prEN ISO 4491-1

Metallic powders - Determination of oxygen content by reduction methods - Part 1: General guidelines (ISO/FDIS 4491-1:2022)

This document is the first part of a series of standards dealing with the determination of oxygen content in metallic powders by reduction methods. It specifies general guidance to these methods and gives some recommendations for the correct interpretation of the results obtained.
The test methods are applicable generally to all powders of metals, alloys, carbides and mixtures thereof. The constituents of the powder shall be non-volatile under the conditions of test. The powder shall be free of lubricant or organic binder.
However, there exist certain limitations which depend upon the nature of the analysed metal. These limitations are discussed in Clause 4.

Metallpulver - Bestimmung des Sauerstoffgehaltes durch Reduktionsverfahren - Teil 1: Allgemeine Hinweise (ISO/FDIS 4491‑1:2022)

Dieses Dokument ist das erste Dokument aus einer Reihe von Normen, die die Bestimmung des Sauerstoffgehalts in Metallpulvern durch Reduktionsverfahren behandelt. Es legt allgemeine Hinweise zu diesen Verfahren fest und enthält einige Empfehlungen für die korrekte Auswertung der erhaltenen Ergebnisse.
Die Prüfverfahren gelten in der Regel für alle Pulver aus Metallen, Legierungen, Carbiden und deren Mischungen. Die Pulverbestandteile dürfen unter den Versuchsbedingungen nicht flüchtig sein. Das Pulver muss frei von Gleitmitteln oder organischen Bindemitteln sein.
Es bestehen jedoch gewisse Beschränkungen aufgrund der Art des analysierten Metalls. Diese Beschränkungen werden in Abschnitt 4 behandelt.

Poudres métalliques - Dosage de l'oxygène par les méthodes de réduction - Partie 1: Directives générales (ISO/FDIS 4491-1:2022)

Le présent document est la première partie d’une série de normes qui traitent du dosage par réduction de l’oxygène dans les poudres métalliques. Il donne des directives générales d’emploi des méthodes de réduction et des recommandations quant à l’interprétation correcte des résultats obtenus.
Les méthodes d’essai sont applicables d’une façon générale à toutes les poudres de métaux, d’alliages, de carbures et de mélanges de ces éléments. Les constituants de la poudre doivent être non volatils dans les conditions de l’essai. La poudre ne doit renfermer ni lubrifiant, ni liant organique.
II existe néanmoins certaines limites liées à la nature du métal analysé. Ces limites sont étudiées dans l’Article 4.

Kovinski praški - Določevanje kisika z metodami redukcije - 1. del: Splošne smernice (ISO/FDIS 4491-1:2022)

General Information

• Status: Not Published
• Publication Date: 18-Jan-2024
• ICS: 77.160 - Powder metallurgy
• Technical Committee: CEN/SS M11 - Powder metallurgy
• Drafting Committee: CEN/SS M11 - Powder metallurgy
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Start Date: 28-Mar-2023
• Completion Date: 28-Mar-2023
• Ref Project: oSIST prEN ISO 4491-1:2023 - Metallic powders - Determination of oxygen content by reduction methods - Part 1: General guidelines (ISO/FDIS 4491-1:2022)

Relations

• Revises: EN 24491-1:1993 - Metallic powders - Determination of oxygen content by reduction methods - Part 1: General guidelines (ISO 4491-1:1989)
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 4491-1:2023
01-februar-2023
Kovinski praški - Določevanje kisika z metodami redukcije - 1. del: Splošne
smernice (ISO/FDIS 4491-1:2022)

Metallic powders - Determination of oxygen content by reduction methods - Part 1:

General guidelines (ISO/FDIS 4491-1:2022)
Metallpulver - Bestimmung des Sauerstoffgehaltes durch Reduktionsverfahren -
Allgemeine Hinweise (ISO/FDIS 4491-1:2022)

Poudres métalliques - Dosage de l'oxygène par les méthodes de réduction - Partie 1:

