▎ 摘　　要

NOVELTY - The galvanized steel sheet comprises a thermal diffusion layer that is formed on an upper part or one side of the steel sheet and is made of thermal diffusion composition including 1-60 wt.% of graphene, 0.1-10 wt.% of alignment agent, 10-70 wt.% of organic binder, 0.1-8% wt.% of dispersant and solvents. The galvanized steel sheet further comprises chromate-free pretreatment layer formed on the upper part or one side or both sides of the steel sheet. The graphene has 2-10 layers, average particle diameter of 100 nm to 25 mu m and carbon-to-oxygen ratio of greater than or equal to 10. USE - The galvanized steel sheet is useful for a steel board, where the galvanized steel is electro galvanized steel, molten galvanized steel or alloying galvanized steel. ADVANTAGE - The galvanized steel sheet has excellent thermal diffusion property, flexibility, mechanical property and durability. DETAILED DESCRIPTION - The galvanized steel sheet comprises a thermal diffusion layer that is formed on an upper part or one side of the steel sheet and is made of thermal diffusion composition including 1-60 wt.% of graphene, 0.1-10 wt.% of alignment agent, 10-70 wt.% of organic binder, 0.1-8% wt.% of dispersant and solvents. The galvanized steel sheet further comprises chromate-free pretreatment layer formed on the upper part or one side or both sides of the steel sheet. The graphene has 2-10 layers, average particle diameter of 100 nm to 25 mu m, carbon-to-oxygen ratio of greater than or equal to 10 and carbon-to-nitrogen ratio of greater than or equal to 30. The organic binder has glass transition temperature of 0-60 degrees C. The solvents have high boiling point of greater than or equal to 200 degrees C.