Steel with 5%Cr for cold rolling rolls is investigated in this paper. Kinetics of the supercooled austenite transformation is studied. The influence of the quenching temperature on the structure and properties of roll steels is investigated. The size of austenitic grain, the amount of residual austenite, hardness and martensite transformation start temperature are determined. The susceptibility of steel to brittle failure is determined after quenching and low tempering, and for this purpose the values of K-1c in the entire temperature and time interval of low tempering are measured.