Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Asahi Kogaku Kogyo Kabushiki Kaisha

Kenichiro Otsuka

Yoshiaki Nakazawa

Ryuichi Nishimura

Masafumi Azuma

Yasuhiro Ito

Masahiro Kubo

Masahiro Saito

Masatoshi Takano

Masami Shirai

Takaaki Yano

Mikio Horie

Tatsuya Yoshida

Masanori Yasuyama

Kazuhiro Ichinokawa

Masakazu Hirano

Eiichi Ito

Satoshi Hokamura

Motohiro Maseki

Toshiya Suzuki

Hiroyuki Kawata

Toru Yonebayashi

Yoshiyuki Kaseda

Naoki Kimoto

Koichi Hamada

Atsushi Ono

Shinji Kodama

Eisaku Sakurada

Takeshi Kawachi

Takeshi Toyoda

Genki Abukawa

Naruhiko Nomura

Satoshi Shirakami

Tuyoshi Ishikawa

Hiroaki Ando

Yasunori Sawa

Yoichiro Mori

Masahiro Matsuba

Koji Hashimoto

Takashi Miyagi

Tomoyuki Nishikawa

Hiroki Fujimoto

Yoshiyuki Ikeda

Keiji Ogawa

Ryo Tabata

Hitoshi Sakuma

Yujiro Tatsumi

Masatoshi Tokunaga

Ryo Urushibata

Yoshihiko Masuo

Yuki Kitahara

Ayaka Musha

Ryuichi Harada

A burring processing method including increasing a diameter of a prepared hole provided in a metal component and bending a part of the metal component to form a burring processed portion () including an upright portion () and a curved portion (), wherein in a cross-section that passes through an axis (cb) of the burring processed portion () and is parallel to the axis (cb) of the buffing processed portion (), a cross-sectional shape of the curved portion () on an inner surface of the curved portion consists of a curve, and a length of the curved portion () in a direction perpendicular to the axis (cb) of the burring processed portion () is at least 1.2 times a height of the curved portion in a direction parallel to the axis (cb) of the burring processed portion ().

Burring processing method, method for manufacturing burring processed product, burring processing mold, burring processing device, and burring processed product

A stiffened panel structure includes a panel-shaped component and a wire. The panel-shaped component has a panel body that curves in such a manner as to be convex outward. The wire has a first end portion and a second end portion. The first end portion is bonded to a first point on the inner surface of the panel body. The second end portion is bonded to a second point on the inner surface of the panel body. The wire is strained between the first point and the second point.

Stiffened panel structure

A steel sheet has a predetermined chemical composition, in which a metallographic structure in a surface layer region ranging from a surface to a position of 20 μm from the surface in a sheet thickness direction consists of ferrite and a secondary phase having a volume fraction of 0.01% to 5.0%, a metallographic structure in an internal region ranging from a position of more than 20 μm from the surface in the sheet thickness direction to a ¼thickness position from the surface in the sheet thickness direction consists of ferrite and a secondary phase having a volume fraction of 2.0% to 10.0%, the volume fraction of the secondary phase in the surface layer region is less than the volume fraction of the secondary phase in the internal region, and in the surface layer region, an average grain size of the secondary phase is 0.01 μm to 4.0 μm, and a texture in which an Xas the ratio of the intensity of {001} orientation to an intensity of {111} orientation in the ferrite is 0.60 or more and less than 2.00 is included.

Steel sheet and method for manufacturing same

A high-strength steel sheet includes a predetermined chemical composition, a microstructure contains, by volume percentage, 95% or more of tempered martensite and bainite in total, and a remainder consists of ferrite and pearlite, the microstructure contains 5.0×10pieces/mm or more of, per unit volume, precipitate having an equivalent circle diameter of 5.0 nm or less and containing Ti, Hvs/Hvc which is a ratio of an average hardness Hvs at a position of a depth of 20 μm from a surface to an average hardness Hvc at a position of 0.20 to 0.50 mm from the surface is 0.85 or more, a tensile strength is 980 MPa or more, and a product of the tensile strength and elongation is 12,000 MPa×% or more.

High-strength steel sheet and method for manufacturing same

A steel sheet includes, as a chemical composition, by mass %: C: 0.0015% to 0.0400%; Mn: 0.20% to 1.50%; P: 0.010% to 0.100%; Cr: 0.001% to 0.500%; Si: 0.200% or less; S: 0.020% or less; sol. Al: 0.200% or less; N: 0.0150% or less; Mo: 0% to 0.500%; B: 0% to 0.0100%; Nb: 0% to 0.200%; Ti: 0% to 0.200%; Ni: 0% to 0.200%; Cu: 0% to 0.100%; and a remainder including iron and impurities, in which a metallographic structure in a surface layer region includes ferrite having a volume fraction of 90% or more, and in the surface layer region, an average grain size of the ferrite is 1.0 μm to 15.0 μm, and a texture in which an Xas a ratio of an intensity of {001} orientation to an intensity of {111} orientation in the ferrite is 0.30 or more and less than 3.50 is included.

Steel sheet and method for producing same

An automobile undercarriage part of the present invention has a welded joint formed by base steel plate,

Automobile undercarriage part

A suspension arm includes a main body. The main body includes a curved portion curved along a longitudinal direction and has a closed section. The main body includes an inner side wall, an outer side wall, a first side wall, and a second side wall. The inner side wall corresponds to an inner side of a curve of the curved portion. The outer side wall corresponds to an outer side of the curve of the curved portion. A thickness of the inner side wall is larger than a thickness of the outer side wall. In sectional view of the main body perpendicular to the longitudinal direction, each of a length of the first side wall and a length of the second side wall is longer than each of a length of the inner side wall and a length of the outer side wall.

