The influence of heat treatment on homogeneity of strength properties and structural peculiarities of low-carbon steel Fe-Mo-Nb-V-C processed by high-pressure torsion

A homogeneity of strength properties (microhardness) through the specimens and the peculiarities of an ultrafine-grained structure produced in low-carbon steel Fe-Mo-Nb-V-C by cold high-pressure torsion, depending on initial heat treatment of steel were studied. As a result of high-pressure torsion, the microhardness of steel was increased up to 700-770 HV (in the middle part of disk radii), and the mean (sub)grain size was reduced to ≈100 nm. Initial quenching of low-carbon steel provides a more homogeneous distribution of microhardness through the disk and the higher strength properties after high-pressure torsion in comparison with a normalizing initial state.