To provide a bath for surface treatment capable of forming a surface-treating film having excellent corrosion resistance by a high-speed electrolytic treatment, and a method of producing a surface-treated steel plate having excellent corrosion resistance and closely adhering property to the coating maintaining good productivity. A bath for surface treatment used for forming a surface-treating film on the surface of a steel plate by cathodic electrolysis, the bath for surface treatment containing Zr and/or Ti, and a polycarboxylic acid.

A high-strength galvanized steel sheet comprising a cold-rolled steel sheet, an intermetallic compound formed on the cold-rolled steel sheet, and a galvanizing layer formed on the intermetallic compound, the cold-rolled steel sheet having a specific composition and a microstructure having a martensite area ratio of 7% or more and less than 25% and a ferrite area ratio of 50% or more and which includes a base metal surface portion in which the amount of internal oxides per single side is 0.05 g/m.sup.2 or less.

The present invention relates to a ZnMg alloy-coated steel sheet with excellent blackening resistance and excellent coating adhesion and to a method for manufacturing same. Provided are a ZnMg alloy-coated steel sheet with excellent blackening resistance and excellent adhesion and a method for manufacturing same, the steel sheet comprising: a substrate steel sheet; a ZnFe intermetallic compound layer formed on the substrate steel sheet; a first ZnMg coating layer formed on the ZnFe intermetallic compound layer and comprising a ZnFe intermetallic compound in which the content of Zn is 95% by weight or higher; a second ZnMg coating layer formed on the first ZnMg coating layer and comprising a ZnMg intermetallic compound in which the content of Zn is 80 to 95% by weight; and an oxide film formed on the second ZnMg coating layer and comprising a metallic oxide.

A high-strength galvanized steel sheet comprising a cold-rolled steel sheet, an intermetallic compound formed on the cold-rolled steel sheet, and a galvanizing layer formed on the intermetallic compound, the cold-rolled steel sheet having a specific composition and a microstructure having a martensite area ratio of 7% or more and less than 25% and a ferrite area ratio of 50% or more and which includes a base metal surface portion in which the amount of internal oxides per single side is 0.05 g/m.sup.2 or less.

A hot-pressed member includes a steel sheet, a Ni-diffusion region present in a surface layer of the steel sheet, and an intermetallic compound layer and a ZnO layer which are provided in order on the Ni-diffusion region, the intermetallic compound layer corresponding to a phase present in a phase equilibrium diagram of a ZnNi alloy, wherein a spontaneous immersion potential indicated in a 0.5 M NaCl aqueous air-saturated solution at 25 C.5 C. is 600 to 360 mV based on a standard hydrogen electrode.

An electric contact material for a connector includes a base material made of a metal material; an alloy layer that is formed on the base material and made of an alloy containing at least three elements including Sn and Cu as well as at least one metal selected from Zn, Co, Ni, and Pd; and a conductive coating layer formed on the surface of the alloy layer. The alloy layer contains an intermetallic compound obtained by replacing some of the Cu atoms in Cu.sub.6Sn.sub.5 with at least one metal selected from Zn, Co, Ni, and Pd. It is preferable that the content of at least one metal selected from Zn, Co, Ni, and Pd in the alloy layer is in a range of 1 to 50 atom % when the total content of the metal and Cu is regarded as 100 atom %.

A coating system on a superalloy or silicon-containing substrate of an article exposed to high temperatures. The coating system includes a coating layer that overlies the substrate and is susceptible to hot corrosion promoted by molten salt impurities. A corrosion barrier coating overlies the coating layer and contains at least one rare-earth oxide-containing compound that reacts with the molten salt impurities to form a dense, protective byproduct barrier layer.

Methods of enhancing the corrosion resistance of an oxidizable material exposed to a supercritical fluid is disclosed One method includes placing a surface layer on an oxidizable material, and choosing a buffered supercritical fluid containing a reducing agent with the composition of the buffered supercritical fluid containing the reducing agent chosen to avoid the corrosion of the surface layer or reduce the rate of corrosion of the surface layer and avoid the corrosion of the oxidizable material or reduce the rate of corrosion of the oxidizable material at a temperature above the supercritical temperature and supercritical pressure of the supercritical fluid.

A substrate for flexible device, including a stainless steel sheet, an oxide layer formed on a surface of the stainless steel sheet, and a glass layer of electrically-insulating bismuth-based glass formed in a form of layer on the surface of the oxide layer. Also disclosed is a sheet for flexible device, including a stainless steel sheet, and an oxide layer on a surface of the stainless steel sheet, the oxide layer having a thickness of not less than 30 nm.

A steel sheet for a container includes: a steel sheet; a coated layer which contains Ni and is provided as an upper layer of the steel sheet; and a chemical treatment layer which is provided as an upper layer of the coated layer, and contains a Zr compound in an amount of 3.0 to 30.0 mg/m.sup.2 in terms of Zr metal, and a Mg compound in an amount of 0.50 to 5.00 mg/m.sup.2 in terms of Mg metal, in which the coated layer is one of the group consisting of a Ni coated layer which contains Ni in amount of 10 to 1000 mg/m.sup.2 in terms of Ni metal, and a composite coated layer which contains Ni in an amount of 5 to 150 mg/m.sup.2 in terms of Ni metal and Sn in an amount of 300 to 3000 mg/m.sup.2 in terms of Sn metal, and has an island-shaped Sn coated layer formed on an FeNiSn alloy layer.