Stainless Steel in Structural Applications

Stainless steel has been used in building construction for many years. Most applications have been for the non-structural purposes of appearance, durability, and ease of maintenance. In order to provide rational methods for the design of stainless-steel structural members, so that architectural applications could also fulfill a load-bearing function, American Iron and Steel Institute initiated a research project at Cornell University. The mechanical properties of wrought austenitic stainless steels are different from those of carbon and low-alloy steels. Cold working increases yield and ultimate strengths, decreases ductility, accentuates anisotropy, causes an increasing difference in stress-strain curves in longitudinal tension and compression, and may reduce moduli of elasticity—all to a greater degree than in structural carbon and low-alloy steels. The mechanical properties encountered in the annealed and the temper-rolled grades which are necessary for structural design are discussed. Emphasis is given to static, room-temperature response. Because most material specifications for stainless steel give only tensile properties, and do not recognize the anisotropic character of stainless steel, it is necessary to establish reliable design values for properties not normally specified. To demonstrate the significance of the mechanical properties of wrought austenitic stainless steels, an example is taken from the field of thinwalled structures. It is shown that rational structural design of cold-formed stainless-steel members is possible, provided the mechanical properties of stainless steel are known and are applied in the proper manner.