Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corporation

Kyb Corporation

Toyota Jidosha Kabushiki Kaisha

Asahi Kasei E-Materials Corporation

Takeshi Yasui

Hiroyuki Kawata

Naoki Maruyama

Akinobu Murasato

Akinobu Minami

Yuji Yamaguchi

Takuya Kuwayama

Hiroyuki Ban

Satoshi Uchida

Kohei Ueda

Kaoru Hiramatsu

Ryosuke Komami

Toyomitsu Nakamura

Hayato Arai

Kazuyuki Kimishima

Akio Saito

Satoru Tanaka

Katsumi Suzuki

Naoki Yamamoto

Kiyokazu Ishizuka

Natsuko Sugiura

Shigeru Yonemura

Masaki Koyama

Koki Tanaka

Kazuyuki Mizuno

Tooru Oohashi

Yasuaki Konomi

Takayuki Kitazawa

Tomohiko Baba

Yasuhiro Nakashima

Kojiro Akiba

Nayuta Kawazu

Motonori Nakamichi

A shock absorber is provided. The shock absorber of the present invention includes a shock absorber main body, a damping passage, a primary damping force generation component, and a secondary damping force generation component. The shock absorber main body has an outer tube and a rod and is stretchable. The damping passage communicates operating chambers with each other provided in the shock absorber main body. The primary and secondary damping force generation components are provided in series with the damping passage. The secondary damping force generation component includes a secondary valve, an annular facing portion, and a valve stopper. The annular facing portion faces the secondary valve with an annular gap between the annular facing portion and the secondary valve. The valve stopper has elasticity to allow bending, and when the secondary valve bends and comes in contact with the valve stopper, restricts the secondary valve from bending.

Shock absorber

A valve includes: a valve case; and an annular valve body, one of the inner circumference end and the outer circumference end of the valve body being formed as the free end capable of moving towards both sides in the axial direction with respect to the valve case. The valve case has the annular opposing surface capable of opposing to the free end so as to form the gap therebetween, and the guide surface that is positioned on one side of the opposing surface in the axial direction, the guide surface being continuous with the part of the opposing surface in the circumferential direction. The guide surface is inclined in the direction away from the valve body as the distance from the opposing surface is increased.

Valve and shock absorber

A damping valve includes: a ring-shaped leaf valve having either one of an outer circumference and an inner circumference as a free end, the free end being allowed to be deflected toward both sides in the axial direction; a ring-shaped opposing portion that opposes the free end of the leaf valve with a gap; a first sub leaf valve stacked on one side of the leaf valve in the axial direction; and a first passage formed in the leaf valve so as to extend in parallel with the gap, the first passage being configured to be opened when the leaf valve is deflected in the direction away from the first sub leaf valve.

The valve includes a valve case; an annular valve body, an outer peripheral end of which is a free end movable to both sides in an axial direction with respect to the valve case; a facing portion provided in the valve case, the facing portion including an annular facing surface which is located on an outer peripheral side of the valve body and is configured to face the free end with a gap; and first and second valve stoppers which are located on both sides respectively in the axial direction of the valve body. The first and second valve stoppers, respectively, have a plurality of support portions that are configured to support different positions of the valve body in a radial direction at different heights when the valve body deflects.

A steel sheet has a predetermined chemical composition, and a surface exhibits an absorption peak at which a reflectance is not less than 50% nor more than 85% in a range of wave numbers of 1200 cmto 1300 cmby a Fourier transform-infrared spectroscopy analysis by a reflection absorption spectrometry method, and does not exhibit an absorption peak in a range of wave numbers of 1000 cmto 1100 cm, or exhibits an absorption peak at which a reflectance is 85% or more in the range of wave numbers of 1000 cmto 1100 cm, wherein Ni of 3 mg/mto 100 mg/madheres to the surface.

