1、March 2015 Translation by DIN-Sprachendienst.English price group 11No 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
2、77.060!%ARM“2304742www.din.deDDIN EN ISO 7539-10Corrosion of metals and alloys Stress corrosion testing Part 10: Reverse U-bend method (ISO 7539-10:2013);English version EN ISO 7539-10:2014,English translation of DIN EN ISO 7539-10:2015-03Korrosion der Metalle und Legierungen Prfung der Spannungsris
3、skorrosion Teil 10: Vorbereitung und Anwendung von reversierten Bgelproben (ISO 7539-10:2013);Englische Fassung EN ISO 7539-10:2014,Englische bersetzung von DIN EN ISO 7539-10:2015-03Corrosion des mtaux et alliages Essais de corrosion sous contrainte Partie 10: Mthode dessai par cintrage en U invers
4、 (ISO 7539-10:2013);Version anglaise EN ISO 7539-10:2014,Traduction anglaise de DIN EN ISO 7539-10:2015-03www.beuth.deDocument comprises 18 pagesIn case of doubt, the German-language original shall be considered authoritative.03.15 DIN EN ISO 7539-10:2015-03 2 A comma is used as the decimal marker.
5、National foreword The text of ISO 7539-10:2013 has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys” and has been taken over as EN ISO 7539-10:2014 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” (Secretariat: BSI, United Kingdom). The respons
6、ible German body involved in its preparation was the DIN-Normenausschuss Materialprfung (DIN Standards Committee Materials Testing), Working Committee NA 062-01-77 AA Korrosionsprfverfahren. EN ISO 7539 consists of the following parts, under the general title Corrosion of metals and alloys Stress co
7、rrosion 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: Method for the preparation and use of uniaxially loaded tension specimens Part 5: Preparation and use of C-ring specimens Part 6:
8、 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: Preparation and use of pre-cracked specimens for tests under rising load or rising d
9、isplacement Part 10: Reverse U-bend test method Part 11: Guidelines for testing the resistance of metals and alloys to hydrogen embrittlement and hydrogen-assisted cracking The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 7539-1 DIN EN I
10、SO 7539-1 ISO 8407 DIN EN ISO 8407 DIN EN ISO 7539-10:2015-03 3 National Annex NA (informative) Bibliography DIN EN ISO 7539-1, Corrosion of metals and alloys Stress corrosion testing Part 1: General guidance on testing procedures DIN EN ISO 8407, Corrosion of metals and alloys Removal of corrosion
11、products from corrosion test specimens DIN EN ISO 7539-10:2015-03 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 7539-10 December 2014 ICS 77.060 English Version Corrosion of metals and alloys - Stress corrosion testing - Part 10: Reverse U-bend method (I
12、SO 7539-10:2013) Corrosion des mtaux et alliages - Essais de corrosion souscontrainte - Partie 10: Mthode dessai par cintrage en U invers (ISO 7539-10:2013) Korrosion der Metalle und Legierungen - Prfung der Spannungsrisskorrosion - Teil 10: Vorbereitung und Anwendung von reversierten Bgelproben (IS
13、O 7539-10:2013) This European Standard was approved by CEN on 16 December 2014. 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 bi
14、bliographical references concerning 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 resp
15、onsibility of a CEN member into its 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 Re
16、public of Macedonia, France, Germany, 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 NOR
17、MALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 7539-10:2014 EContents PageForeword 31 Scope . 42 Normative referen
18、ce . 43 Terms and definitions . 44 Principle 45 Specimens 55.1 General . 55.2 Tubing and piping 55.3 Other products 66 Experimental procedure 67 Post-exposure evaluation 68 Test report . 7Annex A (informative) Preparation of non-pre-strained half tube RUB specimen 8Annex B (informative) RUB specimen
19、s with a gauge section . 10DIN EN ISO 7539-10:2015-03 EN ISO 7539-10:2014 (E) 2Foreword The text of ISO 7539-10:2013 has been prepared by Technical 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
20、-10:2014 by 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 by publication of an identical text or by endorsement, at the latest by June 2015, and conflicti
21、ng national standards shall be withdrawn at the latest by June 2015. 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. According to the
22、CEN-CENELEC Internal Regulations, the national standards organizations 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, Hun
23、gary, Iceland, Ireland, 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 7539-10:2013 has been approved by CEN as EN ISO 7539-10:2014 without
24、any modification. DIN EN ISO 7539-10:2015-03EN ISO 7539-10:2014 (E)3WARNING null This International Standard may involve hazardous materials, operations, and equipment. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determi
25、ne the applicability of regulatory limitations prior to use.1 ScopeThis part of ISO 7539 covers procedures for designing, preparing and using reversed U-bend (RUB) test specimens for investigating the susceptibility of the metal to stress corrosion cracking. The term “metal” as used in this standard
26、 includes alloys.2 Normative referenceThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (incl
27、uding any amendments) applies. Members of IEC and ISO maintain registers of currently valid International Standards.ISO 7539-1, Corrosion of metals and alloys Stress corrosion testing Part 1: General guidance on testing proceduresISO 8407, Corrosion of metals and alloys Removal of corrosion products
28、 from corrosion test specimens3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 7539-1 apply.4 PrincipleThe RUB test is a particularly severe test for assessing susceptibility to stress corrosion cracking. The test is intended primarily for application
29、to metals with high corrosion resistance, such as Ni-based alloys, with the advantage compared to methods such as the conventional U-bend test of having significantly less stress relaxation. It is used primarily as a screening test for tubing, piping, plate, bar and other products including welded m
