SIST EN ISO 2624:1998

SLOVENSKI STANDARD
01-april-1998
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Copper and copper alloys - Estimation of average grain size (ISO 2624:1990)
Kupfer und Kupferlegierungen - Bestimmen der mittleren Korngröße (ISO 2624:1990)
Cuivre et alliages de cuivre - Evaluation de la dimension moyenne du grain (ISO
2624:1990)
Ta slovenski standard je istoveten z: EN ISO 2624:1995
ICS:
77.120.30 Baker in bakrove zlitine Copper and copper alloys
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD
Second edition
1990-02-01
Copper and topper alloys - Estimation of
awerage grain size
Evaluation de Ia dimension moyenne du grain
Cuivre et alliages de cuivre -
Reference number
ISO 2624 : 1990 (E)
ISO 2624 : 1990 (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 technicai committees. Esch 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, govern-
mental 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.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for approval before their acceptance as International Standards by
the ISO Council. They are approved in accordance with ISO procedures requiring at
least 75 % approval by the member bodies voting.
International Standard ISO 2624 was prepared by Technical Committee ISO/TC 26,
Copper and topper alloys.
This second edition cancels and replaces the first edition (ISO 2624 : 19731, of which it
constitutes a minor revision.
Annex A forms an integral part of this International Standard.
0 ISO 1990
All rights reserved. No part of this publication may be reproduced or utilized in any form or by any
means, electronie or mechanical, including photocopying and microfilm, without Permission in
writing from the publisher.
International Organkation for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
ISO2624:199O(E)
Intra-duction
On a section of metal, a grain is that area within the boundary of a crystal. For the pur-
pose of applying the methods described in this International Standard, a crystal and its
twin bands are considered as one grain. Sub-grains, minor constituent phases, in-
clusions and additives are not considered in the estimation of the grain size.
lt is important, in using these methods, to recognize that the estimation of grain size is
not a precise measurement. A metal structure is an aggregate of three-dimensional
crystals of varying sizes and shapes. Even if all these crystals were identical in size and
shape, the grain Cross-sections produced by a random plane (surface of Observation)
through such a structure would have a distribution of areas varying from a maximum
value to Zero, depending upon where the plane cuts each individual crystal. Clearly, no
two fields of Observation tan be exactly the Same.
Practical reasons limit the number of grains that tan reasona b counted to less
ily be than
the number statistically desirable.
. . .
Ill
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ISO 2624 : 1990 (E)
INTERNATIONAL STANDARD
Estimation of average
Copper and topper alloys -
grain size
3.2 The specimen shall be carefully prepared to reveal the
1 Scope
grain boundaries using a contrast etch to match the Standard
Charts.
This International Standard specifies three procedures for
estimating, and rules for expressing, the average grain size of
topper and topper alloys consisting principally of a Single
Phase. The respective procedures are termed the comparison
4 Procedures
procedure, the intercept procedure and the planimetric pro-
cedure.
4.1 Comparison procedure
The comparison procedure (comparing the specimen with a
Standard Chart) is most convenient and is sufficiently accurate
The estimation of grain size is made by direct comparison of a
for most commercial purposes.
projected image of a photomicrograph of a representative field
of the test specimen, either with the photomicrographs of the
Higher degreees of accuracy in estimating grain size are ob-
Standard grain size series or with suitable reproductions of
tainable by using the intercept (Heyn) or planimetric (Jeffries)
them (for Standard grain size Charts, see annex AI; when a pro-
procedures. In cases of dispute, it is recommended that the use
jection microscope is not available a bench microscope may be
of one of these procedures be agreed between the Parties.
used. lt is recommended that, to facilitate comparison,
mechanical arrangements be made to permit bringing the stan-
For material with non-equiaxial structures it is recommended
dard photomicrographs successively into juxtaposition with the
that the intercept procedure be used.
projected image.
4.2 Intercept procedure
2 Symbols and designations
4.2.1 The grain size is estimated by counting, on the ground
Symbol Designation
glass Screen of a projection microscope, on the image in a
Jeffries’ multiplier used to obtain number
f
bench microscope fitted with a graticule, on a photo-
of grains per Square millimetre by
micrograph of a representative field of the specimen, or on the
planimetric method
specimen itself, the number of grains intercepted by one or
Number of grains per Square millimetre
more straight lines sufficiently long to yie
...