The possibility of mechanical properties improvement in cast low carbon manganese steels for thin-walled castings via appropriate microalloying and heat treatment was studied. The steels (0.15 C and 1.2 Mn) microalloyed by vanadium, titanium and niobium were undergone the solution heat treatment. Mechanical testing and detailed microstructural analyses were performed using light, transmission and scanning electron microscopy. Precipitation processes in individual steels were discussed and the steel with the most promising composition was selected for following experiments.