Effect of Non-Uniform Concentration Field on TiN Growth in Two-Phase Region with Electropulsing

Abstract

Ti microalloyed steel has the advantages of high toughness and high strength, but it is easy to form TiN particles with large dimensions at high temperatures, which is harmful to the metal and seriously affects the quality of cast billets. In this paper, by analyzing the kinetic characteristics of Ti element diffusion in the two-phase region with electropulsing, the influence mechanism of pulsed current on the growth of TiN particles in the two-phase region is investigated. The results show that the pulsed current improves the flow rate of Ti and N elements in the molten steel, reduces the concentration of Ti in the liquidoid along the solid-liquid interface, and the more the current intensity, the more obvious the impact; in addition, with the increase of the flow rate, the diffusion flux of Ti elements is also gradually improved. Therefore, the pulsed current promotes the diffusion of Ti elements by improving the concentration field of Ti and other solute elements in the two-phase region, thus inhibiting the growth of TiN.