ISO 3887
(Main)Steels — Determination of the depth of decarburization
Steels — Determination of the depth of decarburization
ISO 3887:2017 defines the decarburization and specifies three methods of measuring the depth of decarburization of steel products.
Aciers — Détermination de la profondeur de décarburation
L'ISO 3887 :2017 définit la décarburation et spécifie trois méthodes de mesure de la profondeur de décarburation des produits acier.
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FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 3887
ISO/TC 17/SC 7
Steels — Determination of the depth
Secretariat: AFNOR
of decarburization
Voting begins on:
2023-05-25
Aciers — Détermination de la profondeur de décarburation
Voting terminates on:
2023-08-17
ISO/CEN PARALLEL PROCESSING
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Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 3887:2023(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
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NATIONAL REGULATIONS. © ISO 2023
---------------------- Page: 1 ----------------------
ISO/FDIS 3887:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 3887
ISO/TC 17/SC 7
Steels — Determination of the depth
Secretariat: AFNOR
of decarburization
Voting begins on:
Aciers — Détermination de la profondeur de décarburation
Voting terminates on:
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
ISO/CEN PARALLEL PROCESSING
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.
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DOCUMENTATION.
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Reference number
Email: copyright@iso.org
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
ISO/FDIS 3887:2023(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
© ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023
---------------------- Page: 2 ----------------------
ISO/FDIS 3887:2023(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling . 2
5 Measuring methods . 2
5.1 General . 2
5.2 Metallographic method . 3
5.2.1 General . 3
5.2.2 Selection and preparation of the sample . 3
5.2.3 Measurement . 3
5.3 Methods for measuring the microindentation hardness . 5
5.3.1 General . 5
5.3.2 Selection and preparation of the sample . 6
5.3.3 Measurement . 6
5.4 Methods of determination of the carbon content . 7
5.4.1 General . 7
5.4.2 Chemical analysis . 8
5.4.3 Spectrographic analysis. 8
5.4.4 Interpretation of the results (chemical and spectrographic methods) . 8
5.4.5 Electron probe microanalysis (EPMA) . 8
5.4.6 Glow discharge optical emission spectrometry (GDOES) . 9
6 Test report . 9
Annex A (informative) Examples of typical decarburization microstructure .11
iii
© ISO 2023 – All rights reserved
---------------------- Page: 3 ----------------------
ISO/FDIS 3887:2023(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 nongovernmental, 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 document 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 17, Steel, Subcommittee SC 7, Methods
of testing (other than mechanical tests and chemical analysis), in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 459, Non-alloy carbon ferrous
scrap categories and related specifications, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 3887:2017), which has been revised.
The main change is as follows:
— In 5.2.1 a NOTE was added concerning the use of automatic image analysis.
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
© ISO 2023 – All rights reserved
---------------------- Page: 4 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 3887:2023(E)
Steels — Determination of the depth of decarburization
1 Scope
This document defines the decarburization and specifies three methods of measuring the depth of
decarburization of steel products.
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 45451, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 65071, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 9556, Steel and iron — Determination of total carbon content — Infrared absorption method after
combustion in an induction furnace
ISO 14594, Microbeam analysis — Electron probe microanalysis — Guidelines for the determination of
experimental parameters for wavelength dispersive spectroscopy
ISO 14707, Surface chemical analysis — Glow discharge optical emission spectrometry (GD-OES) —
Introduction to use
ISO 153492, Unalloyed steel — Determination of low carbon content — Part 2: Infrared absorption method
after combustion in an induction furnace (with preheating)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
decarburization
reduction of carbon content from the surface zone of the steel
Note 1 to entry: A distinction is made between
a) partial decarburization, d , measured as the distance from the point at which the carbon content exceeds
3
the solubility limit in ferrite, becoming visible as, e.g. pearlite, to the point at which there is no more visible
difference to the core carbon concentration, and
b) complete decarburization, also called ferrite decarburization, d , measured as the distance between the
1
surface of the product and the point up to which the carbon content is below the solubility limit of carbon in
ferrite so that only ferrite is present.
