SIST EN ISO 17640:2019

Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment (ISO 17640:2018)

This document specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic
materials of thickness ≥8 mm which exhibit low ultrasonic attenuation (especially that due to scatter)
at object temperatures from 0 °C to 60 °C. It is primarily intended for use on full penetration welded
joints where both the welded and parent material are ferritic.
Where material-dependent ultrasonic values are specified in this document, they are based on steels
having an ultrasonic sound velocity of (5 920 ± 50) m/s for longitudinal waves and (3 255 ± 30) m/s for
transverse waves.
This document specifies four testing levels, each corresponding to a different probability of detection of
imperfections. Guidance on the selection of testing levels A, B, and C is given in Annex A.
This document specifies that the requirements of testing level D, which is intended for special
applications, be in accordance with general requirements. Testing level D can only be used when defined
by specification. This includes tests of metals other than ferritic steel, tests on partial penetration welds,
tests with automated equipment, and tests at object temperatures outside the range 0 °C to 60 °C.
This document can be used for the assessment of discontinuities, for acceptance purposes, by either of
the following techniques:
a) evaluation based primarily on length and echo amplitude of the discontinuity;
b) evaluation based on characterization and sizing of the discontinuity by probe movement techniques.

Zerstörungsfreie Prüfung von Schweißverbindungen - Ultraschallprüfung - Techniken, Prüfklassen und Bewertung (ISO 17640:2018)

Essais non destructifs des assemblages soudés - Contrôle par ultrasons - Techniques, niveaux d'essai et évaluation (ISO 17640:2018)

Le présent document spécifie des techniques de contrôle manuel par ultrasons des assemblages en matériaux métalliques soudés par fusion, d'épaisseur égale ou supérieure à 8 mm, présentant une atténuation relativement faible des ultrasons (en particulier celle due à la diffusion) à des températures d'objet comprises entre 0 °C et 60 °C. Elle vise particulièrement les assemblages soudés à pleine pénétration dont le métal de base et la soudure sont ferritiques.
Lorsque les valeurs des caractéristiques ultrasonores dépendantes des matériaux sont précisées dans le présent document, elles concernent des aciers dans lesquels la vitesse des ondes ultrasonores est égale à (5 920 ± 50) m/s pour les ondes longitudinales et à (3 255 ± 30) m/s pour les ondes transversales.
Le présent document spécifie quatre niveaux de contrôle, chacun correspondant à une probabilité différente de détection des défauts. Un guide du choix des niveaux de contrôle A, B et C est donné dans l'Annexe A.
Le présent document spécifie que les exigences relatives au niveau de contrôle D, qui est prévu pour des applications spéciales, sont conformes aux exigences générales. Le niveau de contrôle D ne peut être utilisé que lorsqu'il est défini par une spécification. Cela inclut les contrôles de métaux autres que les aciers ferritiques, les contrôles sur des soudures à pénétration partielle, les contrôles avec des équipements automatisés, et les contrôles à des températures d'objet situées hors de la plage 0 °C à 60 °C.
Le présent document peut être utilisé pour l'évaluation des discontinuités, aux fins d'acceptation, par l'une des techniques suivantes:
a)    évaluation fondée principalement sur la longueur et l'amplitude d'écho de la discontinuité;
b)    évaluation fondée sur la caractérisation et le dimensionnement de la discontinuité par des techniques de déplacement du traducteur.

Neporušitveno preskušanje zvarnih spojev - Ultrazvočno preskušanje - Tehnike, stopnje preskušanja in ocenjevanje (ISO 17640:2018)

Ta dokument določa tehnike za ročno ultrazvočno preskušanje talilno zvarjenih spojev v kovinskih materialih debeline ≥ 8 mm, ki izkazujejo nizko stopnjo ultrazvočne atenuacije (zlasti tiste, do katere pride zaradi razprševanja) pri temperaturi predmetov med 0 in 60 °C. Primarno je namenjeno za uporabo pri zvarnih spojih s popolno penetracijo, kjer sta tako zvarjeni kot osnovni material feritna.
Kadar so v tem dokumentu določene od materiala odvisne ultrazvočne vrednosti, temeljijo na jeklih z ultrazvočno hitrostjo (5920 ± 50) m/s za longitudinalne valove in (3255 ± 30) m/s za
transverzalne valove.
Ta dokument določa štiri ravni preskusa, pri čemer vsaka označuje drugačno verjetnost zaznavanja nepravilnosti. Navodila o izbiri ravni preskušanja A, B in C so na voljo v dodatku A.
Ta dokument določa, da so zahteve ravni preskušanja D, ki je namenjena za posebno uporabo, skladne s splošnimi zahtevami. Raven preskušanja D je mogoče uporabljati le takrat, ko to določajo specifikacije. To vključuje preskuse kovin, ki niso feritno jeklo, preskuse na zvarih z delno prevaritvijo, preskuse z avtomatizirano opremo in preskuse pri temperaturah predmetov, ki so izven razpona 0–60 °C.
Ta dokument je mogoče uporabiti za ocenjevanje nehomogenosti, za namene sprejemanja, po kateri koli od naslednjih tehnik:
a) vrednotenje, ki primarno temelji na amplitudi dolžine in odmeva nehomogenosti;
b) vrednotenje, ki temelji na karakterizaciji in ugotavljanju velikosti nehomogenosti prek tehnik premikanja preskuševalne glave.

