METHOD FOR MANUFACTURING COLD ROLLED STEEL SHEET FOR AUTOMOBILE AND ELECTRIC HOME APPLIANCE PANEL WITH EXCELLENT IMAGE CLARITY

摘要

PURPOSE: A method for manufacturing cold rolled steel sheets with excellent image clarity after painting and processability for the application to automobile and electric home appliance panel is provided. CONSTITUTION: The method includes the steps of processing a cold-rolling roll to have the average roughness (Ra) of 2.2 to 2.5 μm and the high spot count (HSC) of 30 to 33 by electrochemical discharging texturing (EDT), so that the waviness coefficient average (Wca) and the average roughness of cold rolled steel sheet are each controlled to less than 0.65 μm and 1.0 to 1.4 μm; and temper rolling the cold rolled steel sheet with a rolling roll having an average roughness (Ra) of 2.0 to 2.3 μm and the high spot count (HSC) of 30 to 33 so that final temper rolled steel sheet has an average roughness of 1.5 to 1.8 μm and a waviness coefficient average (Wca) of less than 0.6 μm.