The effect of sequential tensile and cyclic torsion straining on work hardening of steel and brass

Plastic straining in metal forming often involves changes in the strain path, either in the process itself or in successive forming operations. This fact, however, is usually not taken into account in the analyses of forming processes, where the effective strain, temperature and strain rate are commonly considered as the sole process variables. In this paper, the effects of strain path changes on the work hardening behavior of low carbon steel and brass have been investigated under sequential tension and cyclic torsion. Both materials developed saturation flow stresses in pure cyclic torsion. Double stage experiments showed different hardening behaviors according to the deformation sequence and the material. The results were compared to those previously obtained for monotonic tensile and torsion tests.