SIST EN ISO 12944-2:2018
(Main)Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 2: Classification of environments (ISO 12944-2:2017)
Paints and varnishes - Corrosion protection of steel structures by protective paint systems - Part 2: Classification of environments (ISO 12944-2:2017)
ISO 12944-2:2017 deals with the classification of the principal environments to which steel structures are exposed, and the corrosivity of these environments. ISO 12944-2:2017
- defines atmospheric-corrosivity categories, based on mass loss (or thickness loss) by standard specimens, and describes typical natural atmospheric environments to which steel structures are exposed, giving advice on the estimation of the corrosivity,
- describes different categories of environment for structures immersed in water or buried in soil, and
- gives information on some special corrosion stresses that can cause a significant increase in corrosion rate or place higher demands on the performance of the protective paint system.
The corrosion stresses associated with a particular environment or corrosivity category represent one essential parameter governing the selection of protective paint systems.
Beschichtungsstoffe - Korrosionsschutz von Stahlbauten durch Beschichtungssysteme - Teil 2: Einteilung der Umgebungsbedingungen (ISO 12944-2:2017)
Dieser Teil von ISO 12944 behandelt die Einteilung der wesentlichen Umgebungsbedingungen, denen Stahl¬bauten ausgesetzt sind, und die Korrosivität dieser Umgebungsbedingungen. Er
— definiert Korrosivitätskategorien der Atmosphäre, die auf Massenverlusten (oder Dickenverlusten) von Standardproben basieren, beschreibt typische natürliche atmosphärische Umgebungs¬be¬din¬gun¬gen und gibt Hinweise zum Abschätzen Ihrer Korrosivität;
— beschreibt verschiedene Kategorien der Umgebungsbedingungen von Stahlbauten in Wasser oder im Erd¬reich;
— macht Angaben zu einigen speziellen Korrosionsbelastungen, die eine deutliche Zunahme der Korro-sions¬geschwindigkeit verursachen oder erhöhte Anforderungen an die Leistungsfähigkeit des Be-schichtungssystems stellen können.
Die Korrosionsbelastungen, die einer bestimmten Umgebungsbedingung oder einer Korrosivi¬täts¬kate¬go¬rie ent¬sprechen, bilden einen wesentlichen Parameter für die Auswahl von geeigneten Beschich¬tungs-systemen für den Korrosionsschutz.
Peintures et vernis - Anticorrosion des structures en acier par systèmes de peinture - Partie 2: Classification des environnements (ISO 12944-2:2017)
ISO 12944-2:2017 traite de la classification des principaux environnements auxquels sont exposées les structures en acier peintes et de la corrosivité de ces environnements. Le présent document
- définit les catégories de corrosivité atmosphérique, basées sur la perte de masse (ou la perte d'épaisseur) au moyen d'éprouvettes standard, et décrit les environnements atmosphériques naturels types auxquels sont exposées les structures en acier, en donnant des conseils pour l'estimation de la corrosivité,
- décrit différentes catégories d'environnement pour les structures immergées ou enterrées, et
- fournit des informations sur certaines contraintes de corrosion particulières, susceptibles d'augmenter de façon significative la vitesse de corrosion ou de nécessiter une plus grande performance du système de peinture.
Des contraintes de corrosion associées à un environnement particulier ou à une catégorie de corrosivité représentent un paramètre essentiel pour le choix de systèmes de peinture.