General Information

• Status: Published
• Public Enquiry End Date: 09-Sep-2018
• Publication Date: 30-Jan-2019
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: VAR - Welding
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 09-Jan-2019
• Due Date: 16-Mar-2019
• Completion Date: 31-Jan-2019
• Ref Project: EN ISO 17640:2018 - Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment (ISO 17640:2018)

Relations

• Replaces: SIST EN ISO 17640:2018 - Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment (ISO 17640:2017)
• Effective Date: 01-Mar-2019
• Replaces: SIST EN ISO 17640:2018 - Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and assessment (ISO 17640:2017)
• Effective Date: 08-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 17640:2019
01-marec-2019
1DGRPHãþD
SIST EN ISO 17640:2018
1HSRUXãLWYHQRSUHVNXãDQMH]YDUQLKVSRMHY8OWUD]YRþQRSUHVNXãDQMH7HKQLNH
VWRSQMHSUHVNXãDQMDLQRFHQMHYDQMH,62
Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and
assessment (ISO 17640:2018)
Zerstörungsfreie Prüfung von Schweißverbindungen - Ultraschallprüfung - Techniken,
Prüfklassen und Bewertung (ISO 17640:2018)
Essais non destructifs des assemblages soudés - Contrôle par ultrasons - Techniques,
niveaux d'essai et évaluation (ISO 17640:2018)
Ta slovenski standard je istoveten z: EN ISO 17640:2018
ICS:
25.160.40 Varjeni spoji in vari Welded joints and welds
SIST EN ISO 17640:2019 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 17640:2019

---------------------- Page: 2 ----------------------

SIST EN ISO 17640:2019


EN ISO 17640
EUROPEAN STANDARD

NORME EUROPÉENNE

November 2018
EUROPÄISCHE NORM
ICS 25.160.40 Supersedes EN ISO 17640:2017
English Version

Non-destructive testing of welds - Ultrasonic testing -
Techniques, testing levels, and assessment (ISO
17640:2018)
Essais non destructifs des assemblages soudés -
Contrôle par ultrasons - Techniques, niveaux d'essai et
évaluation (ISO 17640:2018)
This European Standard was approved by CEN on 11 October 2018.

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 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 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 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 17640:2018 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO 17640:2019
EN ISO 17640:2018 (E)
Contents Page
European foreword . 3

2

---------------------- Page: 4 ----------------------

SIST EN ISO 17640:2019
EN ISO 17640:2018 (E)
European foreword
This document (EN ISO 17640:2018) has been prepared by Technical Committee ISO/TC 44 "Welding
and allied processes" in collaboration with Technical Committee CEN/TC 121 “Welding and allied
processes” the secretariat 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 May 2019, and conflicting national standards shall be
withdrawn at the latest by May 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 17640:2017.
According to the 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, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 17640:2018 has been approved by CEN as EN ISO 17640:2018 without any modification.

3

---------------------- Page: 5 ----------------------

SIST EN ISO 17640:2019

---------------------- Page: 6 ----------------------

SIST EN ISO 17640:2019
INTERNATIONAL ISO
STANDARD 17640
Fourth edition
2018-10
Non-destructive testing of welds —
Ultrasonic testing — Techniques,
testing levels, and assessment
Essais non destructifs des assemblages soudés — Contrôle par
ultrasons — Techniques, niveaux d'essai et évaluation
Reference number
ISO 17640:2018(E)
©
ISO 2018

