Steel for automobile outer plate and preparation method thereof

The invention relates to steel for an automobile outer plate and a preparation method thereof, and belongs to the technical field of steel preparation. The method comprises the steps that a casting blank is rolled and annealed, and strip steel is obtained; flattening the strip steel; and electroplating the flattened strip steel to obtain the steel for the automobile outer plate. Wherein the electroplating adopts a gravity method, the pH value of the electroplating meets a set pH value, and the temperature of an electroplating solution of the electroplating meets a set temperature; by adopting a gravitational electroplating mode and controlling the pH value and the electroplating temperature of an electroplating solution, roughness attenuation caused in the electroplating process is effectively reduced, the steel is prepared by adopting the method, the roughness Ra attenuation of the electroplating process can be smaller than or equal to 0.1 mu m, compared with the roughness Ra attenuation of 0.2-0.4 mu m in t