HIGH-CARBON HOT-ROLLED STEEL SHEET, COLD-ROLLED STEEL SHEET AND A PRODUCTION METHOD THEREFOR

• Main Authors: PARK, KYONG-SU, SHIN, HANUL
• Format: Patent
• Language: English; French; German
• Published: 24.07.2013
• 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

The present invention relates to a high-carbon hot-rolled steel sheet capable of satisfying quality of the final product even without some of processes subsequent to hot rolling and a method of manufacturing the same. An exemplary embodiment of the present invention provides a method of manufacturing a high-carbon hot-rolled steel sheet, including the steps of i) preparing high-carbon steel materials comprising C: 0.7 to 0.9%, Si: 0.5% or less, Mn: 0.1 to 1.5%, Cr: 0.5% or less, P: 0.05% or less, and S: 0.03% or less in wt% and remaining Fe and other inevitable impurities; ii) heating the high-carbon steel materials again and manufacturing a steel sheet by performing hot rolling in an austenite region in which a finishing temperature for the hot rolling is an Ar3 transformation temperature or higher; iii) rapidly cooling the steel sheet at 520 to 620°C before phase transformation is started in a Run-Out Table (ROT); iv) uniformly maintaining a cooling retention temperature so that the cooled steel sheet is subject to phase transformation in any one temperature between 520 to 620°C; and v) winding the steel sheet in the cooling retention temperature.