DIN EN ISO 17081-2014 Method of measurement of hydrogen permeation and determination of hydrogen uptake and transport in metals by an electrochemical technique (ISO 17081 2014) Ger.pdf

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1、October 2014 Translation 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).IC

2、S 77.060!%;jn“2247175www.din.deDDIN EN ISO 17081Method of measurement of hydrogen permeation and determination ofhydrogen uptake and transport in metals by an electrochemicaltechnique (ISO 17081:2014);English version EN ISO 17081:2014,English translation of DIN EN ISO 17081:2014-10Elektrochemisches

3、Verfahren zur Messung der Wasserstoffpermeation und zurBestimmung von Wasserstoffaufnahme und -transport in Metallen (ISO 17081:2014);Englische Fassung EN ISO 17081:2014,Englische bersetzung von DIN EN ISO 17081:2014-10Mthode de mesure de la permation de lhydrogne et dtermination de labsorptiondhydr

4、ogne et de son transport dans les mtaux laide dune technique lectrochimique(ISO 17081:2014);Version anglaise EN ISO 17081:2014,Traduction anglaise de DIN EN ISO 17081:2014-10SupersedesDIN EN ISO 17081:2008-07www.beuth.deDocument comprises 26 pagesIn case of doubt, the German-language original shall

5、be considered authoritative.09.14 DIN EN ISO 17081:2014-10 2 A comma is used as the decimal marker. National foreword This document (EN ISO 17081:2014) has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and alloys” in collaboration with Technical Committee CEN/TC 262 “Metallic

6、and other inorganic coatings” (Secretariat: BSI, United Kingdom). The responsible German body involved in its preparation was the DIN-Normenausschuss Materialprfung (DIN Standards Committee Materials Testing), Working Committee NA 062-01-77 AA Korrosionsprfverfahren. The DIN Standards corresponding

7、to the International Standards referred to in this document are as follows: ISO 17475 DIN EN ISO 17475 ISO 8044 DIN EN ISO 8044 Amendments This standard differs from DIN EN ISO 17081:2008-07 as follows: a) minor revisions have been made to the text of the standard. Previous editions DIN EN ISO 17081

8、: 2008-07 DIN EN ISO 17081:2014-10 3 National Annex NA (informative) Bibliography DIN EN ISO 17475, Corrosion of metals and alloys Electrochemical test methods Guidelines for conducting potentiostatic and potentiodynamic polarization measurements DIN EN ISO 8044, Corrosion of metals and alloys Basic

9、 terms and definitions DIN EN ISO 17081:2014-10 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 17081 June 2014 ICS 77.060 Supersedes EN ISO 17081:2008English Version Method of measurement of hydrogen permeation and determination of hydrogen uptake and tra

10、nsport in metals by an electrochemical technique (ISO 17081:2014) Mthode de mesure de la permation de lhydrogne et dtermination de labsorption dhydrogne et de son transport dans les mtaux laide dune technique lectrochimique (ISO 17081:2014) Elektrochemisches Verfahren zur Messung der Wasserstoffperm

11、eation und zur Bestimmung von Wasserstoffaufnahme und -transport in Metallen(ISO 17081:2014) This European Standard was approved by CEN on 13 April 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the sta

12、tus 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 to any CEN member. This European Standard exists in three official versions (English, French, G

13、erman). 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 official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croa

14、tia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic 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 U

15、nited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION 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.

