EN ISO 18279:2023

SLOVENSKI STANDARD
01-marec-2024
Nadomešča:
SIST EN ISO 18279:2004
Trdo spajkanje - Nepravilnosti v trdo spajkanih spojih (ISO 18279:2023)
Brazing - Imperfections in brazed joints (ISO 18279:2023)
Hartlöten - Unregelmäßigkeiten in hartgelöteten Verbindungen (ISO 18279:2023)
Brasage fort - Défauts dans les assemblages réalisés par brasage fort (ISO 18279:2023)
Ta slovenski standard je istoveten z: EN ISO 18279:2023
ICS:
25.160.50 Trdo in mehko lotanje Brazing and soldering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 18279
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2023
EUROPÄISCHE NORM
ICS 25.160.50 Supersedes EN ISO 18279:2003
English Version
Brazing - Imperfections in brazed joints (ISO 18279:2023)
Brasage fort - Défauts dans les assemblages réalisés Hartlöten - Unregelmäßigkeiten in hartgelöteten
par brasage fort (ISO 18279:2023) Verbindungen (ISO 18279:2023)
This European Standard was approved by CEN on 10 February 2023.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18279:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 18279:2023) 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 2024, and conflicting national standards shall be
withdrawn at the latest by May 2024.
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 18279:2003.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 18279:2023 has been approved by CEN as EN ISO 18279:2023 without any modification.

INTERNATIONAL ISO
STANDARD 18279
Second edition
2023-11
Brazing — Imperfections in brazed
joints
Brasage fort — Défauts dans les assemblages réalisés par brasage
fort
Reference number
ISO 18279:2023(E)
ISO 18279:2023(E)
© ISO 2023
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: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 18279:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols . 3
5 Classification . 3
5.1 General . 3
5.2 External imperfections . 4
5.3 Internal imperfections . 4
Annex A (informative) Guidelines for practical evaluation of imperfections .10
Annex B (informative) Evaluation.11
Bibliography .15
iii
ISO 18279:2023(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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
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 13, Brazing materials and processes, in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 121, Welding and allied processes, in accordance
with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 18279:2003), which has been technically
revised.
The main changes are as follows:
— An additional quality level for brazed joint imperfections has been added in Annex B in order to
reflect the technical progress that has been achieved over the past decade as well as the need for
increased requirements regarding reliability of brazed joints for critical applications. Quality levels
have been revaluated.
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. Official
interpretations of ISO/TC 44 documents, where they exist, are available from this page:
https://committee.iso.org/sites/tc44/home/interpretation.html.
iv
ISO 18279:2023(E)
Introduction
Brazed joints usually contain imperfections of various types, some of which are detrimental in almost
every case while others can be detrimental or harmless, depending entirely on the service requirements
of the joint in question. Therefore, it is often necessary to classify the imperfections in a brazed joint
and then try to assess the significance of their effects on the behaviour of the joint in service. The
classification is relatively easy and Table 1 describes the imperfections that most commonly occur. The
assessment of significance is not easy (see also Annex A).
For welded joints, there has been extensive work carried out for many years on the significance of
imperfections in service; however, such work has not been carried out on brazed joints. Moreover,
the work on welded joints is only rarely relevant to brazed joints, mainly because of differences in
geometry and stressing. Therefore, this document cannot give definitive quality levels for brazed joints.
These can only be produced as experience is gained from industrial applications. However, Annex B
gives some suggestions for quality levels for general applications, which can be of help where detailed
information is not available. The use of quality levels can only be successful if the imperfections that
are relevant to the application of the brazed joint are determined.
v
INTERNATIONAL STANDARD ISO 18279:2023(E)
Brazing — Imperfections in brazed joints
1 Scope
This document details a classification of imperfections that can occur in brazing joints. In addition,
guidance is provided on quality levels and suggested limits for imperfections are detailed.
For requirements not covered by this document, reference can be made to other sources, such as
statutory regulations, codes of practice and technical delivery conditions.
No information is given on how imperfections are to be assessed in individual cases because this
depends on the requirements for the particular brazed joint. These imperfections are not always
detectable by the use of non-destructive testing alone.
This document covers only imperfections that can occur in connection with brazing without the effect
of any additional service loads. Only the type, shape and position of such imperfections are covered; no
indication is given of the conditions of occurrence or causes.
For requirements for brazed joints which are relevant and essential to the particular function of
the component, reference can be made to the relevant documentation, for example manufacturing
documents or procedure sheets.
It is important that these requirements be precisely prescribed and that conformity with them be
verifiable. Conformity can be established by testing either the brazed assembly itself or a test piece
produced under comparable conditions.
This document does not specify requirements for acceptance levels for imperfections, since these will
differ very markedly depending on the application, but it does suggest some quality levels which can be
of value in the absence of more detailed information.
For the purposes of this document, the areas of a brazed assembly are designated as shown schematically
in Figure 1.
a) Simple brazed assembly
ISO 18279:2023(E)
b) Section through assembly in a)
Key
parent material
parent material affected by brazing [heat-affected zone (HAZ)]
diffusion-transition zone
braze metal
NOTE Extent of HAZ will vary with materials and brazing process.
Figure 1 — Schematic of brazed assembly
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
imperfection
irregularity in the brazed joint or deviation from the intended relative positions of the parts joined by
brazing and from the intended shape of the brazed component, where such deviations are dependent on
the brazing
EXAMPLE For an example of an imperfection, see Figure 2.
ISO 18279:2023(E)
4 Symbols
For the purposes of this document, the following symbols apply.
l length of the brazed overlap
l required brazed length
r
l length of overlap before brazing
u
l dimensions of the brazed imperfection
1,2
t thickness of brazed joint
j
t wall or plate thickness or thicknesses
1,2
Figure 2 illustrates a planar imperfection by using the symbols.
Figure 2 — Symbols used for dimensions
5 Classification
5.1 General
The imperfections are classified into six groups as follows:
— group I: cracks;
— group II: cavities;
— group III: solid inclusions;
— group IV: bonding imperfections;
ISO 18279:2023(E)
— group V: shape and size imperfections;
— group VI: miscellaneous imperfections.
Imperfections are identified by designations which are given with descriptions in Table 1.
A further distinction can be made between the external and internal imperfections that can occur in
brazed joints.
5.2 External imperfections
External imperfections in brazed joints include:
— underfill;
— crack(s);
— surface-breaking porosity;
— incomplete fillet;
— overlap;
— localized melting;
...