A method of treating a substrate, wherein the substrate comprises a layer deposited from a trivalent chromium electrolyte, is described. The method includes the steps of providing an anode and the chromium(III) plated substrate as a cathode in an electrolyte comprising (i) a trivalent chromium salt; and (ii) a complexant; and passing an electrical current between the anode and the cathode to passivate the chromium(III) plated substrate. The substrate may be first plated with a plated nickel layer so that the chromium(III) plated layer is deposited over the nickel plated layer.

To provide a surface-treated copper foil that is excellent in adhesiveness to an insulating substrate at ordinary temperature, and is capable of suppressing the formation of blister on application of a thermal load of reflow soldering to a copper-clad laminate board constituted by the copper foil. A surface-treated copper foil having a surface-treated surface, the surface-treated copper foil satisfying one or more of the following conditions (1) to (3): by an XPS measurement at a depth after sputtering from the surface-treated surface for 0.5 min at a rate of 1.1 nm/min (SiO.sub.2 conversion), (1) the N concentration is from 1.5 to 7.5 atomic %; (2) the C concentration is from 12 to 30 atomic %; and (3) the Si concentration is 3.1 atomic % or more and the O concentration is from 40 to 48 atomic %.

To provide a surface-treated copper foil that is excellent in adhesiveness to an insulating substrate at ordinary temperature, and is capable of suppressing the formation of blister on application of a thermal load of reflow soldering to a copper-clad laminate board constituted by the copper foil. A surface-treated copper foil having a surface-treated surface, the surface-treated copper foil satisfying one or more of the following conditions (1) to (3): by an XPS measurement at a depth after sputtering from the surface-treated surface for 0.5 min at a rate of 1.1 nm/min (SiO.sub.2 conversion), (1) the N concentration is from 1.5 to 7.5 atomic %; (2) the C concentration is from 12 to 30 atomic %; and (3) the Si concentration is 3.1 atomic % or more and the O concentration is from 40 to 48 atomic %.

A method for post-treatment of a chromium finish surface to improve corrosion resistance comprising a) providing a substrate having a chromium finish surface, and at least one intermediate layer between the chromium finish surface and the substrate, selected from the group consisting of nickel, nickel alloys, copper and copper alloys, wherein the chromium finish surface is a surface of a trivalent chromium plated layer, obtained by electroplating the substrate, having the at least one intermediate layer, in a plating bath, the plating bath comprising chromium (III) ions; b) contacting the chromium finish surface with an aqueous solution, comprising a permanganate, at least one compound which is selected from a phosphorus-oxygen compound, a hydroxide, a nitrate, a borate, boric acid, a silicate, or a mixture of two or more of these compounds; c) forming a transparent corrosion protection layer onto the chromium finish surface during step b.

A passivation surface treatment method of stainless steel that improves corrosion resistance including in a brine environment without changing the appearance of the surface of stainless steel. A passivation surface treatment method for stainless steel includes: performing degreasing of stainless steel, performing electrolytic pickling where the stainless steel that underwent the degreasing is immersed in a pickling solution having phosphoric acid (H.sub.3PO.sub.4) and is connected to the anode and a voltage of about 0.5 to 5.0 V for about 10 seconds or more is applied, performing electrolytic degreasing of the stainless steel, and performing electrolytic passivation where the stainless steel that underwent the electrolytic degreasing is immersed in a passivation solution including dichromic acid and chromium sulfate and a voltage of about 0.5 to 5.0 V is applied for 5 seconds or more.

A passivation surface treatment method of stainless steel that improves corrosion resistance including in a brine environment without changing the appearance of the surface of stainless steel. A passivation surface treatment method for stainless steel includes: performing degreasing of stainless steel, performing electrolytic pickling where the stainless steel that underwent the degreasing is immersed in a pickling solution having phosphoric acid (H.sub.3PO.sub.4) and is connected to the anode and a voltage of about 0.5 to 5.0 V for about 10 seconds or more is applied, performing electrolytic degreasing of the stainless steel, and performing electrolytic passivation where the stainless steel that underwent the electrolytic degreasing is immersed in a passivation solution including dichromic acid and chromium sulfate and a voltage of about 0.5 to 5.0 V is applied for 5 seconds or more.