Suspension arm

An automobile undercarriage part of the present invention is an automobile undercarriage part including a welded joint in which a first steel sheet and a second steel sheet are overlapped and a fillet weld is formed between an end surface of the first steel sheet and a surface of the second steel sheet, in which a chemical composition of a weld metal that forms the welded joint contains, with respect to a total mass of the weld metal, by mass %, C: 0.02% to 0.20%, Si: more than 0% to less than 0.10%, Mn: 0.3% to 2.0%, Al: 0.002% to 0.30%. Ti: 0.005% to 0.30%, P: more than 0% to 0.015%, and S: more than 0% to 0.030%, and the following formula (1) and formula (2) are satisfied.[Al]+[Ti]>0.05  Formula (1)7×[Mn]−112×[Ti]−30×[Al]≤4.0  Formula (2)

A long formed article made of one steel sheet includes a top sheet portion, a standing wall portion, and a protrusion portion formed in a portion of the top sheet portion by overlapping a portion extending toward an outside from each of both ends of the top sheet portion and a portion extending toward the outside from an upper end of the standing wall portion, in a non-protrusion region, a recessed part is formed in the top sheet portion, and a total value α of inner surface peripheral lengths of the top sheet portion and the standing wall portion in a cross section of the formed article in a protrusion region and a total value β of inner surface peripheral lengths of the top sheet portion, the standing wall portion, and the recessed part in the cross section of the formed article in the non-protrusion region satisfy 1.01≤β/α≤1.50.

Formed article, structural member using the same, and manufacturing method of formed article

A high-strength steel sheet includes a predetermined chemical composition, a microstructure contains, by volume percentage, 80% or more of tempered martensite, and a remainder consists of ferrite and bainite, the microstructure contains 5.0×10pieces/mmor more of, per unit volume, precipitate containing Ti and having an equivalent circle diameter of 5.0 nm or less, Hvs/Hvc which is a ratio of an average hardness Hvs at a position of a depth of 20 μm from a surface to an average hardness Hvc at a position of 0.20 to 0.50 mm from the surface is 0.85 or more, and the tensile strength is 1,180 MPa or more.

An objective of the present disclosure is to provide a front pillar outer that is inexpensive, lightweight and strong. In an area in which a first door-side flange part and a second door-side flange part overlap with each other, a first plate part that is connected to a side edge of the first door-side flange part is folded so that a second door-side flange part is sandwiched between the first door-side flange part and the folded first plate part. In an area in which a first glass-face-side flange part and a second glass-face-side flange part overlap with each other, a second plate part that is connected to a side edge of the first glass-face-side flange part is folded so that the second glass-face-side flange part is sandwiched between the first glass-face-side flange part and the folded second plate part.

Front pillar outer

A panel-shaped formed product made of a metal sheet includes a top panel portion, an opening portion, and a vertical wall portion. The top panel portion is polygonal. The opening portion is provided in the top panel portion. The vertical wall portion extends from at least not less than two adjacent borders among the borders of the top panel portion. At least one pair of each vertical wall portion of pairs of adjacent vertical wall portions of the vertical wall portions has a stepped portion. As a result, the panel shaped formed product has fewer defects such as cracks and wrinkles even when it has a shape that is difficult to form.

Panel-shaped formed product

A steel sheet has a predetermined chemical composition, in which a metallographic structure in a surface layer region ranging from a surface to a position of 20 μm from the surface in a sheet thickness direction consists of ferrite and a secondary phase having a volume fraction of 1.0% to 15.0%, the metallographic structure in an internal region ranging from a position of more than 20 μm from the surface in the sheet thickness direction to a ¼ thickness position from the surface in the sheet thickness direction consists of ferrite and a secondary phase having a volume fraction of 5.0% to 25.0%, the volume fraction of the secondary phase in the surface layer region is less than the volume fraction of the secondary phase in the internal region, and in the surface layer region, the average grain size of the secondary phase is 0.5 μm to 4.0 μm.

Steel sheet and manufacturing method thereof

An objective of the present disclosure is to provide a front pillar outer that is inexpensive, lightweight and strong. A front pillar outer includes a glass-face-side flange part, a door-side flange part, and a main body part that connects the glass-face-side flange part and the door-side flange part to each other. In a partial area of the door-side flange part in a longitudinal direction thereof, a first plate part that is connected to a side edge of the door-side flange part is folded so that the first plate part is overlaid on the door-side flange part. In a partial area of the glass-face-side flange part in a longitudinal direction thereof, a second plate part that is connected to a side edge of the glass-face-side flange part is folded so that the second plate part is overlaid on the glass-face-side flange part.

An objective of the present invention is to provide a front pillar outer that has high strength and high rigidity. In an area in which the first door-side flange part and a second door-side flange part overlap with each other, the first door-side flange part and the second door-side flange part are joined to each other. In an area in which the first glass-face-side flange part and the second glass-face-side flange part overlap with each other, the first glass-face-side flange part and the second glass-face-side flange part are joined to each other.

Growing community of inventors

Tokyo, Japan

Kenichiro Otsuka