SIST EN ISO 6892-2:2011

SLOVENSKI STANDARD
SIST EN ISO 6892-2:2011
01-september-2011
1DGRPHãþD
SIST EN 10002-5:1997
Kovinski materiali - Natezni preskus - 2. del: Metoda preskušanja pri povišani
temperaturi (ISO 6892-2:2011)
Metallic materials - Tensile testing - Part 2: Method of test at elevated temperature (ISO
6892-2:2011)
Metallische Werkstoffe - Zugversuch - Teil 2: Prüfverfahren bei erhöhter Temperatur
(ISO 6892-2:2011)
Matériaux métalliques - Essai de traction - Partie 2: Méthode d'essai à température
élevée (ISO 6892-2:2011)
Ta slovenski standard je istoveten z: EN ISO 6892-2:2011
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
SIST EN ISO 6892-2:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 6892-2:2011

---------------------- Page: 2 ----------------------

SIST EN ISO 6892-2:2011


EUROPEAN STANDARD
EN ISO 6892-2

NORME EUROPÉENNE

EUROPÄISCHE NORM
February 2011
ICS 77.040.10 Supersedes EN 10002-5:1991
English Version
Metallic materials - Tensile testing - Part 2: Method of test at
elevated temperature (ISO 6892-2:2011)
Matériaux métalliques - Essai de traction - Partie 2: Metallische Werkstoffe - Zugversuch - Teil 2: Prüfverfahren
Méthode d'essai à température élevée (ISO 6892-2:2011) bei erhöhter Temperatur (ISO 6892-2:2011)
This European Standard was approved by CEN on 14 February 2011.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6892-2:2011: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO 6892-2:2011
EN ISO 6892-2:2011 (E)
Contents Page
Foreword .3

2

---------------------- Page: 4 ----------------------

SIST EN ISO 6892-2:2011
EN ISO 6892-2:2011 (E)
Foreword
This document (EN ISO 6892-2:2011) has been prepared by Technical Committee ISO/TC 164 "Mechanical
testing of metals" in collaboration with Technical Committee ECISS/TC 101 “Test methods for steel (other
than chemical analysis)” the secretariat of which is held by AFNOR.
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 August 2011, and conflicting national standards shall be withdrawn at
the latest by August 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 10002-5:1991.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 6892-2:2011 has been approved by CEN as a EN ISO 6892-2:2011 without any modification.

3

---------------------- Page: 5 ----------------------

SIST EN ISO 6892-2:2011

---------------------- Page: 6 ----------------------

SIST EN ISO 6892-2:2011

INTERNATIONAL ISO
STANDARD 6892-2
First edition
2011-02-15


Metallic materials — Tensile testing —
Part 2:
Method of test at elevated temperature
Matériaux métalliques — Essai de traction —
Partie 2: Méthode d'essai à température élevée





Reference number
ISO 6892-2:2011(E)
©
ISO 2011

---------------------- Page: 7 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(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.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2011
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 2011 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Symbols and designations.2
5 Principle .3
6 Test piece .3
7 Determination of original cross-sectional area (S ).3
o
8 Marking the original gauge length (L ).3
o
9 Apparatus.3
10 Test conditions .5
11 Determination or calculation of the properties .8
12 Test report.8
13 Measurement uncertainty.9
14 Figures.9
15 Annexes.10
Annex A (informative) Addition to Annexes B and D of ISO 6892-1:2009.11
Annex B (informative) Measurement uncertainty .17
Bibliography.20

© ISO 2011 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(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 6892-2 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee
SC 1, Uniaxial testing.
This first edition of ISO 6892-2 cancels and replaces ISO 783:1999.
ISO 6892 consists of the following parts, under the general title Metallic materials — Tensile testing:
⎯ Part 1: Method of test at room temperature
⎯ Part 2: Method of test at elevated temperature
The following parts are planned:
⎯ Part 3: Method of test at low temperature
⎯ Part 4: Method of test in liquid helium
iv © ISO 2011 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
Introduction
In this part of ISO 6892, two methods of testing speeds are described. The first, Method A, is based on strain
rates (including crosshead separation rate) with narrow tolerances (±20 %) and the second, Method B, is
based on conventional strain rate ranges and tolerances. Method A is intended to minimize the variation of the
test rates during the moment when strain rate sensitive parameters are determined and to minimize the
measurement uncertainty of the test results.
The influence of the testing speed on the mechanical properties, determined by the tensile test, is normally
greater at an elevated temperature than at room temperature.
Traditionally, mechanical properties determined by tensile tests at elevated temperatures have been
determined at a slower strain or stressing rate than at room temperature. This part of ISO 6892 recommends
the use of slow strain rates but, in addition, higher strain rates are permitted for particular applications, such
as comparison with room temperature properties at the same strain rate.
During discussions concerning the speed of testing in the preparation of this part of ISO 6892, it was decided
to consider deleting the stress rate method in future revisions.