16、EN ISO 17081:2014 EContents PageForeword 31 Scope . 42 Normative references 43 Terms and definitions . 44 Symbols 55 Principle 66 Samples 76.1 Dimensions . 76.2 Preparation 87 Apparatus . 98 Test environment considerations . 119 Test procedure 1210 Control and monitoring of test environment .1411 An

17、alysis of results .1411.1 General 1411.2 Analysis of steady-state current 1411.3 Analysis of permeation transient . 1512 Test report 17Annex A (informative) Recommended test environments for specific alloys .19Bibliography .222DIN EN ISO 17081:2014-10EN ISO 17081:2014(E)3Foreword This document (EN I

18、SO 17081:2014) 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 secretariat of which is held by BSI. This European Standard shall be given the status of a national sta

19、ndard, either by publication of an identical text or by endorsement, at the latest by December 2014, and conflicting national standards shall be withdrawn at the latest by December 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rig

20、hts. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 17081:2008. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Sta

21、ndard: 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, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, S

22、pain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 17081:2014 has been approved by CEN as EN ISO 17081:2014 without any modification. DIN EN ISO 17081:2014-10EN ISO 17081:2014(E)1 Scope1.1 This International Standard specifies a laboratory method for the mea

23、surement of hydrogen permeation and for the determination of hydrogen atom uptake and transport in metals, using an electrochemical technique. The term “metal” as used in this International Standard includes alloys.1.2 This International Standard describes a method for evaluating hydrogen uptake in

24、metals, based on measurement of steady-state hydrogen flux. It also describes a method for determining effective diffusivity of hydrogen atoms in a metal and for distinguishing reversible and irreversible trapping.1.3 This International Standard gives requirements for the preparation of specimens, c

25、ontrol and monitoring of the environmental variables, test procedures and analysis of results.1.4 This International Standard may be applied, in principle, to all metals for which hydrogen permeation is measurable and the method can be used to rank the relative aggressivity of different environments

26、 in terms of the hydrogen uptake of the exposed metal.2 Normative referencesThe 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 ed

27、ition of the referenced document (including any amendments) applies.ISO 17475, Corrosion of metals and alloys Electrochemical test methods Guidelines for conducting potentiostatic and potentiodynamic polarization measurements3 Terms and definitionsFor the purposes of this document, the following ter

28、ms and definitions apply.3.1chargingmethod of introducing atomic hydrogen into the metal by exposure to an aqueous environment under galvanostatic control (constant charging current), potentiostatic control (constant electrode potential), free corrosion or by gaseous exposure3.2charging cellcompartm

29、ent in which hydrogen atoms are generated on the sample surface, including both aqueous and gaseous charging3.3decay currentdecay of the hydrogen atom oxidation current, after attainment of steady state, following a decrease in charging current4DIN EN ISO 17081:2014-10EN ISO 17081:2014(E)3.4Ficks se

30、cond lawsecond-order differential equation describing, in this case, the concentration of atomic hydrogen in the sample as a function of position and timeNote 1 to entry: The equation is of the form C (x, t)/t = D2C(x, t)/x2for lattice diffusion in one dimension where diffusivity is independent of c

31、oncentration. See Table 1 for an explanation of the symbols.3.5hydrogen fluxamount of hydrogen passing through the metal sample per unit area per unit time3.6hydrogen uptakeatomic hydrogen absorbed into the metal as a result of charging3.7irreversible trapmicrostructural site at which the residence

32、time for a hydrogen atom is infinite or extremely long compared to the time-scale for permeation testing at the relevant temperature3.8mobile hydrogen atomshydrogen atoms in interstitial sites in the lattice (lattice sites) and reversible trap sites3.9oxidation cellcompartment in which hydrogen atom

33、s exiting from the metal sample are oxidized3.10permeation currentcurrent measured in oxidation cell associated with oxidation of hydrogen atoms3.11permeation fluxhydrogen flux exiting the test sample in the oxidation cell3.12permeation transientvariation of the permeation current with time, from co

34、mmencement of charging to the attainment of steady state, or modification of charging conditions3.13recombination poisonchemical within the test environment in the charging cell which enhances hydrogen absorption by retarding the recombination of hydrogen atoms on the metal surface3.14reversible tra

35、pmicrostructural site at which the residence time for a hydrogen atom is greater than that for the lattice site but is small in relation to the time to attain steady-state permeation4 SymbolsTable 1 gives a list of symbols and their designations.5DIN EN ISO 17081:2014-10 EN ISO 17081:2014(E)Table 1

