ANALYSIS OF HOT ROLLING VARIABLES CONTRIBUTIONS ON GRAIN REFINEMENT AND MECHANICAL PROPERTIES OF V- AND Ti-MICROALLOYED STEELS

Microalloying is one of the most attractive technique used in the past three decades to improve the mechanical properties of steel. Although the interaction of hot rolling variables and microalloying has been intensively investigated, the magnitude of such variables and their mutual interactions on the grain refinement and mechanical properties have not attracted attention of metallurgists.

In the current study, a 23 factorial design was used to investigate the contribution magnitude of hot rolling variables on grain refinement and mechanical properties of vanadium- and titanium- microalloyed steels. A regression model was used to deduce a mathematical formulation to predict the individual and mutual combination influence of reheating temperature, finishing temperature and cooling rate after rolling on grain size and mechanical properties: hardness, yield strength, ultimate tensile strength and elongation of low carbon V- and Ti-microalloyed steels. The calculated values from the driven models are compared with the results of previous experimental work. It was found that the predicted values are very close to the measured values.