Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Sintokogio, Ltd.

Other

Dai Nippon Toryo Co., Ltd.

Nippon Steel & Sumikin Anti-corrosion Co., Ltd.

Sintobrator, Ltd.

Hiroshi Kihira

Koki Tanaka

Michio Kaneko

Wataru Hisada

Kazuhiro Takahashi

Kiyonori Tokuno

Satoshi Ito

Kazumi Matsuoka

Mitsuharu Yamagata

Takumi Nishimoto

Yoichi Ikematsu

Yoichi Matsuzaki

Tomomi Murata

Kazuto Kawakami

Taku Kagawa

Tamotsu Itoh

Youichi Ikematsu

Suguru Suzuki

Noriyuki Suzuki

Masao Kikuchi

Kazuo Yamamoto

Shunji Sakamoto

Takayuki Sato

Masanori Nagai

Takashi Domoto

Yoshiyuki Harada

Tsutomu Haeno

Masao Kimura

Yuichi Yoshida

Takashi Kusunoki

Yuuichi Yosida

Koji Homma

Hiroshi Takezawa

Kenji Fujimoto

Tsuyoshi Matsumoto

Noriyuki Hirosawa

Tomoki Oka

Atsumi Imai

Takehide Aiga

Hiromichi Yasunami

Norihito Fujikawa

Yasumori Fujii

Yoshihiko Mitsuzuka

Kanjiro Hiramatsu

A titanium or titanium alloy material for a separator of a polymer electrolyte fuel cell having high contact conductivity with carbon and high durability, and including an oxide film formed on a titanium or titanium alloy substrate by a stabilization treatment performed after a passivation treatment, and one or more kinds of conductive materials selected from carbide, nitride, carbonitride, and boride of tantalum, titanium, vanadium, zirconium, and chromium, the conductive materials being dispersed in the oxide film and having a major axis diameter of from 1 nm to 100 nm. A contact resistance value with a carbon paper is 20 m&#x3a9;&#xb7;cmor less at a surface pressure of 10 kgf/cmbefore and after an accelerated deterioration test in which the titanium or titanium alloy material is immersed in a sulfuric acid aqueous solution having an adjusted pH of 4 at 80&#xb0; C. for four days.

Titanium or titanium alloy material for fuel cell separator having high contact conductivity with carbon and high durability, fuel cell separator including the same, and manufacturing method therefor

A titanium or titanium alloy material for a fuel cell separator has a surface shape in which a plurality of projections are distributed, and a titanium oxide film on a surface of the projections. Fine projections are assumed to increase the contact conductivity remarkably. By increasing contact conductivity with carbon and durability of a titanium or titanium alloy material for a fuel cell separator, the lifetime of a fuel cell may be increased. The material has high usability in the cell manufacturing industry.

Titanium material or titanium alloy material for fuel cell separator having high contact conductivity with carbon and high durability, fuel cell separator including the same, and fuel cell

The present invention provides titanium material for a separator for solid polymer fuel cell use comprised of titanium which has a surface layer part where conductive compound particles are affixed, which is excellent in contact resistance between the separator surface and carbon paper and in durability, and which is low in cost and superior in recyclability and a method of production of the same. This titanium material for separator use has on the surface of the titanium base material a film comprised of the titanium compound particles made of titanium carbide, titanium nitride, or titanium carbonitride and titanium oxide. The film has a thickness of 0.1 to 1 &#x3bc;m, the coverage rate is an area percentage of 20% or more, and the contents of carbon and nitrogen in the film total 5 to 40 at %. The titanium material for a separator is produced by annealing or shot blasting and pickling.

Titanium material for solid polymer fuel cell separator use and method of production of same

An inexpensive rotary grinding tool with reduced noise level of the grinding is provided. The rotary grinding tool comprises a metal disk having a grinding surface on at least a part of its surface and a holder for supporting the metal disk. The grinding surface has hard grains having a Mohs hardness in excess of 9 brazed thereon at a surface density of at least 20 grains/cm. The holder has at its center a securing means for securing the holder on rotary shaft of a rotary drive unit. The holder and the metal disk are joined together to constitute the rotary grinding tool.

