Surface-treated steel sheet and method of manufacturing the same

1. A surface-treated steel sheet comprising:

a steel sheet; and

a coated layer which is formed on one surface or both surfaces of the steel sheet and includes zinc and vanadium,

wherein the coated layer has a vanadium content of 1% or higher and 20% or less and a coating weight of 3 g/m 2 or higher and 40 g/m 2 or less, and has a plurality of dendritic arms that are grown in a thickness direction of the steel sheet, and

wherein a ratio x/y of a content x of the vanadium that is present outside the arms to a content y of the vanadium that is present inside the arms is 1.1 or higher and 3.0 or less in terms of the vanadium element.

2. The surface-treated steel sheet according to claim 1 ,

wherein the coated layer has an emissivity of 0.30 or higher and 0.95 or less in a region where a wave number measured under a condition of a surface temperature of 100° C. is 600 to 3000 cm −1 .

3. The surface-treated steel sheet according to claim 1 or 2 ,

wherein a surface roughness of the coated layer is 1.0 μm or higher and 4.0 μm or less in terms of center-line average roughness Ra specified in JIS B 0601:2001.

4. The surface-treated steel sheet according to claim 1 or 2 ,

wherein one or more layers of films are further formed on the coated layer.

5. The surface-treated steel sheet according to claim 4 ,

wherein the film contains an organic resin.

6. The surface-treated steel sheet according to claim 5 ,

wherein the film is a resin film, and contains:

5 to 50 parts by mass of metal oxide particles with respect to 100 parts by mass of a solid content of the resin film; and

0.1 to 30 mass % of a lubricant with respect to 100 mass % of the solid content of the resin film.

7. The surface-treated steel sheet according to claim 5 ,

wherein the organic resin has at least one type of a carboxyl group, a hydroxyl group, a sulfonic acid group, and a silanol group in its structure, and includes:

a polyester resin containing a sulfonic acid group;

a curing agent; and

a coloring pigment containing carbon black.

8. The surface-treated steel sheet according to claim 4 ,

wherein the film is obtained by applying and drying a water-based metal surface treatment agent containing a silane coupling agent onto the steel sheet.

9. The surface-treated steel sheet according to claim 8 ,

wherein the film further contains an inhibitor component which essentially includes a fluorometal complex compound having at least one type selected from titanium and zirconium.

10. The surface-treated steel sheet according to claim 8 ,

wherein the film is a composite film including:

a polyether polyurethane resin; and

a coloring pigment containing carbon black.

11. The surface-treated steel sheet according to claim 5 ,

wherein the film is a coloring painted film layer including a coloring pigment layer.

12. The surface-treated steel sheet according to claim 11 ,

wherein the coloring painted film layer includes a primer-painted film layer, and

the primer-painted film layer is formed between the coated layer and the coloring pigment layer and includes a rust-preventive agent.

13. The surface-treated steel sheet according to claim 11 ,

wherein the coloring painted film layer is formed on the coated layer to be in contact therewith.

14. The surface-treated steel sheet according to claim 11 ,

wherein a chemical conversion treatment layer is further included between the coloring painted film layer and the coated layer.