Methods for Determining Resistance Indices of Structural Steels under Various Atmospheric Conditions
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METHODS FOR DETERMINING RESISTANCE INDICES OF STRUCTURAL STEELS UNDER VARIOUS ATMOSPHERIC CONDITIONS J. S. Gladchenkova Corrosion testing determines the resistance of materials to corrosion under certain environmental conditions including temperature, humidity, and salt water. There are many methods to measure or access corrosion resistance or materials. The study reviews the main methods for assessing the corrosion resistance of structural steels in aquatic environments and moist atmosphere conditions. The method of alternate immersion in a 3.5% NaCl solution has been established as the most complete and reliable method for determining the corrosion resistance of auto-plate steels under atmospheric conditions. There are many standardized corrosion test methods used to assess the corrosion resistance of structural steels in seawater (ASTM G52, ISO 11306, ISO 20340, ISO 2812-2, and GOST 9.909). However, in the Russian Federation, it is nowadays necessary to update the existing standards and develop a new set of standards for testing materials in different zones of exposure to seawater with different corrosion activities. Keywords: structural steel, auto-plate steel, electrochemical corrosion, corrosion resistance, corrosion tests, microstructure, highly corrosive nonmetallic inclusions.
Corrosion of metal products and structures causes significant economic, social, and environmental damages to the national economy of all industrially advanced and developed nations. The problem of corrosion is currently aggravated by the rapid aging of the main metal fund, physical and moral depreciation, and an insufficient degree of reconstruction and renewability of equipment vulnerable to corrosion [1]. The growth of losses due to corrosion is contributed by the constant and intensive growth of metal-consuming industries such as transport, motor-vehicle construction, thermal and nuclear energy, petrochemicals, and industries where metals are processed in abnormal and extreme conditions such as elevated temperatures, pressures, and chemical environments. This necessitates the requirement of reliable and technically sound methods to measure the corrosion resistance of structural materials in various conditions and atmospheres. In addition, there is an increasing demand to optimize the existing techniques and find new techniques to protect the materials from the corrosion. However, the development of new methods and techniques for corrosion tests reflecting adequately the corrosion resistance of structural steels under real operating conditions is a daunting task. Advancements in metallurgical technologies have led to changes in the types of nonmetallic materials (inclusions) added to modern steels. It is found from practice and experience that a significant number of elements of nonmetallic inclusions (NI) in modern steels does not have any negative effect on the corrosion resistance of steel. Therefore, a purely quantitative assessment of steel contamination with nonmetallic inclusions will currently not give a correct picture and
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