SIST EN ISO 643:2020
(Main)Steels - Micrographic determination of the apparent grain size (ISO 643:2019, Corrected version 2020-03)
Steels - Micrographic determination of the apparent grain size (ISO 643:2019, Corrected version 2020-03)
EN-ISO 643 specifies a micrographic method of determining apparent ferritic oraustenitic grain size in steels. It describes the methods of revealing grainboundaries and of estimating the mean grain size of specimens with unimodal sizedistribution. Although grains are three-dimensional in shape, the metallographicsectioning plane can cut through a grain at any point from a grain corner, tothe maximum diameter of the grain, thus producing a range of apparent grainsizes on the two-dimensional plane, even in a sample with a perfectly consistentgrain size.
Stahl - Mikrophotographische Bestimmung der erkennbaren Korngröße (ISO 643:2019, korrigierte Fassung 2020-03)
Dieses Dokument legt mikrophotographische Verfahren zur Bestimmung der erkennbaren Ferrit oder Austenitkorngröße von Stählen fest. Es werden Verfahren zum Sichtbarmachen der Korngrenzen und zur Schätzung der mittleren Korngröße von Proben mit einer gleichmäßigen Größenverteilung beschrieben. Obwohl die Körner dreidimensional sind, können sie durch eine metallographische Schnittebene an einem beliebigen Punkt am Rand eines Korns bis einschließlich durch seinen größten Durchmesser so durchschnitten werden, dass auch in einer Probe mit völlig konstanter Korngröße in der zweidimensionalen Ebene eine erkennbare Bandbreite von Korngrößen erzeugt wird.
Aciers - Détermination micrographique de la grosseur de grain apparente (ISO 643:2019, Version corrigée 2020-03)
La présente document spécifie une méthode de détermination micrographique de la grosseur apparente du grain ferritique ou austénitique des aciers. Elle décrit les méthodes de mise en évidence des joints de grains et d'estimation de la grosseur moyenne de grain d'un échantillon ayant une distribution granulométrique unimodale. Bien que les grains soient de forme tridimensionnelle, le plan de la préparation métallographique peut couper un grain en tout point, passant par un coin du grain ou au travers du diamètre maximal du grain ou entre les deux, produisant de ce fait une gamme de grosseurs de grain apparentes sur le plan bidimensionnel, même dans le cas d'un échantillon présentant une grosseur de grain parfaitement cohérente.
Jekla - Mikrografsko določevanje navidezne velikosti kristalnih zrn (ISO 643:2019, popravljena različica 2020-03)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2020
Jekla - Mikrografsko določevanje navidezne velikosti kristalnih zrn (ISO 643:2019,
popravljena različica 2020-03)
Steels - Micrographic determination of the apparent grain size (ISO 643:2019, Corrected
version 2020-03)
Stahl - Mikrophotographische Bestimmung der erkennbaren Korngröße (ISO 643:2019,
korrigierte Fassung 2020-03)
Aciers - Détermination micrographique de la grosseur de grain apparente (ISO
643:2019, Version corrigée 2020-03)
Ta slovenski standard je istoveten z: EN ISO 643:2020
ICS:
77.040.99 Druge metode za Other methods of testing of
preskušanje kovin metals
77.080.20 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 643
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2020
EUROPÄISCHE NORM
ICS 77.040.99 Supersedes EN ISO 643:2012
English Version
Steels - Micrographic determination of the apparent grain
size (ISO 643:2019, Corrected version 2020-03)
Aciers - Détermination micrographique de la grosseur Stahl - Mikrophotographische Bestimmung der
de grain apparente (ISO 643:2019, Version corrigée erkennbaren Korngröße (ISO 643:2019, korrigierte
2020-03) Fassung 2020-03)
This European Standard was approved by CEN on 26 October 2018.
This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 08 April 2020.
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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 643:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 643:2020) has been prepared by Technical Committee ISO/TC 17 "Steel" in
collaboration with Technical Committee CEN/TC 459/SC 1 “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 July 2020, and conflicting national standards shall be
withdrawn at the latest by July 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 643:2012.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 643:2019, Corrected version 2020-03 has been approved by CEN as EN ISO 643:2020
without any modification.