Barve in laki - Protikorozijska zaščita jeklenih konstrukcij z zaščitnimi premaznimi sistemi - 2. del: Klasifikacija okoljskih pogojev (ISO 12944-2:2017)
ISO 12944-2:2017 obravnava klasifikacijo glavnih okoljskih pogojev, ki so jim izpostavljene jeklene konstrukcije, in korozivnost teh pogojev. ISO 12944-2:2017
- opredeljuje kategorije atmosferske korozivnosti na podlagi izgube mase (ali debeline) s standardnimi vzorci in opisuje običajne naravne atmosferske okoljske pogoje, ki so jim izpostavljene jeklene konstrukcije, ter podaja nasvete glede vrednotenja korozivnosti;
- opisuje različne kategorije okoljskih pogojev za konstrukcije, potopljene v vodo ali zakopane v zemljo; in
- podaja informacije o nekaterih posebnih korozijskih obremenitvah, ki lahko povzročijo znatno povečanje stopnje korozije ali postavijo višje zahteve glede učinkovitosti zaščitnega premaznega sistema.
Korozijske obremenitve, povezane z določenimi okoljskimi pogoji ali kategorijo korozivnosti, predstavljajo enega od osnovnih parametrov, ki vplivajo na izbiro zaščitnih premaznih sistemov.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 12944-2:2018
01-februar-2018
1DGRPHãþD
SIST EN ISO 12944-2:1998
%DUYHLQODNL3URWLNRUR]LMVND]DãþLWDMHNOHQLKNRQVWUXNFLM]]DãþLWQLPLSUHPD]QLPL
VLVWHPLGHO .ODVLILNDFLMDRNROMVNLKSRJRMHY ,62
Paints and varnishes - Corrosion protection of steel structures by protective paint
systems - Part 2: Classification of environments (ISO 12944-2:2017)
Beschichtungsstoffe - Korrosionsschutz von Stahlbauten durch Beschichtungssysteme -
Teil 2: Einteilung der Umgebungsbedingungen (ISO 12944-2:2017)
Peintures et vernis - Anticorrosion des structures en acier par systèmes de peinture -
Partie 2: Classification des environnements (ISO 12944-2:2017)
Ta slovenski standard je istoveten z: EN ISO 12944-2:2017
ICS:
25.220.20 Površinska obdelava Surface treatment
87.040 Barve in laki Paints and varnishes
91.080.13 Jeklene konstrukcije Steel structures
SIST EN ISO 12944-2:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 12944-2:2018
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SIST EN ISO 12944-2:2018
EN ISO 12944-2
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2017
EUROPÄISCHE NORM
ICS 87.020; 91.080.13 Supersedes EN ISO 12944-2:1998
English Version
Paints and varnishes - Corrosion protection of steel
structures by protective paint systems - Part 2:
Classification of environments (ISO 12944-2:2017)
Peintures et vernis - Anticorrosion des structures en Beschichtungsstoffe - Korrosionsschutz von
acier par systèmes de peinture - Partie 2: Classification Stahlbauten durch Beschichtungssysteme - Teil 2:
des environnements (ISO 12944-2:2017) Einteilung der Umgebungsbedingungen (ISO 12944-
2:2017)
This European Standard was approved by CEN on 30 October 2017.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12944-2:2017 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 12944-2:2018
EN ISO 12944-2:2017 (E)
Contents Page
European foreword . 3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 12944-2:2018
EN ISO 12944-2:2017 (E)
European foreword
This document (EN ISO 12944-2:2017) has been prepared by Technical Committee ISO/TC 35 “Paints
and varnishes” in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the
secretariat of which is held by DIN.
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 June 2018, and conflicting national standards shall be
withdrawn at the latest by June 2018.
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 12944-2:1998.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 12944-2:2017 has been approved by CEN as EN ISO 12944-2:2017 without any
modification.
