Improving the Chemical Composition of High-Strength Special-Purpose Steels with the Formation of a Bainite Structure

The work considers the improvement of the chemical composition of high-strength special-purpose steels in order to reduce the mass of products, the content of expensive alloying elements while increasing the level of mechanical properties. The main attention is paid to the alloying of steels of the Cr-Ni-Mo system using microalloying elements (V, Ti, Nb, B), which contributes to the formation of a homogeneous bainite structure after heat treatment. Four variants of experimental steels were manufactured in laboratory conditions, for which the chemical composition, microstructure and microhardness were studied. Metallographic analysis was carried out, the nature of the liquation, the morphology of bainite, the presence of retained austenite and other structural components were determined. It is shown that by changing the content of alloying elements, it is possible to controllably influence the structure and properties of steels. The results obtained can be used to develop new materials with improved performance characteristics for special-purpose products.