SIST EN ISO 21207:2025

SLOVENSKI STANDARD
01-julij-2025
Korozijski preskusi v umetnih atmosferah - Pospešeni korozijski preskusi, ki
vključujejo izmenično izpostavljenost plinom, spodbujajo korozijo, nevtralno
razprševanje soli in sušenje (ISO 21207:2025)
Corrosion tests in artificial atmospheres - Accelerated corrosion tests involving alternate
exposure to corrosion-promoting gases, neutral salt-spray and drying (ISO 21207:2025)
Korrosionsprüfungen in künstlichen Atmosphären - Beschleunigte Korrosionstests mit
alternativer Einwirkung von korrosionsfördernden Gasen, neutraler Salzsprühung und
Trocknung (ISO 21207:2025)
Essais de corrosion en atmosphères artificielles - Essais de corrosion accélérée par
expositions alternées à des gaz favorisant la corrosion ou au brouillard salin neutre et à
un séchage (ISO 21207:2025)
Ta slovenski standard je istoveten z: EN ISO 21207:2025
ICS:
77.060 Korozija kovin Corrosion of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21207
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2025
EUROPÄISCHE NORM
ICS 77.060 Supersedes EN ISO 21207:2022
English Version
Corrosion tests in artificial atmospheres - Accelerated
corrosion tests involving alternate exposure to corrosion-
promoting gases, neutral salt-spray and drying (ISO
21207:2025)
Essais de corrosion en atmosphères artificielles - Korrosionsprüfungen in künstlichen Atmosphären -
Essais de corrosion accélérée par expositions alternées Beschleunigte Korrosionstests mit alternativer
à des gaz favorisant la corrosion ou au brouillard salin Einwirkung von korrosionsfördernden Gasen,
neutre et à un séchage (ISO 21207:2025) neutraler Salzsprühung und Trocknung (ISO
21207:2025)
This European Standard was approved by CEN on 2 May 2025.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21207:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21207:2025) has been prepared by Technical Committee ISO/TC 156
"Corrosion of metals and alloys" in collaboration with Technical Committee CEN/TC 262 “Metallic and
other inorganic coatings, including for corrosion protection and corrosion testing of metals and alloys”
the secretariat of which is held by BSI.
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 November 2025, and conflicting national standards
shall be withdrawn at the latest by November 2025.
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 21207:2022.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 21207:2025 has been approved by CEN as EN ISO 21207:2025 without any modification.

International
Standard
ISO 21207
Third edition
Corrosion tests in artificial
2025-04
atmospheres — Accelerated
corrosion tests involving alternate
exposure to corrosion-promoting
gases, neutral salt-spray and drying
Essais de corrosion en atmosphères artificielles — Essais de
corrosion accélérée par expositions alternées à des gaz favorisant
la corrosion ou au brouillard salin neutre et à un séchage
Reference number
ISO 21207:2025(en) © ISO 2025
ISO 21207:2025(en)
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ii
ISO 21207:2025(en)
Contents Page
Foreword .iv
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus and reagents . 1
4.1 Exposure of test objects to mixtures of NO and SO .2
2 2
4.2 Salt spray testing in accordance with ISO 9227 .2
4.3 Drying in standard atmosphere .2
5 Validation of the corrosivity of the tests . 3
5.1 Reference test panels .3
5.2 Arrangement of the reference panels during testing .3
5.3 Determination of mass loss after testing .3
5.4 Specifying the acceptance criteria .4
6 Test objects . 4
7 Procedure . 5
7.1 Test method A .5
7.1.1 Test cycle .5
7.1.2 Salt spray testing followed by drying (step a).5
7.1.3 Exposure to corrosive gases followed by drying (step b) .5
7.1.4 Test duration .6
7.2 Test method B .6
7.2.1 Test cycle .6
7.2.2 Salt spray testing followed by drying (step a or step c) .6
7.2.3 Exposure to corrosive gases (step b or step d) .6
7.2.4 Test duration .7
8 Evaluation of results . 7
9 Test report . 7
Annex A (informative) Recommended test periods . 9
Annex B (informative) Results from interlaboratory comparison .10
Bibliography .11

iii
ISO 21207:2025(en)
Foreword
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This document was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 262,
Metallic and other inorganic coatings, including for corrosion protection and corrosion testing of metals and
alloys, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 21207:2015), which has been technically
revised.
The main changes are as follows:
— Clause 3 “Terms and definitions” added and numbering of the following clauses adjusted.
— Bibliography updated.
— Table A.2 has been withdrawn.
— Annex B has been added, which includes an interlaboratory comparison comprising three laboratories.
— The dispersion limits of Cu mass loss have been increased to approximately 30 % in Table 1.
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iv
ISO 21207:2025(en)
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v
ISO 21207:2025(en)
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vi
ISO 21207:2025(en)
Introduction
The corrosion of metallic materials with or without corrosion protection is influenced by many
environmental factors. The extent of this influence depends on the type of metallic material and on the type
of environment. Laboratory tests are designed to simulate the effects of the most significant factors that
enhance the corrosion of metallic materials. They are not intended to be used for comparative testing as a
means of ranking different materials relative to each other with respect to corrosion resistance or as means
of predicting long-term corrosion resistance of the tested material (merely for testing the whole product).
There are two accelerated corrosion test methods described in this document, methods A and B. These
methods are designed to simulate and enhance an outdoor climate that can promote corrosion such as an
industrial or traffic environment with salt-contaminated conditions and corrosion-promoting gases. Test
method A simulates a moderately aggressive traffic environment. Test method B simulates a more severe
industrial or traffic environment.
In test method A, the test objects are exposed to the following test cycle:
— neutral salt spray testing in accordance with ISO 9227 for 2 h in a mist of a sodium chloride salt solution
of mass fraction 5 % at 35 °C, followed by drying for 22 h in a standard atmosphere;
— exposure for 120 h in a test atmosphere containing a mixture of corrosion-promoting gases, a volume
−6 −6
fraction of nitrogen dioxide (NO ) equal to 1,5 × 10 and of sulphur dioxide (SO ) equal to 0,5 × 10 , at
2 2
a relative humidity (RH) of 95 % and at a temperature of 25 °C, followed by drying for 24 h in a standard
atmosphere.
In test method B, the test objects are exposed to the following test cycle:
a) neutral salt spray testing in accordance with ISO 9227 for 2 h in a mist of a sodium chloride salt solution
of mass fraction 5 % at 35 °C, followed by drying for 22 h in a standard atmosphere;
b) exposure for 48 h in a test atmosphere containing a mixture of corrosion-promoting gases, a volume
−6 −6
fraction of NO equal to 10 × 10 and of SO equal to 5 × 10 , at a RH of 95 % and at a temperature of 25 °C;
2 2
c) neutral salt spray testing in accordance with ISO 9227 for 2 h in a mist of a sodium chloride salt solution
of mass fraction 5 % at 35 °C, followed by drying for 22 h in a standard atmosphere;
d) exposure for 72 h in a test atmosphere containing a mixture of corrosion-promoting gases, a volume
−6 −6
fraction of NO equal to 10 × 10 and of SO equal to 5 × 10 , at a RH of 95 % and at a temperature of 25 °C.
2 2
These methods (A and B) are not intended to be
...