36、Symbols and their designations and unitsSymbol Designation UnitA Exposed area of sample in the oxidation cell m2C(x, t) Lattice concentration of hydrogen as a function of position and time molm3C0Sub-surface concentration of atomic hydrogen in interstitial lattice sites on the charging side of the s

37、amplemolm3C0RSummation of the sub-surface concentration of hydrogen in interstitial lattice sites and reversible trap sites on the charging side of the samplemolm3DlLattice diffusion coefficient of atomic hydrogen m2s1DeffEffective diffusion coefficient of atomic hydrogen based on elapsed time corre

38、spond-ing to J (t)/Jss= 0,63m2s1F Faradays constant (F = 96 485 Cmol1) Cmol1J (t) Time-dependent atomic hydrogen permeation flux as measured on the oxidation side of the samplemolm2s1JssAtomic hydrogen permeation flux at steady-state as measured on the oxidation side of the samplemolm2s1J (t)/JssNor

39、malized flux of atomic hydrogen 1I (t) Time-dependent atomic hydrogen permeation current Am2IssSteady-state atomic hydrogen permeation current Am2L Sample thickness mt Time elapsed from commencement of hydrogen charging stbElapsed time measured by extrapolating the linear portion of the rising perme

40、ation current transientstlagTime to achieve a value of J (t)/Jss= 0,63 sx Distance in sample measured in the thickness direction m Normalized time (Dlt/L2) 1lagNormalized time to achieve a value of J (t)/Jss= 0,63 15 Principle5.1 The technique involves locating the metal sample of interest between t

41、he charging and oxidation cells, where the charging cell contains the environment of interest. Hydrogen atoms are generated on the sample surface exposed to this environment.5.2 In gaseous environments, the hydrogen atoms are generated by adsorption and dissociation of the gaseous species. In aqueou

42、s environments, hydrogen atoms are produced by electrochemical reactions. In both cases, some of the hydrogen atoms diffuse through the metal sample and are then oxidized to hydrogen cations on exiting from the other side of the metal in the oxidation cell.A palladium coating is sometimes applied to

43、 one or both sides of the membrane following initial removal of oxide films. A palladium coating on the charging face of the membrane affects the sub-surface hydrogen concentration in the substrate and the measured permeation current. It is important to verify that the calculated diffusivity is not

44、influenced by the coating. Palladium coating is particularly useful for gaseous charging.5.3 The environment and the electrode potential on the oxidation side of the membrane are selected so that the metal is either passive or immune to corrosion. The background current established prior to hydrogen

45、 transport is steady, and small compared to the hydrogen atom oxidation current.6DIN EN ISO 17081:2014-10EN ISO 17081:2014(E)5.4 The electrode potential of the sample in the oxidation cell is controlled at a value sufficiently positive to ensure that the kinetics of oxidation of hydrogen atoms are l

46、imited by the flux of hydrogen atoms, i.e. the hydrogen atom oxidation current density is transport limited.NOTE Palladium coating of the oxidation side of the sample can enhance the rate of oxidation and thereby enable attainment of transport-limited oxidation of hydrogen atoms at less positive pot

47、entials than for the uncoated sample.5.5 The oxidation current is monitored as a function of time. The total oxidation current comprises the background current and the permeation current.5.6 The thickness of the sample, L, is usually selected to ensure that the measured flux reflects volume (bulk) c

48、ontrolled hydrogen atom transport.NOTE Thin specimens may be used for evaluation of the effect of surface processes on hydrogen entry (absorption kinetics or transport in oxide films).5.7 In reasonably pure metals with a sufficiently low density of microstructural trap sites, atomic hydrogen transport through the material is controlled by lattice diffusion.5.8 The effect of alloying and of microstructural features such as dislocations, grain boundaries, inclusions, and precipitate pa