Effect of cold rolling on the mechanical properties of an FeCo-2V alloy

Abstract

The embrittlement of an FeCo-2V alloy, which is caused by ordering, has been found to be prevented or reduced by means of cold rolling over about 72% reduction. The specimens annealed after such rolling, in which lattice imperfections are virtually annihilated, do not always show embrittlement even after ordering. A simultaneous increase in strength and elongation, rather than an embrittlement, is brought about by the ordering at an early stage. This rolling effect has been shown not to depend on the following factors: existence of lattice imperfections, formation of textures, and changes in shape of grains. An attempt is made to explain the rolling effect in terms of the LCD zone model, local concentration-disordered zones, combining with an assumption that clusters composed of the composition near Co₃V are already formed in the course of the solidification: the clusters are, by the rolling, elongated and aligned along the rolling direction to form a fibrous structure, so that the same function as that in the fibrereinforced materials would be induced by the forming of a ductile fibrous structure, which is produced around the individual elongated clusters as the LCD zones are developed by the ordering.