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

• Main Authors: AOYAGI Akihiro, JIN Takayoshi, YAMAMOTO Masaaki, KIZU Taro
• Format: Patent
• Language: English
• Published: 27.09.2019
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

NON-PICKLED HOT-ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING SAME 5 Provided is a non-pickled hot-rolled steel sheet demonstrating sufficient blackness seen from any direction and excellent scale adhesion. The non-pickled hot-rolled steel sheet comprises a base hot-rolled steel sheet and scale on a surface of the base hot-rolled steel sheet, the scale consisting of Fe 3O4 and Fe and having a thickness of 3.0-20 µm, wherein an average grain 10 size on a surface layer of the scale comprises 3.0 µm or less, an area ratio of Fe in a cross-section of the scale comprises less than 1.0 % in a region of 0-1.0 µm in a thickness direction of the scale from an outermost surface layer of the scale, while 1.0 % or more in a region of 0-1.0 µm in the thickness direction of the scale from an interface between the scale and the base 15 hot-rolled steel sheet. (FIG. 2)