Note 2 to entry: The depth of complete decarburization as described in b) is determined by examination of the
microstructure.
1
© ISO 2023 – All rights reserved
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ISO/FDIS 3887:2023(E)
3.2
depth of functional decarburization
d
2
distance between the surface of the product and the point at which the carbon content or hardness is at
the level where the performance of the product would be unaffected by a reduction in carbon content
(i.e. at the minimum level specified in the product standard)
3.3
depth of total decarburization
d
4
distance between the surface of the product and the point at which the carbon content is that of the
unaffected core, the sum of the partial and the complete decarburization (3.1) d + d being designated
3 1
by the letters DD
EXAMPLE DD = 0,08 mm.
Note 1 to entry: Expressed in millimetres.
3.4
depth profile of carbon content
curve indicating the relationship between the perpendicular distance from the surface of steel material
and the carbon content
3.5
depth profile of hardness
curve indicating the relationship between the perpendicular distance from the surface of steel material
and the hardness
4 Sampling
Samples should be taken at locations that are representative of the bulk specimen. The location
and number of samples taken depend on the nature of the material to be tested and are defined by
agreement between the parties concerned.
Specimens for the metallographic methods or microindentation hardness tests or electron probe
microanalysis should be cut from the bulk specimen perpendicular to the longitudinal axis of the product
so that measurements are made on a transverse plane. This procedure permits the determination of
the variation of decarburization around the periphery of the specimen. Unless otherwise specified, the
corner parts which can generate abnormal decarburization shall not be included. For specimens up to
about 2,5 cm diameter, the entire cross-section is polished and examined. For larger cross-sections,
one or more specimens shall be prepared to assess variations in surface decarburization. The sampling
scheme for large sections should be determined by agreement between the parties concerned.
Specimens for chemical analytical methods shall be of sufficient length so that the weight of incremental
turnings is adequate for chemical analysis or the size of milled surfaces is large enough for sparking yet
small enough to fit in the specimen holder.
5 Measuring methods
5.1 General
The choice of the method and its accuracy depend on the degree of decarburization, the microstructure,
the carbon content of the product examined and the shape of the component.
The usual methods employed on finished products are as follows:
— metallographic method (see 5.2);
2
© ISO 2023 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/FDIS 3887:2023(E)
— method for measuring the microindentation hardness (Vickers or Knoop) for steels in the hardened
or quenched and tempered condition (see 5.3);
— method for the determination of the carbon content by chemical analysis (see 5.4.2), spectrographic
analysis (see 5.4.3), electron probe microanalysis (EPMA) (see 5.4.5), or glow discharge optical
emission spectrometry (GDOES) (see 5.4.6).
The sample shall be examined in the as-delivered condition. Nevertheless if, by agreement between
the parties concerned, a supplementary heat treatment is applied, every precaution shall be taken to
prevent changes in mass percentage and/or in the distribution of carbon, e.g. a small sample, a short
austenitization time, a neutral atmosphere.
The measuring method shall be agreed upon in writing by the parties concerned, unless it is defined
in the product standard. In the absence of any agreement or requirement in a product standard, the
metallographic method should be used.
5.2 Metallographic method
5.2.1 General
Unless otherwise specified, this method shall only be applied in situations where changes in the carbon
content are reflected by resulting variations in microstructure.
This method is especially valid for steels showing an annealed, normalized, as-rolled or as-forged
structure. It may apply, with reservations, for products showing a hardened or tempered structure
where the interpretation of the structural variations becomes difficult.
NOTE Automatic image analysis can be used to measure the depth of decarburization. Preferably, the
accuracy of the methods is previously proven by an extensive cross correlation.
5.2.2 Selection and preparation of the sample
The metallographic polishing, carried out by a
...
