METHOD FOR MANUFACTURING HOT ROLLED HIGH CARBON STEEL SHEET HAVING SUPERIOR SURFACE QUALITY

摘要

PURPOSE: A method for manufacturing hot rolled high carbon steel sheet having superior surface quality is provided to suppress scale defects and edge cracks by controlling inlet temperature of finish rolling and the number of cooling banks. CONSTITUTION: In a hot rolled steel sheet manufacturing method comprising the processes of hot rolling a high carbon steel slab containing carbon content of 0.4 wt.% or more, injecting cooling water onto the hot rolled steel sheet using a plurality of cooling banks in cooling section, and coiling the cooled hot rolled steel sheet, the method for manufacturing hot rolled high carbon steel sheet having superior surface quality is characterized in that an inlet temperature of hot finish rolling is controlled to 900 to 950 deg.C during the hot rolling process, and the number of cooling banks for injecting cooling water onto the hot rolled steel sheet in the cooling section is controlled so that the number of cooling banks satisfy the following relational expression: the number of cooling banks<=-11.6+0.016Te+0.006Vr, where Te is temperature (deg.C) of the edge part of finish rolling completed steel sheet, and Vr is rolling speed (m/min).