Directives générales (ISO/FDIS 4491-1:2022)
Ta slovenski standard je istoveten z: prEN ISO 4491-1
ICS:
77.160 Metalurgija prahov Powder metallurgy
oSIST prEN ISO 4491-1:2023 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 4491-1:2023
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oSIST prEN ISO 4491-1:2023
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 4491-1
ISO/TC 119/SC 2
Metallic powders — Determination
Secretariat: SIS
of oxygen content by reduction
Voting begins on:
2022-12-05 methods —
Voting terminates on:
Part 1:
2023-02-27
General guidelines
Poudres métalliques — Dosage de l'oxygène par les méthodes de
réduction —
Partie 1: Directives générales
ISO/CEN PARALLEL PROCESSING
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 4491-1:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2022
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oSIST prEN ISO 4491-1:2023
ISO/FDIS 4491-1:2022(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 4491-1
ISO/TC 119/SC 2
Metallic powders — Determination
Secretariat: SIS
of oxygen content by reduction
Voting begins on:
methods —
Voting terminates on:
Part 1:
General guidelines
Poudres métalliques — Dosage de l'oxygène par les méthodes de
réduction —
Partie 1: Directives générales
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
ISO/CEN PARALLEL PROCESSING

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or ISO’s member body in the country of the requester.
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ISO copyright office
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OF ANY RELEVANT PATENT RIGHTS OF WHICH
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DOCUMENTATION.
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Reference number
Email: [e-mail]
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 4491-1:2022(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
© ISO 2022 – All rights reserved
NATIONAL REGULATIONS. © ISO 2022
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oSIST prEN ISO 4491-1:2023
ISO/FDIS 4491-1:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 cope .................................................................................................................................................................................................................................... 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

5 Meaning of the results according to the method used................................................................................................. 2

5.1 Hydrogen as a reducing agent ................................................................................................................................................... 2

5.2 Carbon as a reducing agent: reduction extraction method ............................................................................ 3

6 Summary of the implementation of methods for oxygen determination by reduction ...........3

7 Practical application of the standard methods ................................................................................................................... 4

iii
© ISO 2022 – All rights reserved
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oSIST prEN ISO 4491-1:2023
ISO/FDIS 4491-1:2022(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 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 119, Powder metallurgy, Subcommittee

SC 2, Sampling and testing methods for powders (including powders for hardmetals), in collaboration

with the European Committee for Standardization (CEN) Technical Committee CEN/SS M11, Powder

metallurgy, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna

Agreement).

This second edition cancels and replaces the first edition (ISO 4491-1:1989), of which it constitutes a

minor revision.
The main changes are as follows:
— the normative references in Clause 2 have been updated;
— Clause 6 and 7 have changed place;
— editorial corrections and updated ISO format have been applied.
A list of all parts in the ISO 4491 series can be found on the ISO website.

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.
© ISO 2022 – All rights reserved
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oSIST prEN ISO 4491-1:2023
ISO/FDIS 4491-1:2022(E)
Introduction

In powder metallurgy, the purity of the powders is an important parameter for the manufacture of

sintered metals. Among the various impurities which may be present in a powder, oxygen plays a

particular role as it is always present in any metal or alloy powder, and in amounts greater than those

encountered in compact metals. Oxygen is mostly combined in the form of oxides which appear in the

following ways:

— Oxide film coatings on particle surfaces, spontaneously formed by oxidation of the metal by air or

moisture during powder preparation and during handling and storage.

— Oxide inclusions, being either oxides of the main metal remaining locally unreduced during the

production process (in the case of reduced powders), or other oxide impurities originating from

the raw material and/or from the equipment (e.g. refractory ceramics from melting furnace in

atomization processes).

In practice, oxygen contents in metallic powders lie mostly in the range of a mass fraction of 0,1 % to a

mass fraction of 1 %.

The determination of oxygen content can be made by means of many physical or chemical methods, for

example:

a) specific methods, such as activation analysis or mass spectrometry, in which the element 0 is

directly determined;

b) reduction methods, in which oxides present are, totally or partially, reduced by hydrogen or by

carbon. Oxygen content is related, either to the loss of mass of the sample through reduction, or to

the amount of water or CO/C0 produced by the reaction;
c) separation methods, in which:

— either the oxide phase is selectively dissolved and determined chemically (for example in copper

powder, where copper oxide is dissolved by hydrochloric acid); or

— the metal phase is selectively dissolved, and the insoluble residue (assumed to be oxide) is

evaluated (for example in aluminium powder, aluminium is dissolved in bromine-methanol

reagent,
...