Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Nippon Steel Stainless Steel Corporation

Nippon Steel Chemical & Material Co., Ltd.

Takumi Nishimoto

Kazuhiro Takahashi

Yoshitaka Nishiyama

Koki Tanaka

Kenichi Uemura

Hiromitsu Date

Takashi Fujii

Takashi Iijima

Hiroshi Kihira

Kenichiro Tadokoro

Kiyonori Tokuno

Taku Kagawa

Noriyuki Negi

Masaharu Hatano

Hiroyuki Hayashida

Shinya Furukawa

Kazuhiko Mizuuchi

Masataka Hiyoshi

Akira Taniyama

Katsumasa Matsumoto

Takashi Domoto

Masao Kimura

Yuuichi Yosida

Takumi Kouno

Yoshio Tarutani

Eri Hoshiba

Mitsuki Sugeoi

Ferritic stainless steel is characterized by including, by mass %: Cr: 12.0% to 16.0%; C: 0.020% or less; Si: 2.50% or less; Mn: 1.00% or less; P: 0.050% or less; S: 0.0030% or less; Al: 2.50% or less; N: 0.030% or less; Nb: 0.001% to 1.00%; one or more of B: 0.0200% or less, Sn: 0.20% or less, Ga: 0.0200% or less, Mg: 0.0200% or less, and Ca: 0.0100% or less; and a balance consisting of Fe and impurities, in which Expression (1) is satisfied.10(B+Ga)+Sn+Mg+Ca&#x3e;0.020&#x2003;&#x2003;(1)

Ferritic stainless steel and method for manufacturing same, ferritic stainless steel sheet and method for manufacturing same, and fuel cell member

A stainless steel material including a base material made of ferritic stainless steel, a Cr oxide layer formed on a surface of the base material, and a spinel oxide layer formed on a surface of the Cr oxide layer, wherein a chemical composition of the base material satisfies [16.0&#x2264;Cr+3&#xd7;Mo&#x2212;2.5&#xd7;B&#x2212;17&#xd7;C&#x2212;3&#x2212;Si&#x2264;35.0], a thickness of the Cr oxide layer (T) and a thickness of the spinel oxide layer (T) satisfy [0.55&#x2264;T/T&#x2264;6.7], the base material contains precipitate including one or more kinds selected from a MC, a MB, a complex precipitate in which MB acts as a precipitation nucleus, and MCprecipitates on a surface of the MB, and a complex precipitate in which NbC acts as a precipitation nucleus, and MCprecipitates on a surface of the NbC, and a part of the precipitate protrude from the surface of the Cr oxide layer.

Stainless steel material, constituting component, cell, and fuel cell stack

Provided is an austenitic heat resistant alloy capable of exhibiting sufficient molten-salt corrosion resistance even when exposed to a molten salt of 600&#xb0; C., and a production method thereof. The austenitic heat resistant alloy includes a base metal and a Fe&#x2014;Cr&#x2014;Ni&#x2014;W film on the surface of the base metal. The base metal has a chemical composition consisting of: C: 0.030 to 0.120%, Si: 0.02 to 1.00%, Mn: 0.10 to 2.00%, Cr: 20.0% or more to less than 28.0%, Ni: more than 35.0% to 50.0% or less, W: 4.0 to 10.0%, Ti: 0.01 to 0.30%, Nb: 0.01 to 1.00%, sol. Al: 0.0005 to 0.0400%, and B: 0.0005 to 0.0100%, with the balance being Fe and impurities. The Fe&#x2014;Cr&#x2014;Ni&#x2014;W film contains, as oxides, Fe: 15.0 to 35.0 at %, Cr: 15.0 to 35.0 at %, Ni: 10.0 to 45.0 at %, and W: 0.5 to 16.5 at %.

