Abstract: An austenitic alloy material is provided that includes a base metal having a surface, and a film containing chromium oxide having a thickness of 0.1 to 50 ?m on at least one portion of the surface. A chemical composition at a depth position in the film at which the Cr concentration is highest contains, by atom %, 50% or more of Cr as a proportion occupied among components excluding O, C and N. The chemical composition of the base metal consists of, by mass %, C: 0.001 to 0.6%, Si: 0.01 to 5.0%, Mn: 0.1 to 10.0%, P: 0.08% or less, S: 0.05% or less, Cr: 15.0 to 55.0%, Ni: 30.0 to 80.0%, N: 0.001 to 0.25%, O: 0.02% or less, Mo: 0 to 20.0%, Cu: 0 to 5.0%, Co: 0 to 5.0%, W: 0 to 10.0%, Ta: 0 to 6.0%, Nb: 0 to 5.0%, Ti: 0 to 1.0%, B: 0 to 0.1%, Zr: 0 to 0.1%, Hf: 0 to 0.1%, Al: 0 to 1.0%, Mg: 0 to 0.1%, and Ca: 0 to 0.1%, the balance being Fe and impurities.

Abstract: A titanium product for a separator of a proton exchange membrane fuel cell according to the present invention includes: a base material that consists of commercially pure titanium; a first oxide layer that is formed in a surface layer of the titanium product, consists of TiO2 of a rutile crystallinity, and has a thickness of 0.1 to 1.5 nm; and a second oxide layer that is formed between the base material and the first oxide layer, consists of TiOx (1<x<2), and has a thickness of 3 to 20 nm. This titanium product is suitable to be used as a separator of a proton exchange membrane fuel cell that has a high corrosion resistance in an environment in a fuel cell, is capable of keeping a low contact resistance with an electrode consisting of carbon fiber and the like, and is inexpensive.

Abstract: Provided is a metallic material including: a base metal made of a metal; a metal compound layer stacked on a surface of the base metal, the metal compound layer mainly containing a compound of at least one transition metal in the fourth period and oxygen; a platinum group portion dispersed on a surface of the metal compound layer, the platinum group portion mainly containing at least one platinum group element; and a platinum group compound coating film which covers the platinum group portion, the platinum group compound coating film mainly containing a compound of at least one platinum group element and oxygen. The at least one platinum group element contained in the platinum group portion is preferably one or more of Ru, Rh, Os, and Ir.

Abstract: A Ni-based alloy tube includes a base metal having a chemical composition consisting, by mass percent, of C: 0.15% or less, Si: 1.0% or less, Mn: 2.0% or less, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 50.0 to 80.0%, Ti: 0.50% or less, Cu: 0.60% or less, Al: 0.20% or less, N: 0.20% or less, and the balance: Fe and impurities; and a low Cr content complex oxide film having a thickness of 25 nm or smaller at least on an inner surface of the base metal, wherein contents of Al, Ni, Si, Ti, and Cr in the film satisfy [at % Al/at % Cr?2.00], [at % Ni/at % Cr?1.40], and [(at % Si+at % Ti)/at % Cr?0.10].

Abstract: There is provided a titanium product for a separator of a polymer electrolyte fuel cell (PEFC). The titanium product includes a substrate made of a titanium or a titanium alloy, and a passivation film formed on a surface of the substrate, wherein the passivation film includes a Li-containing titanium oxide layer in its surface layer. This titanium product can keep a low contact resistance with an electrode film and is inexpensive.

Abstract: A titanium product for a separator of a proton exchange membrane fuel cell according to the present invention includes: a base material that consists of commercially pure titanium; a first oxide layer that is formed in a surface layer of the titanium product, consists of TiO2 of a rutile crystallinity, and has a thickness of 0.1 to 1.5 nm; and a second oxide layer that is formed between the base material and the first oxide layer, consists of TiOx (1<x<2), and has a thickness of 3 to 20 nm. This titanium product is suitable to be used as a separator of a proton exchange membrane fuel cell that has a high corrosion resistance in an environment in a fuel cell, is capable of keeping a low contact resistance with an electrode consisting of carbon fiber and the like, and is inexpensive.

