SIST EN ISO 4761:2023

Non-destructive testing of welds - Phased array ultrasonic testing (UT-PA) for thin-walled steel components - Acceptance levels (ISO 4761:2022)

This document specifies acceptance levels for the phased array ultrasonic testing technique (UT-PA) of full-penetration welds in low-alloy and/or fine-grained steels in the wall thickness range from 3,2 mm to 8 mm which correspond to the quality levels of ISO 5817.
These acceptance levels are applicable to indications detected according to ISO 20601.

Zerstörungsfreie Prüfung von Schweißverbindungen - Phased-Array-Ultraschallprüfung (UT‑PA) dünnwandiger Stahlkomponenten - Zulässigkeitsgrenzen (ISO 4761:2022)

Essais non destructifs des assemblages soudés - Technique ultrasons multi-éléments (UT-PA) pour les composants en acier à paroi mince - Niveaux d’acceptation (ISO 4761:2022)

Neporušitveno preskušanje zvarnih spojev - Ultrazvočno preskušanje s faznim krmiljenjem (UT-PA) tankostenskih jeklenih delov - Stopnje sprejemljivosti (ISO 4761:2022)

Ta dokument določa stopnje sprejemljivosti za tehniko ultrazvočnega preskušanja s faznim krmiljenjem (UT-PA) zvarnih spojev s popolno penetracijo pri malolegiranih in/ali drobnozrnatih jeklih z debelino sten od 3,2 do 8 mm, ki ustrezajo stopnjam sprejemljivosti iz standarda ISO 5817.
Te stopnje sprejemljivosti se uporabljajo za indikacije, zaznane v skladu s standardom ISO 20601.

General Information

• Status: Published
• Public Enquiry End Date: 01-Oct-2022
• Publication Date: 09-Feb-2023
• ICS: 25.160.40 - Welded joints and welds
• Technical Committee: VAR - Welding
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 20-Jan-2023
• Due Date: 27-Mar-2023
• Completion Date: 10-Feb-2023
• Ref Project: EN ISO 4761:2022 - Non-destructive testing of welds - Phased array ultrasonic testing (UT-PA) for thin-walled steel components - Acceptance levels (ISO 4761:2022)

Overview

EN ISO 4761:2022 specifies acceptance levels for phased array ultrasonic testing (UT‑PA) of full‑penetration welds in thin‑walled low‑alloy or fine‑grained steels (wall thickness 3.2 mm to 8 mm). Adopted by CEN as EN ISO 4761:2022, this document defines how to evaluate indications found using automated phased‑array UT in accordance with ISO 20601, aligning acceptance with ISO 5817 quality levels.

Key topics and requirements

• Scope: Applies to full‑penetration welds in thin‑walled steel components (3.2–8 mm) using UT‑PA.
• Sensitivity setting: Calibration on a 1.0 mm side‑drilled hole per ISO 20601; this becomes the reference level for subsequent testing.
• Signal levels: Uses three levels (reference, acceptance, evaluation). The evaluation level is defined as reference −12 dB.
• Acceptance levels: Three testing/acceptance levels map to ISO 5817 quality grades:
  • ISO 5817 B → Testing level C → Acceptance level 1 (C1)
  • ISO 5817 C → Testing level C → Acceptance level 2 (C2)
  • ISO 5817 D → Testing level C → Acceptance level 3 (C3)
• Indication measurement:
  • Indication length is measured along the weld using the 6 dB drop method.
  • A length correction for unfocused lateral beams is permitted (formula specified in the standard).
• Amplitude vs. length criteria (examples from the standard):
  • For all acceptance levels, indications ≤ 4 mm: maximum allowable amplitude +6 dB (relative to reference).
  • For C1: 4–6 mm → +2 dB; > 6 mm → −10 dB.
  • For C2: 4–7 mm → +3.5 dB; > 7 mm → −10 dB.
  • For C3: 4–8 mm → +5 dB; > 8 mm → −10 dB.
• Testing modes: Separate acceptance criteria are given for two‑sided and single‑sided testing; cumulative lengths of acceptable indications over a weld section are also addressed.