3
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SIST EN ISO 12944-2:2018
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SIST EN ISO 12944-2:2018
INTERNATIONAL ISO
STANDARD 12944-2
Second edition
2017-11
Paints and varnishes — Corrosion
protection of steel structures by
protective paint systems —
Part 2:
Classification of environments
Peintures et vernis — Anticorrosion des structures en acier par
systèmes de peinture —
Partie 2: Classification des environnements
Reference number
ISO 12944-2:2017(E)
©
ISO 2017
---------------------- Page: 7 ----------------------
SIST EN ISO 12944-2:2018
ISO 12944-2:2017(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 12944-2:2018
ISO 12944-2:2017(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Corrosion stresses due to the atmosphere, water and soil . 3
4.1 Atmospheric corrosion . 3
4.2 Corrosion in water and soil . 3
4.2.1 General. 3
4.2.2 Structures immersed in water . 3
4.2.3 Structures buried in soil . 4
4.3 Special cases . 4
5 Classification of environments . 4
5.1 Atmospheric-corrosivity categories . 4
5.2 Categories for water and soil . 5
Annex A (informative) Climatic conditions . 7
Annex B (informative) Special cases . 8
Bibliography .11
© ISO 2017 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 12944-2:2018
ISO 12944-2:2017(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 on 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 the following
URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee
SC 14, Protective paint systems for steel structures.
This second edition cancels and replaces the first edition (ISO 12944-2:1998), which has been
technically revised.
The main changes compared to the previous edition are as follows:
— the normative references have been updated;
— 4.2.1 "General" has been added;
— the units in Table 1 have been corrected;
— the bibliography has been updated;
— the text has been editorially revised.
A list of all parts in the ISO 12944 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 12944-2:2018
ISO 12944-2:2017(E)
Introduction
Unprotected steel in the atmosphere, in water and in soil is subjected to corrosion that can lead to
damage. Therefore, to avoid corrosion damage, steel structures are normally protected to withstand
the corrosion stresses to which they will be subjected during the service life required of the structure.
There are different ways of protecting steel structures from corrosion. ISO 12944 (all parts) deals with
protection by paint systems and covers, in the various parts, all features that are important in achieving
adequate corrosion protection. Additional or other measures are possible but require particular
agreement between the interested parties.
In order to ensure effective corrosion protection of steel structures, owners of such structures, planners,
consultants, companies carrying out corrosion protection work, inspectors of protective coatings
and manufacturers of coating materials need to have at their disposal state-of-the-art information in
concise form on corrosion protection by paint systems. It is vital that such information is as complete as
possible, unambiguous and easily understandable to avoid difficulties and misunderstandings between
the parties concerned with the practical implementation of protection work.
ISO 12944 (all parts) is intended to give this information in the form of a series of instructions. It is
written for those who have some technical knowledge. It is also assumed that the user of ISO 12944 (all
parts) is familiar with other relevant International Standards, in particular those dealing with surface
preparation.
Although ISO 12944 (all parts) does not deal with financial and contractual questions, attention is
drawn to the fact that, because of the considerable implications of inadequate corrosion protection,
non-compliance with requirements and recommendations given in ISO 12944 (all parts) can result in
serious financial consequences.
ISO 12944-1 defines the overall scope of ISO 12944. It gives some basic terms and definitions and a
general introduction to the other parts of ISO 12944. Furthermore, it includes a general statement on
health, safety and environmental protection, and guidelines for using ISO 12944 (all parts) for a given
project.
This document describes the environmental impact on steel structures. It covers structures exposed
to the atmosphere as well as those immersed in water or buried in soil. For different atmospheric
environments, a classification system based on corrosivity categories is also presented. Different
environments for immersed and buried structures are also described. All these environments are
relevant to the choice of protective paint systems.
© ISO 2017 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 12944-2:2018
---------------------- Page: 12 ----------------------
SIST EN ISO 12944-2:2018
INTERNATIONAL STANDARD ISO 12944-2:2017(E)
Paints and varnishes — Corrosion protection of steel
structures by protective paint systems —
Part 2:
Classification of environments
1 Scope
This document deals with the classification of the principal environments to which steel structures are
exposed, and the corrosivity of these environments. This document
— defines atmospheric-corrosivity categories, based on mass loss (or thickness loss) by standard
specimens, and describes typical natural atmospheric environments to which steel structures are
exposed, giving advice on the estimation of the corrosivity,
— describes different categories of environment for structures immersed in water or buried in soil, and
— gives information on some special corrosion stresses that can cause a significant increase in
corrosion rate or place higher demands on the performance of the protective paint system.
