SIST EN ISO 11970:2026

SLOVENSKI STANDARD
01-januar-2026
Popis in kvalifikacija varilnih postopkov za proizvodno varjenje jeklenih ulitkov
(ISO 11970:2025)
Specification and qualification of welding procedures for production welding of steel
castings (ISO 11970:2025)
Anforderungen und Anerkennung von Schweißverfahren für das Produktionsschweißen
von Stahlguss (ISO 11970:2025)
Descriptif et qualification de modes opératoires de soudage pour le soudage de
production des aciers moulés (ISO 11970:2025)
Ta slovenski standard je istoveten z: EN ISO 11970:2025
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
77.140.80 Železni in jekleni ulitki Iron and steel castings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11970
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2025
EUROPÄISCHE NORM
ICS 25.160.10; 77.140.80 Supersedes EN ISO 11970:2016
English Version
Specification and qualification of welding procedures for
production welding of steel and nickel-base castings (ISO
11970:2025)
Descriptif et qualification de modes opératoires de Schweißanweisungen für das Produktionsschweißen
soudage pour le soudage de production des pièces von Stahlgussteilen und deren Qualifizierung (ISO
moulées en acier et à base de nickel (ISO 11970:2025) 11970:2025)
This European Standard was approved by CEN on 24 November 2025.

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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11970:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11970:2025) has been prepared by Technical Committee ISO/TC 17 "Steel" in
collaboration with Technical Committee CEN/TC 459/SC 11 “Steel castings and forgings” the secretariat
of which is held by AFNOR.
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 2026, and conflicting national standards shall be
withdrawn at the latest by May 2026.
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 11970:2016.
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 11970:2025 has been approved by CEN as EN ISO 11970:2025 without any modification.

International
Standard
ISO 11970
Third edition
Specification and qualification of
2025-11
welding procedures for production
welding of steel and nickel-base
castings
Descriptif et qualification de modes opératoires de soudage pour
le soudage de production des pièces moulées en acier et à base
de nickel
Reference number
ISO 11970:2025(en) © ISO 2025
ISO 11970:2025(en)
© ISO 2025
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 11970:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 2
3.1 Terms and definitions .2
4 Preliminary welding procedure specification (pWPS) . 2
5 Welding procedure qualification . 2
6 Test piece . 2
6.1 General .2
6.2 Shape and dimensions of test piece .2
6.3 Welding of the test piece .3
7 Examination and testing .4
7.1 Extent of testing .4
7.2 Location and cutting of test specimens .5
7.3 Non-destructive testing .5
7.4 Destructive test .6
7.4.1 Transverse (to weld groove) tensile test .6
7.4.2 Macro examination .6
7.4.3 Micro examination .6
7.4.4 Impact test .6
7.4.5 Hardness test .7
7.5 Qualification and retesting . .7
7.6 Welder qualification .8
8 Range of qualification .8
8.1 General .8
8.2 Related to the manufacturer .8
8.3 Related to the material .8
8.3.1 Parent metal — Grouping system for cast steel grades .8
8.3.2 Parent metal thickness .9
8.4 Common to all welding procedures .9
8.4.1 Welding process .9
8.4.2 Welding positions .10
8.4.3 Type of joint .10
8.4.4 Filler metal .10
8.4.5 Type of current . .10
8.4.6 Heat input .11
8.4.7 Preheat temperature .11
8.4.8 Interpass temperature .11
8.4.9 Post-weld heat treatment .11
8.5 Specific to process .11
9 Welding procedure qualification record (WPQR).12
Annex A (informative) Record form (WPQR) welding procedure qualification — Test certificate .13
Annex B (normative) Details of weld testing . 14
Bibliography . 17

iii
ISO 11970:2025(en)
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 17, Steel, Subcommittee SC 11, Steel castings, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 459/
SC 11, Steel castings and forgings, in accordance with the Agreement on technical cooperation between ISO
and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 11970:2016), which has been technically
revised.
The main changes are as follows:
— appropriate reference standards have been added;
— minor grammatical changes were made.
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.

