Universal Entertainment Corporation

Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Aruze Gaming America, Inc.

Aruze Corporation

Kengo Takeda

Katsuya Nakano

Yuya Suzuki

Hiroyuki Kawata

Akihiro Uenishi

Eriko Tsukamoto

Kazuo Okada

Masayuki Abe

Kunio Hayashi

Riki Okamoto

Kazuo Hikida

Genki Abukawa

Kazuhisa Kusumi

Yasushi Tsukano

Takashi Aramaki

Shinichi Yamaguchi

Yuri Toda

Toshimasa Tomokiyo

Takafumi Yokoyama

Toyomitsu Nakamura

Shintarou Fujii

Jun Hirowatari

Jun Maki

Masafumi Azuma

Yuji Ogawa

Kohichi Sano

Eisaku Sakurada

Satoshi Nishimura

Shintaro Yamanaka

Yasunobu Miyazaki

Shuji Yamamoto

Seiji Furusako

Takayuki Nozaki

Hidekuni Murakami

Hideaki Kishi

Motonori Hashimoto

Mai Nagano

Chisato Yoshinaga

Ken Takata

Hitoshi Nikaido

Arisa Ikeda

In a steel sheet according to the present embodiment, a Ti content and a N content satisfy Ti−3.5×N≥0.003, at a sheet thickness ¼ position, a metallographic structure includes 90% or more of martensite in terms of volume fraction, at the sheet thickness ¼ position, a number density of TiC having a circle equivalent diameter of 1 to 500 nm is 3.5×10particles/mmor more, at the sheet, thickness ¼ position, a value of a median value of a Mn concentration+3σ is 5.00% or less, and a hardness measured at the sheet thickness ¼ position is 1.30 times or more a hardness measured at a position 50 μm deep from a surface of the steel sheet.

Steel sheet and method for manufacturing steel sheet

The present invention provides steel sheet having both bendability and hydrogen embrittlement resistance. The steel sheet of the present invention includes a central part of sheet thickness and a surface sort part formed at one side or both sides of the central part of sheet thickness. The microstructure of the central part of sheet thickness comprises, by volume ratio, 60% or more of tempered martensite, respectively less than 30% of ferrite, bainite, pearlite, and retained austenite, and less than 5% of as-quenched martensite. A thickness of the surface soft part is more than 10 μm per side and 15% or less of a thickness of the central part of sheet thickness, an average hardness of the surface soft part is 0.90 time or less of an average hardness of the central part of sheet thickness, the surface soft part includes carbides in a number density of 1×10/mmor more, an average particle size of the carbides is 0.250 μm or less, and a standard deviation of a log of a particle size is 0.05 or less.

Steel sheet

Provided is a steel sheet having a predetermined chemical composition, wherein precipitates having a diameter of less than 0.1 μm are present in a number density of 10 to 200/μmin a depth region of 1 to 10 μm from a surface, an amount of dissolved C in a depth region of 10 to 60 μm from the surface is less than 0.20 mass %, and a tensile strength is 1200 MPa or more. Further, provided is a method for producing a steel sheet comprising a step of hot rolling a steel slab having a predetermined chemical composition, then coiling it at 580° C. or less, a step of pickling the hot rolled steel sheet to remove oxide scale and remove the surface layer of the hot rolled steel sheet down to at least 5 μm, and a step of cold rolling the hot rolled steel sheet, then holding it in an atmosphere of a dew point of −20 to 20° C. at a temperature region of 200 to 400° C. for 20 to 180 seconds and holding it at a temperature region of 740 to 900° C. for 40 to 300 seconds.

Steel sheet and method for producing same

A steel sheet includes a predetermined composition, in which a microstructure at a ¼ thickness position from a surface in a sheet thickness direction includes, by vol %, ferrite: 80% or more, martensite: 2% or less, and residual austenite: 2% or less, a proportion of unrecrystallized ferrite in the ferrite of 5% or less, and in the microstructure of the steel sheet stretched by 10% at the ¼ thickness position from the surface in the sheet thickness direction, a number density of voids having a maximum diameter of 1.0 μm or more is 1.0×10pieces/mor less.

Steel sheet and method of manufacturing the same

In the present invention, provided is a steel sheet having a predetermined chemical composition and a metallographic structure, in which A/B, which is a ratio of a length A of an interface between epitaxial ferrite and ferrite to a length B of an interface between the epitaxial ferrite and martensite in a cross section that is along a rolling direction and perpendicular to a surface of the steel sheet at a position of ¼ of a sheet thickness from the surface of the steel sheet is more than 1.5, a ratio of a major axis to a minor axis of the martensite is 5.0 or more, and a tensile strength is 980 MPa or more.

Steel sheet and manufacturing method thereof

This steel sheet has a predetermined chemical composition, the metallurgical structure at a thickness ¼ portion is, by area ratio, martensite: 40% to 97%, ferrite+bainite: 50% or less, residual austenite: 3% to 20% and a remainder in microstructure: 5% or less, the aspect ratio of residual austenite having an aspect ratio of 3 or more is 80% or more with respect to the total area of residual austenite, and the number of carbides having a grain diameter of 8 to 40 nm per square micrometer is five or more in the residual austenite.

