EN ISO 16151:2008

SLOVENSKI STANDARD
01-julij-2008
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Corrosion of metals and alloys - Accelerated cyclic tests with exposure to acidified salt
spray, "dry" and "wet" conditions (ISO 16151:2005)
Corrosion des métaux et alliages - Essais cycliques accélérés avec exposition au
brouillard salin acidifié, en conditions "seches" et en conditions "humides" (ISO
16151:2005)
Ta slovenski standard je istoveten z: EN ISO 16151:2008
ICS:
77.060 Korozija kovin Corrosion of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 16151
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2008
ICS 77.060
English Version
Corrosion of metals and alloys - Accelerated cyclic tests with
exposure to acidified salt spray, ''dry'' and ''wet'' conditions (ISO
16151:2005)
Corrosion des métaux et alliages - Essais cycliques Korrosion von Metallen und Legierungen -
accélérés avec exposition au brouillard salin acidifié, en Schnellprüfungen unter wechselnder Einwirkung von
conditions ''sèches'' et en conditions ''humides'' (ISO saurem Salzsprühnebel, ''trockenen'' und ''feuchten''
16151:2005) Bedingungen (ISO 16151:2007)
This European Standard was approved by CEN on 21 March 2008.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
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EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16151:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.3

Foreword
The text of ISO 16151:2005 has been prepared by Technical Committee ISO/TC 156 “Corrosion of metals and
alloys” of the International Organization for Standardization (ISO) and has been taken over as EN ISO
16151:2008 by Technical Committee CEN/TC 262 “Metallic and other inorganic coatings” 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 October 2008, and conflicting national standards shall be withdrawn at
the latest by October 2008.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 16151:2005 has been approved by CEN as a EN ISO 16151:2008 without any modification.

INTERNATIONAL ISO
STANDARD 16151
First edition
2005-10-15
Corrosion of metals and alloys —
Accelerated cyclic tests with exposure
to acidified salt spray, “dry” and “wet”
conditions
Corrosion des métaux et alliages — Essais cycliques accélérés avec
exposition au brouillard salin acidifié, en conditions «sèches» et en
conditions «humides»
Reference number
ISO 16151:2005(E)
©
ISO 2005
ISO 16151:2005(E)
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ii © ISO 2005 – All rights reserved

ISO 16151:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Test solution. 2
3.1 Method A. 2
3.1.1 Preparation of acidic 5 % sodium chloride solution . 2
3.2 Method B. 3
3.2.1 Preparation of the mixed salt solution . 3
3.2.2 Preparation of the acidic solution. 3
3.2.3 Preparation of the acidified-salt solution. 3
4 Apparatus . 4
4.1 Exposure cabinet. 4
4.2 Humidity and temperature control . 4
4.3 Spraying device . 4
4.4 Air saturator . 4
4.5 Collecting devices . 4
4.6 Air dryer . 5
4.7 Exhaust system. 5
4.8 Drain system . 5
5 Test specimens . 5
6 Arrangement of the test specimens. 5
7 Operating conditions. 6
8 Continuity of tests . 8
9 Duration of tests . 8
10 Treatment of specimens after test . 8
11 Evaluation of results. 8
12 Test report . 9
Annex A (informative) Relationship between amount of acidic stock solution added to mixed salt
solution and pH of the resulting acidified-salt solution . 10
Annex B (informative) Typical apparatus for accelerated cyclic tests with exposure to acidified
salt spray, “dry” and “wet” conditions. 11
Annex C (informative) Method of evaluation of the corrosivity of the chamber. 13
Bibliography . 15

ISO 16151:2005(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.
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 16151 was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys.
iv © ISO 2005 – All rights reserved