Austenitic heat resistant alloy and method for producing the same

Provided are an austenitic heat resistant alloy capable of exhibiting sufficient molten-salt corrosion resistance even when exposed to a molten salt of 600&#xb0; C. and a production method thereof, and an austenitic heat-resistant alloy material. An austenitic heat resistant alloy includes a base metal, and a Ni&#x2014;Fe oxide having a spinel structure on or above the surface of the base metal. The base metal has a chemical composition consisting of, in mass %, C: 0.030 to 0.120%, Si: 0.02 to 1.00%, Mn: 0.10 to 2.00%, Cr: 20.0% or more to less than 28.0%, Ni: more than 35.0% to 50.0% or less, W: 4.0 to 10.0%, Ti: 0.01 to 0.30%, Nb: 0.01 to 1.00%, sol. Al: 0.0005 to 0.0400%, B: 0.0005 to 0.0100%, Mo: less than 0.5%, Co: 0 to 0.80%, and Cu: 0 to 0.50%, with the balance being Fe and impurities.

Austenitic heat resistant alloy and method for producing same, and austenitic heat-resistant alloy material

A Si/Mn ratio of steel material components of a base material is not less than 0.27 nor more than 0.90 in mass ratio, an internal oxide layer having a thickness of not less than 1 &#x3bc;m nor more than 30 &#x3bc;m is provided right below an oxide scale of a steel sheet surface layer portion, and regarding the internal oxide layer, an internal oxide in a crystal grain of the internal oxide layer is an oxide containing Si and having a thickness of not less than 10 nm nor more than 200 nm in a crystal grain in a range of greater than 0% and 30% or less of a thickness of the internal oxide layer from an interface between the internal oxide layer and base iron toward a direction of the surface layer oxide scale, one or more branches of the internal oxide exist in a cross section of 1 &#x3bc;m&#xd7;1 &#x3bc;m square, and in any crystal grain boundary having a length of 1 &#x3bc;m, one or more of the internal oxides in the crystal grain are connected to an internal oxide of the crystal grain boundary to form a net-like structure.

Hot-rolled steel sheet and manufacturing method thereof, and manufacturing method of cold-rolled steel sheet

An ultrasonic cleaning equipment () according to the present invention includes a treatment tank () that stores a cleaning liquid that cleans an object to be cleaned and in which the object to be cleaned is immersed; an ultrasonic application mechanism () that applies ultrasonic waves to the cleaning liquid retained in an interior of the treatment tank; and a curved surface member () that is located in a range defined by an angle of inclination from a perpendicular direction in an end portion of a vibrating surface of the ultrasonic application mechanism to an outside with respect to the vibrating surface and that is held on a wall surface and/or a bottom surface of the treatment tank.

Ultrasonic cleaning equipment and ultrasonic cleaning method

A carbon material for catalyst carrier use excellent in both durability and power generation performance under operating conditions at the time of low humidity, in particular both durability of a carbon material for catalyst carrier use with respect to repeated load fluctuations due to startup and shutdown and power generation performance under operating conditions at the time of low humidity, and a catalyst for solid-polymer fuel cell use prepared using the same etc. are provided. To solve this technical problem, according to one aspect of the present invention, there is provided a carbon material for catalyst carrier use satisfying the following (A) to (D):

Catalyst-carrier carbon material, solid-polymer fuel cell catalyst, solid-polymer fuel cell, and method for manufacturing catalyst-carrier carbon material

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 is a method of pickling of steel plate which contains silicon comprising applying ultrasonic waves of at least two types of frequencies of 28.0 kHz or more to less than 1.0 MHz to an acidic cleaning solution which contains microbubbles and, in that state, dipping the steel plate which contains silicon in that cleaning solution. The present invention is a continuous pickling system of steel plate which contains silicon which is provided with at least a support part which supports the steel plate, a conveyor which makes the steel plate move, and a pickling tank which pickles the steel plate, wherein the pickling tank has means for feeding microbubbles and means for applying ultrasonic waves of at least two types of frequencies of 28.0 kHz or more to less than 1.0 MHz.

Pickling method and pickling system of steel plate

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Tokyo, Japan

Takumi Nishimoto