oSIST prEN ISO 4885:2025

SLOVENSKI STANDARD
01-december-2025
Železove zlitine - Toplotna obdelava - Slovar (ISO/DIS 4885:2025)
Ferrous materials - Heat treatments - Vocabulary (ISO/DIS 4885:2025)
Eisenwerkstoffe - Wärmebehandlung - Begriffe (ISO/DIS 4885:2025)
Matériaux ferreux - Traitements thermiques - Vocabulaire (ISO/DIS 4885:2025)
Ta slovenski standard je istoveten z: prEN ISO 4885
ICS:
01.040.77 Metalurgija (Slovarji) Metallurgy (Vocabularies)
25.200 Toplotna obdelava Heat treatment
77.140.01 Železni in jekleni izdelki na Iron and steel products in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 4885
ISO/TC 17
Ferrous materials — Heat
Secretariat: JISC
treatments — Vocabulary
Voting begins on:
Matériaux ferreux — Traitements thermiques — Vocabulaire
2025-10-10
Voting terminates on:
ICS: 01.040.77; 01.040.25; 25.200; 77.140.01
2026-01-02
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
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This document has not been edited by the ISO Central Secretariat.
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Reference number
ISO/DIS 4885:2025(en)
DRAFT
ISO/DIS 4885:2025(en)
International
Standard
ISO/DIS 4885
ISO/TC 17
Ferrous materials — Heat
Secretariat: JISC
treatments — Vocabulary
Voting begins on:
Matériaux ferreux — Traitements thermiques — Vocabulaire
ICS: 01.040.77; 01.040.25; 25.200; 77.140.01 Voting terminates on:
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 has not been edited by the ISO Central 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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BE CONSIDERED IN THE LIGHT OF THEIR
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Published in Switzerland Reference number
ISO/DIS 4885:2025(en)
ii
ISO/DIS 4885:2025(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms .1
3.2 Terms related to annealing and normalizing . 12
3.3 Terms related to quenching .16
3.4 Terms related to tempering and partitioning .19
3.5 Terms related to ageing .21
3.6 Terms related to surface heat treatment . 22
3.7 Terms related to thermochemical treatment . 23
3.8 Terms related to structure . 33
3.9 Terms related to defects . 38
Annex A (informative) Equivalent terms .42
Bibliography .58
Index .59

iii
ISO/DIS 4885:2025(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
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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.
The document was prepared by Technical Committee ISO/TC17,Steel.

iv
DRAFT International Standard ISO/DIS 4885:2025(en)
Ferrous materials — Heat treatments — Vocabulary
1 Scope
This document defines important terms used in the heat treatment of ferrous materials.
Annex A provides an alphabetical list of terms defined in this document, as well as their equivalents in
French, German, Russian, Chinese and Japanese.
Table 1 shows the various iron-carbon (Fe-C) phases.
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 18203:2016, Steel — Determination of the thickness of surface-hardened layers
3 Terms and definitions
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
There are 3 types of terms specified in this document, preferred terms, admitted terms and deprecated
terms. Preferred terms are the primary terms for a given concept. The preferred term is the form which is
used throughout the main body of the text. If there is more than one preferred term, only one of the preferred
terms shall be used except in the case where both a full form and an abbreviated form are preferred terms (in
which case they may be used interchangeably). Preferred terms are written in bold type (with the exception
of symbols, which shall be presented as used in running text). Admitted terms are accepted synonyms for
the preferred term. They are written in regular type. Deprecated terms are synonyms of the preferred term,
which are no longer in use or whose use is discouraged. They are written in regular type.
There can be more than one term of each type. An abbreviated term or a symbol can constitute a term.
EXAMPLE
3.1 General terms
3.1.1
accelerated cooling
method of cooling in the rolling process and which aims at conditioning the crystal structure of steels and
improving the mechanical properties by means of rolling followed by cooling down through the temperature
range for transformation with a greater speed than that of air-cooling
Note 1 to entry: This does not include the cooling method for quenching which merely cools rapidly on a rolling line
using the accelerated cooling equipment.
Note 2 to entry: Cooling for equipment protection, capability compensation of cooling bed, etc are not included in the
accelerated cooling because they do not affect mechanical properties of steel.
Note 3 to entry: Accelerated cooling is frequently used for tubes, forgings and thick plates.

ISO/DIS 4885:2025(en)
3.1.2
austenitizing
heating (3.1.37) a ferrous material above A or A temperature and soaking (3.1.57) for enough time to form
1 3
partial or complete austenite
Note 1 to entry: Complete austenitizing takes place above A temperature, while partial austenitizing takes place
between A and A temperatures.
1 cm
Note 2 to entry: The minimum temperature and the length of the soaking time required depend on the steel
composition, the initial microstructure and the heating conditions used.
3.1.3
austenitizing temperature
temperature at which the ferrous material is maintained during austenitizing (3.1.2)
3.1.4
bake hardening steel
steel with the ability to gain an increase of yield strength after a plastic pre-strain and a subsequent heat
treatment (3.1.35) in the usual industrial paint processes (in the region of 170 °C for 20 min)
Note 1 to entry: These steels have a good suitability for cold forming and present a high resistance to plastic straining
(which is increased on finished parts during heat treatment (3.1.35) and a good dent resistance.
3.1.5
cast iron
alloy of iron, carbon and silicon where the carbon content is approximately more than 2 %
3.1.6
characteristic cooling curve
diagram showing the variations of cooling rate in the core of a specimen with temperature
Note 1 to entry: Characteristic cooling curve reflects the cooling capacity of a specimen in a cooling medium at
different temperatures.
3.1.7
controlled atmosphere
furnace atmosphere (3.1.31) of which composition may be controlled for the purpose of oxidation or
reduction, carbonization or decarbonization
Note 1 to entry: The main purpose of controlled atmosphere is to effectively carry out thermo-chemical treatment such
as carburizing and carbonitriding, and to prevent oxidation or decarburization of ferrous materials during heating.
3.1.8
controlled atmosphere heat treatment
heat treatment carried out in a controlled atmosphere to achieve non-oxidation and non-decarburization, or
carburizing (nitriding) as required
Note 1 to entry: Heat treatment in a protective atmosphere or inert gas is also called protective atmosphere heat
treatment.
3.1.9
controlled cooling
cooling according to the predetermined cooling schedule during heat treatment
3.1.10
controlled rolling
rolling process where rolling temperature and reduction are controlled to achieve enhanced mechanical
properties
Note 1 to entry: Examples of controlled rolling are normalizing rolling (3.1.73), thermomechanical rolling (3.1.64).
Note 2 to entry: Contro
...