NON-PICKLED HOT-ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING SAME

Provided is a non-pickled hot-rolled steel sheet which has sufficient blackness as seen from every direction, and which has excellent scale adhesion. The non-pickled hot-rolled steel sheet comprises abase material hot-rolled steel sheet and a scale on a surface of the base material hot-rolled steel sheet, the scale comprising Fe3O4 and Fe and having a thickness of 3.0 to 20 [mu]m. In an upper layer of the scale, an average grain size is not more than 3.0 [mu]m. In a cross section of the scale, an Fe area ratio is less than 1.0 % in the region of 0 to 1.0 [mu]m from an upper-most layer of thescale in a thickness direction of the scale, and is not less than 1.0% in the region of 0 to 1.0 [mu]m from the interface between the scale and the base material hot-rolled steel sheet in the thickness direction of the scale. 本发明提供从任何方向观察均具备足够的黑色性、且氧化皮的密合性优异的黑皮热轧钢板。所述黑皮热轧钢板包含母材热轧钢板、和所述母材热轧钢板的表面上的氧化皮，所述氧化皮由FeO和Fe构成且厚度为3.0～20μm，其中，所述氧化皮的表层的平均粒径为3.0μm以下，从所述氧化皮的最表层起沿所述氧化皮的厚度方向的0～1.0μm的区域中，所述氧化皮的截面中的Fe面积率低于1.0％，从所述氧化皮与所述母材热轧钢板之