EN 12680-2:2025

SLOVENSKI STANDARD
01-januar-2026
Livarstvo - Ultrazvočno preskušanje - 2. del: Jekleni ulitki za visoko obremenjene
sestavne dele
Founding - Ultrasonic testing - Part 2: Steel castings for highly stressed components
Gießereiwesen - Ultraschallprüfung - Teil 2: Stahlgussstücke für hoch beanspruchte
Bauteile
Fonderie - Contrôle par ultrasons - Partie 2: Pièces moulées en acier pour composants
fortement sollicités
Ta slovenski standard je istoveten z: EN 12680-2:2025
ICS:
77.040.20 Neporušitveno preskušanje Non-destructive testing of
kovin metals
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 12680-2
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2025
EUROPÄISCHE NORM
ICS 77.040.20; 77.140.80 Supersedes EN 12680-2:2003
English Version
Founding - Ultrasonic testing - Part 2: Steel castings for
highly stressed components
Fonderie - Contrôle par ultrasons - Partie 2: Pièces Gießereiwesen - Ultraschallprüfung - Teil 2:
moulées en acier pour composants fortement sollicités Stahlgussstücke für hoch beanspruchte Bauteile
This European Standard was approved by CEN on 22 September 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 12680-2:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Requirements . 6
4.1 Order information . 6
4.2 Extent of testing . 6
4.3 Wall section zones . 6
4.4 Maximum acceptable size of discontinuities . 6
4.4.1 General. 6
4.4.2 Indications without measurable dimensions . 6
4.4.3 Indications with measurable dimensions . 6
4.5 Qualification of personnel . 7
4.6 Severity levels . 8
5 Testing . 8
5.1 Principles . 8
5.2 Material . 8
5.3 Equipment and coupling medium . 9
5.3.1 Ultrasonic instrument . 9
5.3.2 Probes . 9
5.3.3 Checking of the ultrasonic test equipment . 9
5.3.4 Coupling medium . 9
5.3.5 Test sensitivity and resolution of detection . 9
5.4 Preparation of casting surfaces for testing. 10
5.5 Test procedure . 10
5.5.1 General. 10
5.5.2 Range setting . 10
5.5.3 Sensitivity setting . 11
5.5.4 Consideration of various types of indications . 11
5.5.5 Recording limits . 12
5.5.6 Evaluation of discontinuities to be recorded . 12
5.5.7 Characterization and sizing of discontinuities . 12
5.6 Test report . 13
Annex A (normative) Resolution of detection of the instrument-probe combination . 21
Annex B (informative) Sound-beam diameters . 22
Annex C (informative) Types of indications generated by typical discontinuities . 24
Annex D (informative) Significant technical changes between this document and the
previous edition . 36
Bibliography . 37

European foreword
This document (EN 12680-2:2025) has been prepared by Technical Committee CEN/TC 190 “Foundry
technology”, 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 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 12680-2:2003.
Annex D provides details of significant technical changes between EN 12680-2:2025 and
EN 12680-2:2003.
Within its programme of work, Technical Committee CEN/TC 190 requested CEN/TC 190/WG 10
“Testing for inner discontinuities” to prepare the following standard:
EN 12680-2, Founding — Ultrasonic testing — Part 2: Steel castings for highly stressed components.
This is one of four European Standards for ultrasonic testing. The other standards are:
— EN 12680-1, Founding — Ultrasonic testing — Part 1: Steel castings for general purposes.
— EN 12680-3, Founding — Ultrasonic testing — Part 3: Spheroidal graphite cast iron castings.
— EN 12680-4, Founding — Ultrasonic testing — Part 4: Phased array ultrasonic testing of steel castings.
Annex A is normative. Annex B and Annex C are informative.
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 organisations 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.
1 Scope
This document specifies the requirements for the ultrasonic testing of steel castings (with ferritic
structure) for highly stressed components and the methods for determining internal discontinuities by
the pulse-echo technique.
Highly-stressed means for example:
— High material utilization (close to R )
p0,2
— High static and cyclic load
— For fail-safe assessment, requiring a fracture-mechanic assessment
An example for a highly-stressed cast component is a turbine housing, subjected to combined high static,
cyclic and thermal load.
Purchasers determine if components are highly stressed based on the need for performance or safety.
For lower-stressed cast components for general purposes, EN 12680-1 applies.
