1、BSI Standards PublicationBS EN ISO 15626:2013Non-destructive testingof welds Time-of-flightdiffraction technique (TOFD) Acceptance levels (ISO15626:2011)BS EN ISO 15626:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO15626:2013. It is identical to ISO 15
2、626:2011. It supersedes BS EN15617:2009 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee WEE/46, Non-destructive testing.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to
3、 include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 81136 4ICS 25.160.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This
4、British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 November 2013.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 15626 August 2013 ICS 25.160.40 Supersedes EN 15617:2009English Version N
5、on-destructive testing of welds - Time-of-flight diffraction technique (TOFD) - Acceptance levels (ISO 15626:2011) Contrle non destructif des assemblages souds - Technique de diffraction des temps de vol (TOFD) - Niveaux dacceptation (ISO 15626:2011) Zerstrungsfreie Prfung von Schweiverbindungen - B
6、eugungslaufzeittechnik (TOFD) - Zulssigkeitsgrenzen (ISO 15626:2011) This European Standard was approved by CEN on 8 August 2013. 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 standa
7、rd 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, German). A version in any
8、 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, Croatia, Cyprus, Czech Repub
9、lic, 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 United Kingdom. EUROPEAN
10、COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 15626:2013: EBS EN ISO 15626:
11、2013EN ISO 15626:2013 (E) 3 Foreword The text of ISO 15626:2011 has been prepared by Technical Committee ISO/TC 44 “Welding and allied processes” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 15626:2013 by Technical Committee CEN/TC 121 “Welding” the s
12、ecretariat of which is held by DIN. 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 February 2014, and conflicting national standards shall be withdrawn at the latest by February 2014. Attention i
13、s 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 15617:2009. According to the CEN-CENELEC Internal Regulations, the na
14、tional 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, Hungary, Iceland, Ireland, Italy, Latvia, L
15、ithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 15626:2011 has been approved by CEN as EN ISO 15626:2013 without any modification. BS EN ISO 15626:2013ISO 15
16、626:2011(E) ISO 2011 All rights reserved 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 membe
17、r 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 International Elec
18、trotechnical 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 adopt
19、ed 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 paten
20、t rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 15626 was prepared by CEN (as EN 15617) and was adopted, under a special “fast-track procedure”, by Technical Committee ISO/TC 44, Welding and allied processes, Subcommittee SC 5, Testing and inspection of
21、 welds, in parallel with its approval by the ISO member bodies. Request for official interpretations of any aspect of ISO 15626 should be directed to the Secretariat of ISO/TC 44/SC 5 via your national standards body. A complete listing of these bodies can be found at www.iso.org. BS EN ISO 15626:20
22、13BS EN ISO 15626:2013INTERNATIONAL STANDARD ISO 15626:2011(E) ISO 201 All rights reserved 11Non-destructive testing of welds Time-of-flight diffraction technique (TOFD) Acceptance levels 1 Scope This International Standard specifies acceptance levels for the time-of-flight diffraction technique (TO
23、FD) of These acceptance levels are applicable to indications classified in accordance with ISO 10863. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the la
24、test edition of the referenced document (including any amendments) applies. ISO 5817, Welding Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) Quality levels for imperfections (ISO 5817:2003, corrected version:2005, including Technical Corrigendum 1:2006) 3 Sy
25、mbols, terms and definitions 3.1 Symbols h height of an indication (see Figures 1, 2 and 3) l length of an indication (see Figures 1, 2 and 3) t nominal wall thickness in accordance with construction drawing or dimension table (see Figures 1, 2 and 3) 3.2 Terms and definitions For the purposes of th
26、is document, the following terms and definitions apply. 3.2.1 embedded discontinuity discontinuity within the volume of the material, separated from the surfaces 3.2.2 surface-breaking discontinuity discontinuity connected to the near (contact) surface or far (reflecting) surface of ISO 5817. full p
27、enetration welds in ferritic steels from 6 mm up to 300 mm thickness which correspond to the quality levels ISO 10863, Non-destructive testing of welds Ultrasonic testing Use of time-of-flight diffraction technique (TOFD)1)1) To be published. BS EN ISO 15626:2013ISO 15626:2011(E) 2 ISO 201 All right
28、s reserved14 Relation between quality levels and acceptance levels Three different acceptance levels are defined. The relation between these acceptance levels and the quality levels as mentioned in ISO 5817 are given in Table 1. Table 1 Acceptance levels Quality level according to ISO 5817 Examinati
29、on level in accordance with Acceptance level B (Stringent) C 1 C (Intermediate) at least B 2 D (Moderate) at least A 3 5 Definition and determination of length and height 5.1 General The size of a discontinuity is described by the length and height of its indication. Length is defined by the differe
30、nce of the x-coordinates of the indication. The height is defined as the maximum difference of the z-coordinates at any given x-position. 5.2 Determination of length 5.2.1 General Dependent upon the type of indication, one of the techniques for length sizing according to 5.2.2 or 5.2.3 shall be appl
31、ied: 5.2.2 Length sizing of elongated straight indications This type of indication does not change significantly in the through-wall direction. A hyperbolic cursor is fitted to the indication. Assuming the discontinuity is elongated and has a finite length, this will only be possible at each end. Th
32、e distance moved between acceptable fits at each end of the indication is taken to represent the length of the discontinuity (see Figure 1). Key 1 Length of indication Figure 1 Length sizing by fitting arc-shaped cursors ISO 10863BS EN ISO 15626:2013ISO 15626:2011(E) ISO 201 All rights reserved 315.