Steel sheet

A hot-dip galvanized steel sheet includes a base steel sheet and a hot-dip galvanized layer formed on at least one surface of the base steel sheet, in which the hot-dip galvanized layer includes Fe in a content of more than 0% to 5% or less, Al in a content of more than 0% to 1.0% or less, and columnar grains formed by a &#x3b6; phase on the surface of the steel sheet, further, 20% or more of the entire interface between the hot-dip galvanized layer and the base steel sheet is coated with the &#x3b6; phase, and a ratio of an interface formed between &#x3b6; grains in which coarse oxides are present among grains and the base steel sheet with respect to the entire interface between the &#x3b6; phase and the base steel sheet in the hot-dip galvanized layer is 50% or less, the base steel sheet has predetermined chemical components and a refined layer in direct contact with the interface between the base steel sheet and the hot-dip galvanized layer, an average thickness of the refined layer is 0.1 to 5.0 &#x3bc;m, an average grain size of ferrite in the refined layer is 0.1 to 3.0 &#x3bc;m, one or two or more of oxides of Si and Mn are contained in the refined layer, and a maximum size of the oxide is 0.01 to 0.4 &#x3bc;m, and a volume fraction of residual austenite in a range of &#x215b; thickness to &#x215c; thickness centered at a position of &#xbc; thickness from the surface of the base steel sheet is 1% or more.

Hot-dip galvanized steel sheet

A hot-dip galvanized steel sheet includes a base steel sheet and a hot-dip galvanized layer formed on at least one surface of the base steel sheet, in which the hot-dip galvanized layer includes Fe in a content of more than 0% to 5% or less, Al in a content of more than 0% to 1.0% or less, and columnar grains formed by a &#x3b6; phase on the surface of the steel sheet, further, 20% or more of the entire interface between the hot-dip galvanized layer and the base steel sheet is coated with the &#x3b6; phase, and a ratio of an interface formed between &#x3b6; grains in which coarse oxides are present among &#x3b6; grains and the base steel sheet with respect to the entire interface between the &#x3b6; phase and the base steel sheet in the hot-dip galvanized layer is 50% or less, the base steel sheet has predetermined chemical components and a refined layer in direct contact with the interface between the base steel sheet and the hot-dip galvanized layer, an average thickness of the refined layer is 0.1 to 5.0 &#x3bc;m, an average grain size of ferrite in the refined layer is 0.1 to 3.0 &#x3bc;m, one or two or more of oxides of Si and Mn are contained in the refined layer, and a maximum size of the oxide is 0.01 to 0.4 &#x3bc;m.

A high-strength hot-dip galvanized steel sheet excellent in impact resistance and worked portion corrosion resistance including a hot-dip galvanized plating layer on a steel sheet base material whose tensile strength is 590 MPa or more, wherein the plating layer includes projecting alloy layers being in contact with the steel sheet base material, a number density of the projecting alloy layers is 4 pieces/mm or more, wherein the steel sheet base material includes: a miniaturized layer being directly in contact with the interface between the steel sheet base material and the plating layer; a decarburized layer being in contact with the miniaturized layer; and an inner layer other than the miniaturized layer and the decarburized layer, and one or more kinds of oxides of Si and Mn are contained in layers of the miniaturized layer, the decarburized layer, and the projecting alloy layers.

High-strength hot-dip galvanized steel sheet excellent in impact peeling resistance and worked portion corrosion resistance

A hot-dip galvanized steel sheet wherein the hot-dip galvanized steel sheet comprises a base steel sheet and a hot-dip galvanized layer, a ferrite phase is, by volume fraction, 40% or more and 97% or less in a range of &#x215b; thickness to &#x215c; thickness centered at a position of &#xbc; thickness from the surface of the base steel sheet, a hard structure is 3% or more in total, wherein the hot-dip galvanized steel sheet has the hot-dip galvanized layer in which Fe is 5.0% or less and Al is 1.0% or less, and columnar grains formed of a &#x3b6; phase is 20% or more in an entire interface between the plated layer and the base steel sheet on the surface of the base steel sheet in which a ratio of a volume fraction of the hard structure in a surface layer range of 20 &#x3bc;m depth in a steel sheet direction from an interface between the hot-dip galvanized layer and the base steel sheet is 0.10 times or more to 0.90 times or less of a volume fraction of the hard structure in the range of &#x215b; thickness to &#x215c; thickness, and wherein the hot-dip galvanized steel sheet has a refined layer at the side of the interface in the base steel sheet, and wherein an average thickness of the refined layer, an average grain size of ferrite in the refined layer and a maximum size of the oxide included in the refined layer are defined respectively.