This document is applicable to the ultrasonic testing of steel castings which have usually received a grain-
refining heat treatment and which have wall thicknesses up to and including 600 mm.
For greater wall thicknesses, special agreements are applicable with respect to test procedure and
recording levels.
This document does not apply to austenitic steels and joint welds.
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.
EN 1370, Founding — Examination of surface condition
EN ISO 2400, Non-destructive testing — Ultrasonic testing — Specification for standard block No. 1
(ISO 2400)
EN ISO 5577, Non-destructive testing — Ultrasonic testing — Vocabulary (ISO 5577)
EN ISO 7963, Non-destructive testing — Ultrasonic testing — Specification for calibration block No.
2 (ISO 7963)
EN ISO 16810, Non-destructive testing — Ultrasonic testing — General principles (ISO 16810)
EN ISO 16811, Non-destructive testing — Ultrasonic testing — Sensitivity and range setting
(ISO 16811)
EN ISO 16827, Non-destructive testing — Ultrasonic testing — Characterization and sizing of
discontinuities (ISO 16827)
EN ISO 22232-1, Non-destructive testing — Characterization and verification of ultrasonic test
equipment — Part 1: Instruments (ISO 22232-1)
EN ISO 22232-2, Non-destructive testing — Characterization and verification of ultrasonic test
equipment — Part 2: Probes (ISO 22232-2)
EN ISO 22232-3, Non-destructive testing — Characterization and verification of ultrasonic test
equipment — Part 3: Combined equipment (ISO 22232-3)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 5577 and the following
apply.
ISO and IEC maintain terminology 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
point-like discontinuity
discontinuity, the dimensions of which are smaller than or equal to the sound-beam width
Note 1 to entry: Dimensions in this document relate to length, width and/or dimension in through-wall direction.
3.2
extended discontinuity
discontinuity, the dimensions of which are larger than the sound-beam width
Note 1 to entry: Dimensions in this document relate to length, width and/or dimension in through-wall direction.
3.3
planar discontinuity
discontinuity having two measurable dimensions
3.4
volumetric discontinuity
discontinuity having three measurable dimensions
3.5
rim zone
1/3 of the through-wall thickness from the surface with a maximum of 30 mm
3.6
special rim zone
outer rim zone of the test object with special requirements
Note 1 to entry: Examples of special requirements are machined surfaces, higher stresses and sealing surfaces.
3.7
non-measurable dimension
dimension of a discontinuity that is smaller than the beam width, which depends on the probe size and
the frequency used
Note 1 to entry: Current state of the industry is < 3 mm.
3.8
finishing welding
welding carried out in order to ensure the agreed quality of the casting
3.9
Severity level
upper size limit for acceptable discontinuities, depending on the wall thickness zone
4 Requirements
4.1 Order information
The following information shall be available at the time of enquiry and order (see also ISO 16810):
a) the areas of the casting and the number or percentage of castings to which the requirements of
ultrasonic testing apply;
b) the severity levels shall be applied to the various zones or areas of the casting (acceptance criteria);
c) requirements for a written test procedure;
d) whether there are any additional requirements for the test procedure, see also 5.5.1.
4.2 Extent of testing
The casting shall be tested so that the agreed areas are covered (insofar as this is possible from the shape
of the casting) by the use of the best applicable test technique.
For wall thicknesses greater than 600 mm, agreement shall be made between the manufacturer and the
customer on the severity levels, test procedure and the recording of the test results.
4.3 Wall section zones
The wall section shall be divided into core and rim zones as shown in Figure 1. These zones relate to the
dimensions of the casting ready for assembly (finish-machined).
If the foundry does not know the final condition of the casting, the test result applies to the condition “as
delivered”.
NOTE An acceptable discontinuity in the core zone in the raw casting condition can be shifted to the rim zone
after final machining by the customer and can become unacceptable.
Single discontinuities extending into the rim zone and core zone shall be evaluated as rim zone.
4.4 Maximum acceptable size of discontinuities
4.4.1 General
The purchaser shall specify the acceptance level according to the required severity level for planar and
volumetric discontinuities within each zone and in each specified area of the casting.
4.4.2 Indications without measurable dimensions
In core zone, indications without measurable dimensions are acceptable.
In special rim zones and at weld preparation ends, indications without measurable dimensions are
limited to a maximum number of indications and shall not exceed the limits given in Table 1.
