1. Quenching from 1100 to 1200°C, followed by water or air cooling and cold plastic deformation by 30 to 40% at temperatures within the 200 to 600°C range and 850 to 900°C annealing for 90 to 120 min with rapid cooling, enhance impact toughness at room temperature In 1Kh16S2MB2 steel, raising it from 1–1.5 to 10–11 kg/cm2 and to 11.2 and 19 kg/cm2 in 0Kh13MV4FB and 1Kh25T steel, respectively, and reduce the range of cold brittleness by 60 to 80°C. 2. Strength and plasticity during extension are not changed by the above treatment. 3. Apparently, the reasons for the increased impact toughness of steel after the proposed heat treatment lie in the change of the condition of intergranular transition zones under the action of plastic deformation and crystallization and due to the precipitation of Fe2(Mo, Nb). These changes may enhance the resistance to breaking away. 4. The recommended heat treatment is facilitated by substituting cooling off in air for quenching until the temperature of plastic deformation is achieved, or by applying only plastic deformation and a recrystallization anneal. The impact toughness remains unaltered. The proposed method is suitable for improving impact toughness in ferrite-type stainless chromium steel.