Nippon Steel Corporation

Nippon Steel & Sumitomo Metal Corporation

Toyota Jidosha Kabushiki Kaisha

Olympus Optical Company, Ltd.

Denken Co., Ltd.

Arcelor France

Arcelormittal

Arcelormittal France

Manabu Takahashi

Nobuhiro Fujita

Naoki Yoshinaga

Riki Okamoto

Natsuko Sugiura

Masafumi Azuma

Akihiro Miyasaka

Yasuhiro Shinohara

Takehide Senuma

Kaoru Kawasaki

Takayuki Nozaki

Chisato Wakabayashi

Koji Hashimoto

Hiroshi Yoshida

Kunio Hayashi

Osamu Kawano

Shinya Sakamoto

Junichi Wakita

Takeshi Yamamoto

Kazuhiro Watanabe

Tohru Yoshida

Masao Kurosaki

Yasuharu Hakamatsuka

Shunji Hiwatashi

Yasuharu Sakuma

Koji Hanya

Mamoru Aihara

Yasuhide Morimoto

Yuzo Takahashi

Tetsuo Kishimoto

Toshio Shimizu

Naoki Maruyama

Yasuyuki Asai

Akihiro Uenishi

Shinichiro Watanabe

Yukihisa Kuriyama

Chisato Kato

Masaharu Oka

Ryoichi Kanno

Tsutomu Ochi

Nobuyoshi Uno

Matsuo Usuda

Hidesato Mabuchi

Kazuyoshi Esaka

Noriyuki Suzuki

Masayuki Abe

Hiroyuki Okada

Hiroyuki Imanishi

Jun Maki

Yasushi Hasegawa

Masahiro Ito

Tatsuo Yokoi

Tomotaka Ishikawa

Kohichi Sano

Hitoshi Asahi

Toshimitsu Aso

Hiroo Yoshikawa

Ken Kimura

Hironori Sato

Tomokazu Hayashi

Osamu Akisue

Kazuo Koyama

Kazuhisa Kusumi

Kazuaki Nakano

Ryouichi Namba

Koichi Karaki

Iwao Myojin

Toshihiko Kadota

Kiyoshi Fujii

Tsunemasa Nishida

Fumio Uchino

Masahiro Ohno

Hiroya Nakaji

Hiroshi Arisawa

Yuzo Nakamura

Soji Yamamoto

Hitoshi Tateoka

Masaaki Sugiyama

Kenichiroh Matsumura

Koji Kishida

Kanae Nakasato

Yasushi Satoh

Jun-ichi Ishibashi

Shinya Nakajima

Koichiro Kawakami

Yohji Nakamura

Masahiro Oogami

Toshiyuki Kanda

A fuel cell system includes a fuel cell stack and a control device that controls operation of the fuel cell system based on a measured voltage value measured by a voltage sensor. When the fuel cell system is started and a value measured by a temperature sensor is equal to or less than a temperature determined in advance, the control device raises the voltage of the fuel cell stack until a voltage condition determined in advance is met, by supplying a cathode with an oxidant gas before current sweep is started. The control device sets a voltage command value and a current command value such that an operation point of the fuel cell stack is on an equal power line of the fuel cell stack when the operation point is caused to transition in at least a part of a transition period.

Fuel cell system with improved low temperature operation

The inspection method for a fuel cell stack including a plurality of unit cells comprises: (a) operating a fuel cell system, including the fuel cell stack and an anode gas circulation flow path that is connected between an anode gas discharge port and an anode gas supply port of the fuel cell stack to circulate anode gas, under a predetermined liquid water accumulation condition to accumulate liquid water in the anode gas circulation flow path; (b) causing, after the step (a), the fuel cell system to stop and stand by until a predetermined restarting condition is satisfied; and (c) restarting, after the step (b), the fuel cell system to implement power generation by the fuel cell stack, and measuring voltage of each of the unit cells to detect a unit cell having negative voltage.

Inspection method for fuel cell stack

A fuel cell system includes a component in a circulation passage for off-gas, a battery temperature acquisition unit configured to acquire a fuel cell temperature, a component temperature acquisition unit configured to acquire a component temperature, a state-of-charge acquisition unit configured to acquire a state of charge of a secondary battery, and a controller configured to, when a temperature difference between the acquired fuel cell temperature and the acquired component temperature is greater than or equal to a predetermined temperature difference at the time of a stop of power generation of the fuel cell system, perform a warm-up operation of a fuel cell and store electric power generated through the warm-up operation in the secondary battery while the state of charge of the secondary battery is lower than a predetermined state of charge, and, after completion of the warm-up operation, perform the scavenging operation at predetermined scavenging power.

