EN ISO 16432:2007

SLOVENSKI STANDARD
01-september-2007
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Resistance welding - Procedure for projection welding of uncoated and coated low
carbon steels using embossed projection(s) (ISO 16432:2006)
Widerstandsschweißen - Verfahren zum Buckelschweißen von niedriglegierten Stählen
mit oder ohne metallischem Überzug (ISO 16432:2006)
Soudage par résistance - Mode opératoire de soudage par bossage(s) embouti(s) des
aciers a bas carbone revetus et non revetus (ISO 16432:2006)
Ta slovenski standard je istoveten z: EN ISO 16432:2007
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 16432
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2007
ICS 25.160.10
English Version
Resistance welding - Procedure for projection welding of
uncoated and coated low carbon steels using embossed
projection(s) (ISO 16432:2006)
Soudage par résistance - Mode opératoire de soudage par Widerstandsschweißen - Verfahren zum Buckelschweißen
bossage(s) embouti(s) des aciers à bas carbone revêtus et von niedriglegierten Stählen mit oder ohne metallischem
non revêtus (ISO 16432:2006) Überzug (ISO 16432:2006)
This European Standard was approved by CEN on 19 May 2007.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, 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
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16432:2007: E
worldwide for CEN national Members.

Foreword
The text of ISO 16432:2006 has been prepared by IIW, International Institute of Welding, and has been taken
over as EN ISO 16432:2007 by Technical Committee CEN/TC 121 “Welding” 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 December 2007, and conflicting national standards shall be withdrawn
at the latest by December 2007.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and United Kingdom.
Endorsement notice
The text of ISO 16432:2006 has been approved by CEN as a EN ISO 16432:2007 without any modification.

INTERNATIONAL ISO
STANDARD 16432
First edition
2006-02-01
Resistance welding — Procedure for
projection welding of uncoated and
coated low carbon steels using
embossed projection(s)
Soudage par résistance — Procédure pour le soudage par bossage(s)
embouti(s) des aciers à bas carbone revêtus et non revêtus

Reference number
ISO 16432:2006(E)
©
ISO 2006
ISO 16432:2006(E)
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ii © ISO 2006 – All rights reserved

ISO 16432:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Symbols . 2
5 Materials . 2
5.1 Form . 2
5.2 Steel grades. 3
5.3 Surface conditions. 3
6 Component design and manufacture . 3
6.1 Component design . 3
6.1.1 General. 3
6.1.2 Placement of projections . 3
6.2 Projection dimensions . 4
6.2.1 General. 4
6.2.2 Dissimilar sheet thickness. 4
6.2.3 Multi-weld arrays. 5
6.3 Ancillary manufacturing considerations. 5
7 Welding equipment. 5
7.1 Welding machine . 5
7.2 Electrode assembly (tooling). 5
7.3 Design of electrode assembly. 5
7.3.1 Contact face . 5
7.3.2 Electrode inserts. 5
7.3.3 Electrode cooling. 6
7.3.4 Location of components (tooling). 6
7.3.5 Tooling design considerations. 6
8 Weld assessment — Type tests . 6
8.1 General. 6
8.2 Test requirements. 7
8.2.1 Weld diameter . 7
8.2.2 Weld fracture mode . 7
8.2.3 Weld strength . 7
8.2.4 Visual and metallographic examination . 8
8.3 Weld appearance — Surface condition . 8
8.4 Distortion . 8
9 Weld assessment — Routine tests . 8
9.1 General. 8
9.2 Frequency of testing. 9
10 Repair of non-conforming assemblies . 9
Annex A (informative) Recommendations for projection welding equipment. 10
Annex B (informative) Relationship between sheet thickness and projection diameter (derived
from ISO 8167) . 11
Annex C (informative) Typical projection welding conditions. 12
Annex D (informative) Partial list of steel types applicable to the standard . 14
Bibliography . 15
ISO 16432:2006(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.
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
adopted 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 patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16432 was prepared by the International Institute of Welding, recognized as an international
standardizing body in the field of welding in accordance with Council Resolution 42/1999.
iv © ISO 2006 – All rights reserved

ISO 16432:2006(E)
Introduction
Requests for official interpretations of provisions in this standard should be made in writing and sent to the
ISO Central Secretariat who will forward them to the IIW Secretariat for an official response.

INTERNATIONAL STANDARD ISO 16432:2006(E)

