ISO 17577:2006

INTERNATIONAL ISO
STANDARD 17577
First edition
2006-09-15

Steel — Ultrasonic testing for steel flat
products of thickness equal to or greater
than 6 mm
Aciers — Contrôle ultrasonore des produits plats en acier d'épaisseur
égale ou supérieure à 6 mm




Reference number
ISO 17577:2006(E)
©
ISO 2006

---------------------- Page: 1 ----------------------
ISO 17577:2006(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2006
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2006 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 17577:2006(E)
Contents Page
Foreword. iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Principle. 2
5 Personnel. 2
6 Testing system. 3
6.1 General requirements. 3
6.2 Manual-testing instrument. 3
6.3 Automated testing system. 3
6.4 Performance of electronic equipment . 4
6.5 Probes. 4
6.6 Coupling medium. 5
7 Procedure . 5
7.1 Inspection timing . 5
7.2 Scanning plan . 5
7.2.1 General. 5
7.2.2 Testing of the flat-product body. 5
7.2.3 Testing of the edges of the flat products . 6
7.3 Scanning condition. 6
7.4 Sensitivity and range setting. 6
8 Determination of the discontinuity size. 8
8.1 Testing the flat-product body . 8
8.1.1 Testing with dual-element probes. 8
8.1.2 Testing with single-element probes. 8
8.2 Testing the edges . 8
9 Acceptance criteria. 9
10 Test report . 9
Bibliography . 12

© ISO 2006 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 17577:2006(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.
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 17577 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of testing
(other than mechanical tests and chemical analysis).

iv © ISO 2006 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 17577:2006(E)