30、aterials. It may also be used as an acceptance test for performance in service subject to agreement between the parties.The principle of the test is to introduce very severe stresses in a high corrosion resistance metal, with minimum relaxation, in order to enhance the likelihood of inducing stress
31、corrosion cracking.The test consists of exposing to the corroding medium a piece of metal of semicircular section bent back on itself (i.e. reversed bent) into a U-shape and held in a manner which ensures that there are initial tensile stresses in excess of the yield strength over a large proportion
32、 of the inner surface. The test is accelerated by the presence of complex bi-axial stresses that may or may not exist in service. In the act of forming specimens, varying amounts of cold work may be introduced and this deformation may influence the stress corrosion cracking tendency as compared to t
33、hat of the material in the original condition.The test is normally performed in the laboratory by exposing the specimens to simulated service conditions.DIN EN ISO 7539-10:2015-03 EN ISO 7539-10:2014 (E) 4A further objective of the test is to compare and evaluate the influence of different material
34、parameters.The principal advantages of the test are its simplicity and its ability to provide rapid screening: if conventional U-bend or C-ring specimens are used for screening tests in high temperature solution as 573 K or higher, marked stress relaxation occurs and a long testing time is needed fo
35、r the evaluation. However, the stress relaxation in RUB specimens is smaller than that in conventional U-bend and C-ring specimens, due to the bi-axial stresses in RUB specimens. Therefore, screening tests can be done within a relatively short time through the use of RUB specimens.A disadvantage is
36、that the stress state is complicated and is difficult to quantify with accuracy. If an accurate stress state is desired an alternative method should be used.Wide variations in test results may be obtained for a given metal and environment even when testing nominally identical specimens and the repli
37、cation of tests is frequently necessary.If specimens are prepared from tubing of different dimensions or are subjected to different stressing procedures test results may be even more variable.5 Specimens5.1 GeneralRUB specimens are prepared from pieces of production tubing, piping, and other hollow
38、cylindrical products cut into half longitudinally or from plate, bar or other products formed into a semicircular shape along the axial direction. In this case, forming of the specimen should be followed by a heat treatment to relieve residual stresses before undertaking the reversed U-bending proce
39、ss.5.2 Tubing and pipingA variety of tube dimensions and specimen sizes can be employed. The tube is cut to selected specimen lengths and then sectioned axially to produce specimens with a semi-circular section.The tubing shall retain its original surface finish.During bending, deformation of the tu
40、be half may be constrained by the forming jig to force it to maintain its semicircular cross-section or its sides may be allowed to deform freely in which case it may tend to flatten at the apex. Both methods may be used. The latter procedure results in lower stresses, but has the advantage of avoid
41、ing cracking at the edges. The former type specimen is named as “Half tube RUB specimen”, and the latter type specimen is named as “RUB specimen with a gauge section”, in this standard.When testing RUB specimens with a gauge section (in which the stresses generated during reverse bending are lower b
42、ecause of reduced constraint), pre-straining can be used to achieve the desired stress level.Examples of preparation of half tube RUB specimens are shown in Annex A. Examples of preparation of non-pre-strained and pre-strained RUB specimens with a gauge section are shown in Annex B.Final heat treatm
43、ent shall be performed before bending (and pre-straining if this is adopted).Either single-stage or two-stage stressing may be performed. In single-stage stressing the specimen is not allowed to spring back after bending before final stressing. In two-stage stressing the specimen is allowed to sprin
44、g back after bending before final re-stressing.When stressing specimens with a loading bolt after forming, care should be taken to ensure that the deflection is restored beyond that pertaining at the end of the forming operation. The final distance between the specimen legs at the loading bolt shall
45、 be at least 1 mm less than that at the end of the forming operation. The final separation of the legs should be the same for all specimens in a given series; overloading should be avoided. To obtain consistency a micrometer measuring device should be used.DIN EN ISO 7539-10:2015-03EN ISO 7539-10:20
46、14 (E)5The bolting material should have a similar (or lower) coefficient of thermal expansion to that of the specimen. In addition, the use of double nuts to reduce the likelihood of loosening of the bolts is recommended.5.3 Other productsA variety of bar stock, plate and other forged or rolled mate
47、rial or welded material can be employed. These materials shall be machined into a plate after final heat treatment and pressed into a semicircular shape between inner and outer formers. Specimen preparation from a plate is shown in Annexes A and B.When testing welds, consideration shall be given to
48、the orientation of the weld relative to the longitudinal axis of the specimen and this shall be noted. Tests may be conducted on the weld metal itself or on sections containing the weld metal and heat- affected zone.Either single-stage or two-stage stressing may be performed. In single-stage stressing the specimen is not allowed to spring back after bending before final stressing. In two-stage stressing the specimen is allowed to spring back after bending before final re-stressing.When stressing sp
