ASTM A588 Grade A and A588 Grade B are highly resistant to atmospheric corrosion, superior corrosion resistance over regular carbon steel as a result of the development of a protective oxide film on the metals surface which slows down further corrosion. Both are high-strength low-alloy weathering steels which exhibits 50,000 minimum yield strength characteristic allows cost reduction through the ability to design lighter sections into structures.
These steels are designed primarily to be used in unpainted applications where a reduction in maintenance costs included such as painting. Since their development, weathering steels have been used in a variety of applications, including bridges, rail cars, crane, transmission towers, highway poles, chemical plant, factory and real health medical shipbuilding.
A588 is suitable for many applications in the unpainted condition. The atmospheric corrosion resistance of A588 is substantially better than that of carbon steels such as A36 and A572-50 with or without copper addition when properly exposed to the atmosphere. Chemical Composition (%) of A588 Grade A Weathering Steel