Iso 22825 2012
Iso 22825 2012
Iso 22825 2012
STANDARD 22825
Second edition
2012-05-15
Reference number
ISO 22825:2012(E)
© ISO 2012
ISO 22825:2012(E)
Contents Page
Foreword............................................................................................................................................................................. iv
Introduction......................................................................................................................................................................... v
1 Scope....................................................................................................................................................................... 1
2 Normative references.......................................................................................................................................... 1
3 Terms and definitions.......................................................................................................................................... 2
4 Information required prior to testing.............................................................................................................. 2
4.1 Items to be defined by specification............................................................................................................... 2
4.2 Specific information required by the operator prior to testing................................................................ 2
5 Personnel................................................................................................................................................................ 3
6 Equipment.............................................................................................................................................................. 3
7 Range setting for compression waves........................................................................................................... 3
8 Sensitivity setting................................................................................................................................................. 4
8.1 General.................................................................................................................................................................... 4
8.2 Use of side-drilled holes..................................................................................................................................... 4
8.3 Use of other reference reflectors..................................................................................................................... 5
9 Test procedure and ultrasonic techniques.................................................................................................... 5
9.1 Development of the test procedure................................................................................................................. 5
9.2
9.3
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Content of the procedure................................................................................................................................... 5
Selection of ultrasonic technique(s)............................................................................................................... 6
9.4 (standards.iteh.ai)
Optimization of technique and draft of procedure...................................................................................... 7
9.5 Practical implications of the use of refracted compression waves........................................................ 7
10 ISO 22825:2012
Classification and sizing of indications......................................................................................................... 8
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11 Testing of welds....................................................................................................................................................
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11.1 General.................................................................................................................................................................... 8
11.2 Surface condition and couplant fluid.............................................................................................................. 8
11.3 Parent metal testing............................................................................................................................................. 8
11.4 Scanning................................................................................................................................................................. 8
11.5 Evaluation of indications.................................................................................................................................... 9
12 Test report.............................................................................................................................................................. 9
12.1 General data........................................................................................................................................................... 9
12.2 Information related to equipment.................................................................................................................... 9
12.3 Information related to testing technique........................................................................................................ 9
12.4 Results of testing............................................................................................................................................... 10
Annex A (informative) Compression wave angle beam techniques.................................................................... 11
Annex B (informative) Stainless steel calibration blocks for range setting...................................................... 17
Annex C (informative) Reference blocks for sensitivity setting........................................................................... 19
Bibliography...................................................................................................................................................................... 22
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 22825 was prepared by the European Committee for Standardization (CEN) Technical Committee TC 121,
Welding, Sub-committee SC 5, Testing of welds, in collaboration with Technical Committee ISO/TC 44, Welding
and allied processes, Subcommittee SC 5, Testing and inspection of welds, in accordance with the Agreement
on technical cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 22825:2006), which has been technically revised.
Introduction
Welds in austenitic steel components and dissimilar metal welds are widely regarded as very difficult to inspect
by ultrasound. The problems are mainly associated with unfavourable structure and grain size, as well as
with different material properties which result in inhomogeneous and anisotropic mechanical and acoustic
properties that contrast with the relatively homogeneous and isotropic behaviour in low-alloy steel welds.
Austenitic weld metal and other coarse-grained, anisotropic materials can significantly affect ultrasound
propagation. In addition, beam distortion, unexpected reflections and wave mode conversions on the fusion
line and/or columnar grains can occur. Therefore it can be difficult and sometimes impossible for ultrasonic
waves to penetrate the weld metal.
Ultrasonic testing of these metals may require techniques that differ from conventional techniques. These special
techniques often include the use of dual-element probes designed for refracted compression (longitudinal)
waves or creeping waves rather than for conventional shear waves.
In addition, it is necessary to produce representative reference blocks with welds in order to develop a testing
procedure, set a preliminary sensitivity level, assess the procedure and demonstrate effectiveness before a
definitive procedure is written. Material, weld preparation and welding procedure, as well as the geometry and
surface condition of reference blocks are the same as for the component being tested.
1 Scope
This International Standard specifies the approach to be followed when developing procedures for the ultrasonic
testing of the following welds:
— austenitic welds.
ISO 7963, Non-destructive testing — Ultrasonic testing — Specification for calibration block No. 2
ISO 17640, Non-destructive testing of welds — Ultrasonic testing — Techniques, testing levels, and assessment
EN 473, Non-destructive testing — Qualification and certification of NDT personnel — General principles
3.1
dual-element probe
ultrasonic probe in which the transmit and receive transducers are separate and are electrically and acoustically
isolated from each other
3.2
focal distance
〈dual element probes〉 distance between probe and focal point on the acoustical axis where the acoustic
pressure is at its maximum
3.3
focal curve
〈dual element probes〉 curve, representing the relationship between sound path and sensitivity of a probe on a
specified material containing specified reflectors
f) whether or not parent metal testing shall be carried out prior to and/or after welding (see 11.3);
b) type(s) of parent material and product form (i.e. cast, forged, rolled);
e) the time of the inspection with regard to any post-weld heat treatment;
f) the result of any parent metal testing carried out prior to and/or after welding;
g) reference points and details of co-ordinate systems for the test object.