---------------------- Page: 7 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 2
5 General . 3
6 Information required prior to testing . 3
6.1 Items to be specified . 3
6.2 Specific information required before testing . 4
6.3 Written test procedure . 4
7 Requirements for personnel and equipment . 4
7.1 Personnel qualifications . 4
7.2 Test equipment . 4
7.3 Probe parameters . 5
7.3.1 Test frequency . 5
7.3.2 Angles of incidence . 5
7.3.3 Transducer size . 5
7.3.4 Adaptation of probes to curved scanning surfaces . 5
7.3.5 Coupling media . 6
8 Testing volume . 6
9 Preparation of scanning surfaces . 6
10 Parent metal testing . 6
11 Range and sensitivity setting . 7
11.1 General . 7
11.2 Reference for sensitivity setting . 8
11.3 Evaluation levels . 9
11.4 Transfer correction . 9
11.5 Signal-to-noise ratio . 9
12 Testing levels . 9
13 Testing techniques .10
13.1 General .10
13.2 Manual scan path .10
13.3 Testing for imperfections perpendicular to the testing surface .10
13.4 Location of discontinuities .10
13.5 Evaluation of indications .10
13.5.1 General.10
13.5.2 Maximum echo amplitude .10
13.5.3 Discontinuity length.10
13.5.4 Discontinuity height . .10
13.5.5 Characterization of discontinuities .10
14 Test report .11
Annex A (normative) Testing levels for various types of welded joints .13
Bibliography .30
© ISO 2018 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

Foreword
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 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 International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes,
Subcommittee SC 5, Testing and inspection of welds.
Any feedback, question or request for official interpretation related to any aspect of this document
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/members .html. Official interpretations, where they
exist, are available from this page: https: //committee .iso .org/sites/tc44/home/interpretation .html.
This fourth edition cancels and replaces the third edition (ISO 17640:2017), which has been technically
revised. The main change compared to the previous edition is that Figure A.4 a) and b) has been
corrected.
iv © ISO 2018 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO 17640:2019
INTERNATIONAL STANDARD ISO 17640:2018(E)
Non-destructive testing of welds — Ultrasonic testing —
Techniques, testing levels, and assessment
1 Scope
This document specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic
materials of thickness ≥8 mm which exhibit low ultrasonic attenuation (especially that due to scatter)
at object temperatures from 0 °C to 60 °C. It is primarily intended for use on full penetration welded
joints where both the welded and parent material are ferritic.
Where material-dependent ultrasonic values are specified in this document, they are based on steels
having an ultrasonic sound velocity of (5 920 ± 50) m/s for longitudinal waves and (3 255 ± 30) m/s for
transverse waves.
This document specifies four testing levels, each corresponding to a different probability of detection of
imperfections. Guidance on the selection of testing levels A, B, and C is given in Annex A.
This document specifies that the requirements of testing level D, which is intended for special
applications, be in accordance with general requirements. Testing level D can only be used when defined
by specification. This includes tests of metals other than ferritic steel, tests on partial penetration welds,
tests with automated equipment, and tests at object temperatures outside the range 0 °C to 60 °C.
This document can be used for the assessment of discontinuities, for acceptance purposes, by either of
the following techniques:
a) evaluation based primarily on length and echo amplitude of the discontinuity;
b) evaluation based on characterization and sizing of the discontinuity by probe movement techniques.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5577, Non-destructive testing — Ultrasonic testing — Vocabulary
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 11666, Non-destructive testing of welds — Ultrasonic testing— Acceptance levels
ISO 16810, Non-destructive testing — Ultrasonic testing — General principles
ISO 16811, Non-destructive testing — Ultrasonic testing — Sensitivity and range setting
ISO 16826, Non-destructive testing — Ultrasonic testing — Examination for discontinuities perpendicular
to the surface
ISO 17635, Non-destructive testing of welds — General rules for metallic materials
ISO 23279, Non-destructive testing of welds — Ultrasonic testing — Characterization of discontinuities
in welds
EN 12668 (all parts), Non-destructive testing — Characterization and verification of ultrasonic
examination equipment
© ISO 2018 – All rights reserved 1

---------------------- Page: 11 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5577 and ISO 17635 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Symbols
The symbols in Table 1 apply.
Table 1 — Symbols
Symbol Definition Unit
AL acceptance level —
D diameter of the disk-shaped reflector (flat-bottomed hole) mm
DSR
h extension of the discontinuity in depth direction mm
l length of the discontinuity mm
l projected length of the discontinuity in the x-direction mm
x
l projected length of the discontinuity in the y-direction mm
y
p full skip distance mm
a
t thickness of parent material mm
x position of the discontinuity in the longitudinal direction mm
y position of the discontinuity in the transverse direction mm
z position of the discontinuity in the depth direction mm
a
If the joined parts are not of equal thickness, t represents the smallest thickness.
Indications shall be considered to be originating from either longitudinal or transverse discontinuities,
depending on the direction of their major dimension with respect to the weld axis, x, in accordance with
Figure 1.
2 © ISO 2018 – All rights reserved

