Industrial alloyed steels were investigated. Transformations in supercooled austenite upon continuous cooling was analyzed by dilatometry, and thermokinetic diagrams for the studied steels in the cooling rate range from 0.1 to 30°C/s were built based on obtained results. The influence of alloying elements on the stability of supercooled austenite and on the structure formation upon thermal treatment was shown. Statistical analysis of the results allowed finding analytical dependences which relate the chemical composition of the steels with their properties: temperatures of onset of bainite and austenite formation, stability of austenite.