EN ISO 18279:2003
(Main)Brazing - Imperfections in brazed joints (ISO 18279:2003)
Brazing - Imperfections in brazed joints (ISO 18279:2003)
ISO 18279:2003 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 standard, reference is to be made to other sources, e.g. 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.
The standard 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 should be made to the relevant documentation, e.g. manufacturing documents or procedure sheets.
This International Standard does not lay down requirements for acceptance levels for imperfections since these will differ very markedly, depending on the application, but it does suggest some quality levels which may be of value in the absence of more detailed information.
Hartlöten - Unregelmäßigkeiten in hartgelöteten Verbindungen (ISO 18279:2003)
Brasage fort - Défauts dans les assemblages réalisés par brasage fort (ISO 18279:2003)
L'ISO 18279:2003 décrit en détail une classification des défauts qui peuvent apparaître dans les assemblages réalisés par brasage fort. De plus, elle constitue un guide sur les niveaux de qualité et décrit en détail les limites suggérées pour les défauts.
Pour les exigences qui ne sont pas couvertes par l'ISO 18279:2003, il y a lieu de se référer à d'autres sources, par exemple à des règlements officiels, des codes de bonne pratique et des conditions techniques de livraison.
Aucune information n'est fournie sur la manière dont les défauts sont à évaluer dans chaque cas, car cette évaluation dépend des exigences relatives à l'assemblage brasé en question. Ces défauts ne sont pas toujours détectables en utilisant seulement des essais non destructifs.
L'ISO 18279:2003 ne traite que des défauts liés au brasage fort, et non pas à des charges supplémentaires de service. Seuls le type, la forme et la position de tels défauts sont traités; aucune indication sur les conditions ou les causes d'apparition n'est fournie.
Pour les exigences relatives aux assemblages brasés qui revêtent un intérêt particulier et qui sont essentiels pour le fonctionnement de la pièce brasée, il convient de faire référence à la documentation correspondante, par exemple aux documents de fabrication ou aux procédures.
L'ISO 18279:2003 ne spécifie pas d'exigences relatives aux niveaux d'acceptation des défauts car ceux-ci diffèrent largement selon l'application, mais elle propose des niveaux de qualité qui peuvent être utiles s'il n'existe pas d'informations plus détaillées.
Trdo spajkanje - Nepopolnosti v trdo spajkanih spojih (ISO 18279:2003)
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Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2004
Trdo spajkanje - Nepopolnosti v trdo spajkanih spojih (ISO 18279:2003)
Brazing - Imperfections in brazed joints (ISO 18279:2003)
Hartlöten - Unregelmäßigkeiten in hartgelöteten Verbindungen (ISO 18279:2003)
Brasage fort - Défauts dans les assemblages réalisés par brasage fort (ISO 18279:2003)
Ta slovenski standard je istoveten z: EN ISO 18279:2003
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.
EUROPEAN STANDARD
EN ISO 18279
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2003
ICS 25.160.50
English version
Brazing - Imperfections in brazed joints (ISO 18279:2003)
Brasage fort - Défauts dans les assemblages réalisés par Hartlöten - Unregelmäßigkeiten in hartgelöteten
brasage fort (ISO 18279:2003) Verbindungen (ISO 18279:2003)
This European Standard was approved by CEN on 17 March 2003.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18279:2003 E
worldwide for CEN national Members.
Contents
Page
Foreword.3
Introduction .4
1 Scope .5
2 Terms and definitions.6
3 Symbols .7
4 Classification.8
4.1 General.8
4.2 External imperfections .8
4.3 Internal imperfections .8
Annex A (informative) Guidelines for practical evaluation of imperfections .20
Annex B (informative) Evaluation .21
Bibliography .28
Foreword
This document (EN ISO 18279:2003) has been prepared by Technical Committee CEN/TC 121 "Welding", the
secretariat of which is held by DS, in collaboration with Technical Committee ISO/TC 44 “Welding and allied
processes”.
This European Standard EN ISO 18279:2003 shall be given the status of a national standard, either by publication
of an identical text or by endorsement, at the latest by June 2004 and conflicting national standards shall be
withdrawn at the latest by June 2004.
Annexes A and B are informative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal,
Slovakia, Spain, Sweden, Switzerland and the United Kingdom.
Introduction
Brazed joints usually contain imperfections of various types, some of which will be detrimental in almost every case
but others may be detrimental or harmless, depending entirely on the service requirements of the joint in question.
Therefore it will frequently be 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 but 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 standard 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 may be of
help where detailed information is not available. It has to be emphasized that the use of quality levels can only be
successful if the imperfections that are relevant to the application of the brazed joint are determined.
1 Scope
This European Standard 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 standard, reference is to be made to other sources, e.g. 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.