The corrosion stresses associated with a particular environment or corrosivity category represent one
essential parameter governing the selection of protective paint systems.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 12944-1, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 1: General introduction
ISO 12944-3, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 3: Design considerations
ISO 12944-4, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 4: Types of surface and surface preparation
ISO 12944-5, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 5: Protective paint systems
ISO 12944-6, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 6: Laboratory performance test methods
ISO 12944-7, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 7: Execution and supervision of paint work
ISO 12944-8, Paints and varnishes — Corrosion protection of steel structures by protective paint systems —
Part 8: Development of specifications for new work and maintenance
ISO 12944-9, Paints and varnishes — Corrosion protection of steel structures by protective paint
systems — Part 9: Protective paint systems and laboratory performance test methods for offshore and
related structures
© ISO 2017 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 12944-2:2018
ISO 12944-2:2017(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12944-1, ISO 12944-3,
ISO 12944-4, ISO 12944-5, ISO 12944-6, ISO 12944-7, ISO 12944-8, ISO 12944-9 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
corrosivity
ability of an environment to cause corrosion of a metal in a given corrosion system
[SOURCE: ISO 8044:2015, 2.
...
SLOVENSKI STANDARD
oSIST prEN ISO 12944-2:2016
01-april-2016
%DUYHLQODNL.RUR]LMVND]DãþLWDMHNOHQLKNRQVWUXNFLM]]DãþLWQLPLSUHPD]QLPL
VLVWHPLGHO .ODVLILNDFLMDRNROLM ,62',6
Paints and varnishes - Corrosion protection of steel structures by protective coating
systems - Part 2: Classification of environments (ISO/DIS 12944-2:2016)
Beschichtungsstoffe - Korrosionsschutz von Stahlbauten durch Beschichtungssysteme -
Teil 2: Einteilung der Umgebungsbedingungen (ISO/DIS 12944-2:2016)
Peintures et vernis - Anticorrosion des structures en acier par systèmes de revêtement -
Partie 2: Classification des environnements (ISO/DIS 12944-2:2016)
Ta slovenski standard je istoveten z: prEN ISO 12944-2
ICS:
25.220.20 Površinska obdelava Surface treatment
87.020 Postopki za nanašanje Paint coating processes
barvnih premazov
91.080.10 Kovinske konstrukcije Metal structures
oSIST prEN ISO 12944-2:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN ISO 12944-2:2016
---------------------- Page: 2 ----------------------
oSIST prEN ISO 12944-2:2016
DRAFT INTERNATIONAL STANDARD
ISO/DIS 12944-2
ISO/TC 35/SC 14 Secretariat: DIN
Voting begins on: Voting terminates on:
2016-01-28 2016-04-28
Paints and varnishes — Corrosion protection of steel
structures by protective coating systems —
Part 2:
Classification of environments
Peintures et vernis — Anticorrosion des structures en acier par systèmes de revêtement —
Partie 2: Classification des environnements
ICS: 87.020
ISO/CEN PARALLEL PROCESSING
This draft has been developed within the International Organization for
Standardization (ISO), and processed under the ISO lead mode of collaboration
as defined in the Vienna Agreement.
This draft is hereby submitted to the ISO member bodies and to the CEN member
bodies for a parallel five month enquiry.
