МОДЕЛЮВАННЯ ВПЛИВУ НА СТРУКТУРУ ТА ВЛАСТИВОСТІ ЗМІНИ РЕЖИМІВ ОБРОБКИ НИЗЬКОВУГЛЕЦЕВОЇ СТАЛІ

Abstract

Round bar sections made from the low-carbon SAE 1008 steel grades require a continuously increase of the improvements of the reliable quality assurance of the system. The grain size, leading to changes in mechanical properties, is the most important microstructure parameter. Influence of the parameters of the deformation and heat treatment on the structure of the investigated steel, which is ferrite with small areas of lamellar pearlite, was determined due to metallographic examinations. Established, based on the conducted computational and analytical investigations, that after high-speed hot deformation, exactly the temperature of the end of the cooling affected the average conditional diameter of the grain. Cooling to temperatures ~ А1 + 150ºС after hot deformation, followed by slow cooling, during which forms a more uniform grain, which ensures minimal dispersion of the mechanical properties, is rational for rolled steels of the SAE 1008 grades.