PHYSICAL MODELING DURING THE RESEACRCH OF EFFECT OF ROLLING AND COOLING MODES BY WATER-AIR MIXTURE ON THE QUALITY OF RAILS
In the article the patterns of deformation resistance change and microstructure of steel 76F were investigated during physical modeling of rolling and cooling in the rolling mill by the use of modern high-precision installation Gleeble 3500. The behavior of steel 76F is described during multi-stage compression at different temperatures. The analysis of the influence of temperature modes of cooling on the microstructure of steel 76F during heat treatment is demonstrated. The kinetics of growth and decomposition of austenite, marked by conditions of formation of fine-grained structure, is revealed. It is found that heating to temperatures of 700 - 800 ° C and with a degree of deformation of 65 - 70% when the water-cooling air mixture 3 and 6 seconds does not always ensure the formation of a fine-grained structure of high-sorbitol samples. It was found that heating to 1000 ° C, with a degree of deformation of 65 - 70% when the water-cooling-air mixture for 3 and 6 seconds results in formation of a fine-grained structure in the sorbitol samples studied diameters and the chemical composition.