© ISO 2011 – All rights reserved v

---------------------- Page: 11 ----------------------

SIST EN ISO 6892-2:2011

---------------------- Page: 12 ----------------------

SIST EN ISO 6892-2:2011
INTERNATIONAL STANDARD ISO 6892-2:2011(E)

Metallic materials — Tensile testing —
Part 2:
Method of test at elevated temperature
WARNING — This International Standard calls for the use of substances and/or procedures that may
be injurious to health if adequate safety measures are not taken. This International Standard does not
address any health hazards, safety or environmental matters associated with its use. It is the
responsibility of the user of this International Standard to establish appropriate health, safety and
environmentally acceptable practices and take suitable actions for any national and international
regulations. Compliance with this International Standard does not in itself confer immunity from legal
obligations.
1 Scope
This part of ISO 6892 specifies a method of tensile testing of metallic materials at temperatures higher than
room temperature.
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 6892-1:2009, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7500-1, Metallic materials — Verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Verification and calibration of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometers used in uniaxial testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6892-1:2009 apply with the
following exceptions and supplements.
In general, all test piece geometries/dimensions are based on measurements taken at room temperature. The
exception may be the extensometer gauge length (see 3.3 and 10.2.2).
NOTE The following properties are generally not determined at elevated temperature unless required by relevant
specifications or agreement:
⎯ permanent set strength (R );
r
⎯ percentage permanent elongation;
⎯ percentage permanent extension;
⎯ percentage yield point extension (A );
e
© ISO 2011 – All rights reserved 1

---------------------- Page: 13 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
⎯ percentage total extension at maximum force (A );
gt
⎯ percentage plastic extension at maximum force (A );
g
⎯ percentage total extension at fracture (A ).
t
3.1
original gauge length
L
o
gauge length measured at room temperature before heating of the test piece and before application of force
3.2
percentage elongation after fracture
A
permanent elongation at room temperature of the gauge length after fracture (L − L ), expressed as a
u o
percentage of the original gauge length (L )
o
NOTE For further details, see ISO 6892-1:2009.
3.3
extensometer gauge length
L
e
length within the parallel portion of the test piece used for the measurement of extension by means of an
extensometer
3.4
extension
increase in the extensometer gauge length (L ) at a given moment during the test
e
3.5
percentage extension
extension expressed as a percentage of the extensometer gauge length (L )
e
3.6
percentage reduction of area
Z
maximum change in cross-sectional area which has occurred during the test (S − S ), expressed as a
o u
percentage of the original cross-sectional area (S ), where S and S are calculated from the dimensions at
o o u
room temperature
3.7
stress
R
force at any moment during the test divided by the original cross-sectional area (S ) of the test piece
o
NOTE All stresses referred to in this part of ISO 6892 are engineering stresses, calculated using the cross-sectional
area of the test piece derived from dimensions measured at room temperature.
3.8
soaking time
t
s
time taken to stabilize the temperature of the test piece prior to mechanical loading
4 Symbols and designations
ISO 6892-1:2009, Table 1 provides an extensive listing of symbols and their related designations.
The additional symbols used in this part of ISO 6892 are given in Table 1.
2 © ISO 2011 – All rights reserved

---------------------- Page: 14 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
Table 1 — Symbols and designations
Symbol Unit Designation
T °C specified temperature or nominal temperature at which the test should be performed
T °C indicated temperature or measured temperature on the surface of the parallel length of the test piece
i
t min soaking time
s

5 Principle
The test involves straining a test piece by tensile force for the determination of one or more of the mechanical
properties defined in Clause 3.
The test is carried out at a temperature higher than 35 °C, which means at temperatures higher than room
temperature as specified in ISO 6892-1.
6 Test piece
For requirements concerning test pieces, see ISO 6892-1:2009, Clause 6.
NOTE Additional examples of test pieces are given in Annex A.
7 Determination of original cross-sectional area (S )
o
For requirements concerning determination of the original cross-sectional area, see ISO 6892-1:2009,
Clause 7.
NOTE This parameter is calculated from measurements taken at room temperature.
8 Marking the original gauge length (L )
o
For requirements concerning marking the original gauge length, see ISO 6892-1:2009, Clause 8.
9 Apparatus
9.1 Force-measuring system
The force-measuring system of the testing machine shall be calibrated in accordance with ISO 7500-1,
class 1, or better.
9.2 Extensometer
For the determination of proof strength (plastic or total extension), the used extensometer shall be in
accordance with ISO 9513, class 1 or better, in the relevant range. For other properties (with higher extension)
an ISO 9513 class 2 extensometer in the relevant range may be used.
The extensometer gauge length shall be not less than 10 mm and shall correspond to the central portion of
the parallel length.
Any part of the extensometer projecting beyond the furnace shall be designed or protected from draughts so
that fluctuations in the room temperature have only a minimal effect on the readings. It is advisable to maintain
reasonable stability of the temperature and speed of the air surrounding the testing machine.
© ISO 2011 – All rights reserved 3