Applications and who uses it

EN ISO 4761:2022 is used by:

• NDT technicians and inspection engineers implementing automated UT‑PA on thin‑walled steel welds
• Quality assurance / QC teams responsible for weld acceptance to ISO 5817 quality grades
• Fabricators and OEMs in industries with thin‑walled steel components (e.g., automotive, pressure equipment, shipbuilding, pipelines and general fabrication) requiring objective acceptance criteria
• Certification bodies and inspectors specifying test levels and reporting criteria

Related standards

• ISO 20601 - Use of automated phased array technology for thin‑walled steel components (normative reference)
• ISO 5817 - Quality levels for imperfections in fusion welded joints
• ISO 5577, ISO 23243 - Terminology and array‑UT vocabulary

This standard helps standardize UT‑PA acceptance decisions, improve reproducibility of weld inspections, and align phased‑array testing with established ISO quality grades for thin‑walled steel welds.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2023
Neporušitveno preskušanje zvarnih spojev - Ultrazvočno preskušanje s faznim
krmiljenjem (UT-PA) tankostenskih jeklenih delov - Stopnje sprejemljivosti (ISO
4761:2022)
Non-destructive testing of welds - Phased array ultrasonic testing (UT-PA) for thin-walled
steel components - Acceptance levels (ISO 4761:2022)
Zerstörungsfreie Prüfung von Schweißverbindungen - Phased-Array-Ultraschallprüfung
(UT‑PA) dünnwandiger Stahlkomponenten - Zulässigkeitsgrenzen (ISO 4761:2022)
Essais non destructifs des assemblages soudés - Technique ultrasons multi-éléments
(UT-PA) pour les composants en acier à paroi mince - Niveaux d’acceptation (ISO
4761:2022)
Ta slovenski standard je istoveten z: EN ISO 4761:2022
ICS:
25.160.40 Varjeni spoji in vari Welded joints and welds
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 4761
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 25.160.40
English Version
Non-destructive testing of welds - Phased array ultrasonic
testing (UT-PA) for thin-walled steel components -
Acceptance levels (ISO 4761:2022)
Essais non destructifs des assemblages soudés - Zerstörungsfreie Prüfung von Schweißverbindungen -
Technique ultrasons multi-éléments (UT-PA) pour les Phased-Array-Ultraschallprüfung (UT-PA)
composants en acier à paroi mince - Niveaux dünnwandiger Stahlkomponenten -
d'acceptation (ISO 4761:2022) Zulässigkeitsgrenzen (ISO 4761:2022)
This European Standard was approved by CEN on 20 December 2022.

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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4761:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 4761:2022 has been prepared by Technical Committee ISO/TC 44 "Welding and allied
processes” of the International Organization for Standardization (ISO) and has been taken over as
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 June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
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.
Any feedback and questions on this document should be directed to the users’ national standards body.
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 4761:2022 has been approved by CEN as EN ISO 4761:2022 without any modification.

INTERNATIONAL ISO
STANDARD 4761
First edition
2022-01
Non-destructive testing of welds —
Phased array ultrasonic testing (UT-
PA) for thin-walled steel components
— Acceptance levels
Essais non destructifs des assemblages soudés — Technique ultrasons
multi-éléments (UT-PA) pour les composants en acier à paroi mince
— Niveaux d’acceptation
Reference number
ISO 4761:2022(E)
ISO 4761:2022(E)
© ISO 2022
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 4761:2022(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 1
5 Sensitivity setting and levels .2
6 Acceptance levels.2
7 Evaluation of indications . 2
8 Acceptance criteria for two-sided testing . 3
8.1 General . 3
8.2 Longitudinal indications . 3
8.3 Transverse indications . 5
8.4 Cumulative length of indications . 5
9 Acceptance criteria for single-sided testing . 6
9.1 General . 6
9.2 Longitudinal indications . 6
9.3 Transverse indications . 7
9.4 Cumulative length of indications . 7
Bibliography . 8
iii
ISO 4761:2022(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
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electrotechnical standardization.
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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
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