PRODUCING PROCESS FOR SURFACE-TREATED STEEL SHEET WITH SUPERIOR WELDABILITY

摘要

PURPOSE: A process for producing surface-treated steel sheet with superior weldability is provided to improve adhesion between a tin plate layer and a matrix steel by controlling the concentration of gloss additive precisely. CONSTITUTION: The process includes the steps of degreasing and pickling a steel sheet; electrolytic tin plating the steel sheet with a plating solution containing Ti¬2+ 10-40g/L, phenolsulfonate 10-20g/L, ethoxylated naphthol sulfonate 2-12g/L (gloss additive) in a current density of 0.1-3A/dm¬2 and in the temperature range of 25-55°C so that a tin is plated in an amount of 0-150mg/m¬2; and plating the obtained tinplate with metal chrome and chrome hydroxide in an amount of 50-150mg/m¬2 and in an amount of 5-25mg/m¬2, respectively.