EN ISO 4945:2018

SLOVENSKI STANDARD
01-februar-2019
1DGRPHãþD
SIST EN ISO 4945:2010
-HNOR'RORþHYDQMHGXãLND6SHNWURPHWULþQDPHWRGD,62
Steel - Determination of nitrogen - Spectrophotometric method (ISO 4945:2018)
Stahl - Bestimmung des Stickstoffgehalts - Spektralphotometrisches Verfahren (ISO
4945:2018)
Acier - Détermination de l'azote - Méthode spectrophotométrique (ISO 4945:2018)
Ta slovenski standard je istoveten z: EN ISO 4945:2018
ICS:
77.040.30 Kemijska analiza kovin Chemical analysis of metals
77.080.20 Jekla Steels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 4945
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2018
EUROPÄISCHE NORM
ICS 77.080.20 Supersedes EN ISO 4945:2009
English Version
Steel - Determination of nitrogen - Spectrophotometric
method (ISO 4945:2018)
Acier - Détermination de l'azote - Méthode Stahl - Bestimmung des Stickstoffgehalts -
spectrophotométrique (ISO 4945:2018) Spektralphotometrisches Verfahren (ISO 4945:2018)
This European Standard was approved by CEN on 29 September 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4945:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 4945:2018) has been prepared by Technical Committee ISO/TC 17 "Steel" in
collaboration with Technical Committee ECISS/TC 102 “Methods of chemical analysis for iron and steel
” the secretariat of which is held by SIS.
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 May 2019, and conflicting national standards shall be
withdrawn at the latest by May 2019.
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 4945:2009.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 4945:2018 has been approved by CEN as EN ISO 4945:2018 without any modification.

INTERNATIONAL ISO
STANDARD 4945
Second edition
2018-10
Steel — Determination of nitrogen —
Spectrophotometric method
Acier — Détermination de l'azote — Méthode spectrophotométrique
Reference number
ISO 4945:2018(E)
©
ISO 2018
ISO 4945:2018(E)
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 4945:2018(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Reagents . 2
6 Apparatus . 3
7 Sampling . 3
8 Procedure. 3
8.1 Test portion . 3
8.2 Blank test . 4
8.3 Determination . 4
8.3.1 Dissolution . 4
8.3.2 Treatment of insoluble residue . 4
8.3.3 Steam distillation (see Figure A.1, A.2 or A.3) . 4
8.3.4 Formation of the coloured complex . 5
8.3.5 Spectrophotometric measurements . 5
8.4 Establishment of the calibration curve . 5
8.4.1 Preparation of the calibration solutions . 5
8.4.2 Spectrophotometric measurements . 6
8.4.3 Plotting the calibration curve . 6
9 Expression of results . 6
9.1 Method of calculation . 6
9.2 Precision . 7
10 Test report . 7
Annex A (informative) Examples of distillation apparatus . 8
Annex B (informative) Additional information on the international interlaboratory test.11
Annex C (informative) Graphical representation of precision data .14
Bibliography .15
ISO 4945:2018(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.o rg/patents).
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constitute an endorsement.
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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 1, Methods of
determination of chemical composition.
This second edition cancels and replaces the first edition (ISO 4945:1977), which has been technically
revised. The following changes have been made:
— the scope and applicable range has been expanded as a result of the interlaboratory test;
— addition of copper(II) sulfate pentahydrate for the treatment of the insoluble residue.
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 2018 – All rights reserved

INTERNATIONAL STANDARD ISO 4945:2018(E)
Steel — Determination of nitrogen —
Spectrophotometric method
1 Scope
This document specifies a spectrophotometric method for the determination of nitrogen in steel.
The method is applicable to the determination of nitrogen mass fraction between 0,000 6 % and
0,050 % in low alloy steels and between 0,010 % and 0,050 % in high alloy steels.
The method does not apply to samples containing silicon nitrides or having silicon contents higher
than 0,6 %.
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 t
...