COLD ROLLED STEEL SHEET, TIN PLATED STEEL SHEET HAVING SUPERIOR SURFACE GLOSSINESS AND METHOD FOR MANUFACTURING THE SAME

摘要

PURPOSE: A cold rolled steel sheet and a tin plated steel sheet are provided which have superior surface glossiness after plating by controlling an average roughness as well as a roughness peak per inch, thereby minimizing scattering of an incident light. CONSTITUTION: The cold rolled steel sheet has 1.0 to 2.5 microns of an average roughness of the surface thereof, and 60 to 80 of peak value of roughness of the surface thereof. The tin plated steel sheet has 1.0 to 2.5 microns of an average roughness of the surface thereof, 60 to 80 of roughness peak per inch and 200 or more surface glossiness of the surface thereof. In a method for manufacturing a tin plated steel sheet by tin plating the skin-pass rolled steel after skin-pass rolling a cold rolled steel sheet using a skin-pass rolling mill, the method comprises the processes of providing roughness on a work roll of the skin-pass rolling mill by the roto blaster in a revolution of 1150 to 1200 rpm for 2 to 4 minutes as supplying grits having a size of 0.5 to 1.0mm from a dull machine to a roto blaster; and tin plating the skin-passed steel sheet after skin-passing the cold rolled steel sheet so that an average roughness and a roughness peak per inch of the surface of the cold rolled steel sheet are 1.0 to 2.5 microns, and 60 to 80 respectively.