introduction
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The committee responsible for this document is ISO/TC 156, Corrosion of Metals and Alloys.

The second edition cancelled and replaced the first edition (ISO 16701:2003), which was a minor revision.

ISO 16701-2015 Corrosion of metals and alloys Accelerated corrosion tests in artificial atmospheres involving exposure to controlled conditions of moisture cycling and intermittent spray of salt solutions

introduce
Atmospheric corrosion of metal materials, with or without corrosion protection, is affected by a number of environmental factors, the importance of which may vary depending on the type of metal material and the type of environment. Therefore, when designing laboratory corrosion tests, it is impossible to take into account the full complexity of actual conditions of use. Such an acceleration (forced condition) can also negatively affect the correlation of magnetic field properties. However, tests with a humidity cycle and only intermittent exposure to salt solutions generally have a better correlation with field performance than tests using continuous salt spray.

This international standard was developed in the automotive environment, where the main factor of corrosion is the use of winter deicing road salt in cool/cold temperate regions around the world, where it functions as a sodium chloride compound under cyclic humidity conditions. This test procedure is moderately affected by humidity and salinity and is designed to be suitable for quality assurance of metal and corrosion protection commonly encountered in motor vehicles. The method may also be relevant in other applications, providing similar climatic conditions that represent the effects of sodium chloride compounds.

1 Range
This standard specifies test methods, reagents and procedures to be used in accelerated atmospheric corrosion tests, including conditions of exposure to a slightly acidified solution of 1% NaCl for 6 hours twice a week followed by a controlled humidity cycle between 95% RH and 50% RH at a constant temperature of 35 °C.

This international standard does not specify the size of the sample, the exposure period for a particular product or the interpretation of the results. Such details are provided in the corresponding product specifications.

Accelerated laboratory corrosion tests are available

– Metals and their alloys,

– Metal coating (anode or cathode),

– Chemical conversion coatings, as well

– Organic coating on metal materials.

Note 1 There is a risk of exaggerated pitting if low-alloy stainless steels, especially austenitic grades, are tested according to this international standard, which is not applicable in most service environments.

ISO 16701-2015 Corrosion of metals and alloys Accelerated corrosion tests in artificial atmospheres involving exposure to controlled conditions of moisture cycling and intermittent spray of salt solutions

Note 2 This standard does not apply to the testing of waxes and oil-based rust inhibitors due to increasing temperature conditions.

2 Normative references
All or part of the following documents are referred to normatively in this document and are required for their application. For dated references, only the cited version applies. For undated references, a new version of the reference (including any revisions) applies.

ISO 4628-1, Paints and varnishes – Assessment of degradation of coatings – number and size of defects and designation of intensity of uniform change in appearance – Part 1: General introduction and designation of systems

ISO 4628-2, Paints and varnishes – Assessment of coating degradation – designation of number and size of defects, and intensity of uniform changes in appearance – Part 2: Assessment of degree of foaming

ISO 16701-2015 Corrosion of metals and alloys Accelerated corrosion tests in artificial atmospheres involving exposure to controlled conditions of moisture cycling and intermittent spray of salt solutions

ISO 4628-4, Paints and varnishes – Assessment of coating degradation – designation of number and size of defects, and intensity of uniform changes in appearance – Part 4: Assessment of degree of cracking

ISO 4628-5, Paints and varnishes – Assessment of degradation of coatings – Number and size of defects and designation of intensity of uniform change in appearance – Part 5: Assessment of degree of peeling

ISO 8407, Corrosion of metals and alloys – Removal of corrosion products from corrosion samples

ISO 10289, Corrosion test methods for metallic and other inorganic coatings on metallic substrates – Rating of corrosion tested specimens and finished products

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