4.4.3 Indications with measurable dimensions
4.4.3.1 Acceptance levels for planar discontinuities
The acceptance levels for planar discontinuities are given in Figure 2.
Discontinuities exceeding 3 mm FBH shall not be acceptable in severity level 1.
The largest dimension of a discontinuity in through-wall direction shall not exceed 10 % of the wall
thickness, except discontinuities with a length ≤ 10 mm. Discontinuities with a length of ≤ 10 mm shall
not exceed a dimension in the through-wall dimension of 25 % of the wall thickness or maximum 20 mm.
The greatest distance between discontinuities, as criterion for evaluation as an individual discontinuity
or a discontinuity area in the through-wall direction or lateral to the surface, shall be 10 mm.
For a discontinuity with more than 3 mm in length and non-measurable dimension in through-wall
direction, this non-measurable dimension shall be taken as 3 mm and the discontinuity area shall be
calculated according to Formula (1):
AL= 3 (1)
where
A is the area of discontinuity expressed in square millimetres;
3 is the width in millimetres;
L is the length in millimetres.
The sizing of small planar discontinuities, as given in Figure 2, becomes more difficult with increasing
beam-path length and sound-beam diameter. As a guide, these sizings are normally applied to a rim zone
of 30 mm. It makes the use of probes with focussed beams such as dual- transducer probes necessary.
4.4.3.2 Acceptance levels for volumetric discontinuities
Volumetric discontinuities shall not exceed the sizes given in Figure 3 for rim zone and Figure 4 for the
core zone.
Indications with measurable dimensions shall not be acceptable in severity level 1.
The maximum acceptable dimensions of discontinuity areas in the through-wall direction in the rim zone
shall be 15 % of the rim zone thickness. The maximum acceptable dimensions of discontinuity areas in
the through-wall direction in the core zone shall be 15 % of the wall thickness.
The maximum distance between discontinuities, as a criterion for evaluation as an individual indication
in the through-wall direction or lateral to the surface, shall be 10 mm in the rim zone and 20 mm in the
core zone.
Groups of individual discontinuities (reference code GIR, see Table 4) consist of individual areas, each
containing a group of several, individually resolved indications. An area of grouped indications is treated
as an individual area when its distance to the neighbouring area is bigger than the biggest lateral
dimension of each area. An example is given in Figure C.6.
Unless otherwise agreed at the time of enquiry and order, when conducting radiographic and ultrasonic
testing in combination it was proven that if a discontinuity indicated by radiographic testing is situated
in the core zone, the discontinuity is acceptable at one lower level of severity, e.g. severity level 3 instead
of severity level 2 for radiographic testing. For further information, see EN 1559-2.
4.5 Qualification of personnel
Ultrasonic testing shall be performed by qualified personnel. Qualification of personnel may be in
accordance with EN ISO 9712 or other equivalent recognized standards.

4.6 Severity levels
If the purchaser specifies different severity levels in different areas of the same casting, all of these areas
shall be clearly identified and shall include:
a) all necessary dimensions for accurate location of zones;
b) the full extent of all weld preparations and the thickness of any special rim zone.
Severity level 1 is only applied to weld preparations and special rim zones.
Unless other requirements have been agreed at the time of acceptance of the order, for finishing welds,
the requirements for the parent metal shall apply.
5 Testing
5.1 Principles
The principles of ultrasonic testing given in EN ISO 16810, EN ISO 16811 and EN ISO 16827 shall apply.
5.2 Material
The suitability of material for ultrasonic testing is assessed by comparison with the echo height of a
reference reflector (usually the first back-wall echo) and the noise level. This assessment shall be carried
out on selected casting areas which are representative of the surface finish and of the total thickness
range of the objects to be tested. The assessment areas shall have parallel surfaces.
The reference echo height according to Table 2 shall be at least 6 dB above the noise level.
If the echo height is less than 6 dB above the noise level, then ultrasonic testing has reduced performance.
In this case, the next larger detectable FBH or side-drilled holes (SDH) diameter which can be detected
with a signal-to-noise ratio of at least 6 dB shall be noted in the test report.
The further procedure shall be agreed between the manufacturer and the purchaser.
