Army Materials and Mechanics Research Center, Watertown, Mass.
The torsional flow and fracture characteristics of several high strength steels are examined. Comparison is made to flow curves obtained in uniaxial tension. It is noted that the flow curve obtained in torsion may not necessarily duplicate the flow curve determined in tension. It is suggested that lack of agreement may be due to the presence of microcracks. Nonuniform deformation localizes the formation of microcracks. It is shown that the tendency to deform locally is influenced not only by strength level but by the value of the strain hardening exponent as well. Torsional strains are also presented and compared to corresponding tensile fracture strain data. It is noted that the value of the torsional fracture strain may be low and less than the tensile fracture strain despite a fracture surface which appears ductile.
Paper ID: JTE10044J