▎ 摘　　要

NOVELTY - Composite passivating agent comprises 200-600 grams/L acrylic acid, 40-100 grams/L graphene, 0.005-0.05 grams/L polyurethane, 2-4 grams/L chelating agent, 8-15 grams/L corrosion inhibitor and 5-15 grams/L surfactant. USE - Composite passivating agent for passivating hot dip coating plating unit (claimed). ADVANTAGE - The composite passivating agent does not harm human health and ecological environment, improves the corrosion resistance property by 5% neutral salt spray test in which average salt spray resistance time is reaches to 81 hour. It gives good protection to workpiece under the strict working condition and has good application prospect. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing composite passivating agent, which involves: (A) adding surfactant, corrosion inhibitor and chelating agent into the reactor; (B) adding water, heating and agitating, dissolving at 50-70 degrees C and stirring to dissolve completely; (C) adding sequence of the surfactants, corrosion inhibitors, chelating agents and stirring to mix uniformly at 50-70 degrees C and cooling to room temperature to obtain mixed solution; (D) adding acrylic acid into the mixed solution, stirring to completely dissolve and adding the polyurethane; (E) stirring the graphene to mix uniformly, adding water to prescription amount and stirring for 3-5 hours under ultrasonic condition to obtain transparent graphene oxide solution; and (F) adding graphene oxide solution is added into the solution and adding 1 L water and stirring uniformly to obtain composite passivator.