Abstract: A high-strength galvanized steel sheet having excellent formability contains as a chemical component of steel on a mass percent basis: 0.05% to 0.3% of C; more than 0.60% to 2.0% of Si; 0.50% to 3.50% of Mn; 0.003% to 0.100% of P; 0.010% or less of S; 0.010% to 0.06% of Al; 0.007% or less of N; and the balance including Fe and inevitable impurities, and in the microstructure of the steel sheet, the standard deviation of nano-hardness is 1.50 GPa or less.

Abstract: A method of manufacturing a hot dip galvannealed steel sheet, including the steps of: subjecting a steel sheet to hot dip galvanizing to manufacture a hot dip galvanized steel sheet; heating the hot dip galvanized steel sheet for alloying; subjecting the hot dip galvanized steel sheet to temper rolling; bringing the temper-rolled hot dip galvanized steel sheet into contact with an acid solution containing at least one ion selected from the group consisting of Zr ions, Ti ions, and Sn ions to thereby form an acid solution film on the surface of the steel sheet; after completion of the contact, a state where the acid solution film is formed on the surface of the steel sheet is held for at least 1 second; and washing with water the hot dip galvanized steel sheet after holding, to thereby form a Zn oxide layer having a thickness of 10 nm or more on the surface of the galvanized steel sheet.

Abstract: A method for producing a hot-dip galvanized steel sheet which includes a hot-dip galvanization step, a temper rolling step and an oxidation step.

Abstract: A hot-dip galvanized steel sheet includes a plating layer substantially composed of the ? phase and an oxide layer disposed on a surface of the plating layer. The oxide layer has an average thickness of 10 nm or more and includes a Zn-based oxide layer and an Al-based oxide layer. A method for producing the hot-dip galvanized steel sheet includes a hot-dip galvanization step, a temper rolling step, and an oxidation step.

Abstract: A galvannealed steel sheet is manufactured by preparing a hot-dip galvanized steel sheet, alloying the steel sheet, and controlling time and temperature for alloying thereof depending on Si and Al contents. The hot-dip galvanized steel sheet contains 0.05 to 0.30% C, 0.01 to 2.0% Si, 0.08 to 3.0% Mn, 0.003 to 0.1% P, 0 to 0.07% S, 0.01 to 2.5% Al, 0 to 0.007% N, by mass, and the balance being Fe and inevitable impurities. Alloying time and temperature are controlled by the formula [Si+Al?1.5×10?7×t0.75×(T?465)3+0.117], where t is the total time (sec) of holding the sheet at 465° C. or more on alloying the coating layer thereon, and T is the average temperature (° C.) of the sheet during the total time t (sec) of holding the steel sheet at 465° C. or more on alloying the coating layer thereon.

Abstract: The invention provides a hot dip galvanized steel sheet which has: a hot dip galvanizing layer having a flat part on a surface thereof; and a film formed on the flat part. The film is composed of a compound containing Zn, Fe, and O, having an average film thickness A in a range from 10 to 100 nm determined by an element analysis of the film, and has {[Fe]/([Zn]+[Fe]} in the film in a range from 0.002 to 0.25, where [Zn] and [Fe] designate the content (% by atom) of Zn and Fe in the film, respectively. Since the hot dip galvanized steel sheet of the invention has excellent press-formability, bondability, and phosphatability, it is suitable for automobiles and electrical appliances.

Abstract: A hot-dip galvanized steel sheet includes a plating layer substantially composed of the ? phase and an oxide layer disposed on a surface of the plating layer. The oxide layer has an average thickness of 10 nm or more and includes a Zn-based oxide layer and an Al-based oxide layer. A method for producing the hot-dip galvanized steel sheet includes a hot-dip galvanization step, a temper rolling step, and an oxidation step.

Abstract: The zinc-base plated steel sheet has a steel sheet, a zinc-base plating layer on the steel sheet, and a composite coating film formed on the plating layer, which composite coating layer contains a P ingredient, an N ingredient, and at least one element selected from the group consisting of Mg, Al, Ca, Ti, Fe, Co, Ni, Cu, and Mo, and is prepared by applying an aqueous solution containing a cationic ingredient (?) and a phosphoric acid ingredient (?) onto the surface of plating layer on the zinc-base plated steel sheet, and then drying the applied aqueous solution, without giving washing with water, and which cationic ingredient (?) consists essentially of at least one metallic ion selected from the group consisting of Mg, Al, Ca, Ti, Fe, Co, Ni, Cu, Mo, and NH4+ ions.

Abstract: The method for manufacturing galvanized steel sheet has a step of adjusting the surface texture thereof by blasting solid particles against the surface thereof. The surface texture is defined by at least one parameter selected from the group of parameters consisting of mean roughness Ra on the surface of steel sheet, peak count PPI on the surface of steel sheet, and filtered centerline waviness Wca on the surface of steel sheet. The galvanized steel sheet has a surface in dimple-pattern texture.

Abstract: The invention provides a galvannealed steel sheet which has an oxide layer having 10 nm or larger thickness on the plateau of the coating layer flattened by temper rolling. With the use of the galvannealed steel sheet, no powdering occurs during press-forming, and stable and excellent sliding performance is attained. By selecting the area percentage of the plateau of the flattened coating layer to a range from 20 to 80%, making the coating layer single layer of &dgr;1 phase, and letting &zgr; phase exist in the &dgr;1 phase, further improved sliding performance and anti-powdering property are obtained.

