Investigation of the Plastic Properties of Certain Ferrous and Nonferrous Materials at High Temperature

Plastic properties of certain carbon steels, brasses, copper, and aluminum are determined between room and recyrstallization temperatures. The investigations are carried out using the tension test conducted in a specially constructed furnace. Equivalent-stress, equivalent-strain curves and plastic anisotropy parameters are obtained. The equivalent-stress, equivalent-strain curves are then fitted to an empirical equation σ¯ = A(B + ε¯)ⁿ by a computer program employing a numerical gradient method. The results show that equivalent stress decreases as the temperature increases, and it increases as the strain-rate increases. Materials obtained as round bars show very little plastic anisotropy in their transverse planes whereas materials in the form of sheets have pronounced anisotropy. Plastic anisotropy decreases as temperature increases. The results obtained and techniques used may prove to be useful for designers of metal forming equipments, and researchers in the area of plasticity.