METHOD FOR MANUFACTURING NON-PICKLING HOT DIP GALVANIZED HOT ROLLED STEEL SHEET WITH SUPERIOR COATING ADHESION

摘要

PURPOSE: A method for manufacturing non-pickling hot dip galvanized hot rolled steel sheet having superior coating adhesion in ordinary reduction heating conditions and Al concentration of plating pot of the hot dip galvanized steel sheet manufacturing process by controlling constituents of the plating pot and plating conditions is provided. CONSTITUTION: In a non-pickling hot dip galvanized hot rolled steel sheet manufacturing method using a hot rolled steel sheet to which hot rolling scale is adhered as a material to be plated, the method for manufacturing non-pickling hot dip galvanized hot rolled steel sheet with superior coating adhesion comprises the steps of reducing scale layer formed on the hot rolled steel sheet under the reduction heat treatment conditions at 550 to 650 deg.C for 55 to 65 seconds; and dipping the scale layer reduced steel sheet into a plating pot containing 0.2 to 0.25 wt.% of Al, 1.7 to 3.2 wt.% of Sb and a balance of Zn and having a temperature of 480 to 500 deg.C so that the scale layer reduced steel sheet is plated.