Abstract: A surface-treated metal plate including: a metal plate; and a nickel-cobalt binary alloy layer formed on the metal plate. When a part having a content ratio of oxygen atoms of 5 atomic % or more as measured by X-ray photoelectron spectroscopic analysis is an oxide coating film, the nickel-cobalt binary alloy layer contains the oxide coating film with a thickness of 0.5 to 30 nm on a surface thereof, and when a pressure cooker test including temperature increasing, retention for 72 hours under a water-vapor atmosphere at a temperature of 105° C. and a relative humidity of 100% RH, and temperature decreasing is performed, the amount of increase in the thickness of the oxide coating film is 28 nm or less.

Abstract: There is provided a method for producing a surface-treated steel sheet for battery containers (1) comprising forming a dull or semi-bright nickel plating layer (12) on at least the surface to be the outside of a battery container in a steel sheet (11), wherein the nickel plating layer (12) is formed by performing plating treatment under a condition of a bath temperature of 70° C. or more.

Abstract: A surface-treated steel sheet, including: a steel sheet; and a nickel-cobalt-iron diffusion layer formed as an outermost surface layer on the steel sheet. When a content of Ni, a content of Co and a content of Fe of the nickel-cobalt-iron diffusion layer are determined based on a Ni intensity, a Co intensity and a Fe intensity each sequentially measured in the depth direction from the surface side of the nickel-cobalt-iron diffusion layer by a radio frequency glow discharge optical emission spectrometry, a content of Co at a specific depth position D, InCo_D, is 5% by mass or higher and a content of Fe at the specific depth position D, InFe_D, is 11% by mass or higher, the specific depth position D being a position where the Ni intensity is 0.5% of the maximum value of the Ni intensity. Also disclosed is a method for manufacturing the surface-treated steel sheet.

Abstract: A surface-treated metal plate including: a metal plate; and a nickel-cobalt binary alloy layer formed on the metal plate. When a part having a content ratio of oxygen atoms of 5 atomic % or more as measured by X-ray photoelectron spectroscopic analysis is an oxide coating film, the nickel-cobalt binary alloy layer contains the oxide coating film with a thickness of 0.5 to 30 nm on a surface thereof, and when a pressure cooker test including temperature increasing, retention for 72 hours under a water-vapor atmosphere at a temperature of 105° C. and a relative humidity of 100% RH, and temperature decreasing is performed, the amount of increase in the thickness of the oxide coating film is 28 nm or less.

Abstract: There is provided a method of manufacturing a metal sheet having an alloy plated layer, the method including a step of passing a metal strip continuously through a plating bath to perform electroplating in the plating bath, the plating bath including a plating liquid and an anode, the plating liquid containing two or more kinds of metal ions for forming the alloy plated layer, wherein an anode obtained by mixing two or more kinds of metal pellets is used as the anode, the metal pellets being formed of respective metals that form the alloy plated layer, wherein a mixing ratio of each metal pellet that constitutes the anode is determined based on a total surface area ratio of each metal pellet in the anode so that a dissolution ratio of each metal pellet that constitutes the anode is a dissolution ratio corresponding to a weight ratio of each metal that constitutes the alloy plated layer.

Abstract: There is provided a method for producing a surface-treated steel sheet for battery containers (1) comprising forming a dull or semi-bright nickel plating layer (12) on at least the surface to be the outside of a battery container in a steel sheet (11), wherein the nickel plating layer (12) is formed by performing plating treatment under a condition of a bath temperature of 70° C. or more.

Abstract: There is provided a method of manufacturing a metal sheet having an alloy plated layer, the method including a step of passing a metal strip continuously through a plating bath to perform electroplating in the plating bath, the plating bath including a plating liquid and an anode, the plating liquid containing two or more kinds of metal ions for forming the alloy plated layer, wherein an anode obtained by mixing two or more kinds of metal pellets is used as the anode, the metal pellets being formed of respective metals that form the alloy plated layer, wherein a mixing ratio of each metal pellet that constitutes the anode is determined based on a total surface area ratio of each metal pellet in the anode so that a dissolution ratio of each metal pellet that constitutes the anode is a dissolution ratio corresponding to a weight ratio of each metal that constitutes the alloy plated layer.