NOTE 1 For the definition of an adequate diameter of a flat-bottomed hole, the distance-gain-size system (DGS)
or a test block of identical material, heat treatment and thickness containing flat-bottomed holes with a diameter
according to Table 2 or equivalent side-drilled holes, can be used. Formula (2) can be used for converting a flat-
bottomed hole diameter into an equivalent side-drilled hole diameter:
4, 935 D
FBH
D = (2)
Q
λ s
where
D is the side-drilled hole diameter, in millimetres;
Q
D is the flat-bottomed hole diameter, in millimetres;
FBH
λ is the wavelength, in millimetres;
s is the path length, in millimetres.
The formula is applicable for D ≥ 2 λ and s ≥ 5 times the near-field length and is only defined for single-
Q
transducer probes.
NOTE 2 Steel castings usually receive at least an austenitizing heat treatment before ultrasonic testing.
5.3 Equipment and coupling medium
5.3.1 Ultrasonic instrument
The ultrasonic instrument shall meet the requirements given in EN ISO 22232-1 and shall have the
following characteristics:
a) range setting capability, from at least 10 mm to 2 m, continuously selectable, for longitudinal and
transverse waves in steel;
b) gain span, adjustable in 2 dB maximum steps over a range of at least 80 dB with an accuracy of 1 dB;
c) inaccuracy of time-base and vertical linearities less than 5 % of the adjustment range of the screen;
d) operating in combined transmitter-receiver mode or in separate transmitter-receiver-mode;
e) suitability, at least for nominal frequencies from 1 MHz up to and including 5 MHz, for the pulse-echo
technique with single-transducer and dual-transducer probes.
NOTE Higher frequencies up to 10 MHz can be used for high resolution applications.
5.3.2 Probes
The probes shall meet the requirements given in EN ISO 22232-2 and EN ISO 22232-3 with the following
exceptions:
a) nominal frequencies shall be in the range 1 MHz to 5 MHz;
b) for oblique incidence, angle-beam probes with angles between 35° and 70° shall be used.
NOTE 1 Higher frequencies up to 10 MHz can be used for high resolution applications.
NOTE 2 Normal-beam or angle-beam probes can be used for the testing of steel castings for highly stressed
components. The type of probe depends on the geometry of the casting and the type of discontinuity to be detected.
For test zones close to the surface, dual-transducer probes (normal-beam or angle-beam) should be
preferred.
5.3.3 Checking of the ultrasonic test equipment
The ultrasonic test equipment shall be checked regularly by the operator according to EN ISO 22232-3.
5.3.4 Coupling medium
A coupling medium in accordance with EN ISO 16810 shall be used. The coupling medium shall wet the
test surface to ensure satisfactory sound transmission. The same coupling medium shall be used for the
setting and all subsequent test operations.
NOTE The sound transmission can be checked by one or more stable back-wall echoes in areas with parallel
surfaces.
5.3.5 Test sensitivity and resolution of detection
The test sensitivity of the instrument shall allow at least the setting of the sensitivity in accordance with
the requirements of 5.5.2.
The resolution of detection of the instrument-probe combination shall meet the requirements of Annex A.
5.4 Preparation of casting surfaces for testing
For the preparation of casting surfaces for ultrasonic testing, see EN ISO 16810.
The casting surfaces to be tested shall be such that satisfactory coupling with the probe can be achieved.
With single-transducer probes, satisfactory coupling can be achieved if can be achieved if the surfaces
correspond at least to the limit comparator the condition of the surfaces to be used for testing
corresponds at least to the limit comparator 4 S1 or 4 S2 according to EN 1370.
The roughness of any machined surface used for testing shall be R ≤ 12,5 μm.
a
For special test techniques, higher surface qualities such as 2 S1, 2 S2 (see EN 1370) and R ≤ 6,3 μm can
a
be necessary.
5.5 Test procedure
5.5.1 General
Because the choice of both the direction of incidence and suitable probes largely depends on the shape of
the casting, or on the possible discontinuities in the casting or on the possible discontinuities from
finishing welding, the applicable test procedure shall be specified by the manufacturer of the casting.
If geometrically possible, the areas to be tested shall be tested from both sides. When testing from only
one side, short-range resolving probes shall be used additionally for the detection of discontinuities close
to the surface. Testing with dual-transducer probes is only adequate for parts of all thicknesses/scanning
depths or wall thickness zones up to 50 mm.
Additionally, when not otherwise agreed between the purchaser and the manufacturer, for all castings,
dual-transducer normal-beam and/or angle-beam probes shall be used to test the following areas up to
a depth o
...