The effect of V(C,N) precipitates undissolved in austenite on structure and mechanical properties of the medium carbon microalloyed V-N steels has been studied. The forgings have been produced in the process of controlled plastic deformation by forging followed by accelerated cooling. It was shown that lowering austenitizing temperature and increasing amount of undissolved V(C,N) particles provided fine grain recrystallized austenite structure after plastic deformation in the temperature range of 1000-900°C, and led to improvement of steel toughness at low temperatures.