Fuel cell system

A fuel cell system comprises: a fuel cell stack having a plurality of unit cells in which anode gas flow paths are formed; an anode gas supply unit configured to supply anode gas to the fuel cell stack via an anode gas supply port of the fuel cell stack; a pressure sensor provided between the anode gas supply port and the anode gas supply unit to measure anode gas supply pressure; a current sensor configured to measure electric current of the fuel cell stack; and a controller configured to control anode gas supply quantity of the anode gas supply unit to thereby control the anode gas supply pressure. The controller is configured to, when there has been satisfied a blockage-predictable condition indicating that occurrence of blockage due to liquid water in the anode gas flow paths of at least one unit cell is predictable, calculate a first pressure for setting a stoichiometric ratio of anode gas to a predetermined value, the stoichiometric ratio being calculated from a current of the fuel cell stack and the anode gas supply quantity, then compare the first pressure with a second pressure for resolving blockage in the anode gas flow paths due to liquid water to determine a higher-in-value one of the first pressure and the second pressure as a selected pressure, and control the anode gas supply quantity so that the anode gas supply pressure becomes the selected pressure.

A hot-dip galvanized steel sheet includes: a steel sheet; and a plated layer on a surface of the steel sheet, a microstructure contains, by volume fraction, equal to or more than 20% and equal to or less than 99% in total of one or two of martensite and bainite, a residual structure contains one or two of ferrite, residual austenite of less than 8% by volume fraction, and pearlite of equal to or less than 10% by volume fraction, tensile strength is equal to or greater than 980 MPa, the plated layer is a hot-dip galvanized layer which contains oxides including one or two or more of Si, Mn, and Al, contains equal to or less than 15 mass % of Fe, and a remainder including Zn, Al, and unavoidable impurities, and when a cross section including the steel sheet and the hot-dip galvanized layer is seen in a sheet thickness direction, a projected area ratio is equal to or more than 10% and equal to or less than 90%.

Hot-dip galvanized steel sheet and manufacturing method thereof

A galvanized steel sheet according to the present invention includes a steel sheet and a galvanizing layer which is formed on a surface of the steel sheet. The steel sheet includes as a chemical component, by mass %, C: more than 0.100% to 0.500%, Si: 0.0001% to less than 0.20%, Mn: more than 0.20% to 3.00%, Al: 3.0% to 10.0%, N: 0.0030% to 0.0100%, Ti: more than 0.100% to 1.000%, P: 0.00001% to 0.0200%, S: 0.00001% to 0.0100% and a remainder including Fe and impurities. The galvanizing layer includes as a chemical composition, by mass %, Fe: 0.01% to 15% and a remainder including Zn and impurities. The galvanized steel sheet has a specific gravity of 5.5 to less than 7.5.

Galvanized steel sheet and method for producing the same

A steel sheet including, by mass %, C: more than 0.100% and 0.500% or less, Si: 0.0001% or more and less than 0.20%, Mn: more than 0.20% and 0.50% or less, Al: 3.0% or more and 10.0% or less, N: 0.0030% or more and 0.0100% or less, Ti: more than 0.100% and 1.000% or less, P: 0.00001% or more and 0.0200% or less, S: 0.00001% or more and 0.0100% or less, and a remainder including Fe and impurities, in which a sum of a C content and a Ti content satisfies 0.200&#x3c;C+Ti&#x2264;1.500 by mass %, a product of an Al content and an Si content satisfies Al&#xd7;Si&#x2264;0.8 by mass %, and a specific gravity is 5.5 to less than 7.5.

High-strength low-specific-gravity steel sheet having superior spot weldability

A galvanized steel sheet includes a steel sheet and a plating layer on the surface of the steel sheet, in which the steel sheet includes, as a steel chemical composition, by mass %, C: 0.05 to 0.40%, Si: 0.5 to 3.0% and Mn: 1.5 to 3.0%, a microstructure of the steel sheet includes ferrite, bainite, by volume fraction, 30% or more of a tempered martensite, and 8% or more of an austenite, and tensile strength of the steel sheet is 980 MPa or more, and the plating layer includes an oxide including at least one chemical element selected from Si, Mn and Al, and when seen at a cross section including the steel sheet and the plating layer in a plate thickness direction, a projection area fraction of the oxide is 10% or more.