ISO/TC 17/SC 7
Date: 2023-03
ISO/FDIS 3887:2023(E)
ISO/TC 17/SC 7
Secretariat: AFNOR
Date: 2023-05-10
Steels — Determination of the depth of decarburization
Aciers — Détermination de la profondeur de décarburation
Edited DIS - MUST BE USED FOR FINAL DRAFT
FDIS stage
© ISO 2023 —– All rights reserved
---------------------- Page: 1 ----------------------
ISO/FDIS 3887:2023(E)
© ISO 2023
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
EmailE-mail: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland
© ISO 2023 — All rights reserved
---------------------- Page: 2 ----------------------
ISO/FDIS 3887:2023(E)
Contents
Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling . 2
5 Measuring methods . 2
5.1 General . 2
5.2 Metallographic method . 3
5.2.1 General . 3
5.2.2 Selection and preparation of the sample . 3
5.2.3 Measurement . 3
5.3 Methods for measuring the micro-indentation hardness . 5
5.3.1 General . 5
5.3.2 Selection and preparation of the sample . 7
5.3.3 Measurement . 7
5.4 Methods of determination of the carbon content . 9
5.4.1 General . 9
5.4.2 Chemical analysis . 9
5.4.3 Spectrographic analysis . 10
5.4.4 Interpretation of the results (chemical and spectrographic methods) . 10
5.4.5 Electron probe microanalysis (EPMA) . 10
5.4.6 Glow discharge optical emission spectrometry (GDOES) . 10
6 Test report . 11
Annex A (informative) Examples of typical decarburization microstructure . 12
© ISO 2023 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/FDIS 3887:2023(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.
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 documentsdocument 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 drawnISO draws attention to the possibility that some of the elementsimplementation of this
document may beinvolve the subjectuse 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. 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 ).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation onof 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.htmlthe following URL: .
This document was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of
testing (other than mechanical tests and chemical analysis), in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/TC 459, Non-alloy carbon ferrous scrap categories
and related specifications, in accordance with the Agreement on technical cooperation between ISO and
CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 3887:2017), which has been revised. The
main change is as follows:
The main change is as follows:
— — In 5.2.15.2.1 a NoteNOTE was added concerning the use of automatic image analysis.
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 © ISO 2023 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/FDIS 3887:2023(E)
Steels — Determination of the depth of decarburization
1 Scope
This document defines the decarburization and specifies three methods of measuring the depth of
decarburization of steel products.
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 4545--1, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 6507--1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 9556, Steel and iron — Determination of total carbon content — Infrared absorption method after
combustion in an induction furnace
ISO 14594, Microbeam analysis — Electron probe microanalysis — Guidelines for the determination of
experimental parameters for wavelength dispersive spectroscopy
ISO 14707, Surface chemical analysis — Glow discharge optical emission spectrometry (GD-OES) —
Introduction to use
ISO 15349--2, Unalloyed steel — Determination of low carbon content — Part 2: Infrared absorption
method after combustion in an induction furnace (with preheating)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminologicalterminology databases for use in standardization at the following
addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1
decarburization
reduction of carbon content from the surface zone of the steel
Note 1 to entry: A distinction is made between
a) a) partial decarburization, d , measured as the distance from the point at which the carbon content
3
exceeds the solubility limit in ferrite, becoming visible as, e.g. pearlite, to the point at which there is
no more visible difference to the core carbon concentration, and
b) b) complete decarburization, also called ferrite decarburization, d , measured as the distance
1
between the surface of the product and the point up to which the carbon content is below the
solubility limit of carbon in ferrite so that only ferrite is present.
Note 2 to entry: The depth of complete decarburization as described in b) is determined by examination of the
microstructure.
© ISO 2023 —– All rights reserved 1
---------------------- Page: 5 ----------------------
ISO/FDIS 3887:2023(E)
3.2
depth of functional decarburization
d
2
distance between the surface of the product and the point at which the carbon content or hardness is at
the level where the performance of the product would be unaffected by a reduction in carbon content (i.e.
at the minimum level specified in the product standard)
3.3
depth of total decarburization
d
4
distance between the surface of the product and the point at which the carbon content is that of the
unaffected core, the sum of the partial and the complete decarburization (3.1)d + d being designated by
3 1
the letters DD
EXAMPLE : DD = 0,08 mm.
