SIST EN ISO 18785-4:2021

SLOVENSKI STANDARD
01-marec-2021
Točkovno varjenje z gnetenjem - Aluminij - 4. del: Popis in kvalifikacija varilnih
postopkov (ISO 18785-4:2018)
Friction stir spot welding - Aluminium - Part 4: Specification and qualification of welding
procedures (ISO 18785-4:2018)
Rührreibpunktschweißen - Aluminium - Teil 4: Festlegung und Qualifizierung des
Schweißverfahrens (ISO 18785-4:2018)
Soudage par friction-malaxage par points - Aluminium - Partie 4: Descriptif et
qualification des modes opératoires de soudage (ISO 18785-4:2018)
Ta slovenski standard je istoveten z: EN ISO 18785-4:2021
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
77.120.10 Aluminij in aluminijeve zlitine Aluminium and aluminium
alloys
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 18785-4
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2021
EUROPÄISCHE NORM
ICS 25.160.10
English Version
Friction stir spot welding - Aluminium - Part 4:
Specification and qualification of welding procedures (ISO
18785-4:2018)
Soudage par friction-malaxage par points - Aluminium Rührreibpunktschweißen - Aluminium - Teil 4:
- Partie 4: Descriptif et qualification des modes Festlegung und Qualifizierung des Schweißverfahrens
opératoires de soudage (ISO 18785-4:2018) (ISO 18785-4:2018)
This European Standard was approved by CEN on 6 December 2020.

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,
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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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18785-4:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 18785-4:2018 has been prepared by Technical Committee ISO/IIW "International
Institute of Welding” of the International Organization for Standardization (ISO) and has been taken
over as EN ISO 18785-4:2021 by 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 July 2021, and conflicting national standards shall be
withdrawn at the latest by July 2021.
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.
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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 18785-4:2018 has been approved by CEN as EN ISO 18785-4:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 18785-4
First edition
2018-11
Friction stir spot
welding — Aluminium —
Part 4:
Specification and qualification of
welding procedures
Soudage par friction-malaxage par points — Aluminium —
Partie 4: Descriptif et qualification des modes opératoires de soudage
Reference number
ISO 18785-4:2018(E)
©
ISO 2018
ISO 18785-4:2018(E)
© ISO 2018
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Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 18785-4:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Development and qualification of welding procedures . 2
4.1 General . 2
4.2 Technical content of a pWPS . 2
4.2.1 Manufacturer information . 2
4.2.2 Composition of parent material . 2
4.2.3 Dimensions of material . 2
4.2.4 Welding method . 2
4.2.5 Machine specifications. 3
4.2.6 Tool identification . 3
4.2.7 Clamping processes and conditions . 3
4.2.8 Joint design . 3
4.2.9 Joint preparation and cleaning methods . 3
4.2.10 Welding technique . 3
4.2.11 Post-weld processing . 3
5 Qualification based on a welding procedure test . 4
5.1 General . 4
5.2 Standardized test piece. 4
5.3 Welding of components, subscale test components or test specimens . 4
6 Examination and testing . 4
6.1 Visual testing . 4
6.1.1 General. 4
6.1.2 Re-testing . 4
6.2 Destructive testing . 4
6.2.1 General. 4
6.2.2 Re-testing . 4
6.3 Macrosection . 5
6.4 Range of qualification . 5
6.4.1 General. 5
6.4.2 Related to the manufacturer . 5
6.4.3 Related to the material . 5
6.4.4 Common to all welding procedures . 5
6.4.5 Other variables . 6
7 Qualification based on pre-production welding test . 6
7.1 General . 6
7.2 Test pieces . 6
7.3 Examination and testing of test pieces . 6
7.4 Range of qualification . 6
7.5 Welding procedure qualification record . 6
Annex A (informative) Example format for a welding procedure specification .7
Annex B (informative) Additional variables to be considered in WPS's for FSSW variants .8
Annex C (informative) Example welding procedure qualification record forms .9
Bibliography .12
ISO 18785-4:2018(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 the IIW, International Institute of Welding, Commission III, Resistance
welding, solid state welding and allied joining processes.
Any feedback, question or request for official interpretation related to any aspect of this document
should be directed to IIW via your national standards body. A complete listing of these bodies can be
found at www .iso .org/members .html.
A list of all parts in the ISO 18785 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved

ISO 18785-4:2018(E)
Introduction
Welding processes are widely used in the fabrication of engineered structures. During the second half
of the twentieth century, fusion welding processes, wherein fusion is obtained by the melting of parent
material and usually a filler metal, dominated the welding of large structures. In 1991, friction stir
welding (FSW), which is carried out entirely in the solid phase (no melting), was invented.
Friction stir spot welding (FSSW) processes are spot-like variants of the FSW process. Unlike FSW, there
is minimal or no traverse motion of the tool. In basic FSSW, the joint is created by plunging a rotating
tool into the work piece and retracting the tool out of the overlapping sheets. Other FSSW variants
include additional tool movements. Frictional heat is generated from the contact between the tool and
the material to be welded resulting in softening of this material. The softened material is stirred to form
a metallurgical connection which is aided by the forge action applied by the tool shoulder contacting
the upper sheet surface.
The increasing use of FSSW has created the need for a FSSW standard in order to ensure that welding
is carried out in the most effective way and that appropriate control is exercised over all aspects of the
operation. The ISO 18785 series focuses on the FSSW of aluminium because, at the time this document
was developed, the majority of commercial applications for FSW involved aluminium. Examples include
railway cars, consumer products, food processing equipment, automotive components, aerospace
structures, and marine vessels.
To be effective, welded structures should be free from serious problems in production and in service. To
achieve that goal, it is necessary to provide controls from the design phase through material selection,
fabrication, and inspection. For example, poor design can create serious and costly difficulties in the
workshop, on site, or in service. Incorrect material selection can result i
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