Hot-rolled steel plate and its manufacturing method

Abstract

The hot-rolled sheet of this disclosure comprises: recrystallized grains, which are grains with a GOS value of less than 3.0°; and non-recrystallized grains, which are the remaining portion of the recrystallized grains in the metal structure; the area fraction of the recrystallized grains is 4.0% or more; and the average KAM value of the recrystallized grains is 0.6° or less. In the hot-rolled sheet of this disclosure, the average KAM value of the non-recrystallized grains is preferably 0.9° or less. In the hot-rolled sheet of this disclosure, the weighted average of the grain size of the recrystallized grains, with area as the weight, is preferably 100µm or less. In the hot-rolled sheet of this disclosure, in the region from the surface to a depth of 1 / 4 of the thickness of the hot-rolled sheet, the area fraction of the recrystallized grains is 30% or more.

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