Bsi bs en 24505 1993 (1999) iso 4505 1978

BRITISH STANDARD BS EN 24505 1993 ISO 4505 1978 Specification for Hardmetals — Metallographic determination of porosity and uncombined carbon The European Standard EN 24505 1993 has the status of a Br[.]

BRITISH STANDARD BS EN

24505:1993 ISO 4505:1978

Specification for

Hardmetals —

Metallographic

determination of

porosity and

uncombined carbon

The European Standard EN 24505:1993 has the status of a

British Standard

UDC 669.018.25:620.186

This British Standard, having

been prepared under the

direction of the Iron and

Steel Standards Policy

Committee, was published

under the authority of the

Standards Board and

comes into effect on

15 June 1993

© BSI 12-1999

The following BSI references

relate to the work on this

standard:

Committee reference ISM/65

Special announcement in

BSI News, January 1993

ISBN 0 580 21920 8

Cooperating organizations

The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries:

Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y

France Association française de normalisation Germany Deutsches Institut für Normung e.V

Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland

Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portuguès da Qualidade Spain Asociación Española de Normalización y Certificación Sweden Standardiseringskommissionen i Sverige

Switzerland Association suisse de normalisation United Kingdom British Standards Institution

Amendments issued since publication

Amd No Date Comments

BS EN 24505:1993

Contents

Page

National annex NA (informative) Committees responsible Inside back cover

ii © BSI 12-1999

National foreword

This British Standard has been prepared under the direction of the Iron and Steel Standards Policy Committee and is the English language version of

EN 24505:1993 Hardmetals — Metallographic determination of porosity and

uncombined carbon, published by the European Committee for Standardization (CEN) It is identical with ISO 4505:1978, prepared by Technical Committee 119

“Powder metallurgy”, of the International Organization for Standardization (ISO) with the active participation of the UK

This British Standard supersedes BS 5600-4.14:1980, which is withdrawn This edition makes no technical changes to the standard

A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application

Compliance with a British Standard does not of itself confer immunity from legal obligations.

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover

This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover

EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 24505 April 1993

UDC 669.018.25:620.186

Descriptors: Powder metallurgy, hard metals, metallography, microscopic analysis, porosity, pores, carbon

English version

Hardmetals — Metallographic determination of porosity

and uncombined carbon

(ISO 4505:1978)

Métaux-durs — Détermination

métallographique de la porosité et du carbone

non combiné

(ISO 4505:1978)

Hartmetalle — Metallographische Bestimmung der Porosität und des ungebundenen Kohlenstoffs

(ISO 4505:1978)

This European Standard was approved by CEN on 1993-04-02 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 Central Secretariat 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 Central Secretariat has the same status as the official versions

CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom

CEN

European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

© 1993 Copyright reserved to CEN members

Ref No EN 24505:1993 E

© BSI 12-1999 2

Foreword

In 1992, ISO 4505:1978 Hardmetals —

Metallographic determination of porosity and

uncombined carbon was submitted to the CEN

Primary Questionnaire procedure

Following the positive result of the CEN/CS

Proposal ISO 4505:1978 was submitted to the CEN

Formal Vote The result of the Formal Vote was

positive

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

October 1993, and conflicting national standards

shall be withdrawn at the latest by October 1993

According to the Internal Regulations of

CEN/CENELEC, the following countries are bound

to implement this European Standard: Austria,

Belgium, Denmark, Finland, France, Germany,

Greece, Iceland, Ireland, Italy, Luxembourg,

Netherlands, Norway, Portugal, Spain, Sweden,

Switzerland and United Kingdom

EN 24505:1993

1 Scope and field of application

This International Standard specifies methods for

the metallographic determination of the presence,

type, and distribution of porosity and uncombined

carbon in hardmetals

2 Apparatus

2.1 Metallographic microscope, or other suitable

equipment permitting observations and

measurements on a screen up to the required

magnification (see clause 4).

2.2 Equipment for preparation of test-piece sections

3 Preparation of test-piece sections

The test-piece section shall be prepared as for

metallographic examination and the surface to be

examined shall be free from grinding and polishing

marks Care shall be taken to avoid tearing out of

particles, which may lead to a wrong evaluation of

porosity

NOTE There are several methods for the preparation of

hardmetal surfaces for metallographic examination Firstly,

careful coarse grinding is carried out to remove sufficient

material to ensure that the true structure is revealed After

grinding with fine diamond grit wheels, polishing is effected by

using diamond paste or diamond powders of progressively finer

grain size down to 1 4m on rigidly supported laps of, for example,

thin plastic, thin felt or paper.

4 Procedure

Pore size is defined as the maximum dimension of

the pore in the section Special reference shall be

made to the presence of cracks or slits

4.1 Pores up to 10 4m shall be assessed by scanning

the surface of the test-piece section at a

magnification of either 100 or 200× An area fully

representative of the test-piece section shall be

examined and compared with the range of

photomicrographs shown in Figure 1 or Figure 2,

according to the chosen magnification The porosity

level shall be reported by reference to the

appropriate photomicrograph and designated as

A02, A04, A06 or A08

4.2 Pores within the range 10 to 25 4m shall be

assessed by scanning the surface of the test-piece

section at a magnification of 100× An area fully

representative of the test-piece section shall be

examined and shall be compared with the range of

photomicrographs shown in Figure 3 The porosity

level shall be reported by reference to the

appropriate photomicrograph and designated

as B02, B04, B06 or B08

4.3 If it is necessary to inspect for pores larger than 25 4m, they shall be examined at a suitable magnification up to 100× and shall be counted and reported as the number of pores per unit area The size ranges shall be chosen as

follows: 25 to 75 4m, 75 to 125 4m, over 125 4m

4.4 Uncombined carbon shall be assessed by scanning the surface of the test-piece section at a magnification of 100× An area fully representative

of the test-piece section shall be examined and shall

be compared with the range of photomicrographs shown in Figure 4 The level of uncombined carbon shall be reported by reference to the appropriate photomicrographs and designated as C02, C04, C06

or C08

4.5 If A or B type porosity or C type uncombined carbon is not detected, it shall be reported

as A00, B00 or C00 as applicable

4.6 If the porosity or uncombined carbon is not uniform over the area of the test-piece section being examined, the locations on the section to which the evaluation refers must be identified, for example as top, bottom, edge, rim (case), core, etc

5 Test report

The test report shall include the following information:

a) reference to this International Standard; b) all details necessary for identification of the test sample;

c) the result obtained;

d) all operations not specified by this International Standard, or regarded as optional; e) details of any occurrence which may have affected the result

4 © BSI 12-1999

Figure 1 — Type A apparent porosity (×100)

EN 24505:1993

Figure 2 — Type A apparent porosity (×200)

6 © BSI 12-1999

Figure 3 — Type B apparent porosity (×100)

EN 24505:1993

Figure 4 — Uncombined carbon (×100)

BS EN 24505:1993

© BSI 12-1999

National annex NA (informative)

Committees responsible

The United Kingdom participation in the preparation of this European Standard was entrusted by the Iron and Steel Standards Policy Committee (ISM/-) to Technical Committee ISM/65 upon which the following bodies were represented:

British Hardmetal Association

Federation of British Engineers (Test Manufacturers)

Society of Motor Manufacturers and Traders Limited

Coopted member

389 Chiswick High Road

London

W4 4AL

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