---------------------- Page: 15 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
9.3 Heating device
9.3.1 Permitted deviations of temperature
The heating device for the test piece shall be such that the test piece can be heated to the specified
temperature T.
The indicated temperatures T are the temperatures measured on the surface of the parallel length of the test
i
piece with corrections applied for any known systematic errors, but with no consideration of the uncertainty of
the temperature measurement equipment.
The permitted deviations between the specified temperature T and the indicated temperatures T, and the
i
maximum permissible temperature variation along the test piece, are given in Table 2.
For specified temperatures greater than 1 100 °C, the permitted deviations shall be defined by previous
agreement between the parties concerned.
Table 2 — Permitted deviations between T and T and maximum permissible temperature variations
i
along the test piece
Specified temperature T Permitted deviation between T and T Maximum permissible
i
 temperature variation along the
 test piece
°C °C °C
T u 600 ±3 3
600 < T u 800 ±4 4
800 < T u 1 000 ±5 5
1 000 < T u 1 100 ±6 6

9.3.2 Measurement of temperature
When the gauge length is less than 50 mm, one temperature sensor shall measure the temperature at each
end of the parallel length directly. When the gauge length is equal to or greater than 50 mm, a third
temperature sensor shall measure near the centre of the parallel length.
This number may be reduced if the general arrangement of the furnace and the test piece is such that, from
experience, it is known that the variation in temperature of the test piece does not exceed the permitted
deviation specified in 9.3.1. However, at least one sensor shall be measuring the test piece temperature
directly.
Temperature sensor junctions shall make good thermal contact with the surface of the test piece and be
suitably screened from direct radiation from the furnace wall.
9.3.3 Verification of the temperature-measuring system
-measuring system shall have a resolution equal to or better than 1 °C and an accuracy of
The temperature
±0,004 T °C or ±2 °C, whichever is greater.
NOTE The temperature-measuring system includes all components of the measuring chain (sensor, cables,
indicating device and reference junction).
All components of the temperature-measuring system shall be verified and calibrated over the working range
at intervals not exceeding one year. Errors shall be recorded on the verification report. The components of the
temperature measuring system shall be verified by methods traceable to the international unit (SI unit) of
temperature.
4 © ISO 2011 – All rights reserved

---------------------- Page: 16 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
10 Test conditions
10.1 Setting the force zero point
The force-measuring system shall be set to zero after the testing equipment has been assembled but before
the test piece is actually placed in the gripping jaws. Once the force zero point has been set, the force-
measuring system may not be changed in any way during the test.
NOTE The use of this method ensures that the weight of the gripping system is compensated in the force
measurement and that any force resulting from the clamping operation does not affect the force zero point.
10.2 Gripping of the test piece, fixing of the extensometer and heating of the test piece, not
necessarily in the following sequence
10.2.1 Method of gripping
For requirements concerning the method of gripping, see ISO 6892-1:2009, 10.2.
10.2.2 Fixing of the extensometer and establishing the gauge length
10.2.2.1 General
Different methods of establishing the extensometer gauge length are used in practice. This may lead to minor
differences in the test results. The method used shall be documented in the test report.
10.2.2.2 L based on room temperature (Method 1)
e
The extensometer is set on the test piece at room temperature with nominal gauge length. The extension is
measured at test temperature and the percentage extension is calculated with the gauge length at room
temperature.
The thermal extension is not considered.
10.2.2.3 L based on test temperature ( Method 2)
e
This L includes the thermal extension of the test piece.
e
10.2.2.3.1 Nominal L at test temperature (Method 2 a)
e
The extensometer is set on the test piece at the test temperature with nominal gauge length before
mechanical loading.
10.2.2.3.2 Reduced L at room temperature (Method 2 b)
e
An extensometer with reduced gauge length is set on the test piece at room temperature such that at test
temperature the nominal gauge length is achieved.
For the calculation of percentage extension, the nominal gauge length is used.
10.2.2.3.3 Corrected L at test temperature (Method 2 c)
e
The extensometer is set on the test piece at room temperature with the nominal gauge length.
For the calculation of percentage extension, the corrected nominal gauge length at test temperature (gauge
length at room temperature and thermal expansion) is used.
© ISO 2011 – All rights reserved 5