INTERNATIONAL ISO
STANDARD 643
Fourth edition
2019-12
Corrected version
2020-03
Steels — Micrographic determination
of the apparent grain size
Aciers — Détermination micrographique de la grosseur de grain
apparente
Reference number
ISO 643:2019(E)
©
ISO 2019
ISO 643:2019(E)
© ISO 2019
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
ISO 643:2019(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Grains . 1
3.2 General . 2
4 Symbols . 2
5 Principle . 3
6 Selection and preparation of the specimen . 4
6.1 Test location . 4
6.2 Revealing ferritic grain boundaries . 5
6.3 Revealing austenitic and prior-austenitic grain boundaries . 5
6.3.1 General. 5
6.3.2 “Bechet-Beaujard” method by etching with aqueous saturated picric acid
solution . 5
6.3.3 “Kohn” method by controlled oxidation . 6
6.3.4 “McQuaid-Ehn” method by carburization at 925 °C . 7
6.3.5 Proeutectoid ferrite method . 8
6.3.6 Bainite or gradient-quench method . 9
6.3.7 Sensitization of austenitic stainless and manganese steels . 9
6.3.8 Other methods for revealing prior-austenitic grain boundaries . 9
7 Characterization of grain size .10
7.1 Characterization by an index .10
7.1.1 Formulae .10
7.1.2 Assessment by comparison with standard grain size charts .10
7.1.3 Planimetric method .11
7.1.4 Estimation of the index .11
7.2 Characterization by the intercept method .11
7.2.1 Linear intercept segment method .11
7.2.2 Circular intercept segment method .12
7.2.3 Assessment of results .13
8 Test report .14
Annex A (informative) Summary of methods for revealing ferritic, austenitic or prior-
austenitic grain boundaries in steels .15
Annex B (normative) Evaluation method .16
Bibliography .21
ISO 643:2019(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 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 17, Steel, Subcommittee SC 7, Methods of
testing (other than mechanical tests and chemical analysis).
This fourth edition cancels and replaces the third edition (ISO 643:2012), which has been technically
revised. The main changes compared to the previous edition are as follows:
— 7.1.2 has been modified
...
SLOVENSKI STANDARD
01-april-2020
Jekla - Mikrografsko določevanje navidezne velikosti kristalnih zrn (ISO 643:2019)
Steels - Micrographic determination of the apparent grain size (ISO 643:2019)
Stahl - Mikrophotographische Bestimmung der erkennbaren Korngröße (ISO 643:2019)
Aciers - Détermination micrographique de la grosseur de grain apparente (ISO
643:2019)
Ta slovenski standard je istoveten z: EN ISO 643:2020
ICS:
77.040.99 Druge metode za Other methods of testing of
preskušanje kovin metals
77.080.20 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 643
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2020
EUROPÄISCHE NORM
ICS 77.040.99 Supersedes EN ISO 643:2012
English Version
Steels - Micrographic determination of the apparent grain
size (ISO 643:2019)
Aciers - Détermination micrographique de la grosseur Stahl - Mikrophotographische Bestimmung der
de grain apparente (ISO 643:2019) erkennbaren Korngröße (ISO 643:2019)
This European Standard was approved by CEN on 26 October 2018.
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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 643:2020 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 643:2020) has been prepared by Technical Committee ISO/TC 17 "Steel" in
collaboration with Technical Committee CEN/TC 459/SC 1 “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 July 2020, and conflicting national standards shall be
withdrawn at the latest by July 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 643:2012.
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, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 643:2019 has been approved by CEN as EN ISO 643:2020 without any modification.
INTERNATIONAL ISO
STANDARD 643
Fourth edition
2019-12
Steels — Micrographic determination
of the apparent grain size
Aciers — Détermination micrographique de la grosseur de grain
apparente
Reference number
ISO 643:2019(E)
©
ISO 2019
ISO 643:2019(E)
© ISO 2019
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
ISO 643:2019(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Grains . 1
3.2 General . 2
4 Symbols . 2
5 Principle . 3
6 Selection and preparation of the specimen . 4
6.1 Test location . 4
6.2 Revealing ferritic grain boundaries . 5
6.3 Revealing austenitic and prior-austenitic grain boundaries . 5
6.3.1 General. 5
6.3.2 “Bechet-Beaujard” method by etching with aqueous saturated picric acid
solution . 5
6.3.3 “Kohn” method by controlled oxidation . 6
6.3.4 “McQuaid-Ehn” method by carburization at 925 °C . 7
6.3.5 Proeutectoid ferrite method . 8
6.3.6 Bainite or gradient-quench method . 9
6.3.7 Sensitization of austenitic stainless and manganese steels . 9
6.3.8 Other methods for revealing prior-austenitic grain boundaries . 9
7 Characterization of grain size .10
7.1 Characterization by an index .10
7.1.1 Formulae .10
7.1.2 Assessment by comparison with standard grain size charts .10
7.1.3 Planimetric method .11
7.1.4 Estimation of the index .11
7.2 Characterization by the intercept method .11
7.2.1 Linear intercept segment method .11
7.2.2 Circular intercept segment method .12
7.2.3 Assessment of results .13
8 Test report .14
Annex A (informative) Summary of methods for revealing ferritic, austenitic or prior-
austenitic grain boundaries in steels .15
Annex B (normative) Evaluation method .16
Bibliography .21
ISO 643:2019(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 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 17, Steel, Subcommittee SC 7, Methods of
testing (other than mechanical tests and chemical analysis).
This fourth edition cancels and replaces the third edition (ISO 643:2012), which has been technically
revised. The main changes compared to the previous edition are as follows:
— 7.1.2 has been modified;
— the original Annex B has been deleted and the original Annex C has been renumbered as Annex B.
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 2019 – All rights reserved
...
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