ISO 16151:2005(E)
Introduction
Corrosion of metallic materials, with or without corrosion protection, is influenced by many environmental
factors, the importance of which may vary with the type of metallic material and with the type of environment.
It is impossible, therefore, to design accelerated laboratory corrosion tests in such a way that all
environmental factors influencing resistance to corrosion are taken into account. Laboratory tests are,
therefore, designed to simulate the effects of the most important factors, which enhance the corrosion of
metallic materials.
The accelerated corrosion-test methods described in this International Standard are designed to simulate and
enhance the environmental influence on a metallic material to outdoor climates, where exposure to acid rain
and to salt-contaminated conditions occur and may promote corrosion. It has been prepared by reference to
technical papers and reports (see the Bibliography).
The test methods involve cyclic exposure of test specimens to a mist of acidified-salt solution, to drying
conditions, and to periods of high humidity. However, the methods are mainly intended for comparative testing
and the results obtained do not permit far-reaching conclusions on the corrosion resistance of the tested
metallic material under the whole range of environmental conditions in which they may be used. Nevertheless,
the methods provide valuable information on the relative performance of materials exposed to salt/acid rain
environments similar to those employed in the test.
INTERNATIONAL STANDARD ISO 16151:2005(E)

Corrosion of metals and alloys — Accelerated cyclic tests with
exposure to acidified salt spray, “dry” and “wet” conditions
1 Scope
This International Standard specifies two accelerated corrosion-test procedures, Methods A and B, for the
comparative evaluation of metallic materials with or without permanent corrosion protection or temporary
corrosion protection in outdoor salt/acid rain environments. It also specifies the apparatus used. The two tests
involve cyclic exposure of the specimens to acidified salt spray, “dry” and “wet” conditions.
The particular advantages of the two tests over conventional accelerated tests, such as the neutral salt spray
test (NSS) as specified in ISO 9227 lie in their better ability to reproduce the corrosion that occurs in outdoor
salt/acid rain environments. They are also useful for evaluating cosmetic corrosion.
Method A applies to
⎯ metals and their alloys,
⎯ metallic coatings (cathodic),
⎯ anodic oxide coatings, and
⎯ organic coatings on metallic materials.
Method B applies to
⎯ steel coated with anodic coatings, and
⎯ steel coated with anodic coatings covered with conversion coatings.
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 4628-1:2003, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 1: General introduction and
designation system
ISO 4628-2:2003, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 2: Assessment of degree of
blistering
ISO 4628-3:2003, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 3: Assessment of degree of
rusting
ISO 16151:2005(E)
ISO 4628-4:2003, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 4: Assessment of degree of
cracking
ISO 4628-5:2003, Paints and varnishes — Evaluation of degradation of coatings — Designation of quantity
and size of defects, and of intensity of uniform changes in appearance — Part 5: Assessment of degree of
flaking
1)
ISO 8407:1991 , Corrosion of metals and alloys — Removal of corrosion products from corrosion test
specimens
ISO 8993:1989, Anodized aluminium and aluminium alloys — Rating system for the evaluation of pitting
corrosion — Chart method
1)
ISO 9227:1990 , Corrosion tests in artificial atmospheres — Salt spray tests
ISO 10289:1999, Method for corrosion testing of metallic and other inorganic coatings on metallic substrate —
Rating of test specimens and manufactured articles subjected to corrosion tests
ISO 11130:1999, Corrosion of metals and alloys — Alternate immersion test in salt solution
3 Test solution
The following clauses give instructions for the preparation and use of the solutions used in Methods A and B.
3.1 Method A
3.1.1 Preparation of acidic 5 % sodium chloride solution
3.1.1.1 Neutral 5 % sodium chloride solution
A sufficient mass of sodium chloride shall be dissolved in distilled or deionized water, with a conductivity not
higher than 20 µS/cm at 25 °C ± 2 °C, to produce a concentration of 50 g/l ± 5 g/l. The specific gravity range
for a 50 g/l ± 5 g/l solution shall be 1,029 to 1,036 at 25 °C.
The sodium chloride shall contain less than 0,001 % mass fraction of copper and less than 0,001 % mass
fraction of nickel, as determined by atomic absorption spectrophotometry or another analytical method of
similar sensitivity. It shall not contain more than 0,1 % mass fraction of sodium iodide, or more than a mass
fraction of total impurities of 0,5 % calculated for dry salt.
If the pH of the prepared solution, measured at 25 °C ± 2 °C, is outside the range 6,0 to 7,0, investigate the
presence of undesirable impurities in the salt and/or the water.
3.1.1.2 Acidification
The pH of the solution shall be adjusted to a value of 3,5 ± 0,1 at 25 °C ± 2 °C, by adding the following
reagents to 10 litres of the prepared neutral 5 % sodium chloride solution as follows:
⎯ 12 ml of nitric acid (HNO , ρ = 1,42 g/ml);
⎯ 17,3 ml of sulfuric acid (H SO , ρ = 1,84 g/ml);
2 4
⎯ a sufficient quantity of 10 % mass fraction of sodium hydroxide (NaOH) solution, to adjust the pH of the
solution to 3,5 ± 0,1 (about 300 ml will be required).

