Influência das temperaturas de encharque e superenvelhecimento nas propriedades mecânicas de um aço ultra baixo carbono com características BH processado via recozimento contínuo

Abstract

This study evaluated the effects of variations in the conditions of soaking and overaging continuous annealing on mechanical properties in tension, drawability Value (R n) and the increase of mechanical strength by aging (BH value) of an ultra low carbon steel microalloyed with Nb. The material was processed on industrial scale, until cold rolling and was subjected to four different soaking temperatures, four temperatures overaging in a continuous annealing simulator. After processing the material in the simulator, the skin pass of 1.4% was applied in the pilot roller, and evaluated the properties of interest. The results showed that among the parameters studied, the greatest influence on the mechanical properties and aging-hardening of steel was soaking temperature. The values of yield strength and tensile strength had a small decrease with increasing temperature. The elongation did not change with any of the temperatures studied. The parameters of formability (Rmédio, nmédio) increased slightly with increasing soaking temperature. The BH value has increased more significantly with increasing soaking temperature, due to greater dissolution of NbC and consequent increase of carbon in solid solution.