Should this draft be accepted, a final draft, established on the basis of comments
received, will be submitted to a parallel two-month approval vote in ISO and
THIS DOCUMENT IS A DRAFT CIRCULATED
formal vote in CEN.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
To expedite distribution, this document is circulated as received from the
IN ADDITION TO THEIR EVALUATION AS
committee secretariat. ISO Central Secretariat work of editing and text
BEING ACCEPTABLE FOR INDUSTRIAL,
composition will be undertaken at publication stage.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 12944-2:2015(E)
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 SUPPORTING DOCUMENTATION. ISO 2015
---------------------- Page: 3 ----------------------
oSIST prEN ISO 12944-2:2016
ISO/DIS 12944-2:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST prEN ISO 12944-2:2016
ISO/DIS 12944-2
Contents Page
Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Corrosion stresses due to the atmosphere, water and soil . 3
4.1 Atmospheric corrosion . 3
4.2 Corrosion in water and soil . 3
4.3 Special cases . 4
5 Classification of environments . 4
5.1 Atmospheric-corrosivity categories . 4
5.2 Categories for water and soil . 5
Annex A (informative) Climatic conditions . 7
Annex B (informative) Special cases . 8
Bibliography . 11
© ISO 2002 – All rights reserved iii
---------------------- Page: 5 ----------------------
oSIST prEN ISO 12944-2:2016
ISO/DIS 12944-2
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 12944-2 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 14,
Protective paint systems for steel structures.
This second edition cancels and replaces the first edition (ISO12944-2:1998), which has been technically
revised.
ISO 12944 consists of the following parts, under the general title Paints and varnishes — Corrosion protection
of steel structures by protective coating systems:
Part 1: General introduction
Part 2: Classification of environments
Part 3: Design considerations
Part 4: Types of surface and surface preparation
Part 5: Protective paint systems
Part 6: Laboratory performance test methods
Part 7: Execution and supervision of paint work
Part 8: Development of specifications for new work and maintenance
Part 9: Protective paint systems and laboratory performance test methods for offshore and related
structures
iv © ISO 2002 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST prEN ISO 12944-2:2016
ISO/DIS 12944-2
Introduction
Unprotected steel in the atmosphere, in water and in soil is subject to corrosion that may lead to damage.
Therefore, to avoid corrosion damage, steel structures are normally protected to withstand the corrosion
stresses during the service life required of the structure.
There are different ways of protecting steel structures from corrosion. ISO 12944 deals with protection by
paint systems and covers, in the various parts, all features that are important in achieving adequate corrosion
protection. Additional or other measures are possible but require particular agreement between the interested
parties.
In order to ensure effective corrosion protection of steel structures, it is necessary for owners of such
structures, planners, consultants, companies carrying out corrosion protection work, inspectors of protective
coatings and manufacturers of coating materials to have at their disposal state-of- the-art information in
concise form on corrosion protection by paint systems. Such information has to be as complete as possible,
unambiguous and easily understandable to avoid difficulties and misunderstandings between the parties
concerned with the practical implementation of protection work.
This International Standard — ISO 12944 — is intended to give this information in the form of a series of
instructions. It is written for those who have some technical knowledge. It is also assumed that the user of ISO
12944 is familiar with other relevant International Standards, in particular those dealing with surface
preparation, as well as relevant national regulations.
Although ISO 12944 does not deal with financial and contractual questions, attention is drawn to the fact that,
because of the considerable implications of inadequate corrosion protection, non-compliance with
requirements and recommendations given in this standard may result in serious financial consequences.
ISO 12944-1 defines the overall scope of all parts of ISO 12944. It gives some basic terms and definitions and
a general introduction to the other parts of ISO 12944. Furthermore, it includes a general statement on health,
safety and environmental protection, and guidelines for using ISO 12944 for a given project.
This part of ISO 12944 describes the environmental impact on steel structures. It covers structures exposed to
the atmosphere as well as those immersed in water or buried in soil. For different atmospheric environments,
a classification system based on corrosivity categories is presented. Different environments for immersed and
buried structures are also described. All these environments are relevant to the choice of protective paint
systems.