In press molding, a colored stainless steel plate and a colored stainless steel coil which are excellent in galling resistance and moldability and have high strength in molded articles, and a method of manufacturing the same.

A color coating layer 11 is formed on the surface of a stainless steel plate 10 by a chemical coloring method or an electrolytic coloring method. Thereafter, a colored stainless steel plate 1 having the color coating layer is cold-rolled, the thickness of the color coating layer 11 is adjusted to 0.05 m or more to 1.0 m or less, and an entire plate thickness is adjusted to 0.5 mm or less. By the cold rolling a Vickers hardness Hv is 250 or more to 550 or less to form a deformed band 5. As surface roughness, an arithmetic average roughness Ra is adjusted to 0.05 m or more to 5.0 m or less. In this manner, the strength and rigidity of a thin colored stainless steel plate can be secured, and a color stainless steel plate 1 and a colored stainless steel coil which do not easily cause galling and are excellent in press moldability can be obtained.

In press molding, a colored stainless steel plate and a colored stainless steel coil which are excellent in galling resistance and moldability and have high strength in molded articles, and a method of manufacturing the same.

A color coating layer 11 is formed on the surface of a stainless steel plate 10 by a chemical coloring method or an electrolytic coloring method. Thereafter, a colored stainless steel plate 1 having the color coating layer is cold-rolled, the thickness of the color coating layer 11 is adjusted to 0.05 m or more to 1.0 m or less, and an entire plate thickness is adjusted to 0.5 mm or less. By the cold rolling a Vickers hardness Hv is 250 or more to 550 or less to form a deformed band 5. As surface roughness, an arithmetic average roughness Ra is adjusted to 0.05 m or more to 5.0 m or less. In this manner, the strength and rigidity of a thin colored stainless steel plate can be secured, and a color stainless steel plate 1 and a colored stainless steel coil which do not easily cause galling and are excellent in press moldability can be obtained.

A steel foil for a power storage device container includes a rolled steel foil, a nickel layer formed on a surface of the rolled steel foil, and a chromium-based surface treatment layer formed on a surface of the nickel layer. The nickel layer includes an upper layer portion which is in contact with the chromium-based surface treatment layer and contains Ni of 90 mass % or more among metal elements, and a lower layer portion which is in contact with the rolled steel foil and contains Ni of less than 90 mass % among the metal elements and Fe. <111> polar density in a reverse pole figure of the nickel layer in a rolling direction is 3.0 to 6.0. The nickel layer has a sub-boundary which is a boundary between two crystals having a relative orientation difference of 2 to 5, and a large angle boundary which is a boundary between two crystals having the relative orientation difference of equal to or more than 15. The average value of a ratio L5/L15 between a boundary length L5 which is the length of the sub-boundary, and a boundary length L15 which is the length of the large angle boundary, is equal to or more than 1.0.

A steel foil for a power storage device container includes a rolled steel foil, a nickel layer formed on a surface of the rolled steel foil, and a chromium-based surface treatment layer formed on a surface of the nickel layer. The nickel layer includes an upper layer portion which is in contact with the chromium-based surface treatment layer and contains Ni of 90 mass % or more among metal elements, and a lower layer portion which is in contact with the rolled steel foil and contains Ni of less than 90 mass % among the metal elements and Fe. <111> polar density in a reverse pole figure of the nickel layer in a rolling direction is 3.0 to 6.0. The nickel layer has a sub-boundary which is a boundary between two crystals having a relative orientation difference of 2 to 5, and a large angle boundary which is a boundary between two crystals having the relative orientation difference of equal to or more than 15. The average value of a ratio L5/L15 between a boundary length L5 which is the length of the sub-boundary, and a boundary length L15 which is the length of the large angle boundary, is equal to or more than 1.0.