Note 1 to entry: Expressed in millimetres.
3.4
depth profile of carbon content
curve indicating the relationship between the perpendicular distance from the surface of steel material
and the carbon content
3.5
depth profile of hardness
curve indicating the relationship between the perpendicular distance from the surface of steel material
and the hardness
4 Sampling
Samples should be taken at locations that are representative of the bulk specimen. The location and
number of samples taken depend on the nature of the material to be tested and are defined by agreement
between the parties concerned.
Specimens for the metallographic methods or micro-indentation hardness tests or electron probe
microanalysis should be cut from the bulk specimen perpendicular to the longitudinal axis of the product
so that measurements are made on a transverse plane. This procedure permits the determination of the
variation of decarburization around the periphery of the specimen. Unless otherwise specified, the corner
parts which can generate abnormal decarburization shall not be included. For specimens up to about
2,5 cm diameter, the entire cross-section is polished and examined. For larger cross-sections, one or more
specimens shall be prepared to assess variations in surface decarburization. The sampling scheme for
large sections should be determined by agreement between the parties concerned.
Specimens for chemical analytical methods shall be of sufficient length so that the weight of incremental
turnings is adequate for chemical analysis or the size of milled surfaces is large enough for sparking yet
small enough to fit in the specimen holder.
5 Measuring methods
5.1 General
The choice of the method and its accuracy depend on the degree of decarburization, the microstructure,
the carbon content of the product examined and the shape of the component.
The usual methods employed on finished products are as follows:
— — metallographic method (see 5.25.2););
2 © ISO 2023 —– All rights reserved
---------------------- Page: 6 ----------------------
ISO/FDIS 3887:2023(E)
— — method for measuring the micro-indentation hardness (Vickers or Knoop) for steels in the
hardened or quenched and tempered condition (see 5.35.3););
— — method for the determination of the carbon content by chemical analysis (see 5.4.25.4.2),),
spectrographic analysis (see 5.4.35.4.3),), electron probe microanalysis (EPMA) (see 5.4.55.4.5),), or
glow discharge optical emission spectrometry (GDOES) (see 5.4.65.4.6).).
The sample shall be examined in the as-delivered condition. Nevertheless if, by agreement between the
parties concerned, a supplementary heat treatment is applied, every precaution shall be taken to prevent
changes in mass percentage and/or in the distribution of carbon, e.g. a small sample, a short
austenitization time, a neutral atmosphere.
The measuring method shall be agreed upon in writing by the parties concerned, unless it is defined in
the product standard. In the absence of any agreement or requirement in a product standard, the
metallographic method should be used.
5.2 Metallographic method
5.2.1 General
Unless otherwise specified, this method shall only be applied in situations where changes in the carbon
content are reflected by resulting variations in microstructure.
This method is especially valid for steels showing an annealed, normalized, as-rolled or as-forged
structure. It may apply, with reservations, for products showing a hardened or tempered structure where
the interpretation of the structural variations becomes difficult.
NoteNOTE Automatic image analysis can be used to measure the depth of decarburization. Preferably, the accuracy
of the methods is previously proven by an extensive cross correlation.
5.2.2 Selection and preparation of the sample
The metallographic polishing, carried out by applying the usual methods, shall not round the edges. In
order to achieve this, the sample may be mounted or held in a clamp, and the surface of the product may,
if necessary, be protected by a metallic deposit obtained by electroless or electrolytic plating.
Automatic/semi-automatic preparation techniques should be used, where possible.
Etching in a solution of 1,5 % to 4 % nitric acid in ethanol (nital) or 2 % to 5 % picric acid in
ethanol(picral) will reveal the structure of the steel.
5.2.3 Measurement
As a rule, the reduction in the carbon content can be determined for the following:
a) a) ferrite and pearlite: from the decrease in the amount of pearlite;
b) b) pearlite and hypereutectoidally developed carbides: from the decrease in the amount of
hypereutectoidally developed carbides and/or of pearlite;
c) c) ferrite mat
...
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