© ISO 2002 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST prEN ISO 12944-2:2016
---------------------- Page: 8 ----------------------
oSIST prEN ISO 12944-2:2016
DRAFT INTERNATIONAL STANDARD ISO/DIS 12944-2
Paints and varnishes — Corrosion protection of steel structures
by protective coating systems — Part 2: Classification of
environments
1 Scope
This part of ISO 12944 deals with the classification of the principal environments to which steel structures are
exposed, and the corrosivity of these environments. It
- defines atmospheric-corrosivity categories, based on mass loss (or thickness loss) by standard
specimens, and describes typical natural atmospheric environments to which steel structures are
exposed, giving advice on the estimation of the corrosivity;
- describes different categories of environment for structures immersed in water or buried in soil;
- gives information on some special corrosion stresses that may cause a significant increase in
corrosion rate or place higher demands on the performance of the protective paint system.
The corrosion stresses associated with a particular environment or corrosivity category represent one
essential parameter governing the selection of protective paint systems.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 9223, Corrosion of metals and alloys — Corrosivity of atmospheres — Classification, determination and
estimation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the other parts of ISO 12944 and the
following apply.
NOTE Some of the definitions have been taken from ISO 8044:1989, Corrosion of metals and alloys —
Vocabulary, as indicated.
3.1
corrosivity
ability of an environment to cause corrosion in a given corrosion system
[ISO 8044]
3.2
corrosion stresses
environmental factors which promote corrosion
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3.3
corrosion system
system consisting of one or more metals and all parts of the environment which influence corrosion
[ISO 8044]
3.4
climate
weather prevailing at a given location or in a given area, as established statistically by meteorological
parameters recorded over a prolonged period
3.5
atmosphere
mixture of gases, and normally also aerosols and particles, that surrounds a given object
3.6
atmospheric corrosion
corrosion with the Earth's atmosphere at ambient temperature as the corrosive environment
[ISO 8044]
3.7
type of atmosphere
characterization of the atmosphere on the basis of the corrosive agents present and their concentration
Note 1 to entry: The main corrosive agents are gases (especially sulfur dioxide) and salts (especially chlorides and/or
sulfates).
3.7.1
rural atmosphere
atmosphere prevailing in rural areas and small towns, without significant contamination by corrosive agents
such as sulfur dioxide and/or chlorides
3.7.2
urban atmosphere
contaminated atmosphere prevailing in densely populated areas without significant industry. It has moderate
concentrations of pollutants such as sulfur dioxide and/or chlorides
3.7.3
industrial atmosphere
atmosphere contaminated by corrosive pollutants from local and regional industry (mainly sulfur dioxide)
3.7.4
marine atmosphere
atmosphere over and near the sea
Note 1 to entry: A marine atmosphere will extend a certain distance inland, depending on topography and prevailing
wind direction. It is heavily polluted with sea-salt aerosols (mainly chlorides).
3.8
local environment
atmospheric conditions prevailing around a constituent element of a structure
Note 1 to entry: These conditions determine the corrosivity category and include both meteorological and pollution
parameters.
3.9
micro-environment
environment at the interface between a constituent element of a structure and its surroundings. The micro-
environment is one of the decisive factors in the assessment of corrosion stresses
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3.10
time of wetness
period during which a metal surface is covered by a film of electrolyte that is capable of causing atmospheric
corrosion. Guidance values for time of wetness can be calculated from temperature and relative humidity by
summing the hours during which the relative humidity is above 80 % and, at same time, the temperature is
above 0 °C
4 Corrosion stresses due to the atmosphere, water and soil
4.1 Atmospheric corrosion
Atmospheric corrosion is a process that takes place in a film of moisture on the metal surface. The moisture
film may be so thin that it is invisible to the naked eye.
The corrosion rate is increased by the following factors:
- an increase in relative humidity;
- the occurrence of condensation (when the surface temperature is at or below the dew point);
- an increase in the amount of pollution in the atmosphere (the corrosive pollutants can react with the
steel and may form deposits on the surface).
Experience has shown that significant corrosion is likely to take place if the relative humidity is above 80 %
and the temperature above 0 °C. However, if pollutants and/or hygroscopic salts are present, corrosion occurs
a
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