oSIST prEN ISO 6892-2:2025

SLOVENSKI STANDARD
01-april-2025
Kovinski materiali - Natezni preskus - 2. del: Metoda preskušanja pri povišani
temperaturi (ISO/DIS 6892-2:2025)
Metallic materials - Tensile testing - Part 2: Method of test at elevated temperature
(ISO/DIS 6892-2:2025)
Metallische Werkstoffe - Zugversuch - Teil 2: Prüfverfahren bei erhöhter Temperatur
(ISO/DIS 6892-2:2025)
Matériaux métalliques - Essai de traction - Partie 2: Méthode d'essai à température
élevée (ISO/DIS 6892-2:2025)
Ta slovenski standard je istoveten z: prEN ISO 6892-2
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 6892-2
ISO/TC 164/SC 1
Metallic materials — Tensile
Secretariat: AFNOR
testing —
Voting begins on:
Part 2: 2025-01-31
Method of test at elevated
Voting terminates on:
2025-04-25
temperature
Matériaux métalliques — Essai de traction —
Partie 2: Méthode d'essai à température élevée
ICS: 77.040.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 6892-2:2025(en)
DRAFT
ISO/DIS 6892-2:2025(en)
International
Standard
ISO/DIS 6892-2
ISO/TC 164/SC 1
Metallic materials — Tensile
Secretariat: AFNOR
testing —
Voting begins on:
Part 2:
Method of test at elevated
Voting terminates on:
temperature
Matériaux métalliques — Essai de traction —
Partie 2: Méthode d'essai à température élevée
ICS: 77.040.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
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Published in Switzerland Reference number
ISO/DIS 6892-2:2025(en)
ii
ISO/DIS 6892-2:2025(en)
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
10.1 Setting the force zero point .5
10.2 Gripping of the test piece, fixing of the extensometer and heating of the test piece, not
necessarily in the following sequence .5
10.2.1 Method of gripping .5
10.2.2 Fixing of the extensometer and establishing the gauge length .5
10.2.3 Heating of the test piece .6
10.3 Testing rate based on strain rate control (Method A) .6
10.3.1 General .6
10.3.2 Strain rate for the determination of the upper yield strength (R ) or proof
eH
strength properties (R and, if required, R ) .6
p t
10.3.3 Strain rate for the determination of the lower yield strength (R ) and
eL
percentage yield point extension (A ), if required .7
e
10.3.4 Strain rate for the determination of the tensile strength (R ), percentage
m
elongation after fracture (A), percentage reduction area (Z), and, if required,
percentage total extension at the maximum force (A ), percentage plastic
gt
extension at maximum force (A ).7
g
10.4 Method of testing with expanded strain rate ranges (Method B) .7
10.4.1 General .7
10.4.2 Rate for the determination of yield strength or proof strength properties .7
10.4.3 Rate for the determination of tensile strength .8
10.5 Choice of the method and rates .8
10.6 Documentation of the chosen testing conditions .8
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 ISO 6892-1:2016, Annexes B and D .11
Annex B (informative) Measurement uncertainty . 17
Bibliography .20

iii
ISO/DIS 6892-2:2025(en)
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).
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. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following URL:
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.
This second edition cancels and replaces the first edition (ISO 6892-2:2011), of which it constitutes a minor
revision.
The main changes compared to the previous edition are as follows:
— a note has been added after the first sentence of 10.2.1;
— some references to subclauses of ISO 6892-1 have been deleted.
A list of all parts in the ISO 6892 series can be found on the ISO website.

iv
ISO/DIS 6892-2:2025(en)
Introduction
In this document, 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 document 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 document, it was decided to
consider deleting the stress rate method in future revisions.

v
DRAFT International Standard ISO/DIS 6892-2:2025(en)
Metallic materials — Tensile testing —
Part 2:
Method of test at elevated temperature
WARNING — This document calls for the use of substances and/or procedures that can be injurious
to health if adequate safety measures are not taken. This document does not address any health
hazards, safety or environmental matters associated with its use. It is the responsibility of the user
of this document to establish appropriate health, safety and environmentally acceptable practices.
1 Scope
This document specifies a method of tensile testing of metallic materials at temperatures higher than room
temperature.
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.
ISO 6892-1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 6892-1 apply with the following
exceptions and supplements.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
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 typically determined at elevated temperature unless other properties defined
in ISO 6892-1 are required by relevant specifications or agreement:
— proof strength, plastic extension (R );
p
— tensile strength (R );
m
— percentage elongation after fracture (A);
— percentage reduction of area (Z).

ISO/DIS 6892-2:2025(en)
3.1
original gauge length
L
o
Distance between gauge length marks on the test piece 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 )
u o
Note 1 to entry: It is expressed as a percentage of the original gauge length (L ) (3.1).
o
Note 2 to entry: For further details, see ISO 6892-1.
3.3
extensometer gauge length
L
e
length within the parallel portion of the test piece used for the measurement of extension (3.4) by means of
an extensometer
3.4
extension
increase in the extensometer gauge length (L ) (3.3) at a given moment during the test
e
3.5
percentage extension
extension (3.4) expressed as a percentage of the extensometer gauge length (L ) (3.3)
e
3.6
percentage reduction of area
Z
maximum change in cross-sectional area which has occurred during the test (S − S )
o u
Note 1 to entry: It is expressed as a percentage of the original cross-sectional area (S ), where S and S are calculated
o o u
from the dimensions at 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 1 to entry: All stresses referred to in this document 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 provides an extensive listing of symbols and their related designations.
The additional symbols used in this document are given in Table 1.

ISO/DIS 6892-2:2025(en)
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
i
test piece
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.
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.
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.
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 fluctuations
in air flow and room temperature, to 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/DIS 6892-2:2025(en)
9.3 Heating device system
The heating device system consists from several parts
— heating device (e. g. furnace or oven)
— temperature controller
— temperature measuring system
The heating device system for the test piece shall be capable of heating the test piece to the specified
temperature, T.
9.3.1 Permitted deviations of temperature
The indicated temperatures, T , are the temperatures measured on the surface of the parallel length of the
i
test piece with corrections applied for any known systematic errors (verified bias).
The permitted deviations between the specified temperature, T, and the indicated temperatures, T , and the
i
maximum permissible temperature difference within the entire parallel length of the test piece are given in
Table 2. The laboratory shall verify that the permitted deviations are fulfilled at the end of the soaking time
to the start of the test. The measured temperature should be recorded during the complete test to identify
deviations.
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
i
differences along the test piece
Maximum permissible
Specified temperature, T Permitted deviation between T and T temperature differences along
i
°C °C the test piece
°C
T ≤ 600 ±3 3
600 < T ≤ 800 ±4 4
800 < T ≤ 1 000 ±5 5
1 000 < T ≤ 1 100 ±6 6
9.3.2 Measurement of temperature
When the parallel length is less than 50 mm, one temperature sensor shall measure the temperature at
each end of the parallel length directly. When the parallel 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 Temperature-measuring system
The temperature-measuring system shall have a resolution equal to or better than 1 °C and a measurement
unc
...