Rotary grinding tool and its production method

The present invention provides a polymer electrolyte fuel cell separator made of pure titanium or a titanium alloy superior in contact resistance with carbon paper and a method of production of the same, that is, a separator having a surface layer part to which conductive compound particles are affixed, characterized in that the surface oxide has a thickness of 3 to 15 nm in range, an average carbon concentration in a range from an outermost surface, including the oxide layer, to a depth of 100 nm is 0.02 to 6 at %, and the conductive compound particles have an average particle size of 0.01 to 20 &#x3bc;m. Further, the method of production of the present invention is characterized by forming, blast treating a surface of the formed article by particles comprised of conductive compound particles of an average particle size of 0.01 to 20 &#x3bc;m covering a surface of superhard core particles, impregnating it by a nitric acid aqueous solution of a concentration of 15 to 71 mass % and a temperature of 40 to 100&#xb0; C. for 30 seconds to 180 minutes by spraying or dipping, then washing it.

Polymer electrolyte fuel cell separator made of pure titanium or titanium alloy and method of production of same

A titanium material for a solid polymer fuel cell separator having a low contact resistance and a method of production of the same, the titanium material having at its surface a surface layer structure in which particles of a Ti compound containing either C or N are dispersed, the particles of Ti compound being covered by titanium oxide and/or metal Ti, characterized in that, when analyzed from the surface by XPS, a Ti2p spectrum of TiOis detected, further, at a Ti2p spectral energy range of TiO and/or a Ti2p spectral energy range of metal Ti, a Ti maximum detection peak height is at least 3 times the standard deviations of the background at the respective spectral energy ranges, and at a C1s spectral energy range and N1s spectral energy range, a maximum detection peak height is less than 3 times the standard deviations of the background at the respective spectral energy ranges of C1s and N1s, are provided.

Titanium material for solid polymer fuel cell separator having low contact resistance and method of production of same

The present invention provides a method of production of a separator for a solid polymer type fuel cell characterized by shaping a substrate comprised of stainless steel, titanium, or a titanium alloy and then spraying the substrate surface with superhard core particles comprised of conductive compound particles of an average particle size of 0.01 to 20 &#x3bc;m mixed with a coating material and coated on their surfaces under conditions of a spray pressure of 0.4 MPa or less and a spray amount per cmof the substrate of 10 to 100 g in blast treatment. The ratio of the conductive compound to the mass of the core particles is 0.5 to 15 mass %.

Solid polymer type fuel cell separator and method of production of same

The present invention releases a method of producing a metal separator for a solid polymer fuel cell by stainless steel, titanium, or titanium alloy during which securing lower cost and mass producibility by using a material having a high workability to form a complicated shape by a high productivity, then using an inexpensive blast process to drive a conductive substance into the surface of the metal separator member, that is, provides a stainless steel, titanium, or titanium alloy solid polymer fuel cell separator comprised of stainless steel, titanium, or titanium alloy in the surface of which a low ion release conductive substance is buried, having an arithmetic mean roughness (Ra) of the separator surface of 0.5 to 5.0 &#x3bc;m, having a 10-point mean roughness (Rz) of 3 to 20 &#x3bc;m, having an average spacing of surface relief shapes (Sm) of 300 &#x3bc;m or less, having values of a warp rate and twist rate of a separator of 0.1 or less, and having a contact resistance value with respect to carbon paper of 15 m&#x3a9;cmor less at a surface pressure of 1 MPa.

