SIST EN ISO 4538:1999

SLOVENSKI STANDARD
SIST EN ISO 4538:1999
01-oktober-1999
Kovinske prevleke - Korozijski preskus s tioacetamidom (preskus TAA) (ISO
4538:1978)
Metallic coatings - Thioacetamide corrosion test (TAA test) (ISO 4538:1978)
Metallische Überzüge - Thioacetamid-Korrosionsprüfung (TAA-Versuch) (ISO
4538:1978)
Revetements métalliques - Essai de corrosion a la thioacétamide (Essai TAA) (ISO
4538:1978)
Ta slovenski standard je istoveten z: EN ISO 4538:1995
ICS:
25.220.40 Kovinske prevleke Metallic coatings
SIST EN ISO 4538:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 4538:1999

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SIST EN ISO 4538:1999

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SIST EN ISO 4538:1999

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SIST EN ISO 4538:1999

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SIST EN ISO 4538:1999

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SIST EN ISO 4538:1999
INTERNATIONAL STANDARD
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.MElKJlYHAPO,QHAR OPTAHM3Al@lR fl0 CTAH~APTkl3A~MM.ORGANISATION INTERNATIONALE DE NORMALISATION
Metallic coatings - Thioacetamide corrosion test (TAA test)
Essai de corrosion 2 Ia thioacbamide (Essai TAA)
Rev&emen ts m&talliques -
First edition - 1978-06-15
Ref. No. ISO 4538-1978 (E)
UDC 620.193.47
Descriptors : metal coati ngs, corrosion tests.
Price based on 3 pages

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SIST EN ISO 4538:1999
FOREWORD
ISO (the International Organization for Standardization) is a worldwide federation
sf national Standards institutes (ISO member bodies). The work of developing
international Standards is carried out through ISO technical committees. Every
member body interested in a subject for which a technical committee has been set
up 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.
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.
International Standard ISO 4538 was developed by Technical Committee
ISO/TC 107, Meta//ic and other non-organic coatings, and was circulated to the
member bodies in November 1976.
lt has been approved by the member bodies of the following countries :
Austral ia
I taly South Africa, Rep. of
Bulgaria Japan Spain
Czechoslovakia Mexico Switzerland
France Netherlands Turkey
Germany Philippines United Kingdom
Hungary Poland U.S.A.
India Portugal U.S.S. R.
Israel Romania
No member body expressed disapproval of the document.
0 International Organkation for Standardkation, 1978 l
Printed in Switzerland

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SIST EN ISO 4538:1999
ISO 4538-1978 (E)
INTERNATIONAL STANDARD
Thioacetamide corrosion test (TAA test)
Metallic coatings -
0 INTRODUCTION 4.2 Sodium acetate, saturated Solution.
The type and number of test specimens, the exposure Dissolve 3 Parts of sodium acetate trihydrate
period required and the criteria of failure are not specified (CH,COONa.3H,O) in 1 part of water.
in this International Standard. Such details should be given
in the appropriate coating or product specification.
5 APPARATUS
1 SCOPE AND FIELD OF APPLICATION
5.1 Test chamber, comprising a Container made of glass
or suitable transparent plastics material, capable of being
1 .l This International Standard specifies the apparatus
closed by a gas-tight cover. The actual dimensions of the
and the procedure for assessment of the resistance of metal
test chamber are not specified but the requirements stated
surfaces to corrosion and tarnish in atmospheres containing
in this and subsequent clauses shall be met. Unless other-
volatile sulphides, carried out in accordance with coating or
wise specified, the capacity of the test chamber shall be
product specif ications.
not less than 2 litres and not more than 20 litres.
1.2 The method is applicable to the assessment of the
All materials used in the construction of the test chamber
efficacy of tarnish-preventing treatments applied to silver
shall be capable of resisting the action of volatile sulphides
or topper and to the detection of discontinuities in precious
and shall not emit any gas or vapour Iikely to influence the
metal coatings on these metals.
corrosion of the materials under test.
5.2 Plate, made of inert non-metallic material, supported
2 REFERENCE
inside the test chamber to provide a level surface occupying
70 to 90 % of the Cross-section of the chamber at least
ISO 1462, Metallic coatings - Coatings other than those
10 mm and not more than 75 mm above the base of the
anodic to the basis me tal - Accelera ted corrosion tests -
chamber.
Method for evaluation of the results.
5.3 Simple framework, made of inert non-metallic material,
3 PRINCIPLE
placed inside the chamber to serve as a support for the
moist Paper (see 7.2) and as a means of Suspension for test
Exposure of test specimens to vapours emitted by thio-
specimens (see 7.1).
acetamide in an atmosphere having a relative humidity of
75 %, maintained by the presence of a saturated Solution
of sodium acetate. 5.4 Constant temperature enclosure or (if the test chamber
cannot be accommodated in such an enclosure) suitable
cover or Screen capable of preventing any sudden tempera-
4 REAGENTS
ture fluctuation or Iocal temperature differente.
Use only reagents of recognized analytical grade and
only distilled water or water of equivalent purity.
6 TEST SPECIMENS
4.1 Thioacetamide, powdered crystals.
6.1 Select the type and number of test specimens to be
WARNING : Thioacetamide is a carcinogen. All contact used according to the specification for the coating or
with human skin should be avoided. products being tested. See also 7.4.
1

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SIST EN ISO 4538:1999
ISO 4538-1978 (E)
6.2 Any cleaning procedure applied to the test specimens
7.6 Observe the appearance of the test specimens after
before
...