Effect of hot-band annealing condition on secondary recrystallization in grain-oriented 2.3%Si-1.7%Mn steel

Abstract

The effect of hot-band annealing temperature on secondary recrystallization was investigated using the hot-rolled steel sheets containing ultra-low C-2.3%Si-1.7%Mn-0.01%sol.Al of 2.3 mm thickness. The followings were found. When the hot-bands doesn't recrystallize after the hot-band annealing at 600 and 625 °C, secondary recrystallization of the {110}〈001〉 orientation mixed with the {211}〈011〉 orientation forms. This is because the {110}〈001〉 orientation density is too weak in the primary recrystallization texture. That also occurs when the inhibitor is too weak in the secondary recrystallization stage. Fully recrystallized hot-band after annealing at 700 °C leads to no secondary recrystallization. The reason is that very coarse primary recrystallized grains at the center layer prevent secondary recrystallization. Secondary recrystallization of the {110}〈001〉 orientation evolves completely when only near surface layer but not the center layer of the hot-band recrystallize after the hot-band annealing at 650 and 675 °C. The reason is because amount of {110}〈001〉 component in the primary texture, the inhibitor intensity and the primary matrix grain size structure are satisfied.