Bare weathering steel with stable rust layer and manufacturing method thereof

The invention discloses bare weathering steel with a stable rust layer. The surface of the bare weathering steel is provided with the rust layer formed within 2 hours. In addition, the invention further discloses a manufacturing method of the bare weathering steel with the stable rust layer, which comprises the following steps that (1), the surface of a steel plate is cleaned, and then residual moisture is removed; (2) a reagent is applied to the surface of the steel plate so as to enable elemental iron on the surface of the steel plate to be converted into ionic-state iron; and (3) water is sprayed to the surface of the steel plate so as to enable the surface of the steel plate to be infiltrated by a water film, a water film is sprayed again after the water film on the surface of the steel plate is completely dried, the operation is repeated a plurality of times so as to enable ionic molten iron to be hydrolyzed into hydroxide precipitates of iron, and then dehydrating is performed toform the rust layer. The