---------------------- Page: 12 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

Key
1 origin
Figure 1 — Coordinate system for defining the location of discontinuities
5 General
The purpose of this document is to describe general techniques of ultrasonic weld testing, using
standard criteria, for the most commonly used welded joints at object temperatures in the range 0 °C to
60 °C. The specific requirements of this document cover the test equipment, preparation, performance
of testing, and reporting. The parameters specified, in particular those for the probes, are compatible
with the requirements of ISO 11666 and ISO 23279.
If the joined parts are not of equal thickness, the smallest thickness shall be considered.
The techniques used shall be specified.
6 Information required prior to testing
6.1 Items to be specified
These include:
a) method for setting the reference level;
b) method to be used for the evaluation of discontinuities;
c) acceptance levels;
d) testing level;
e) manufacturing and operation stage(s) at which the testing is to be carried out;
f) qualification of personnel;
g) extent of the testing for transverse discontinuities;
h) requirements for additional tandem testing (according to ISO 16826);
© ISO 2018 – All rights reserved 3

---------------------- Page: 13 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

i) parent metal testing prior to and/or after welding;
j) whether or not a written test procedure is required;
k) requirements for written test procedures.
6.2 Specific information required before testing
Before any testing of a welded joint can begin, the operator shall have access to the following essential
information:
a) written test procedure, if required (see 6.3);
b) type(s) of parent material and product form (i.e. cast, forged, rolled);
c) manufacturing or operation stage at which testing is to be made, including heat treatment, if any;
d) time and extent of any post-weld heat treatment;
e) joint preparation and dimensions;
f) requirements for surface conditions;
g) welding procedure or relevant information on the welding process;
h) reporting requirements;
i) acceptance levels;
j) extent of testing, including requirements for transverse discontinuities, if relevant;
k) testing level;
l) personnel qualification level;
m) procedures for corrective actions when unacceptable discontinuities are revealed.
6.3 Written test procedure
The definitions and requirements in this document normally satisfy the need for a written test
procedure.
Where this is not the case, or where the techniques described in this document are not applicable to the
welded joint to be tested, additional written test procedures shall be used, if required by specification.
7 Requirements for personnel and equipment
7.1 Personnel qualifications
Personnel performing testing in accordance with this document shall be qualified to an appropriate
level in ultrasonic testing in accordance with ISO 9712 or equivalent in the relevant industrial sector.
In addition to a general knowledge of ultrasonic weld testing, personnel shall also be familiar with
testing problems specifically associated with the type of welded joints to be tested.
7.2 Test equipment
Any equipment used for testing in conjunction with this document shall comply with the requirements
of EN 12668 (all parts).
4 © ISO 2018 – All rights reserved

---------------------- Page: 14 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

7.3 Probe parameters
7.3.1 Test frequency
The frequency shall be within the range 2 MHz to 5 MHz and shall be selected to consider the properties
of the test object and to comply with the specified acceptance levels, e.g. those of ISO 11666.
Higher frequencies may be used to improve range resolution if this is necessary when using standards
for acceptance levels based on characterization of discontinuities, e.g. ISO 23279.
Lower frequencies may be used for testing at long sound paths and/or when the material shows high
attenuation.
7.3.2 Angles of incidence
When testing is carried out with transverse waves and techniques that require the ultrasonic beam to
be reflected from an opposite surface, care shall be taken to ensure that the angle between the beam
and the normal to the opposite reflecting surface is between 35° and 70°. Where more than one beam
angle is used, at least one of the angle-beam probes used shall conform to this requirement. One of the
beam angles used shall ensure that the weld fusion faces are tested at, or as near as possible to, normal
incidence. When the use of two or more beam angles is specified, the difference between the nominal
beam angles shall be 10° or greater.
Angles of incidence at the probe and opposite reflecting surface, when curved, may be determined by
drawing a sectional view of the weld or in accordance with the techniques given in ISO 16811. Where
angles of incidence cannot be determined as specified by this document, the test report shall contain
a comprehensive description of the scans used and the extent of any incomplete coverage caused,
together with an explanation of the difficulties encountered.
7.3.3 Transducer size
The transducer size shall be chosen according to the ultrasonic path to be used and the frequency.
The smaller the transducer, the smaller the length and width of the near field, and the larger the beam
spread in the far field at a given frequency.
Small probes having 6 mm to 12 mm diameter transducers (or rectangular transducers of equivalent
area) are therefore most useful when working at short sound paths. For longer sound paths, i.e. greater
than 100 mm for single-transducer and greater than 200 mm for angle-beam probes, a transducer size
of 12 mm to 24 mm is more suitable.
7.3.4 Adaptation of probes to curved scanning surfaces
The gap, g, between test surface and bottom of the probe shall not be greater than 0,5 mm.
For flat probes on cylindrical or spherical surfaces, this requirement can be checked with Formula (1):
2
ga= 4D (1)
where
a is the dimension of the probe in the direction of curvature, in mm;
D is the diameter of the test object, in mm.
If a value for g larger than 0,5 mm results from Formula (1), the probe shall be adapted to the surface
and the sensitivity and range shall be set accordingly.
© ISO 2018 – All rights reserved 5