The standard 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 should be made to the relevant documentation, e.g. manufacturing documents or procedure sheets.
NOTE It is important that these requirements be precisely prescribed and that compliance with them be verifiable.
Compliance may be established by testing either the brazed assembly itself or a test piece produced under comparable
conditions. The requirements should be established and fully documented before any classification is undertaken.
This European Standard does not lay down requirements for acceptance levels for imperfections since these will
differ very markedly, depending on the application, but it does suggest some quality levels which may be of value in
the absence of more detailed information.
a) Simple brazed assembly
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.
b) Section through assembly in a)
Figure 1 — Schematic of brazed assembly
2 Terms and definitions
For the purposes of this European Standard the areas of a brazed assembly are defined as shown schematically in
Figure 1. In addition the following term and definition apply.
l
2.1
imperfections
irregularities in the brazed joint, deviations 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
3 Symbols
The following symbols are used:
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
l
r
l
l
u
NOTE This figure illustrates a planar imperfection.
Figure 2 — Symbols used for dimensions
l
t
t
j
t
4 Classification
4.1 General
The imperfections are classified into six groups as follows:
group I Cracks;
group II Cavities;
group IIISolid inclusions;
group IVBonding imperfections;
group V Shape and size imperfections;
group VI Miscellaneous imperfections.
Imperfections are identified by designations.
A further distinction can be made between the external and internal imperfections that may occur in brazed joints.
4.2 External imperfections
External imperfections in brazed joints include:
underfill;
cracks;
surface-breaking porosity;
incomplete fillet;
overlap;
localized melting;
rough surface of seam;
flux seepage;
discoloration;
spatter;
residual flux;
surface erosion of parent material.
4.3 Internal imperfections
Internal imperfections in brazed joints include:
cracks;
filling imperfections;
solid inclusions;
gas entrapment;
flux inclusion;
lack of fusion;
excessive alloying of filler material and parent material (sometimes called erosion).
Table 1 — Classification of imperfections
Designation Description Remarks Drawing
I Cracks
a
1A AAA crack Limited separation of the material, predominantly two-
dimensional extension. A crack may be longitudinal or
transverse
1AAAD 1AAAE
It can lie in one or more of the following :
1AAAB
a
1A AAB in the braze metal
a
1A AAC
at the interface and including the diffusion zone
a
1AAAC
1A AAD In the HAZ
a
1A AAE in the unaffected parent material
a
- In the case of an intergranular crack, change this second symbol 'A' to the symbol 'F'.
- In the case of a transgranular crack, change this second symbol 'A' to the symbol 'H'.
Table 1 — Classification of imperfections (continued)
Designation Description Remarks Drawing
II Cavities
2AAAA cavity
2BAAA gas cavity Gas-filled cavity
2BAAA
2BGAA gas pore Spheroidal gas inclusion.
It can occur as :
2BGGA uniformly distributed porosity
2BGMA localized (clustered) porosity
2BGHA linear porosity
2LIAA large gas pockets Large voids may be the width of the joint with elongated
shape
Table 1 — Classification of imperfections (continued)
Designation Description Remarks Drawing
b
2BALF surface pore Gas pore breaking the surface.
b
2MGAF surface bubble Gas pore near the surface which results in swelling
b
These imperfections often occur together.
Table 1 — Classification of imperfections (continued)
Designation Description Remarks Drawing
III. Solid inclusions
3AAAA solid inclusion Inclusion of foreign metal or non-metallic particles in the
3AAAA
braze metal
May be posssible to divide into :
3DAAA oxide inclusion
3FAAA metallic inclusion
3CAAA flux inclusion
IV Bonding imperfections
4BAAA bonding imperfection No bonding or inadequate bonding between the braze metal
and the parent material
Table 1 — Classification of imperfections (continued)
Designation Description Remarks Drawing
4JAAA filling imperfection Incomplete filling of the gap
4JAAA
4CAAA incomplete penetration The braze metal has failed to flow through the required l
r
length of the joint
t
l
l
The arrow indicates the direction of flow through the
joint.
Table 1 — Classification of imperfections (continued)
Designation Description Remarks Drawing
V Shape and size imperfections
6BAAA excess braze metal Braze metal has spilled over onto parent material solidifying
as a bead or a thick layer
6BAAA
5AAAA imperfect shape Departure from the prescribed shape of the brazed joint
5EIAA linear misalignment The components are parallel but offset
(linear offset)
5EJAA angular misalignment The components form an angle deviating from the required
value.
5BAAA distortion Unwanted change in the shape of the brazed assembly
5FABA
Table 1 — Classification of imperfections (continued)
Designation Description Remarks Drawing
5FABA localized melting (or Through-going hole in the brazed joint or next to it
melt-through)
7NABD fused parent material Fused surf
...
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