Galvanized steel sheet and method of manufacturing the same

This is a cold-rolled steel sheet includes, by mass %, C: 0.02% to 0.4%, Si: 0.001% to 2.5%, Mn: 0.001% to 4.0%, and Al: 0.001% to 2.0%. The sum of the Si content and the Al content is 1.0% to 4.5%. An average pole density of an orientation group from {100}&#x3c;011&#x3e; to {223}&#x3c;110&#x3e; is 1.0 to 6.5, and a pole density of a crystal orientation {332}&#x3c;113&#x3e; is 1.0 to 5.0. A microstructure includes, by an area ratio %, 5% to 80% of ferrite, 5% to 80% of bainite, and 2% to 30% of retained austenite. In the microstructure, by an area ratio %, martensite is limited to 20% or less, pearlite is limited to 10% or less, and tempered martensite is limited to 60% or less.

Cold-rolled steel sheet and production method thereof

A hot-rolled steel sheet has an average value of the X-ray random intensity ratio of a {100} &#x3c;011&#x3e; to {223} &#x3c;110&#x3e; orientation group at least in a sheet thickness central portion that is in a sheet thickness range of &#x215d; to &#x215c; from a steel sheet surface of 1.0 to 6.0, an X-ray random intensity ratio of a {332} &#x3c;113&#x3e; crystal orientation of 1.0 to 5.0, rC which is an r value in a direction perpendicular to a rolling direction of 0.70 to 1.10, and r30 which is an r value in a direction that forms an angle of 30&#xb0; with respect to the rolling direction of 0.70 to 1.10.

Hot-rolled steel sheet, cold-rolled steel sheet, galvanized steel sheet, and methods of manufacturing the same

Disclosed is a hot-rolled steel sheet including, by mass %, C:0.02% to 0.5% of C, and the sum of the content of Si and the content of Al is 1.0% to 4.0%. An average pole density of an orientation group from {100}&#x3c;011&#x3e; to {223}&#x3c;110&#x3e; is 1.0 to 6.5, and a pole density of a crystal orientation {332}&#x3c;113&#x3e; is 1.0 to 5.0. A microstructure includes, by of an area ratio, 2% to 30% of retained austenite, 20% to 50% of ferrite, and 10% to 60% of bainite. rC that is a Lankford value in a direction orthogonal to a rolling direction is 0.70 to 1.10, and r30 that is a Lankford value in a direction forming an angle of 30&#xb0; with the rolling direction is 0.70 to 1.10.

Hot-rolled steel sheet and production method thereof

Disclosed is a high-strength hot-dip galvanized steel sheet having small material anisotropy and excellent formability with an ultimate tensile strength of 980 MPa or more. The hot-dip galvanized steel sheet includes a hot-dip galvanized layer formed on a surface of a base steel plate. The base steel plate contains C, Si, Mn, O, P, S, Al and N within predetermined ranges and a balance including Fe and inevitable impurities. The hot-dip galvanized layer contains Fe at less than 7 mass % or 7 to 15 mass % and a balance including Zn, Al, and inevitable impurities.

High-strength hot-dip galvanized steel sheet and high-strength alloyed hot-dip galvanized steel sheet having excellent formability and small material anisotropy with ultimate tensile strength of 980 MPa or more

The invention provides a cold-rolled steel sheet excellent in paint bake hardenability and ordinary-temperature non-aging property comprising, in mass %, C: 0.0005-0.0040%, Si: 0.8% or less, Mn: 2.2% or less, S: 0.0005-0.009%, Cr: 0.4-1.3%, O: 0.003-0.020%, P: 0.045-0.12%, B: 0.0002-0.0010%, Al: 0.008% or less, N: 0.001-0.007%, and a balance of Fe and unavoidable impurities. Ultra-low-carbon steel retaining solute N and containing added Cr, P, B and O is used to produce hot-rolled and cold-rolled steel sheet and hot-dip galvanized cold-rolled steel sheet that exhibit both high paint bake hardenability and ordinary-temperature non-aging property.

Cold-rolled steel sheet excellent in paint bake hardenability and ordinary-temperature non-aging property and method of producing the same

In a hot-rolled sheet, an average value of pole densities of an orientation group {100}&#x3c;011&#x3e; to {223}&#x3c;110&#x3e;, which is represented by an arithmetic mean of pole densities of orientations {100}&#x3c;011&#x3e;, {116}&#x3c;110&#x3e;, {114}&#x3c;110&#x3e;, {112}&#x3c;110&#x3e;, and {223}&#x3c;110&#x3e; in a thickness center portion of a thickness range of &#x215d; to &#x215c; from a surface of the steel sheet, is 1.0 to 6.5 and a pole density of a crystal orientation {332}&#x3c;113&#x3e; is 1.0 to 5.0; and a Lankford value rC in a direction perpendicular to a rolling direction is 0.70 to 1.10 and a Lankford value r30 in a direction that forms 30&#xb0; with respect to the rolling direction is 0.70 to 1.10.

Method of producing a hot rolled steel sheet

Growing community of inventors

Futtsu, Japan

Manabu Takahashi