Resistance welding — Procedure for projection welding of
uncoated and coated low carbon steels using embossed
projection(s)
1 Scope
This International Standard specifies requirements for embossed-resistance-projection welding in the
fabrication of assemblies of uncoated and metallic coated low carbon steel comprising two thicknesses of
metal, where the maximum single sheet thickness of components to be welded is within the range 0,4 mm to
3 mm for the following materials:
⎯ uncoated steels;
⎯ hot-dip zinc or iron-zinc alloy (galvannealed) coated steel;
⎯ electrolytic zinc, zinc-iron, or zinc-nickel coated steel;
⎯ aluminium coated steel;
⎯ zinc-aluminium coated steel.
Organic-coated or primer-coated steels are not covered by this International Standard. Guidelines for
appropriate welding equipment and projection welding conditions for various coated steels are given in
Annexes A to C. These are for guidance only and may need to be adapted to suit the specified service
conditions of the fabrication, prevailing production conditions, type of welding equipment, mechanical and
electrical characteristics of the welding machine, electrode configuration, and material. These requirements
shall be taken from the relevant welding procedure specification for the application or procedure, where these
exist.
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 latest edition of the referenced
document (including any amendments) applies.
ISO 669, Resistance welding — Resistance welding equipment — Mechanical and electrical requirements
ISO 5182:1991, Welding — Materials for resistance welding electrodes and ancillary equipment
ISO 8167, Projections for resistance welding
ISO 10447, Welding — Peel and chisel testing of resistance spot, projection and seam welds
ISO 14270, Specimen dimensions and procedure for mechanized peel testing resistance spot, seam and
embossed projection welds
ISO 14272, Specimen dimensions and procedure for cross tension testing resistance spot and embossed
projection welds
ISO 16432:2006(E)
ISO 14273, Specimen dimensions and procedure for shear testing resistance spot, seam and embossed
projection welds
ISO 14329, Resistance welding — Destructive tests of welds — Failure types and geometric measurements
for resistance spot, seam and projection welds
ISO 15609-5, Specification and qualification of welding procedures for metallic materials — Welding
procedure specification — Part 5: Resistance welding
ISO 15614-12, Specification and qualification of welding procedures for metallic materials — Welding
procedure test — Part 12: Spot, seam and projection welding
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 669 and ISO 14329 and the
following apply.
3.1
edge distance
minimum distance from the nearest edge of the component to the centre of the weld
3.2
embossed projection
projection in a sheet used for welding and produced by mechanical force using a punch to displace a
predetermined amount of material into a cavity
NOTE See ISO 8167 for use on different sheet thicknesses.
3.3
projection base diameter
diameter of an embossed projection measured at the original surface of the stamped sheet
NOTE See ISO 8167.
3.4
weld pitch
distance between centres of adjacent projections
4 Symbols
Symbol Term Unit
d weld diameter mm
d nominal-projection base diameter mm
b
P shear strength of weld kN
s
R ultimate tensile strength of steel MPa
m
t sheet thickness mm
5 Materials
5.1 Form
The steel shall be flat rolled, in coils or cut to length, and shall be free of harmful imperfections.
2 © ISO 2006 – All rights reserved

ISO 16432:2006(E)
5.2 Steel grades
A partial list of steel grades to which this International Standard is applicable is given in Annex D.
5.3 Surface conditions
Prior to welding, all surfaces of components to be projection welded shall be free of contaminants such as
grease, scale, corrosion products, paint, dirt or excessive pitting. This condition shall be maintained until the
welding process is completed. Uncoated hot-rolled steel shall be in the pickled condition.
Certain surface treatments, such as the application of paint primers, rust preventions and oils, may be applied
before welding, provided that the coating is uniform in thickness and it has been demonstrated that consistent
welds, conforming to this International Standard, can be obtained. Excessive use of surface pre-treatments
may adversely affect electrode life and should therefore be avoided.
Coated steels can be supplied with a chromate or phosphate passivation treatment. Phosphated mild steel
may be used in certain applications. These materials can be projection welded, although the welding
parameters outlined in Annex B may require appropriate adjustment. Generally, more care needs to be taken
in selecting welding conditions, particularly with multiple projections. Materials with thicker coatings are more
difficult to weld.
6 Component design and manufacture
6.1 Component design
6.1.1 General
The components/joints shall be designed and manufactured to provide adequate matching flange conditions,
free from potentially harmful physical deformations to accommodate the projections used in the welding
process. The design shall allow unimpeded collapse of the projections during welding, and provide proper
access for the electrodes and any necessary tooling. The procedure shall include provision for reviewing the
design as a result of tests, to ensure that compliance with this International Standard is achieved. Single or
multiple projection arrays may be specified, provided the appropriate welding practices can be maintained.
The design of the assembly to be projection welded shall take into account the process requirements specified
in Clause 7. The shape of both components shall be such that there is proper contact between the projections
and the surface to be welded, to allow unimpeded collapse in response to the welding process.
6.1.2 Placement of projections
The placement of embossed projections from the edge of a component is a function of the projection base
diameter (d ), and hence the sheet thickness (t). The edge distance shall not be less than 1,25 d as shown in
b b
Figure 1.
It should be noted that short edge distances may adversely affect weld quality. In this case, the nominal weld
size may need to be specified below the value given in 8.2.1 and allowance for a lower weld strength shall be
made in the design (see 8.2.3).
The weld pitch (see Figure 1), shall not be less than 4,5 d , and preferably larger. To avoid imbalance of weld
b
sizes in a multiple array, large pitch variations shall be avoided. The linear pitch should be maintained within
± 10 %, provided the interweld distance does not fall below the specified minimum value.
ISO 16432:2006(E)
Key
d Nominal-projection base diameter
b
Figure 1 — Recommended edge conditions and weld pitch
6.2 Projection dimensions
6.2.1 General
Round embossed projections shall be in accordance with ISO 8167. Where a number of projection welds (an
array) are welded in one operation, the height of each individual projection of this group on the component
shall not vary by more than ± 5 % and the spacing should provide for an even current distribution for the whole
group or array.
Elongated projections may replace standard round projections. In this case, the minor axis shall be equal to
the diameter of the round projection specified for the sheet thickness specified in ISO 8167. The size and
shape of the projection shall be designed to give the required weld area or strength.
The projection strength should be capable of supporting the applied load without excessive cold collapse; i.e.
the maximum permissible reduction in projection height shall not exceed 20 %.
6.2.2 Dissimilar sheet thickness
When welding sheets of dissimilar thickness, the dimensions of the projections shall be specified for the
thinner of the two sheets. The projection(s) should be made in the thicker sheet.
4 © ISO 2006 – All rights reserved

ISO 16432:2006(E)
6.2.3 Multi-weld arrays
In applications where more than
...