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}k011l orientation forms. This is because the {110}k001l 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.