Patterns of deformation and fracture in steel R6M5 in a complex stress state

Abstract

1. The resistance of steel to deformation and fracture in the initial state depends upon the type of stress state under which deformation is produced. The limiting state is satisfactorily defined by unified criterion (3) for structurally inhomogeneous materials. 2. The prehistory of loading substantially affects the patterns of deformation and fracture in quasibrittle tool materials of steel R6M5 type: preliminary heatings help to reduce strength and increase plasticity, and resistance to compression declines sharply. 3. Preliminary heating of steel R6M5 curtails the range of safe stresses and distorts the limiting curve in σz − σθ coordinates. Supplementary cyclic conditioning by tension hardens the material somewhat, leading to a shift in the limiting surface in the direction of preliminary loading.