IS 14191 : 2024/ISO 9223 : 2012 Corrosion of Metals and Alloys - Corrosivity of Atmospheres - Classification, Determination and Estimation
NATIONAL FOREWORD
This Indian Standard (First Revision) is identical to ISO 9223 : 2012 'Corrosion of metals and alloys - Corrosivity of atmospheres - Classification, determination and estimation' issued by the International Organization for Standardization (ISO) was adopted by the Bureau of Indian Standards on the recommendation of Corrosion Protection and Finishes Sectional Committee and approval of the Metallurgical Engineering Division Council.
This standard was first published in 1996. The first revision of this standard has been undertaken to align with the International Standard ISO 9223 : 2012 under dual numbering system.
Metals, alloys and metallic coatings may suffer atmospheric corrosion when their surfaces are wetted. The nature and rate of the attack will depend upon the properties of surface formed electrolytes, particularly with regard to the level and type of gaseous and particulate pollutants in the atmosphere and to the duration of their action on the metallic surface.
Data on the corrosivity of the atmosphere are an essential requirement for the development and specification of optimized corrosion resistance for manufactured products.
The corrosivity categories are defined by the first-year corrosion effects on standard specimens as specified in IS 14297 : 2024/ISO 9226 : 2012. The corrosivity categories can be assessed in terms of the most significant atmospheric factors influencing the corrosion of metals and alloys.
The measurement of relevant environmental parameters is specified in IS 14322 : 2024/ISO 9225 : 2012.
The ways of determining and estimating the corrosivity category of a given location according to this Standard and the relationships among them are presented in Fig. 1. It is necessary to distinguish between corrosivity determination and corrosivity estimation. It is also necessary to distinguish between corrosivity estimation based on application of a dose-response function and that based on comparison with the description of typical atmospheric environments.
Former title of the Indian Standard IS 14191 was 'Corrosion of metals and alloys - Classification of corrosivity of atmospheres' which is changed to 'Corrosion of metals and alloys - Corrosivity of atmospheres - Classification, determination and estimation' as per the title of ISO 9223.
The text of ISO standard has been approved as suitable for publication as in Indian Standard without deviations. Certain terminologies and conventions are, however, not identical with those used in Indian Standard. Attention is especially drawn to the following:
a) Wherever the words 'International Standard' appear referring to this standard, it should be read as 'Indian Standard'; and
b) Comma (,) has been used as a decimal marker while in Indian Standards the current practice is to use a point (.) as the decimal marker.