Microstructural features and microhardness of Fe-Mo-Nb-V-C low-carbon steel processed by high-pressure torsion: The significance of the initial structural state

The effect of the initial heat treatment (quenching or tempering) of low-carbon steel (Fe-Mo-Nb-V-C) on special features of the ultrafine-grained structure and microhardness produced by high-pressure torsion was investigated. High-pressure torsion promotes the more apparent refinement of structural elements of the steel (d pr = 55 nm for the quenched state and 74 nm for the tempered state) and an increase in structural homogeneity of microhardness of quenched specimens in comparison with tempered ones. Experimental results reveal a high significance of the initial structural state for the final deformation-processed microstructure and microhardness (radial distribution) of steel specimens.