Abstract: An austenitic alloy tube subjected to a cold working and an annealing heat treatment contains C: 0.01% to 0.15%, Cr: 10.0% to 40.0%, Ni: 8.0% to 80.0%, in mass %, and has a metallographic structure satisfying the following Expressions (i) to (iii). R?f1??(i) R=I220/I111??(ii) f1=0.28×(F1118.0/(F1118.0+0.358.0))??(iii) Where, in the above Expressions, R is a ratio of an integrated intensity of {220} to an integrated intensity of {111} on a surface layer which is measured by a grazing incidence X-ray diffraction method, I220 is the integrated intensity of {220}, I111 is the integrated intensity of {111}, and F111 is full width of half maximum of {111} on the surface layer which is measured by the grazing incidence X-ray diffraction method.

Abstract: A Ni-based alloy tube includes a base metal having a chemical composition consisting, by mass percent, of C: 0.15% or less, Si: 1.0% or less, Mn: 2.0% or less, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 50.0 to 80.0%, Ti: 0.50% or less, Cu: 0.60% or less, Al: 0.20% or less, N: 0.20% or less, and the balance: Fe and impurities; and a low Cr content complex oxide film having a thickness of 25 nm or smaller at least on an inner surface of the base metal, wherein contents of Al, Ni, Si, Ti, and Cr in the film satisfy [at % Al/at % Cr?2.00], [at % Ni/at % Cr?1.40], and [(at % Si+at % Ti)/at % Cr?0.10].

Abstract: Provided is a metallic material including: a base metal made of a metal; a metal compound layer stacked on a surface of the base metal, the metal compound layer mainly containing a compound of at least one transition metal in the fourth period and oxygen; a platinum group portion dispersed on a surface of the metal compound layer, the platinum group portion mainly containing at least one platinum group element; and a platinum group compound coating film which covers the platinum group portion, the platinum group compound coating film mainly containing a compound of at least one platinum group element and oxygen. The at least one platinum group element contained in the platinum group portion is preferably one or more of Ru, Rh, Os, and Ir.

Abstract: There is provided a Cr-containing austenitic alloy having a chromium oxide film with a thickness of 5 nm or larger on the surface, wherein the content of Mn in a base metal is, by mass percent, less than 0.1%. The chemical composition of the base metal desirably consists of, by mass percent, C: 0.15% or less, Si: 1.00% or less, Mn: less than 0.1%, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 8.0 to 80.0%, Ti: 0.5% or less, Cu: 0.6% or less, Al: 0.5% or less, and N: 0.20% or less, the balance being Fe and impurities.

Abstract: A titanium material comprises: a plate-like matrix made of titanium or a titanium alloy and having a rough surface on which minute protrusions are formed; a surface oxide coating film formed along the rough surface and containing one or more titanium oxides; and a tip covering formed on the surface oxide coating film in an area comprising a tip of the minute protrusion and containing one or more noble metals. A composition ratio of TiO [ITiO/(ITi+ITiO)×100] determined from maximum intensity ITiO of diffraction peaks of TiO and maximum intensity ITi of diffraction peaks of metal Ti in an X-ray diffraction intensity curve of the surface oxide coating film is more than or equal to 0.5%.

Abstract: There is provided a chromium-containing austenitic alloy wherein at least one surface of the surfaces of the alloy has a continuous chromium oxide film with a thickness of 5 nm or more and less than 50 nm. A maximum current density determined by a critical passivation current density method is 0.1 ?A/cm2 or less when the chromium oxide film is continuous. A chemical composition of a base metal preferably consists of, by mass percent, C: 0.15% or less, Si: 1.00% or less, Mn: 2.0% or less, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 8.0 to 80.0%, Ti: 0.5% or less, Cu: 0.6% or less, Al: 0.5% or less, and N: 0.20% or less, the balance being Fe and impurities.

Abstract: There is provided a Cr-containing austenitic alloy tube, wherein a chromium oxide film with a thickness of 0.05 to 1.5 ?m having the relationship defined by Formula (i) is formed on the inner surface of the tube, wherein the average concentration of C in the depth range of 5 to 10 ?m from the inner surface is lower than the concentration of C in a base metal; 0.4??1/?2?2.5??(i) wherein ?1 and ?2 are thicknesses (?m) of the chromium oxide film at both ends of tube, respectively.

Abstract: There is provided a Cr-containing austenitic alloy having a chromium oxide film with a thickness of 5 nm or larger on the surface, wherein the content of Mn in a base metal is, by mass percent, less than 0.1%. The chemical composition of the base metal desirably consists of, by mass percent, C: 0.15% or less, Si: 1.00% or less, Mn: less than 0.1%, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 8.0 to 80.0%, Ti: 0.5% or less, Cu: 0.6% or less, Al: 0.5% or less, and N: 0.20% or less, the balance being Fe and impurities.

