Comparison of the Effect of Microadditions of Niobium, Titanium and Vanadium on Formation of Microstructure of Low-Carbon Low-Alloy Steels

Comparative analysis of the effect of microalloying with niobium, vanadium and titanium on the processes of structure formation in low-alloy low-carbon steels subjected to hot plastic deformation by controlled rolling is performed. The concentration and temperature ranges of the influence of these elements on formation of austenite preceding the hot plastic deformation or occurring in the final stage of the controlled rolling before the start of polymorphic & gamma; & RARR; & alpha; transformation are determined. It is shown that the inhibitory effect of the microalloying elements on the growth of the austenite grains in heating in the & gamma; -range intensifies in the V & RARR; Nb & RARR; Ti order, and the capacity to retard recrystallization of the hot-deformed austenite intensifies in the V & RARR; Ti & RARR; Nb order. The microadditions of niobium are shown to have a dual effect on the kinetics of the polymorphic & gamma; & RARR; & alpha; transformation.