International Standard Organization atmospheric corrosion

The International Standard Organization classification of atmospheric corrosion... 

The International Standard Organization (ISO) developed a corrosivity classification system verified through exposure that has been carried worldwide. The ISO classification system is based on the assumptions that only the time of wetness and the concentration of pollutants in the atmosphere, SO2 and chlorides, control the corrosion rates of metals. Table 10.1 shows the Hst of ISO standards related to atmospheric corrosion of metals [39]. 

International Standards Organization. (1992a). ISO 9223, Corrosion of Metals and Alloys—Classification of Corrosivity of Atmospheres, 20 pp. 

International Standards Organization. (1992b). ISO 9224, Corrosion of Metals and Alloys—Values for the Corrosivity Categories of Atmospheres, 5 pp. International Standards Organization. (1992c). ISO 9226, Corrosivity of Atmospheres—Methods of Determination of Corrosion Rate of Standard Specimens for the Evaluation of Corrosivity, 8 pp. 

ISO CORRAG [23], the International Organization for Standardization (ISO) has implemented a classification system for evaluating atmospheric corrosivity and on the basis of variables that are fairly easy to obtain [24, 25]. This ISO classification has found several applications, for example, to predict the long-term corrosion behavior in different environments and to evaluate the effect of protective coatings. It contains two principally different approaches of assessing the corrosivity of any outdoor atmospheric environment. The first is based on exposure of standard specimens of steel, copper, zinc, and aluminum for one year whereby the corrosion effect is measured through mass loss measurements. One of five measured corrosivity classes... 

The International Organization for Standardization Technical Committee on Corrosion of Metals and Alloys, ISO/TC156, has developed a systematic approach to chissifi-cation of atmospheric corrosivity [13], This approach is based on two different methods. The first method involves exposure of standard coupons of steel, zinc, copper, or aluminum to the atmosphere at the site where the classification is to be made. The selection of which metal is to be used will depend on the purpose of the test. Panels are... 

The rural, industrial, and marine atmospheres described earlier are very broad classifications, and do not adequately define specific exposure conditions. Other categories have been proposed, such as desert, tropical, urban, semiindustrial, and industrial-marine, but even these are not satisfactory for predictive purposes [9]. In the mid-1970s. Technical Committee 156 on Corrosion of Metals and Alloys of the International Organization for Standardization (ISO) identified atmospheric corrosion as a priority area for study. From that, a classification system was developed, and described by four standards (Table 3). The system is based on quantitative values for TOW, SO2, and Cl deposition rates, and/or mass loss of steel, aluminum, zinc, and copper samples exposed for at least one yetir. The TOW can be determined from meteorological data or measured by devices such as described in ASTM G 84, the ionic species deposition rates by ASTM G 92 and either of the Cl methods described earlier, and the mass losses determined by the procedures discussed earlier in this section. The levels of ionic species, TOW, and mass losses are placed in categories as to... 

As discussed in previous chapters, there are many variables that affect atmospheric corrosion. Consequently, programs designed to study atmospheric corrosion have placed emphasis on standardization regarding test procedures. Several corrosion testing standards have been developed by the International Organization for Standardization (ISO) as follows ... 

Because of the many parameters capable of influencing atmospheric corrosion rates, exposure programs have placed increased emphasis on standardized test procedures. The International Organization for Standardization (ISO) has formulated several corrosion testing standards [85-88] and also implemented a... 

A wide variety of tests have been developed 1 ASTM for determining the susceptibility of metals to weathering. Tests for flat panels, qren-helix specimens, galvanic specimens, and SCC specimens have been standardized. These tests have resulted from the efforts of ASTM Committee G-1 and the Subcommittee GOl. 04 on Atmospheric Corrosion. In addition, the International Organization for Standardization (ISO)... 

ISO 9223, Corrosion of Metals and Alloys, Classiftcation of Corrosivity Atmospheres, International Organization for Standardization, Geneva, Switzerland, 1991. 

Corrosion of metals and alloys—Corrosivity if atmospheres—Guiding values for the corrosivity categories. ISO 9224 Switzerland, International Organization for Standardization (ISO), 1992. 

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