---------------------- Page: 15 ----------------------

SIST EN ISO 17640:2019
ISO 17640:2018(E)

For spherical or complex shaped surfaces, Formula (1) shall be applied in both length and width
direction of the probe (possible differences in curvature and/or probe dimensions).
7.3.5 Coupling media
The coupling media shall be in accordance with ISO 16810. The coupling medium used for range and
sensitivity setting and for the test shall be the same.
8 Testing volume
The testing volume (see Figure 2) is defined as the zone which includes weld and parent material and
the width of the heat-affected zone on each side of the weld or at least 10 mm if the width of the heat-
affected zone is not known.
In all cases, scanning shall cover the whole testing volume. If individual sections of this volume cannot
be covered in at least one scanning direction, or if the angles of incidence with the opposite surface
do not meet the requirements of 7.3.2, alternative or supplementary ultrasonic techniques or other
non-destructive techniques shall be agreed upon. This may, in some cases, require removal of the weld
reinforcement.
Supplementary techniques can require testing using dual-transducer angle-beam probes, creeping
wave probes, further ultrasonic techniques or any other suitable method, e.g. liquid penetrant, magnetic
particle, radiographic testing. In selecting alternative or supplementary techniques, due consideration
should be given to the type of weld and probable orientation of any imperfections to be detected.
9 Preparation of scanning surfaces
Scanning surfaces shall be wide enough to permit the testing volume (see Figure 2) to be fully covered.
Alternatively, the width of the scanning surfaces may be smaller if equivalent coverage of the testing
volu
...

SLOVENSKI STANDARD
oSIST prEN ISO 17640:2018
01-september-2018
1HSRUXãLWYHQRSUHVNXãDQMH]YDUQLKVSRMHY8OWUD]YRþQRSUHVNXãDQMH7HKQLNH
VWRSQMHSUHVNXãDQMDLQRFHQMHYDQMH,62)',6
Non-destructive testing of welds - Ultrasonic testing - Techniques, testing levels, and
assessment (ISO/FDIS 17640:2018)
Essais non destructifs des assemblages soudés - Contrôle par ultrasons - Techniques,
niveaux d'essai et évaluation (ISO/FDIS 17640:2018)
Ta slovenski standard je istoveten z: prEN ISO 17640
ICS:
25.160.40 Varjeni spoji in vari Welded joints and welds
oSIST prEN ISO 17640:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 17640:2018

---------------------- Page: 2 ----------------------
oSIST prEN ISO 17640:2018
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 17640
ISO/TC 44/SC 5
Non-destructive testing of welds —
Secretariat: AFNOR
Ultrasonic testing — Techniques,
Voting begins on:
2018­06­18 testing levels, and assessment
Voting terminates on:
Essais non destructifs des assemblages soudés — Contrôle par
2018­09-10
ultrasons — Techniques, niveaux d'essai et évaluation
ISO/CEN PARALLEL PROCESSING
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 17640:2018(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2018

---------------------- Page: 3 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH­1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

---------------------- Page: 4 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols . 2
5 Principle . 3
6 Information required prior to testing . 3
6.1 Items to be specified . 3
6.2 Specific information required before testing . 3
6.3 Written test procedure . 4
7 Requirements for personnel and equipment . 4
7.1 Personnel qualifications . 4
7.2 Test equipment . 4
7.3 Probe parameters . 4
7.3.1 Test frequency . 4
7.3.2 Angles of incidence . 4
7.3.3 Element size . 5
7.3.4 Adaptation of probes to curved scanning surfaces . 5
7.3.5 Coupling media . 5
8 Testing volume . 5
9 Preparation of scanning surfaces . 6
10 Parent metal testing . 6
11 Range and sensitivity setting . 7
11.1 General . 7
11.2 Reference for sensitivity setting . 8
11.3 Evaluation levels . 9
11.4 Transfer correction . 9
11.5 Signal­to­noise ratio . 9
12 Testing levels . 9
13 Testing techniques .10
13.1 General .10
13.2 Manual scan path .10
13.3 Testing for imperfections perpendicular to the testing surface .10
13.4 Location of discontinuities .10
13.5 Evaluation of indications .10
13.5.1 General.10
13.5.2 Maximum echo amplitude .10
13.5.3 Discontinuity length.11
13.5.4 Discontinuity height . .11
13.5.5 Characterization of discontinuities .11
14 Test report .11
Annex A (normative) Testing levels for various types of welded joints .13
Bibliography .30
© ISO 2018 – All rights reserved iii

