ISO 7039:2024
(Main)Metallic materials — Tensile testing — Method for evaluating the susceptibility of materials to the effects of high-pressure gas within hollow test pieces
Metallic materials — Tensile testing — Method for evaluating the susceptibility of materials to the effects of high-pressure gas within hollow test pieces
This document specifies the geometries and proposed finishing procedures of the inner surface of hollow test piece of metallic materials, filled with a high-pressure gaseous medium. The document specifies a tensile testing procedure to evaluate the effect of high-pressure gaseous medium compared to a high-pressure inert gas or air. The document can be used for the screening of metallic materials by evaluating mechanical property changes due to the effects of various test gases, including hydrogen. NOTE Temperature range and pressure range depend on the materials to be tested and test gas to be used.
Matériaux métalliques — Essais de traction — Méthode d'évaluation des changements de propriétés dans un environnement gazeux à haute pression en utilisant une pièce d'essai creuse
General Information
Standards Content (Sample)
International
Standard
ISO 7039
First edition
Metallic materials — Tensile
2024-07
testing — Method for evaluating the
susceptibility of materials to the
effects of high-pressure gas within
hollow test pieces
Matériaux métalliques — Essais de traction — Méthode
d'évaluation des changements de propriétés dans un
environnement gazeux à haute pression en utilisant une pièce
d'essai creuse
Reference number
© ISO 2024
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
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 2
6 Test piece . 3
6.1 General .3
6.2 Shape and dimensions .3
6.3 Inner surface of hole .3
6.4 Number of test pieces .4
7 Measurement of original cross-sectional area . 4
8 Marking the original gauge length . 4
9 Test equipment . 4
9.1 Principle .4
9.2 Testing machine .5
9.3 Extensometer .5
9.4 Test deviation .5
10 Test conditions . 5
10.1 Test gas .5
10.2 Test temperature .6
10.3 Test pressure .6
10.4 Testing rate .6
11 Evaluation of the test results . 6
11.1 Yield strength, tensile strength, percentage elongation after fracture with hollow test
piece .6
11.2 Percentage reduction of area at leakage .7
11.3 Relative elongation after fracture with hollow test piece, A .7
h(rel)
11.4 Relative reduction of area at leakage with hollow test piece, Z .7
h(rel)
11.5 Relative 0,2 % proof strength with hollow test piece, R .7
p0,2 h(rel)
11.6 Relative tensile strength with hollow test piece, R .8
mh(rel)
12 Test report . 8
Bibliography . 9
iii
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 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).
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 164, Mechanical testing of metals, Subcommittee
SC 1, Uniaxial testing.
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
Introduction
[1]
Hollow test pieces have been occasionally used for the evaluation of influence of hydrogen since the 1950’s.
But those hollow test pieces were mostly shaped with thin walls or in a tubular form, and the deformation
behaviour was different from that of solid test piece; as a result, neither the percentage elongation after
fracture (the elongation) nor the percentage reduction of area (the reduction of area) can be accurately
obtained. The influence of a high-pressure hydrogen gas environment has been conventionally evaluated
using a solid test piece within a gas-filled cylinder or vessel with the tensile force applied from outside the
[2]
vessel to evaluate the influence of the hydrogen gas on the material under test as described in ASTM G 142
[3]
or ISO 11114-4 .
Since 2005, the use of a hydrogen gas filled hollow test piece has been utilized as a method to evaluate
changes in tensile properties of metallic materials due to concurrent exposure to gaseous hydrogen. It was
[4]-[9]
found in previous studies that testing of a hollow test piece with a small diameter axial hole pressurized
with gaseous hydrogen yielded similar trends for both the elongation and the reduction of area to testing of
solid test pieces stored in a similar gaseous environment. For this reason, this method has been considered
a material screening test method for evaluation of metallic materials in gaseous hydrogen and the resulting
data are not suitable for design.
This document does not address the determination of entirely the same values of mechanical properties for
design purposes as specified by the ISO 6892 series but is suitable as a screening or first selection method
for metallic materials in a gaseous or liquid media. The hollow test piece is suitable for the evaluation of
materials used for high-pressure pipe or vessels, and can be used not only for hydrogen gas, but also for
other gaseous or corrosive media. However, the major concerns for the hollow test piece are the hoop stress
and the roughness of inner surface. In this document, the hollow test piece method is regarded for tests
filled with various media and the required preparation of the test piece, such as an inner surface finish, is
also described.
The type of the pressurized gas in the hollow test piece can affect the tensile properties in the test. Also, the
specific test conditions, e.g., test speed, test gas, internal pressure, temperature, and gas purity, can affect
the outcome. As this document describes in general the test procedure for the hollow test piece, it does not
describe the most suitable test conditions for all possible variations of the test parameters. Preliminary
tests should be conducted to identify technical relevant test conditions. Test conditions in this document
will be revised with the increase of test results.
v
International Standard ISO 7039:2024(en)
Metallic materials — Tensile testing — Method for evaluating
the susceptibility of materials to the effects of high-pressure
gas within hollow test pieces
1 Scope
This document specifies the geometries and proposed finishing procedures of the inner surface of hollow
test piece of metallic materials, filled with a high-pressure gaseous medium. The document specifies
a tensile testing procedure to evaluate the effect of high-pressure gaseous medium compared to a high-
pressure inert gas or air. The document can be used for the screening of metallic materials by evaluating
mechanical property changes due to the effects of various test gases, including hydrogen.
NOTE Temperature range and pressure range depend on the materials to be tested and test gas to be used.
2 Normative references
The following documents are referred
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.