33、2.3 Length sizing of elongated curved indications This type of indication does change significantly in the through-wall direction. A hyperbolic cursor is positioned at either end of the indication at a time delay of one third of the indication penetration. The distance moved between the cursor posit
34、ions at each end of the indication is taken to represent the length of the discontinuity (see Figure 2). Key 1 Length of indication Figure 2 Length sizing of elongated curved indication 5.3 Determination of height 5.3.1 General The height measurement shall be done from the A-scan and by choosing a c
35、onsistent position on the signals, considering phase reversals. It is recommended to use one of the following methods: Method 1: by measuring the transit time between the leading edges of the signals; Method 2: by measuring the transit time between the first peaks; Method 3: by measuring the transit
36、 time between the maximum amplitudes. BS EN ISO 15626:2013ISO 15626:2011(E) 4 ISO 201 All rights reserved1Key 1 Method 1 2 Method 2 3 Method 3 4 Positions for measuring the transit time Figure 3 Position of the cursor for time measurement Methods 1, 2 and 3 5.3.2 Surface-breaking discontinuities The
37、 height of an indication of a surface-breaking discontinuity is determined by the maximum difference between the lateral wave and the lower-tip diffraction signal. Key 1 Scanning surface z1Start depth of discontinuity 2 Opposite surface z2End depth of discontinuity x1Start position of discontinuity
38、h Height x2End position of discontinuity l = x2 x1length Figure 4 Height measurement definition of a scanning surface breaking discontinuity For an opposite surface-breaking discontinuity, the height is determined by the maximum difference between the upper-tip diffraction signal and the back wall r
39、eflection (see Figure 5). BS EN ISO 15626:2013ISO 15626:2011(E) ISO 201 All rights reserved 51Key x1Start position of discontinuity z1 Start depth of discontinuity x2End position of discontinuity z2End depth of discontinuity l = x2 x1length h Height Figure 5 Height definition of an opposite surface-
40、breaking discontinuity 5.3.3 Embedded discontinuities The height of an indication of an embedded discontinuity is determined by the maximum difference between the upper-tip diffraction signal and the lower-tip diffraction signal at the same x-position (see Figure 6). Key x1Start position of disconti
41、nuity z1 Start depth of discontinuity x2 End position of discontinuity z2End depth of discontinuity l = x2 x1length h Height Figure 6 Height definition of an embedded discontinuity 6 Acceptance levels 6.1 General Classified indications are evaluated according to one of the acceptance levels listed i
42、n 6.2, 6.3 and 6.4. For welds joining two different thicknesses, the acceptance levels are based on the thinner of the two. BS EN ISO 15626:2013ISO 15626:2011(E) 6 ISO 201 All rights reserved1For welds subject to dynamic loading or being sensitive to cracking (e.g. longitudinal, transverse), more st
43、ringent near-surface acceptance levels or the use of additional NDT techniques may be specified. The symbols h1, h2and h3used in Tables 2, 3 and 4 are explained in Figure 7. 6.2 Indications from single discontinuities 6.2.1 Acceptance level 1 Table 2 Acceptance level 1 Thickness range Maximum allowa
44、ble length if h lmax h1mm Surface-breaking indicationa h3mm Embedded indication h2mm 6 mm 100 mm 50 mm 3 5 2 aWhen indications from surface-breaking discontinuities are detected, and the resolution is not sufficient to resolve the depth, different techniques or methods shall be applied to determine
45、the acceptability. If it is not possible to apply other techniques or methods all indications from surface-breaking discontinuities shall be considered unacceptable. ,BS EN ISO 15626:2013ISO 15626:2011(E) ISO 201 All rights reserved 716.2.2 Acceptance level 2 Table 3 Acceptance level 2 Thickness ran
46、ge Maximum allowable length if h lmax h1mm Surface-breaking indicationa h3mm Embedded indication h2mm 6 mm 100 mm 60 mm 4 6 3 aWhen indications from surface-breaking discontinuities are detected, and the resolution is not sufficient to resolve the depth, different techniques or methods shall be appl
47、ied to determine the acceptability. If it is not possible to apply other techniques or methods, all indications from surface-breaking discontinuities shall be considered unacceptable. BS EN ISO 15626:2013ISO 15626:2011(E) 8 ISO 201 All rights reserved16.2.3 Acceptance level 3 Table 4 Acceptance leve
48、l 3 Thickness range Maximum allowable length if h lmaxh1mm Surface-breaking indicationa h3mm Embedded indication h2mm 6 mm 100 mm 75 mm 5 8 4 aWhen indications from surface-breaking discontinuities are detected, and the resolution is not sufficient to resolve the depth, different techniques or metho
49、ds shall be applied to determine the acceptability. If it is not possible to apply other techniques or methods, all indications from surface-breaking discontinuities shall be considered unacceptable. Key 1 Acceptance for l lmax2 Acceptance for l lmax3 Rejection h1 Maximum allowable height for any discontinuity if l lmaxa = h2Height for embedded discontinuity a = h3Height for surface-breaking discontinuity Figure 7 General scheme for acceptance conditions BS EN ISO 15626:2013ISO 15626:2011(E)