Stainless steel, titanium, or titanium alloy solid polymer fuel cell separator and its method of production and method of evaluation of warp and twist of separator

The present invention provides a separator for a solid polymer type fuel cell superior in low contact resistance of the fuel cell separator surface with carbon paper and flatness and a method of production of the same, that is, a separator for a solid polymer type fuel cell comprising a substrate of stainless steel or titanium or a titanium alloy having a surface layer part on which conductive compound particles are fixed, wherein said conductive compound particles are comprised of one or more types of metal borides, metal carbides, and metal nitrides with an average particle size of 0.01 to 20 &#x3bc;m, said conductive compound particles are present in a region from said substrate surface to a depth of 10 &#x3bc;m, and a distribution of concentration of the metal element forming the conductive compound in said region satisfies relations between a concentration C of the metal element forming the conductive compound and a depth x from the substrate surface shown by equation &#x3c;1&#x3e; (C=A&#xb7;exp(&#x2212;x/t)+B) and equation &#x3c;2&#x3e; (10&#x2266;A&#x2266;90, &#x2212;4.0&#x2266;B&#x2266;1.0, 0.5&#x2266;t&#x2266;4.0).

A predicted corrosion amount of a painted or unpainted atmospheric corrosion resistant steel is calculated by using extrinsic corrosion information including weather observation data, an amount of airborne salt, and an amount of sulfur oxide in a planned location for use where the atmospheric corrosion resistant steel is to be used, and intrinsic corrosion information on components of the atmospheric corrosion resistant steel. The weather observation data on this occasion preferably includes the annual wetness time, annual mean wind speed, and annual mean temperature. Moreover, it is preferable to calculate a corrosivity index, estimate a first-year corrosion amount of the atmospheric corrosion resistant steel and a rust stabilization index from the corrosivity index, and calculate a corrosion amount accumulated over time.

Method for predicting degree of corrosion of weather-resistant steel

A method for depositing a metal having a high corrosion resistance and a low contact resistance against carbon to a separator for a fuel cell enabling provision of an inexpensive separator for a fuel cell by depositing a metal having a high corrosion resistance and a low contact resistance against carbon to the surface of a metal conveniently by simple equipment while using as a preform a metal such as stainless steel or aluminum as a material having a high productivity and low price and in addition capable of reducing the weight by making the sheet thickness thin, comprising projecting to a separator of a unit cell for forming the fuel cell a solid plating material comprised of core particles having a higher hardness than the separator and coated with a metal having a high corrosion resistance and a low contact resistance against carbon so as to compulsorily deposit the metal coated on this solid plating material to the separator.

Method for depositing metal having high corrosion resistance and low contact resistance against carbon on separator for fuel cell

A highly durable separator for solid polymer fuel cells that can be produced at low cost and that is characterized by the separator having a flat portion in the peripheral portion and channels in the central portion composed of protruded portions and recessed portions which provide flow paths for gases on the front surface and the back surface, and the shape of each channel end portion being tilted.

Separators for solid polymer fuel cells and method for producing same, and solid polymer fuel cells

The present invention provides a metal foil excellent in electrical contact stability, and low in cost, by eliminating plating processes. Specifically, the present invention is a metal foil excellent in electrical contact stability characterized by having a surface roughness wherein the ratio Ra/Sm between the arithmetic average of roughness Ra and the average interval Sm of concavities and convexities is 0.001 or more, which average values are obtained by measuring the roughness in the direction in which the average interval Sm of the concavities and convexities on the surface is smallest. It is preferable that the material of the metal foil is stainless steel or phosphor bronze.

Metal foil excellent in electrical contact stability

A sensor for electrochemical measurement is disclosed which includes a chamber made of an electrically insulative material and having an open end portion, a super absorbent polymer material filled in the chamber and absorbing at a selected rate a liquid electrolyte, an electrode disposed in the chamber, and a screen which covers the open end portion of the chamber and which prevents the super absorbent polymer material from dropping out from the chamber but permits the liquid electrolyte to transmit through the screen. A method is also disclosed which uses the sensor to measure the degree of degradation of a coating film on metal or the corrosion protective properties of a rust film created on the surface of steel.

Sensor for electrochemical measurement and method for diagnosing

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Tokyo, Japan

Hiroshi Kihira