In the present work the amount of retained austenite present in quenched and tempered high carbon-chromium alloyed steel was quantified by X-ray diffraction and magnetization saturation measurements. The steel was forged and directly quenched. The retained austenite partially transformed into martensite on cooling down to -196 degrees C. The M-f temperature of about -150 degrees C was found by thermomagnetic analysis. Tempering at low temperatures (220 degrees C and 270 degrees C) promoted the stabilization effect of austenite. The intrinsic magnetization of the ferromagnetic martensite used in the phase quantification was 206.4 A(2) m/kg. The increase of the tempering temperature above 320 degrees C slightly decreases the m (s) value of the martensite due to tempering reactions.