iv
ISO 11970:2025(en)
Introduction
All welding procedure qualifications for production welding of steel castings are intended to be in accordance
with this document.
All new welding procedure tests are to be carried out in accordance with this document from the date of its
issue. However, this document does not invalidate previous welding procedure tests made to former national
[1]
standards or specifications, such as ASME Section IX or to previous editions of this document.
Previous procedure qualifications that conform to the range of qualification of Clause 8 are valid under this
document.
Where additional tests have to be carried out to complete the qualification, it is only necessary to perform
the additional tests to the requirements of Clauses 6 and 7.
In the case of specific service, material or manufacturing conditions, tests more comprehensive than
those specified by this document can be specified by the purchaser, in order to gain more information, e.g.
longitudinal weld tensile tests, bend tests, chemical analyses, ferrite determination in austenitic stainless
steels, elongation after fracture, Charpy V-notch impact tests, and radiographic tests.

v
International Standard ISO 11970:2025(en)
Specification and qualification of welding procedures for
production welding of steel and nickel-base castings
1 Scope
This document specifies how a welding procedure specification (WPS) for production welding of steel
castings is qualified. Tests are intended to be carried out in accordance with this document, unless additional
tests are specified by the purchaser or by agreement between the contracting parties.
This document defines the conditions for the execution of welding procedure qualification tests and the
limits of validity of a qualified welding procedure for all practical welding operations within the range of
essential variables.
This document applies to the arc welding of steel castings. The principles of this document can be applied to
other fusion welding processes subject to agreement between the contracting parties.
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 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method
ISO 4136, Destructive tests on welds in metallic materials — Transverse tensile test
ISO 4969, Steel — Etching method for macroscopic examination
ISO 4986, Steel and iron castings — Magnetic particle testing
ISO 4987, Steel and iron castings — Liquid penetrant testing
ISO 4992-1, Steel castings — Ultrasonic testing — Part 1: Steel castings for general purposes
ISO 4992-2, Steel castings — Ultrasonic testing — Part 2: Steel castings for highly stressed components
ISO 4993, Steel and iron castings — Radiographic testing
ISO 5817, Welding — Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) —
Quality levels for imperfections
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 6947, Welding and allied processes — Welding positions
ISO 9015-1, Destructive tests on welds in metallic materials — Hardness testing — Part 1: Hardness test on arc
welded joints
ISO 9016, Destructive tests on welds in metallic materials — Impact tests — Test specimen location, notch
orientation and examination
ISO 9606-1, Qualification testing of welders — Fusion welding — Part 1: Steels
ISO 15607, Specification and qualification of welding procedures for metallic materials — General rules

ISO 11970:2025(en)
ISO 15609, Specification and qualification of welding procedures for metallic materials — Welding procedure
specification
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 15607 and the following 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 https:// www .electropedia .org
3.1
production welding
all welding carried out during production before final delivery to the purchaser
3.2
joint welding
production welding (3.1) used to weld cast components together or weld cast components to wrought steels
3.3
finishing welding
production welding (3.1) carried out in order to ensure the agreed quality of the casting
4 Preliminary welding procedure specification (pWPS)
A preliminary welding procedure specification shall be prepared. It shall specify the range of all the relevant
parameters in accordance with ISO 15609.
5 Welding procedure qualification
The making and testing of test specimens representing the type and the position of welding used in
production shall be in accordance with Clauses 6 and 7.
The welder who correctly carries out the welding procedure qualification test in accordance with this
document is approved in the corresponding test area in accordance with ISO 9606-1, provided that the
required tests in ISO 9606-1 are carried out. Additional welders shall be qualified in accordance with 7.6.
6 Test piece
6.1 General
The test piece can be in accordance with those shown in Figures 1, 2, 3 and 4, unless otherwise agreed upon
b
...