---------------------- Page: 17 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
10.2.3 Heating of the test piece
The test piece shall be heated to the specified temperature T and shall be maintained at that temperature for
at least 10 min before loading (soaking time). The loading shall only be started after the output of the
extensometer has stabilized.
NOTE Quite often, longer times may be required to bring the entire cross section of the material up to the specified
temperature.
During heating, the temperature of the test piece shall not exceed the specified temperature with its tolerances,
except by special agreement between the parties concerned.
10.3 Testing rate based on strain rate control (Method A)
10.3.1 General
This method is intended to minimize the variation of the test rates during the moment when strain rate
sensitive parameters are determined and to minimize the measurement uncertainty of the test results.
For additional requirements concerning testing rate based on strain rate control (Method A), see
ISO 6892-1:2009, 10.3.1.
It is not always the case that all properties of the tensile test at room temperature will be determined at
elevated temperature. Hence only the appropriate test rates/modes for the properties to be determined shall
be used (see Figure 1).
10.3.2 Strain rate for the determination of the upper yield strength (R ) or proof strength properties
eH
(R and, if required, R )
p t
For additional requirements concerning strain rate for the determination of the upper yield strength (R ) or
eH
proof strength properties (R and, if required, R), see ISO 6892-1:2009, 10.3.2, but observe the following
p t
specified range:
−1 −1

Range 1: e = 0,000 07 s (equal to 0,004 2 min ), with a relative tolerance of ±20% (recommended
L
e
unless otherwise specified);
−1 −1

Range 2: e = 0,000 25 s (equal to 0,015 min ), with a relative tolerance of ±20 %.
L
e
(See also Figure 1.)
10.3.3 Strain rate for the determination of the lower yield strength (R ) and percentage yield point
eL
extension (A ), if required
e
For additional requirements concerning strain rate for the determination of the lower yield strength (R ) and
eL
percentage yield point extension (A ), if required, see ISO 6892-1:2009, 10.3.3, but observe the following
e
specified range:
−1 −1
Range 1: e = 0,000 07 s (equal to 0,0042 min ), with a relative tolerance of ±20 % (recommended
L
c
unless otherwise specified);
−1 −1
Range 2: e = 0,000 25 s (equal to 0,015 min ), with a relative tolerance of ±20 %.
L
c
(See also Figure 1.)
Recommended: crosshead control.
6 © ISO 2011 – All rights reserved

---------------------- Page: 18 ----------------------

SIST EN ISO 6892-2:2011
ISO 6892-2:2011(E)
10.3.4 Strain rate for the determination of the tensile strength (R ), percentage elongation after
m
fracture (A), percentage reduction area (Z), and, if required, percentage total extension at the maximum
force (A ), percentage plastic extension at maximum force (A )
gt g
For additional requirements concerning strain rate for the determination of the tensile strength (R ),
m
percentage elongation after fracture (A), percentage reduction area (Z) and, if required, percentage total
extension at the maximum force (A ), percentage plastic extension at maximum force (A ), see
gt g
ISO 6892-1:2009, 10.3.4, but observe the following specified range:
−1 −1
Range 1: e = 0,000 07 s (equal to 0,004 2 min ), with a relative tolerance of ±20 %;
L
c
−1 −1

Range 2: e = 0,000 25 s (equal to 0,015 min ), with a relative tolerance of ±20 %;
L
c
−1 −1
Range 3: e = 0,001 4 s (equal to 0,084 min ), with a relative tolerance of ±20 % (recommended
L
c
unless otherwise specified);
−1 −1
Range 4: e = 0,006 7 s (equal to 0,4 min ), with a relative tolerance of ±20 %.
L
c
(See also Figure 1.)
Recommended: crosshead control.
If the purpose of the tensile test is only to determine the tensile strength, then an estimated strain rate over the
parallel length of the test piece according to range 3 may be applied throughout the entire test.
10.4 Method of testing with expanded strain rate ranges (Method B)
10.4.1 General
This method is based on conventional strain rate ranges.
It should be taken into consideration that strain rate sensitivity of metals might be higher at elevated
temperature than at room temperature. The test rate, even within the specified range, can influence the values
of the properties to be determined.
10.4.2 Rate for the determination of yield strength or proof strength properties
This deals with upper and lower yield strengths and proof strength non-proportional extension.
The strain rate of the parallel length of the test piece, from the beginning of the test to the yield strength, shall
−1 −1 −1 −1
be between 0,000 016 7 s and 0,000 083 3 s (0,001 min and 0,005 min ).
When a test system is incapable of displaying strain rate, the stress rate shall be set so that a strain
...