Abstract: The present invention enables quick cooling of steam-treated objects and thus reduces the manufacturing time of steam-treated products such as black coated steel sheets. The present invention provides a method for manufacturing steam-treated products, which involves a steam treatment step that introduces steam into a closed container (10) containing a treatment object (1) and brings the treatment object (1) into contact with the steam, and a treated object cooling step that cools the object (1) treated with steam in the steam treatment step, wherein said treated object cooling step introduces coolant gas into said closed container (10), brings said treated object (1) into contact with the coolant gas, and discharges the introduced coolant gas from said closed container (10).

Abstract: The present invention enables quick cooling of steam-treated objects and thus reduces the manufacturing time of steam-treated products such as black coated steel sheets. The present invention provides a method for manufacturing steam-treated products, which involves a steam treatment step that introduces steam into a closed container (10) containing a treatment object (1) and brings the treatment object (1) into contact with the steam, and a treated object cooling step that cools the object (1) treated with steam in the steam treatment step, wherein said treated object cooling step introduces coolant gas into said closed container (10), brings said treated object (1) into contact with the coolant gas, and discharges the introduced coolant gas from said closed container (10).

Abstract: A coated steel sheet comprises: a steel sheet; a primer coating film which is arranged on the steel sheet and comprises an anti-corrosive pigment and an aggregate composed of primary particles; and a top coating film which is arranged on the primer coating film. The anti-corrosive pigment comprises at least one compound selected from the group consisting of a bivalent tin salt, a trivalent vanadium salt, a tetravalent vanadium salt, a tetravalent molybdenum salt, an oxycarboxylic acid salt, an ascorbic acid, a phosphorous acid salt and a hypophosphorous acid salt.

Abstract: This coated steel sheet comprises: a steel sheet; a primer coating film that is arranged on the steel sheet and contains a chromic acid-based rust preventive pigment and aggregate that serves as primary particles, while not containing porous particles; and a top coating film that is arranged on the primer coating film. The aggregate satisfies the following formula (1) and formula (2). D10?0.6T (1) D90<2.0T (2) (In the formulae, D10 represents the 10% particle diameter (?m) of the aggregate in the number-based cumulative particle size distribution; D90 represents the 90% particle diameter (?m) of the aggregate in the number-based cumulative particle size distribution; and T represents the film thickness (?m) of a portion of the primer coating film, in which the aggregate is not present.

Abstract: A coated steel sheet comprises: a steel sheet; a primer coating film which is arranged on the steel sheet and comprises an anti-corrosive pigment and an aggregate composed of primary particles; and a top coating film which is arranged on the primer coating film. The anti-corrosive pigment comprises at least one compound selected from the group consisting of a bivalent tin salt, a trivalent vanadium salt, a tetravalent vanadium salt, a tetravalent molybdenum salt, an oxycarboxylic acid salt, an ascorbic acid, a phosphorous acid salt and a hypophosphorous acid salt.