---------------------- Page: 5 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

Foreword
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 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 non­governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 44, Welding and allied processes,
Subcommittee SC 5, Testing and inspection of welds.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
This fourth edition cancels and replaces the third edition (ISO 17640:2017), which has been technically
revised. The main change compared to the previous edition is that Figure A.4 a) and b) has been
corrected.
iv © ISO 2018 – All rights reserved

---------------------- Page: 6 ----------------------
oSIST prEN ISO 17640:2018
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 17640:2018(E)
Non-destructive testing of welds — Ultrasonic testing —
Techniques, testing levels, and assessment
1 Scope
This document specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic
materials of thickness ≥8 mm which exhibit low ultrasonic attenuation (especially that due to scatter)
at object temperatures from 0 °C to 60 °C. It is primarily intended for use on full penetration welded
joints where both the welded and parent material are ferritic.
Where material-dependent ultrasonic values are specified in this document, they are based on steels
having an ultrasonic sound velocity of (5 920 ± 50) m/s for longitudinal waves and (3 255 ± 30) m/s for
transverse waves.
This document specifies four testing levels, each corresponding to a different probability of detection of
imperfections. Guidance on the selection of testing levels A, B, and C is given in Annex A.
This document specifies that the requirements of testing level D, which is intended for special
applications, be in accordance with general requirements. Testing level D can only be used when defined
by specification. This includes tests of metals other than ferritic steel, tests on partial penetration welds,
tests with automated equipment, and tests at object temperatures outside the range 0 °C to 60 °C.
This document can be used for the assessment of discontinuities, for acceptance purposes, by either of
the following techniques:
a) evaluation based primarily on length and echo amplitude of the discontinuity;
b) evaluation based on characterization and sizing of the discontinuity by probe movement techniques.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5577, Non-destructive testing — Ultrasonic testing — Vocabulary
ISO 9712, Non-destructive testing — Qualification and certification of NDT personnel
ISO 11666, Non-destructive testing of welds — Ultrasonic testing— Acceptance levels
ISO 16810, Non-destructive testing — Ultrasonic testing — General principles
ISO 16811, Non-destructive testing — Ultrasonic testing — Sensitivity and range setting
ISO 16826, Non-destructive testing — Ultrasonic testing — Examination for discontinuities perpendicular
to the surface
ISO 17635, Non-destructive testing of welds — General rules for metallic materials
ISO 23279, Non-destructive testing of welds — Ultrasonic testing — Characterization of discontinuities
in welds
EN 12668 (all parts), Non-destructive testing — Characterization and verification of ultrasonic
examination equipment
© ISO 2018 – All rights reserved 1

---------------------- Page: 7 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5577 and ISO 17635 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Symbols
Symbol Definition Unit
AL acceptance level —
D diameter of the disk-shaped reflector (flat-bottom hole) mm
DSR
h extension of the discontinuity in depth direction mm
l length of the discontinuity mm
l projected length of the discontinuity in the x­direction mm
x
l projected length of the discontinuity in the y­direction mm
y
p full skip distance mm
a
t thickness of parent material mm
x position of the discontinuity in the longitudinal direction mm
y position of the discontinuity in the transverse direction mm
z position of the discontinuity in the depth direction mm
a
If the joined parts are not of equal thickness, t represents the smallest thickness.
Indications shall be considered to be originating from either longitudinal or transverse discontinuities,
depending on the direction of their major dimension with respect to the weld axis, x, in accordance with
Figure 1.
Key
1 origin
Figure 1 — Coordinate system for defining the location of discontinuities
2 © ISO 2018 – All rights reserved

---------------------- Page: 8 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

