Abstract
Modern production requires the improvement and creation of materials with unique properties, and their use in structures is determined by the ratio between strength and plasticity, therefore metal materials are characterized by the most attractive ratio from the point of view of practical expediency. The increase in strength properties is ensured mainly due to the purposeful formation of a crushed structure.Analysis of the latest research and publications showed that methods of thermomechanical processing of materials re-main promising for the formation of ultra-and nanostructures in metallic materials.The purpose of the work is to establish the patterns of changes in the structure and properties of crystalline materials after deformation and pre-recrystallization heat treatment.The work presents methods for determining the strength properties of metal materials and determining the size of their structural elements.The article highlights the feasibility of using pre-recrystallization heat treatment of previously deformed technically pure iron (GOST 3836-83), carbon steels 20, 45 (GOST 1050-88) and U8 (GOST 1435-88), alloy steels 40X (GOST 2591-2006), 12X13 and 12X18N9T (GOST 2590-2006) to increase their hardness due to the formation of a thermally stable polygonization substructure, mostly on of a nanoscale. It is shown that an increase in the content of carbon and chromium in steels during short-term exposure at a temperature that corresponds to the temperature threshold of recrystallization of the mentioned steels leads to a decrease in the increase in their hardness. Combined deformation, which consists of dynamic deformation by 30% followed by static deformation by 30%, provides an opportunity to increase the exposure time for technically pure iron, carbon and alloy steels up to 60 minutes due to the formation of a thermally stable polygonization substructure in the process of their pre-recrystallization heat treatment. It was established that the increase in hardness of technically pure iron, steel 20and 45 decreases with an increase in the amount of carbon, and the increase in hardness of chromium-alloyed steels increases with an increase in the amount of chromium. The optimal mode of pre-recrystallization heat treatment of a heat-protective plasma coating with ZrO2+ 7% Y2O3was determined, which provides an increase in hardness by 13% and a decrease in the thermal conductivity of the ceramic layer by 15% compared to the state after sputtering due to substructural changes.
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