Steel — Ultrasonic testing for steel flat products of thickness
equal to or greater than 6 mm
1 Scope
This International Standard specifies a method for the automated and/or manual ultrasonic testing of uncoated
steel flat products for internal discontinuities by the reflection method. It is applicable to non-alloyed or alloyed
steel flat products, in a nominal thickness range of 6 mm to 200 mm. However, this standard may be applied
to austenitic and austenitic-ferritic steels, provided that the difference between the amplitude of the noise
signal and that of the echo detection threshold is sufficient for the limit fixed. Unless otherwise agreed, for
testing of steel flat products for welded steel tubes, ISO 12094 applies.
Other methods of testing (e.g. by transmission) or other test equipment may be used at the manufacturer’s
discretion, provided that they give identical results to those obtained under the conditions of this standard. In
the event of a dispute, only the method defined in this standard will prevail.
Testing of flat products, of thickness less than 6 mm and over 200 mm, may be the subject of special
agreements between the parties concerned.
The inspection is normally carried out in the place of production or on the premises of the supplier.
2 Normative references
The following referenced documents are indispensable for the application 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 9712, Non-destructive testing — Qualification and certification of personnel
ISO 12094, Welded steel tubes for pressure purposes — Ultrasonic testing for the detection of laminar
imperfections in strips/plates used in the manufacture of welded tubes
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
internal discontinuity
any imperfection lying within the thickness of the flat products, e.g. planar or laminar imperfection,
single-plane or multi-plane inclusion bands or clusters
3.2
defect
unacceptable internal discontinuities, i.e. exceeding the specified maximum size or population density limits
3.3
population density
number of individual internal discontinuities of a size greater than a specified minimum size and less than a
specified maximum size per specified area of body or length of edge zone
© ISO 2006 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 17577:2006(E)
3.4
manual and assisted manual testing
testing by an operator applying an ultrasonic probe to the flat-product surface, manually executing the
appropriate scanning pattern on the flat-product surface and visually assessing ultrasonic signal indications on
the electronic equipment screen either by direct viewing or by built-in signal amplitude alarm devices
3.5
automated and semi-automated testing
testing using a mechanized means of applying the ultrasonic probe or probes to the flat-product surface and
executing the appropriate scanning pattern, together with ultrasonic signal evaluation by electronic means
NOTE Such testing can be either fully automated with no operator involvement or semi-automated when the operator
performs basic equipment operation functions.
3.6
dead zone
zone to be measured as the point of time base where the transmitted pulse or surface echo drops to less than
20 % of screen height under the specified test sensitivity.
4 Principle
The method used is based on the reflection of ultrasonic waves (generally longitudinal), the mean direction of
which is perpendicular to the main surface of the flat products.
The examination consists of the following:
a) Locating any discontinuity by comparing the amplitude of the discontinuity echo with the amplitude of the
echo of a flat-bottomed hole of a given diameter and located at the same depth as the discontinuity.
NOTE Only those discontinuities giving an echo height exceeding in amplitude that of the echo obtained with the
reference flat-bottomed hole are taken into consideration.
b) Then determining its area, the contour of the discontinuity being defined by the positions of the center of
the probe corresponding to an echo amplitude of half the maximum amplitude of the discontinuity under
consideration (6 dB method).
The examination is carried out during the first ultrasonic scan for all the flat-product thicknesses and from one
side only.
In the case of automated testing, the location of a discontinuity and the determination of its area can be
realized using different algorithms together with high scanning density. In case of dispute, the 6 dB technique
in 8.1.1 should be used.
5 Personnel
Testing shall be carried out by qualified personnel under the responsibility of a Level 3 individual, certified in
accordance with ISO 9712 or an appropriate national/regional standard.
NOTE Examples of appropriate standards are listed in the Bibliography.
2 © ISO 2006 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 17577:2006(E)
6 Testing system
6.1 General requirements
a) The normal beam technique and the reflection technique shall be used for the ultrasonic testing method.
b) The apparatus shall be equipped with time-base regulation and the gain control shall be calibrated in
decibels.
c) The electronic equipment shall be appropriate for the ultrasonic probes and frequencies used.
d) The transmitted pulse repetition frequency shall be appropriate for the applied scanning speed.
e) The apparatus shall detect the ultrasonic signals of internal discontinuities by using a gate function. The
output signal shall be provided for devices like display monitor or recording equipment.
f) The coupling medium shall ensure an adequate contact between the probe and the surface of the flat
products and maintain sufficient coupling.
6.2 Manual-testing instrument
The instrument shall be equipped with an A-scan display monitor that allows the assessment of the path of
ultrasonic waves in the flat products. The oscillograms shall be clearly visible, the peaks corresponding to the
successive echoes being sharp and very clear.
6.3 Automated testing system
The automated testing system shall be equipped with the following:
a) a suitable mechanical means for scanning the surface of flat products with a defined density;
b) probe holders which are capable of following the surface contour of a flat product to be tested, in order to
maintain straight incidence;
c) appropriate electronics including, for example, transmitters, receivers, multiplexer, gates, display monitor,
as well as a means for data collection;
d) appropriate means for signal evaluation, recording (e.g. mapping) and storing;
e) means for calibration of the equipment (i.e. sensitivity, time base and gate position), for example, by the
use of reference blocks, input of artificial signals, input of distance-amplitude curves (DAC) or input of
stored calibration files;
f) means for control of pulse repetition frequency related to the scanning speed;
g) means for coupling and function check (e.g. by surveillance of back-wall echo);
h) function to indicate the location of discontinuities from the edge of flat products (printer, recorder or
display).
© ISO 2006 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 17577:2006(E)
6.4 Performance of electronic equipment
The electronic equipment shall have the following performance.
a) Linearity
⎯ Linear amplifiers: The deviation of the vertical linearity shall not exceed ± 1 dB in any part of a 20 dB
span.
⎯ Logarithmic amplifiers: The deviation of the vertical linearity shall not exceed ± 1 dB in any part of a
20 dB span and ± 2 dB in any part of a 60 dB span.
⎯ Horizontal linearity: The deviation of the horizontal linearity shall not exceed ± 2 % of the testing
range.
The vertical linearity shall be checked at least once a year, unless the conditions dictate a higher
frequency of checking. The results of all checks shall be recorded.
b) Dead zone
The dead zone of single-element probes shall be as small as possible, i.e. max. 15 % of the thickness of
the flat products or 15 mm, whichever is the smaller. For product thicknesses less than 10 mm, their dead
zone shall be less than or equal to 1,5 mm.
6.5 Probes
The probes shall be single-element probes, dual-element probes or multiple dual-element probes, depending
on the thickness of the flat products as given in Table 1.
Table 1 — Type of probe
Specified thickness of the flat products

or path length (e) a, b
Type of probe
mm
6 u e u 60
Dual-element probe
60 < e u 200
Single or dual-element probe
a
In the event of dispute, the type of probe to be used shall be the su
...