The new technology of hot plastic deformation and heat treatment of sheet hire from 20 to 200 mm thick from steel 10Cr15Ni9Si3Nb1-SH (EP302-SH) is developed. Relevance of improvement of the quality of sheet preparations from the EP302-SH steel applied in nuclear power plant engineering is shown. The structure and mechanical properties of steel at different stages of technological process of production of preparations are studied. It is shown that the offered technology of heat treatment from rolling heating of sheet hire from 20 to 120 mm thick from steel 10H15N9S3B1-SH allows to exclude from the technological process a stage of heat treatment in furnaces that increases strength properties, reduces the cost of preparations, the expense of energy carriers, favorably influencing the environment.