5 Personnel
Personnel performing testing in accordance with this International Standard shall be qualified to an appropriate
level in accordance with ISO 9712 or EN 473 or equivalent in the relevant industrial sector.
In addition to a general knowledge of ultrasonic weld testing, the operators shall be familiar with and have
practical experience in testing problems specifically associated with the type of materials and weld joints to be
tested. Specific training and examination of personnel should be performed on representative pieces (duplex,
austenitic, stainless steel) containing welds and using dual-element longitudinal wave probes. This training and
the examination results should be documented.
If this is not the case, specific training and examination should be performed with the finalized ultrasonic testing
procedures and selected ultrasonic testing equipment on representative samples containing natural or artificial
reflectors similar to those expected. This training and the examination results should be documented.
6 Equipment
The equipment used for testing shall fulfil the requirements of EN 12668-1 and EN 12668-2. The verification
of the combined equipment shall be done in accordance with EN 12668-3, with the exception of dual-element
compression wave angle beam probes, which can be verified on appropriate reference blocks other than the
blocks mentioned in EN 12668-3.
The index point of each probe shall be marked on the probe’s side, after having optimized the echo amplitude
on the radius closest to its focal distance. Since echo optimization can be difficult for high-angle probes and
creeping wave probes, the shear wave component may be used for optimization instead. In that case, the
calibration methodology shall be included in the test procedure.
Optimization of the echoes shall be done on the two radii separately, and by iteration until the signals from the
smaller and the larger radius are on their correct positions.
Alternatively, the time base may be set with the aid of a single-element straight beam probe on the width of the
calibration block, and subsequent zero point adjustment with the angle probe placed on the calibration block,
on the radius which is closest to the probe’s focal distance.
Range setting shall be carried out prior to each testing. Checks to confirm these settings shall be performed at
least every 4 h and on completion of testing.
Checks shall also be carried out whenever a system parameter is changed or whenever changes in the
equivalent settings are suspected.
If deviations are found during these checks, corrective actions shall be carried out as specified in Table 1.
8 Sensitivity setting
8.1 General
Sensitivity setting shall be performed on a reference block with a weld. Annex C shows examples for reference
blocks. The wall thickness of the reference block shall be similar to the wall thickness of the component to be
tested within 10 % or 3 mm, whichever is the larger.
Reference reflectors may be side-drilled holes in the weld centre and/or on the fusion line. Alternatively, flat-
bottomed holes on the fusion line may be used, having the flat bottom in the plane of the fusion line (weld
bevel). Surface notches shall be used as references for near-surface defects. See Figures C.1, C.2, and C.3.
Zone coverage related to wall thickness shall be established on the basis of the focal curves as shown in A.6
when dual-element probes are used. Zone overlap shall be documented in the procedure.
Setting of sensitivity shall be carried out prior to each testing in accordance with this International Standard.
The gap, g, between test surface and bottom of the probe shoe shall not be greater than 0,5 mm.
For cylindrical or spherical surfaces, this requirement can be checked with Equation (1):
a2
g= (1)
D
where
D
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is the diameter, in millimetres, of the component;
a
(standards.iteh.ai)
is the dimension, in millimetres, of the probe shoe in the direction of testing.
If a value for g larger than 0,5 mm results from Equation (1), the probe shoe shall be adapted to the surface,
ISO 22825:2012
and the sensitivity and rangehttps://standards.iteh.ai/catalog/standards/sist/1d233f98-0bb7-4216-b56b-
shall be set accordingly.
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Checks to confirm these settings shall be performed at least every 4 h and on completion of testing. Checks
shall also be carried out if a system parameter is changed or if changes in the equivalent settings are suspected.
If deviations are found during these checks, corrective actions shall be carried out as specified in Table 2.
a) by establishing the echo height with the sound beam passing through the parent material only;
b) by establishing the echo height with the sound beam passing through the weld metal.
If the reflectors in the weld centreline are used, sensitivity setting may be performed from one side only, with
the exception of dissimilar metal welds (where the acoustic properties of the parent metal are different on one
side compared to the other).
In pipe weld inspection, flat-bottomed holes and notches are typically used as reference reflectors. An example
for a pipeline girth weld is given in Figure C.2.
The position of the flat-bottomed hole shall be determined from a macro-section of the austenitic weld,
positioned accordingly in the reference block and machined to position the flat bottom at the fusion line.
b) testing techniques;
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c) testing levels;
(standards.iteh.ai)
NOTE For the testing of austenitic steels, theISO 22825:2012
testing levels are not defined in ISO 17640 as for ferritic steels. However,
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it is important to set them to take into account the required probability of detection in each area under consideration.
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d) personnel qualification/training requirements;
e) equipment requirements;
g) reference blocks;
o) reporting requirements;