ISO 9223-2012 pdf download.Corrosion of metals and alloys – Corrosivity of atmospheres – Classification, determination and estimation.
ISO 9223 establishes a classification system for the corrosivity of atmospheric environments.
defines corrosivity categories for the atmospheric environments by the first-year corrosion rate of standard specimens,
gives dose-response functions for normative estimation of the corrosivity category based on the calculated first-year corrosion loss of standard metals, and
— makes possible an informative estimation of the corrosivity category based on knowledge of the local environmental situation.
This International Standard specifies the key factors in the atmospheric corrosion of metals and alloys. These are the temperature-humidity complex, pollution by sulfur dioxide and airbcwne salinity.
Temperature is also considered an important factor for corrosion in areas outside the temperate macroclimatic zone. The temperature-humidity complex can be evaluated in terms of time of wetness. Corrosion effects of other pollutants (ozone, nitrogen oxides, particulates) can influence the corrosivity and the evaluated one-year corrosion loss, but these factors are not considered decisive in the assessment of corrosMty according to this International Standard.
This International Standard does not characterize the corrosivity of specific service atmospheres, e.g. atmospheres in chemical or metallurgical industries.
The classified corrosivity categories and introduced pollution levels can be directly used for technical and economical analyses of corrosion damage and for a rational choice of corrosion protection measures.
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 8044, Corrosion of metals and alloys — Basic terms and defInitions
ISO 9224, Corrosion of metals and alloys — Corrosivity of atmospheres — Guiding values for the corrosivity cafe gones
ISO 11844-1, Corrosion of metals and alloys — Classification of low corrosivity of indoor atmospheres — Part 1: Determination and estimation of indoor corrosivity
ISO 11844-2, Corrosion of metals and alloys — Classification of low corrosivity of indoor atmospheres — Part 2: Determination of corrosion attack in indoor atmospheres
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8044 and the following apply.
3.1 corrosivity of atmosphere
ability of the atmosphere to cause corrosion in a given corrosion system
3.2 category of corrosivity of atmosphere
standardized rating of corrosivity of atmosphere in relation to the one-year corrosion effect
3.3 type of atmosphere
characterization of the atmosphere on the basis of appropriate classification criteria other than corrosivity or of complementary operation factors
EXAMPLE Rural, urban, industrial, marine, chemical, etc.
3.4 temperature-humidity complex
combined effect of temperature and relative humidity on the corrosivity of the atmosphere
3.5 time of wetness
period when a metallic surface is covered by adsorptive and/or liquid films of electrolyte to be capable of causing atmospheric corrosion
3.6 pollution level
numbered rank based on quantitative measurements of specific chemically active substances, corrosive gases or suspended particles in the air (both natural and the result of human activity) that are different from the normal components of the air
3.7 category of location
conventionally defined typical exposure conditions of a component or structure.ISO 9223 pdf free download.