Abstract: An austenitic alloy tube subjected to a cold working and an annealing heat treatment contains C: 0.01% to 0.15%, Cr: 10.0% to 40.0%, Ni: 8.0% to 80.0%, in mass %, and has a metallographic structure satisfying the following Expressions (i) to (iii). R?f1??(i) R=I220/I111??(ii) f1=0.28×(F1118.0/(F1118.0+0.358.0))??(iii) Where, in the above Expressions, R is a ratio of an integrated intensity of {220} to an integrated intensity of {111} on a surface layer which is measured by a grazing incidence X-ray diffraction method, I220 is the integrated intensity of {220}, I111 is the integrated intensity of {111}, and F111 is full width of half maximum of {111} on the surface layer which is measured by the grazing incidence X-ray diffraction method.

Abstract: There is provided a chromium-containing austenitic alloy wherein at least one surface of the surfaces of the alloy has a continuous chromium oxide film with a thickness of 5 nm or more and less than 50 nm. A maximum current density determined by a critical passivation current density method is 0.1 ?A/cm2 or less when the chromium oxide film is continuous. A chemical composition of a base metal preferably consists of, by mass percent, C: 0.15% or less, Si: 1.00% or less, Mn: 2.0% or less, P: 0.030% or less, S: 0.030% or less, Cr: 10.0 to 40.0%, Ni: 8.0 to 80.0%, Ti: 0.5% or less, Cu: 0.6% or less, Al: 0.5% or less, and N: 0.20% or less, the balance being Fe and impurities.

Abstract: There is provided a Cr-containing austenitic alloy tube, wherein a chromium oxide film with a thickness of 0.05 to 1.5 ?m having the relationship defined by Formula (i) is formed on the inner surface of the tube, wherein the average concentration of C in the depth range of 5 to 10 ?m from the inner surface is lower than the concentration of C in a base metal; 0.4??1/?2?2.5??(i) wherein ?1 and ?2 are thicknesses (?m) of the chromium oxide film at both ends of tube, respectively.

Abstract: A titanium oxide-based photocatalyst which can exhibit excellent photocatalytic properties in response to visible light while maintaining its inherent activity in response to ultraviolet light and which is suitable for mass production contains bismuth as a first additional metal component and at least one metal element selected from silicon, zirconium, aluminum, and hafnium as a second additional metal component in titanium oxide. The Bi/Ti atomic ratio is preferably at least 0.0001 and at most 1.0, the atomic ratio of the second additional metal to Ti is preferably at least 0.0001 and at most 0.8, and a portion of bismuth is preferably present in the form of lower valence (Bi2+ or Bi0). The presence of lower valence bismuth can be ascertained by XPS analysis.

Abstract: Titanium oxide-based photocatalysts which contain a metal halide in titanium oxide and which are prepared from titanium oxide and/or its precursor, which may optionally be heat treated, by contact with a reactive gas containing a metal halide of the formula MXn or MOXn (wherein M=a metal, X=a halogen, and n=an integer) with heating stably develop a high photocatalytic activity with visible light irradiation. The photocatalysts may subsequently be stabilized by contact with water or by heat treatment, and/or promoted by contact with a heteropoly acid and/or an isopoly acid so as to include a metal complex in the titanium oxide. Photocatalysts prepared in this manner exhibit novel ESR features. The present invention also provides methods for preparing these photocatalysts, a photocatalyst dispersion and a photocatalytic coating fluid containing such a photocatalyst, and photocatalytic functional products and methods for their manufacture using the photocatalyst.

Abstract: A titanium oxide photocatalyst responsive to visible light which can exhibit a high photocatalytic activity in response to visible light is produced by subjecting titanium oxide and/or titanium hydroxide obtained by neutralizing an acidic titanium compound with a nitrogen-containing base to heat treatment in an atmosphere containing a hydrolyzable metal compound (e.g., a titanium halide) and then to additional heat treatment in a gas having a moisture content of 0.5-4.0 volume % at a temperature of 350° C. or above. The photocatalyst which is a nitrogen-containing titanium oxide has no substantial peak at a temperature of 600° C. or above in a mass fragment spectrum obtained by thermal desorption spectroscopy in which the ratio m/e of the mass number m to the electric charged e of ions is 28, and the peak having the smallest half band width is in the range of 400-600° C. in the spectrum. The nitrogen content calculated from the peak appearing at 400 eV±1.