Characterization of initial structures, texture and precipitates in strip-cast 3wtSi steel sheet

摘要

A Fe-3wt%Si strip was produced using a vertical type twin-roll strip casting process, and two typical initial structures were observed. One was the solidification structure consisting of coarse columnar grains and the other was the deformed structure which was composed of outer inclined columnar grains and inner fine equxied grains. The solidification structure was characterized by {111}//ND fiber while the deformed structure shows a strong Goss texture. In addition, the size distributions of MnS precipitates, which were used as grain growth inhibiters, were investigated in the as-cast strip. The size of these particles in the deformed grains was smaller than that in the solidified grains, which could be attributed to the strain-induced precipitation mechanism. The differences of the initial structures, texture and precipitation behaviors resulted from the different superheating along the transverse direction of the as-cast strip, which originated from the inhomogeneous flowing of liquid steel.