This steel sheet has a specific chemical composition, the tensile strength is 1300 MPa or more, the ratio (R/t) of the limit bend radius to the sheet thickness is less than 3.5, when a depth position of 30 μm from the surface in the sheet thickness direction is defined as a position A and a depth position of ¼ of the sheet thickness from the surface in the sheet thickness direction is defined as a position B, the number density of AlN at the position A is 3000 pieces/mmor more and 6000 pieces/mmor less, a metallographic structure at the position B includes 90% or more of martensite by volume percentage, and the hardness at the position A is 1.20 times or higher than the hardness at the position B.

This steel sheet has a predetermined chemical composition, the metallographic structure includes, by an area ratio, ferrite, bainite and pearlite: 0 to 10% in total, residual austenite: 1 to 15%, and a remainder that is martensite, and a proportion of martensite or residual austenite having a width of 50 nm to 2 μm present at a prior austenite grain boundary is 70% or more.

Steel sheet and method for manufacturing same

Provided is a steel sheet having a predetermined chemical composition and structure wherein (Fe, Mn)B precipitates having a circle equivalent diameter of 50 to 300 nm are present in a number density of 1/500 μmor more in a surface layer region down to a depth of 100 μm from the surface in the sheet thickness direction. Further, provided is a method for producing a steel sheet comprising continuously casting a molten steel having a predetermined chemical composition to form a steel slab, wherein the continuously casting includes introducing more than 10 ppm and less than 100 ppm of oxygen into the surface layer of the steel slab, hot rolling including finish rolling the steel slab, wherein a completion temperature of the finish rolling is 650 to 950° C., coiling the obtained hot rolled steel sheet at a coiling temperature of 400 to 700° C., and cold rolling the hot rolled steel sheet, then annealing it.

This steel sheet has a predetermined chemical composition, and includes, as a metallographic structure, ferrite, bainite, and pearlite in a total volume percentage of 0% or more and 50% or less, residual austenite in a volume percentage of 3% or more and 20% or less, and a remainder of fresh martensite and tempered martensite, in which residual austenite having an aspect ratio of 3.0 or more occupies 80% or more of a total residual austenite by area ratio, the steel sheet includes an internal oxide layer having a thickness of 4.0 μm or more from a surface of the steel sheet and a decarburized layer having a thickness of 10 μm or more and 100 μm or less from the surface of the steel sheet, and an amount of diffusible hydrogen included in the steel sheet is 1.00 ppm or less on a mass basis.

A steel sheet according to an aspect of the present invention has a predetermined chemical composition, in which a metallographic structure at a ¼ thickness portion includes, by volume percentage, a total of 50% or more of one or both of martensite and bainite and 8% or more of residual austenite, an average value of aspect ratios of prior austenite grains is 5.0 or more, number density of AlN is 3000 pieces/mmor more and less than 6000 pieces/mmat a depth position of 30 μm from a sheet surface, an internal oxidation layer in which at least a part of a crystal grain boundary is coated with an oxide is provided from the sheet surface to a depth of 5.0 μm or more, grain boundary coverage of the oxide is 60% or more in a region from the sheet surface to a depth of 5.0 μm, and a tensile strength is 980 MPa or more.

This steel sheet has a predetermined chemical composition, in which the area ratio of plate martensite is 10% or more, the average grain size of prior austenite grains is 2.0 μm to 10.0 μm, the maximum diameter thereof is 20.0 μm or less, the amount of solid solution C in martensite is 0.20 mass % or less, the average carbide size is 0.25 μm or less, the crystal orientation difference between plate martensite and another martensite adjacent thereto in the same prior austenite grain is 10.0° or less, and the P concentration at grain boundaries of the prior austenite grains is 4.0 at % or less.

Provided are: a steel sheet having a high strength and excellent hydrogen embrittlement resistance; and a method of producing the same. The steel sheet has prescribed chemical composition and structure, in which a standard deviation σ of Mn concentration satisfies σ≥0.15 Mn(wherein, Mnrepresents an average Mn concentration) and a region with a Mn concentration of higher than (Mn+1.3σ) has a circle-equivalent diameter of less than 10.0 μm. The method of producing the steel sheet includes: the hot rolling step that includes finish rolling a slab having a prescribed chemical composition under prescribed conditions; the step of coiling the thus obtained hot-rolled steel sheet at a coiling temperature of 450 to 700° C.; and the step of cold rolling the hot-rolled steel sheet and subsequently annealing this steel sheet at 800 to 900° C.

Provided is an information processing apparatus including an interface capable of receiving identification information on a user retrieved by an information reading apparatus installed in a gaming hall, and a controller capable of retrieving locational information on an object related to the user in the gaming hall from a storage device based on the identification information on the user and performing image processing to create a floor map of the gaming hall in which an image associated with the object is mapped to a corresponding position of the object in the gaming hall. The storage device stores identification information for identifying the object together with the identification information on the user and further stores the locational information for locating the object together with the identification information on the object. The information processing apparatus enables grasp of objects related to the user in the gaming hall.

Information processing apparatus, information reading apparatus, gaming machine, and gaming system

A steel sheet including a steel micro-structure containing, in volume fraction,

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Tokyo, Japan

Kengo Takeda