress corrosion testing Part 4: Preparation and use of uniaxially loaded tension specimens DIN EN ISO 7539-5, Corrosion of metals and alloys Stress corrosion testing
9、Part 5: Preparation and use of C-ring specimens DIN EN ISO 7539-6, Corrosion of metals and alloys Stress corrosion testing Part 6: Preparation and use of pre-cracked specimens DIN EN ISO 7539-7, Corrosion of metals and alloys Stress corrosion testing Part 7: Method for slow strain rate testing DIN I
10、SO 857-1, Welding and allied processes Vocabulary Part 1: Metal welding processes 1)these standards are not in conformity with ISO 857-1. DIN ISO 857-1 was withdrawn in February 2008 and replaced by DIN EN 14610 and DIN 1910-100. The contents of EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN I
11、SO 7539-8 April 2008 ICS 77.060 English Version Corrosion of metals and alloys - Stress corrosion testing - Part 8: Preparation and use of specimens to evaluate weldments (ISO 7539-8:2000) Corrosion des mtaux et alliages - Essais de corrosion sous contrainte - Partie 8: Prparation et utilisation des
12、 prouvettes pour valuer les assemblages souds (ISO 7539-8:2000) Korrosion der Metalle und Legierungen - Prfung der Spannungsrisskorrosion - Teil 8: Vorbereitung und Anwendung von Proben zur Bewertung von Schweiverbindungen (ISO 7539-8:2000) This European Standard was approved by CEN on 21 March 2008
13、. 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 obtained on
14、 application to the CEN 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 Management Ce
15、ntre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Pola
16、nd, Portugal, Romania, Slovakia, Slovenia, 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 2008 CEN All rights of exploitation in any form and by
17、 any means reserved worldwide for CEN national Members. Ref. No. EN ISO 7539-8:2008: EContents Page2 DIN EN ISO 7539-8:2008-08EN ISO 7539-8:2008 (E)Foreword3 1 Scope 4 2 Normative references .4 3 Terms and definitions 5 4 Special considerations for weldments6 5 Specimen types7 6 Preparation of weldm
18、ents and test specimens11 7 Testing Procedures 13 8 Assessment14 9 Test report .14 Annex A (informative) Terms and definitions which have not been internationally agreed 16 Bibliography21 3 EN ISO 7539-8:2008 (E)DIN EN ISO 7539-8:2008-08Foreword The text of ISO 7539-8:2000 has been prepared by Techn
19、ical Committee ISO/TC 156 “Corrosion of metals and alloys” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 7539-8:2008 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which is held by BSI. This European Standa
20、rd shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2008, and conflicting national standards shall be withdrawn at the latest by October 2008. Attention is drawn to the possibility that some of the elements of th
21、is 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. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Sta
22、ndard: Austria, Belgium, Bulgaria, 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 and the United Kingdom
23、. Endorsement notice The text of ISO 7539-8:2000 has been approved by CEN as a EN ISO 7539-8:2008 without any modification. 1 ScopeThis part of ISO 7539 covers the procedures available for stress corrosion testing of welded specimens andexamines the additional factors which must be taken into accoun
24、t when conducting tests on welded specimens. Inparticular this part of ISO 7539 gives recommendations for the choice of specimens and test procedures todetermine the resistance of a metal to stress corrosion when it is welded.The term “metal”, as used in this part of ISO 7539, includes alloys.2 Norm
25、ative referencesThe following normative documents contain provisions which, through reference in this text, constitute provisions ofthis part of ISO 7539. For dated references, subsequent amendments to, or revisions of, any of these publicationsdo not apply. However, parties to agreements based on t
26、his part of ISO 7539 are encouraged to investigate thepossibility of applying the most recent editions of the normative documents indicated below. For undatedreferences, the latest edition of the normative document referred to applies. Members of ISO and IEC maintainregisters of currently valid Inte
27、rnational Standards.ISO 857-1:1998, Welding and allied processes Vocabulary Part 1: Metal welding processes.ISO 7539-2:1989, Corrosion of metals and alloys Stress corrosion testing Part 2: Preparation and use ofbent-beam specimens.ISO 7539-3:1989, Corrosion of metals and alloys Stress corrosion test
28、ing Part 3: Preparation and use ofU-bend specimens.ISO 7539-4:1989, Corrosion of metals and alloys Stress corrosion testing Part 4: Preparation and use ofuniaxially loaded tension specimens.ISO 7539-5:1989, Corrosion of metals and alloys Stress corrosion testing Part 5: Preparation and use ofC-ring
29、specimens.ISO 7539-6:1), Corrosion of metals and alloys Stress corrosion testing Part 6: Preparation and use of pre-cracked specimens.ISO 7539-7:1989, Corrosion of metals and alloys Stress corrosion testing Part 7: Slow strain rate testing.IEC 60050-851 (1991-08), International Electrotechnical Voca
30、bulary Chapter 851: Electric Welding.1) To be published. (Revision of ISO 7539-6:1989)4 DIN EN ISO 7539-8:2008-08EN ISO 7539-8:2008 (E)3 Terms and definitionsFor the purposes of this part of ISO 7539 the following terms and definitions apply.3.1weldingoperation which unites materials by means of hea
31、t or pressure, or both, in such a way that there is continuity in thenature of the materials which have been joined and in which filler metal, the melting temperature of which is of thesame order as that of the parent metal(s), may or may not be usedNOTE This definition also includes surfacing.ISO 8
