METHOD FOR MANUFACTURING HOT ROLLED 304 STAINLESS STEEL SHEET HAVING SUPERIOR SURFACE QUALITY

摘要

PURPOSE: A method for manufacturing hot rolled 304 stainless steel sheet is provided to reduce surface defects such as M type sleever formed on final product by selecting appropriate heating conditions according to 304 stainless steel and setting up heating temperature and steel composition system considering hot rolling capacity. CONSTITUTION: The method for manufacturing hot rolled 304 stainless steel sheet having superior surface quality comprises the processes of heating a 304 stainless steel slab comprising 0.08 wt.% or less of C, 1.0 wt.% or less of Si, 2.0 wt.% or less of Mn, 0.045 wt.% or less of P, 18.0 to 20.0 wt.% of Cr, 8.0 to 10.5 wt.% of Ni and a balance of Fe and other inevitable impurities and selectively containing 0.008 to 0.020 wt.% of Ti, 0.0020 to 0.0035 wt.% of B, or a combination thereof in the temperature range of 1,220 to 1,240 deg.C in an atmosphere of SO2 having concentration of 200 to 1,000 ppm; and hot rolling the heated slab. In a method for manufacturing 304 stainless steel sheet comprising the processes of heating a 304 stainless steel slab in the temperature range of 1,220 to 1,300 deg.C in an atmosphere of SO2 having concentration of 200 to 1,000 ppm, and hot rolling the heated slab, the method for manufacturing hot rolled 304 stainless steel sheet having superior surface quality is characterized in that an ordinary 304 stainless steel is used as the slab when a required heating temperature according to hot rolling of the slab is in the temperature range of 1,220 to 1,240 deg.C, a slab is used in which 0.008 to 0.020 wt.% of Ti is added to a composition for the ordinary 304 stainless steel when a required heating temperature according to hot rolling is in the temperature range of 1,241 to 1,260 deg.C, and a slab is used in which 0.008 to 0.020 wt.% of Ti and 0.0020 to 0.0035 wt.% of B are added to the composition for the ordinary 304 stainless steel when the required heating temperature according to hot rolling is in the temperature range of 1,261 to 1,300 deg.C.