1) Under revision.
2 © ISO 2005 – All rights reserved

ISO 16151:2005(E)
3.2 Method B
3.2.1 Preparation of the mixed salt solution
The mass of reagent shown in Table 1 shall be dissolved in distilled or deionized water, with a conductivity not
higher than 20 µS/cm at 25 °C ± 2 °C, to produce a stock solution with a concentration of 36 g/l ± 3,6 g/l. It
shall be diluted by 1:6 to produce a mixed salt solution with a concentration of 6,0 g/l ± 0,6 g/l.
The composition of the stock solution is the same as a typical synthetic ocean water shown in
ISO 11130:1999, Annex A, A.3 Test solution for simulating the corrosive effects of ocean water.
Table 1 — Composition and concentration
of a stock solution for a mixed salt solution
Concentration
Reagents
g/l
NaCl 24,53
MgCl 5,20
Na SO 4,09
2 4
CaCl 1,16
KCl 0,695
NaHCO 0,201
KBr 0,101
H BO 0,027
3 3
SrCl 0,025
NaF 0,003
WARNING — Handling of SrCl and NaF can be hazardous
and shall be resticted to skilled chemists or conducted under
their control.
3.2.2 Preparation of the acidic solution
To prepare the acidic solution, 16,2 g of concentrated nitric acid (HNO , ρ = 1,40 g/ml, with a mass fraction of
HNO equal to 0,65) and 42,5 g of sulfuric acid (H SO , ρ = 1,84 g/ml, with a mass fraction of H SO equal to

3 2 4 2 4
0,96) shall be dissolved in water and diluted to a total volume of 1 litre to make 1 N acid solution with respect
– 2–
to nitric acid and sulfuric acid at an equivalent ratio of [NO ]/[SO ] of 0,4.
3 4
3.2.3 Preparation of the acidified-salt solution
The prepared acidic solution from 3.2.2 shall be added to the mixed salt solution from 3.2.1 to adjust the pH to
2,5 ± 0,1 at 25 °C ± 2 °C.
NOTE The relationship between the amount of mixed acidic solution from 3.2.2 and the pH of the acidified-salt
solution is shown in Annex A. This solution, with pH value near to 2,5, would have a no-buffering action.
ISO 16151:2005(E)
4 Apparatus
All components in contact with the spray or the test solution shall be made of, or lined with, materials which
are resistant to corrosion by the test solution and which do not influence the corrosivity of the sprayed test
solution. The apparatus shall include the components described in the following subclauses.
4.1 Exposure cabinet
The exposure cabinet shall have a minimum capacity of 0,4 m . For large-capacity cabinets, during periods of
exposure to acidified salt spray, it shall be ensured that the necessary condition of homogeneity and
distribution of spray are met. The upper parts of the cabinet shall be designed so that drops of sprayed
solution formed on its surface do not fall on the specimens being tested.
The size and shape of the cabinet shall be such that, during periods of exposure to salt mist spray, the rate of
collection of solution in the cabinet is within the limits specified in 7.2.
NOTE A schematic diagram of one possible design of exposure cabinet and associated apparatus for accelerated
cyclic tests with exposure to acidified salt spray, “dry” and “wet” conditio
...