32、57-13.1.1fusion weldingwelding involving localized melting without the application of force and with or without the addition of filler metalISO 857-13.1.2arc weldingfusion welding in which heat for welding is obtained from an electric arc or arcsISO 857-1; IEC 60050-8513.1.3diffusion weldingpressure
33、 welding in which the workpieces are kept in contact under a specified continual pressure and are heated,either on their faying surfaces or in their entirety, at a defined temperature for a controlled timeNOTE 1 This process results in local plastic deformation and also, owing to the very close cont
34、act between the surfaces, thediffusion of the atoms through the interface. The end result is thus complete continuity of the material.NOTE 2 The operation may take place in a vacuum, under a gas shield or in a fluid, preferably without the addition of a fillermetal.SeeFigure1.ISO 857-15 EN ISO 7539-
35、8:2008 (E)DIN EN ISO 7539-8:2008-08Key1 Induction heating element2 Work chamber3Workpiece4WeldFigure 1 Diffusion welding3.2arc voltagevoltage across the arc, including the anode and cathode voltage drop, measured as near as possible to the arcIEC 60050-851See annex A.4 Special considerations for wel
36、dments4.1 GeneralThe factors given in this clause may all influence the corrosion and/or mechanical properties of a weldment relativeto that of the parent metal and their effects may require consideration in stress corrosion test procedures. Whilstthe considerations listed below are relevant to the
37、more common fusion welding processes, similar considerationshall also be given to solid phase (non-fusion) welding processes and diffusion welding.Weld regions are more likely than the parent metal to contain defects which may influence corrosion and stresscorrosion behaviour, e.g. microcracking, la
38、ck of fusion and porosity. For this reason, examination of the weld shallbe undertaken to assess whether the failure of any specimen is the result of pre-existing defects rather than stresscorrosion.It is recommended that the weldment be characterized with regard to residual welding stresses, surfac
39、e conditionand weld defects prior to testing. See clause 7.4.2 Changes in microstructureIn fusion welding, the application of heat to a parent metal produces microstructural changes in the heat affectedzone (HAZ) of the parent metal adjacent to the weld junction. A rapidly-cooled weld metal differs
40、microstructurally6 DIN EN ISO 7539-8:2008-08EN ISO 7539-8:2008 (E)and chemically from the parent metal and is more typical of a cast structure. These differences may influence bothweldment corrosion and mechanical properties, as well as susceptibility to stress corrosion cracking.Some alloys such as
41、 C-Mn steels display a visible HAZ. However, in some alloys, welding may also produceprecipitation and segregation effects within the parent metal remote from the visible HAZ.4.3 Non-metallic inclusionsIn addition to changes in chemical composition, the welding procedure and conditions used may resu
42、lt in a weldmetal with a non-metallic inclusion content and distribution different from that of the parent metal. This mayinfluence weldment corrosion and stress corrosion cracking behaviour.4.4 Stress concentration effectsShrinkage stresses following welding will introduce residual welding stresses
43、 which will be both transverse andlongitudinal with respect to the welding direction (and through thickness in thick-walled samples). Tensile stressesare usually generated at the weld, with balancing compressive stresses in the parent metal. In addition, weldgeometry may cause further stress concent
44、ration effects.5 Specimen types5.1 GeneralThe design and type of specimen used depend on the form of the metal from which the specimen is to be madeand on the objective of the test.The test specimens described in ISO 7539 parts 2-7 are suitable for tests on weldments, subject to the additionalconsid
45、erations presented in this part of ISO 7539. In addition, a number of other types of specimens, as describedin 5.2.1 to 5.2.8 below, can be used.Specimens can be prepared from weldments in the as-welded or post-weld heat-treated conditions. It isrecommended that specimens be tested in the same condi
46、tion of heat treatment as that of the intended application.5.2 Types of specimen5.2.1 Flat weldmentSeeFigure2.This type of weldment is applicable for all tension and bend specimens and for any welding procedure whetherinvolving single- or multi-pass welds. The weldment may also be used to evaluate t
47、he effect of residual weldingstresses.5.2.2 Circular bead weldmentSeeFigure3.The welding procedure involves one circular bead deposit of weld metal. The circular weld develops residualwelding stresses. It is applicable to any material form that can be machined to the recommended size as specifiedin
48、Figure 3.7 EN ISO 7539-8:2008 (E)DIN EN ISO 7539-8:2008-085.2.3 Bead-on-bar weldmentSeeFigure4.The longitudinal fusion welds at diametrically opposite positions on the bar develop residual welding stresses in thebar. Hence, this weldment can be used to evaluate the tendency for stress corrosion crac
49、king of the parent metal. Itis applicable to materials that can be machined to approximately 25 mm diameter.5.2.4 Direct tension specimenSeeFigure5.This specimen type is stressed in uniaxially loaded tension (see ISO 7539-4 and ISO 7539-7). Notches, with orwithout pre-cracks, may be introduced into the weld metal, parent metal or heat affected zone (see ISO 7539-6).These specimens also may be made exclusively from weld metal.5.2.5 U-bend specimenSeeFigure6.The U-bend specimen is applicable
