The authors construct the thermokinetic diagram describing the decomposition of supercooled austenite in steel 05G2MFB and analyze the effect of cooling rate on the structure of this steel. The mechanical properties of the steel are studied after cooling from the austenite region at rates from 0.1 to 52°C/sec, making it possible to obtain ferritic-pearlitic and bainitic structures with different ratios of the micro-components. It is shown that the most favorable set of properties is obtained by a cooling regime that forms a structure composed mainly of bainite. Plastic deformation of the steel prior to its controlled cooling additionally increases its strength characteristics while also increasing impact toughness at minus temperatures.