Abstract: The zinc-base plated steel sheet has a steel sheet, a zinc-base plating layer on the steel sheet, and a composite coating film formed on the plating layer, which composite coating layer contains a P ingredient, an N ingredient, and at least one element selected from the group consisting of Mg, Al, Ca, Ti, Fe, Co, Ni, Cu, and Mo, and is prepared, by applying an aqueous solution containing a cationic ingredient (&agr;) and a phosphoric acid ingredient (&bgr;) onto the surface of plating layer on the zinc-base plated steel sheet, and then drying the applied aqueous solution, without giving washing with water, and which cationic ingredient (&agr;) consists essentially of at least one metallic ion selected from the group consisting of Mg, Al, Ca, Ti, Fe, Co, Ni, Cu, Mo, and NH4+ ions.

Abstract: The method for manufacturing galvanized steel sheet has a step of adjusting the surface texture thereof by blasting solid particles against the surface thereof. The surface texture is defined by at least one parameter selected from the group of parameters consisting of mean roughness Ra on the surface of steel sheet, peak count PPI on the surface of steel sheet, and filtered centerline waviness Wca on the surface of steel sheet. The galvanized steel sheet has a surface in dimple-pattern texture.

Abstract: The invention provides a galvannealed steel sheet which has an oxide layer having 10 nm or larger thickness on the plateau of the coating layer flattened by temper rolling. With the use of the galvannealed steel sheet, no powdering occurs during press-forming, and stable and excellent sliding performance is attained. By selecting the area percentage of the plateau of the flattened coating layer to a range from 20 to 80%, making the coating layer single layer of &dgr;1 phase, and letting &zgr; phase exist in the &dgr;1 phase, further improved sliding performance and anti-powdering property are obtained.

Abstract: The method for manufacturing galvanized steel sheet has a step of adjusting the surface texture thereof by blasting solid particles against the surface thereof. The surface texture is defined by at least one parameter selected from the group of parameters consisting of mean roughness Ra on the surface of steel sheet, peak count PPI on the surface of steel sheet, and filtered centerline waviness Wca on the surface of steel sheet. The galvanized steel sheet has a surface in dimple-pattern texture.

Abstract: A production method for a lead-containing hot-galvanized chromated steel sheet with excellent resistance to blackening and white rust formation comprises: (a) plating a steel sheet in a hot-galvanizing bath containing 0.05-0.3 wt. % lead and 0.1-0.3 wt. % aluminum; (b) coating this with a chromating solution containing chromium (VI) ions, chromium (III) ions and nitrate ions in which the Cr(III)/Cr(VI) molar ratio is 1/9-1/1 and the nitrate ion to total chromium ion molar ratio is 0.1-1.6; and (c) without washing with water, drying the sheet at 40-250 deg. C., to form a 5-50 mg/m integral 2 (in terms of chromium) chromate film.

Abstract: In order to manufacture a chromate-coated lead-containing galvanized steel sheet having beautiful spangles and excellent anti-black patina and anti-white rust properties without relying upon any flushing treatment with Ni, etc., a lead-containing galvanized steel sheet obtained by plating in a galvanizing bath containing appropriate amounts of Pb and Al, and having beautiful spangles is coated with a chromate coating solution containing trivalent and hexavalent chromium ions in a molar ratio of 1/9 to 1/1, and nitrate ions in a molar ratio of 0.1 to 1.6 to the total of the chromium ions, preferably after treatment with an aqueous alkali solution having a pH of 9 or above, and washing with water, and the sheet is dried at an appropriate sheet temperature without being washed with water, whereby a chromate film having a coating weight of 5 to 50 mg/m2 is formed thereon.

Abstract: Disclosed is an optical fiber-housing metal pipe, comprising a base body of an optical fiber-housing metal pipe, an aluminum layer formed on the surface of the base body, and an oxide layer formed on the aluminum layer, the oxide layer serving to improve the corrosion resistance and wear resistance of the optical fiber-housing metal pipe. Also disclosed is an optical fiber-housing metal pipe comprising a base body of an optical fiber-housing metal pipe, an Al-X alloy layer formed on the surface of the base body, where X is one or two kinds of elements selected from the group consisting of Mn, Ti, Ni, Cr, Nb, Mg, Fe, In and Sn, or an Al-based composite layer containing at least one kind of a material selected from the group consisting of a carbide, an oxide and an organic compound.

Abstract: Disclosed is an organic-composite coated steel plate comprising a steel plate provided with a plated layer made of zinc or a zinc-base alloy, a chromate-treated layer formed on said plated layer with a deposition amount ranging from 1 to 200 g/m.sup.2 in terms of metal chromium, and a resin film formed on said chromate-treated layer with a thickness ranging from 0.1 to 5 .mu.m, wherein said resin film has (A) selected from the group consisting of a reaction product (I) between an ethylene-series ionomer resin and an epoxy-group containing compound, a mixture of an ethylene-series ionomer resin and an epoxy emulsion, a mixture of the reaction product (I) and an epoxy emulsion, and a mixture of the reaction product (I), an ethylene-series ionomer resin and an epoxy emulsion, in an amount of 60 to 99% by weight, and (B) fine silica particles in an amount of 1 to 40% by weight.

Abstract: A method for continuously manganese-electroplating or manganese-alloy-electroplating a steel sheet, which comprises the steps of: using a manganese electroplating solution or a manganese alloy electroplating solution, using an insoluble anode, and causing a DC electric current to flow between the insoluble anode and a steel sheet during travelling through the electroplating solution while replenishing the manganese electroplating solution or the manganese alloy electroplating solution with manganese ions or manganese alloy ions, thereby forming a manganese plating layer or a manganese alloy plating layer on at least one surface of the steel sheet. As the insoluble anode, a hydrogen gas diffusing insoluble anode is used.