5 Principle
The purpose of this document is to describe general techniques of ultrasonic weld testing, using
standard criteria, for the most commonly used welded joints at object temperatures in the range 0 °C to
60 °C. The specific requirements of this document cover the test equipment, preparation, performance
of testing, and reporting. The parameters specified, in particular those for the probes, are compatible
with the requirements of ISO 11666 and ISO 23279.
If the joined parts are not of equal thickness, the smallest thickness shall be considered.
The techniques used shall be specified.
6 Information required prior to testing
6.1 Items to be specified
These include:
a) method for setting the reference level;
b) method to be used for the evaluation of discontinuities;
c) acceptance levels;
d) testing level;
e) manufacturing and operation stage(s) at which the testing is to be carried out;
f) qualification of personnel;
g) extent of the testing for transverse discontinuities;
h) requirements for additional tandem testing (according to ISO 16826);
i) parent metal testing prior to and/or after welding;
j) whether or not a written test procedure is required;
k) requirements for written test procedures.
6.2 Specific information required before testing
Before any testing of a welded joint can begin, the operator shall have access to the following essential
information:
a) written test procedure, if required (see 6.3);
b) type(s) of parent material and product form (i.e. cast, forged, rolled);
c) manufacturing or operation stage at which testing is to be made, including heat treatment, if any;
d) time and extent of any post-weld heat treatment;
e) joint preparation and dimensions;
f) requirements for surface conditions;
g) welding procedure or relevant information on the welding process;
h) reporting requirements;
i) acceptance levels;
© ISO 2018 – All rights reserved 3

---------------------- Page: 9 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

j) extent of testing, including requirements for transverse discontinuities, if relevant;
k) testing level;
l) personnel qualification level;
m) procedures for corrective actions when unacceptable discontinuities are revealed.
6.3 Written test procedure
The definitions and requirements in this document normally satisfy the need for a written test
procedure.
Where this is not the case, or where the techniques described in this document are not applicable to the
weld joint to be tested, additional written test procedures shall be used, if required by specification.
7 Requirements for personnel and equipment
7.1 Personnel qualifications
Personnel performing testing in accordance with this document shall be qualified to an appropriate
level in ultrasonic testing in accordance with ISO 9712 or equivalent in the relevant industrial sector.
In addition to a general knowledge of ultrasonic weld testing, personnel shall also be familiar with
testing problems specifically associated with the type of welded joints to be tested.
7.2 Test equipment
Any equipment used for testing in conjunction with this document shall comply with the requirements
of EN 12668 (all parts).
7.3 Probe parameters
7.3.1 Test frequency
The frequency shall be within the range 2 MHz to 5 MHz and shall be selected to consider the properties
of the test object and to comply with the specified acceptance levels, for example, of ISO 11666.
Higher frequencies may be used to improve range resolution if this is necessary when using standards
for acceptance levels based on characterization of discontinuities, e.g. ISO 23279.
Lower frequencies may be used for testing at long sound paths and/or when the material shows high
attenuation.
7.3.2 Angles of incidence
When testing is carried out with transverse waves and techniques that require the ultrasonic beam to
be reflected from an opposite surface, care shall be taken to ensure that the angle between the beam
and the normal to the opposite reflecting surface is between 35° and 70°. Where more than one beam
angle is used, at least one of the angle-beam probes used shall conform to this requirement. One of the
beam angles used shall ensure that the weld fusion faces are tested at, or as near as possible to, normal
incidence. When the use of two or more beam angles is specified, the difference between the nominal
beam angles shall be 10° or greater.
Angles of incidence at the probe and opposite reflecting surface, when curved, may be determined by
drawing a sectional view of the weld or in accordance with the techniques given in ISO 16811. Where
angles of incidence cannot be determined as specified by this document, the test report shall contain
4 © ISO 2018 – All rights reserved

---------------------- Page: 10 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

