HOT-ROLLED STEEL SHEET, METHOD OF MANUFACTURING THE SAME, AND MANUFACTURING EQUIPMENT FOR THE SAME

摘要

A manufacturing method for a hot-rolled steel sheet is disclosed. The method comprises: a hot rolling step of hot rolling a slab; a first phase transformation step of phase transforming tissue of a surface portion of the slab by cooling a surface of the hot-rolled slab; a second phase transformation step of phase transforming tissue of a central portion of the slab after transforming tissue of the surface portion of the slab; and a winding step of winding the slab having the surface portion and the central portion which are phase transformed.