a comprehensive description of the scans used and the extent of any incomplete coverage caused,
together with an explanation of the difficulties encountered.
7.3.3 Element size
The element size shall be chosen according to the ultrasonic path to be used and the frequency.
The smaller the element, the smaller the length and width of the near field, and the larger the beam
spread in the far field at a given frequency.
Small probes having 6 mm to 12 mm diameter elements (or rectangular elements of equivalent area)
are therefore most useful when working at short sound paths. For longer sound paths, i.e. greater than
100 mm for single straight­beam probes and greater than 200 mm for angle­beam probes, an element
size of 12 mm to 24 mm is more suitable.
7.3.4 Adaptation of probes to curved scanning surfaces
The gap, g, between test surface and bottom of the probe shall not be greater than 0,5 mm.
For flat probes on cylindrical or spherical surfaces, this requirement can be checked with Formula (1):
2
ga= 4D (1)
where
a is the dimension of the probe in the direction of curvature, in mm;
D is the diameter of the test object, in mm.
If a value for g larger than 0,5 mm results from Formula (1), the probe shall be adapted to the surface
and the sensitivity and range shall be set accordingly.
For spherical or complex shaped surfaces, Formula (1) shall be applied in both length and width
direction of the probe (possible differences in curvature and/or probe dimensions).
7.3.5 Coupling media
The coupling media shall be in accordance with ISO 16810. The coupling medium used for range and
sensitivity setting and for the test shall be the same.
8 Testing volume
The testing volume (see Figure 2) is defined as the zone which includes weld and parent material and
the width of the heat­affected zone on each side of the weld or at least 10 mm if the width of the heat­
affected zone is not known.
In all cases, scanning shall cover the whole testing volume. If individual sections of this volume cannot
be covered in at least one scanning direction, or if the angles of incidence with the opposite surface
do not meet the requirements of 7.3.2, alternative or supplementary ultrasonic techniques or other
non-destructive techniques shall be agreed upon. This may, in some cases, require removal of the weld
reinforcement.
Supplementary techniques can require testing using dual-element angle-beam probes, creeping wave
probes, further ultrasonic techniques or any other suitable method, e.g. liquid penetrant, magnetic
particle, radiographic testing. In selecting alternative or supplementary techniques, due consideration
should be given to the type of weld and probable orientation of any imperfections to be detected.
© ISO 2018 – All rights reserved 5

---------------------- Page: 11 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

9 Preparation of scanning surfaces
Scanning surfaces shall be wide enough to permit the testing volume (see Figure 2) to be fully covered.
Alternatively, the width of the scanning surfaces may be smaller if equivalent coverage of the testing
volume can be achieved by scanning from both the upper and the lower surface of the joint.
Scanning surfaces shall be even and free from foreign matter likely to interfere with probe coupling
(e.g. rust, loose scale, weld spatter, notches, grooves). Waviness of the test surface shall not result in a
gap between the probe and test surfaces greater than 0,5 mm. These requirements shall be ensured by
dressing, if necessary. Local variations in surface contour, e.g. along the edge of the weld, which result
in a gap beneath the probe of up to 1 mm, can only be permitted if at least one additional beam angle is
employed from the affected side at the weld. This additional scanning is necessary to compensate for
the reduced weld coverage that will occur with a gap of this dimension.
Scanning surfaces and surfaces from which the sound beam is reflected shall allow undisturbed
coupling and reflection.
10 Parent metal testing
The parent metal, in the scanning zone area (see Figure 2), shall be tested with straight­beam probes
prior to or after welding, unless it can be demonstrated (e.g. by previous testing during the fabrication
process) that the angle-beam testing of the weld is not influenced by the presence of the imperfections
or high attenuation.
Where imperfections are found, their influence on the proposed angle-beam testing shall be assessed
and, if necessary, the techniques adjusted correspondingly. When satisfactory coverage by ultrasonic
testing is seriously affected, other test techniques (e.g. radiographic testing) shall be considered.
6 © ISO 2018 – All rights reserved

---------------------- Page: 12 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

Key
1 position 1, taking into account the width of the heat­affected zone
2 position 2
3 position 3
4 heat­affected zone
a
Width of testing volume.
b
Scanning zone width, not including the width of the weld because of the presence of the weld reinforcement.
Figure 2 — Example of testing volume to be covered when scanning for longitudinal
discontinuities
11 Range and sensitivity setting
11.1 General
Setting of range and sensitivity shall be carried out prior to each testing in accordance with this
document and ISO 16811, taking the influence of temperature into account. The temperature difference
during range and sensitivity setting and during the test shall be within ±15 °C.
Checks to confirm these settings shall be performed at least every 4 h and upon completion of the
testing. Checks shall also be carried out whenever a system parameter is changed or changes in the
equivalent settings are suspected.
If deviations greater than 2 dB, respectively 1 % of range, are found during these checks, the corrections
given in Table 2 shall be carried out.
© ISO 2018 – All rights reserved 7

---------------------- Page: 13 ----------------------
oSIST prEN ISO 17640:2018
ISO/FDIS 17640:2018(E)

Table 2 — Sensitivity and range corrections
Sensitivity
1 Deviations ≤ 2 dB No action required.
2 2 dB < deviation ≤ 4 dB Setting shall be corrected before the testing is continued.
Reduction of the sensitivity > 4 dB Setting shall be corrected and all testing carried out with the
3
equipment over the previous period shall be repeated.
Increase in sensitivity > 4 dB Setting shall be corrected and all recorded indications shall
4
be re-examined.
Range
1 Deviations < 1 % of the range No action required.
1 % of the range < deviation ≤
2 Setting shall be corrected before testing is continued.
2 % of the range
Deviations > 2 % of the range Setting shall be corrected and testing carried out wi
...