A hot-dip galvanized steel sheet having a base steel sheet and a hot-dip galvanized layer, a ferrite phase is, by volume fraction, 50% or less in a range of &#x215b; thickness to &#x215c; thickness centered at a position of &#xbc; thickness from the surface of the base steel sheet, a hard structure is 50% or more, wherein the hot-dip galvanized steel sheet has the hot-dip galvanized layer in which Fe is 5.0% or less and Al is 1.0% or less, and columnar grains formed of a &#x3b6; phase is 20% or more in an entire interface between the plated layer and the base steel sheet. On the surface of the base steel sheet, a volume fraction of a residual austenite is 3% or less.

High strength steel sheet and high strength galvanized steel sheet which are excellent in shapeability which secure a tensile maximum strength 900 MPa or more high strength while obtaining excellent ductility and stretch flangeability, which sheets have predetermined compositions of ingredients, have steel sheet structures which contain volume fraction 1 to 20% of residual austenite phases, and which have martensite transformation points of the residual austenite phases of &#x2212;60&#xb0; C. or less.

High strength steel sheet and high strength galvanized steel sheet excellent in shapeability and methods of production of same

A galvannealed steel sheet includes: a steel sheet; a coating layer on a surface of the steel sheet; and a mixed layer formed between the steel sheet and the coating layer, in which the mixed layer includes a base iron portion having fine grains having a size of greater than 0 &#x3bc;m and equal to or smaller than 2 &#x3bc;m, a Zn&#x2014;Fe alloy phase, and oxides containing one or more types of Mn, Si, Al, and Cr, and in the mixed layer, the oxides and the Zn&#x2014;Fe alloy phase are present in grain boundaries that form the fine grains and the Zn&#x2014;Fe alloy phase is tangled with the base iron portion.[Mn]+[Si]+[Al]+[Cr]&#x2267;0.4&#x2003;&#x2003;(Expression 1)

Galvannealed steel sheet and method of manufacturing the same

There is provided a high-strength hot-dip galvanized steel sheet and the like excellent in mechanical cutting property, which are capable of obtaining high ductility while ensuring high strength with maximum tensile strength of 900 MPa or more. The high-strength hot-dip galvanized steel sheet has a sheet thickness of 0.6 to 5.0 mm and has a plating layer on a surface of a steel sheet with component compositions being set in appropriate ranges, in which the steel sheet structure contains a 40 to 90% ferrite phase and a 3% or more retained austenite phase by volume fraction. In the retained austenite phase, a solid solution carbon amount is 0.70 to 1.00%, an average grain diameter is 2.0 &#x3bc;m or less, an average distance between grains is 0.1 to 5.0 &#x3bc;m, a thickness of a decarburized layer in a steel sheet surface layer portion is 0.01 to 10.0 &#x3bc;m, an average grain diameter of oxides contained in the steel, sheet surface layer portion is 30 to 120 nm and an average density thereof is 1.0&#xd7;10oxides/mor more, and moreover, a work hardening coefficient (n value) during a 3 to 7% plastic deformation is 0.080 or more on average.

High-strength hot-dip galvanized steel sheet and high-strength alloyed hot-dip galvanized steel sheet excellent in mechanical cutting property, and manufacturing method thereof

A base steel sheet has a hot-dip galvanized layer formed on a surface thereof, in which, in a steel sheet structure in a range of &#x215b; thickness to &#x215c; thickness centered around &#xbc; thickness of a sheet thickness from a surface, a volume fraction of a retained austenite phase is 5% or less, and a total volume fraction of phases of bainite, bainitic ferrite, fresh martensite, and tempered martensite is 40% or more, an average effective crystal grain diameter is 5.0 &#x3bc;m or less, a maximum effective crystal grain diameter is 20 &#x3bc;m or less, and a decarburized layer with a thickness of 0.01 &#x3bc;m to 10.0 &#x3bc;m is formed on a surface layer portion, in which a density of oxides dispersed in the decarburized layer is 1.0&#xd7;10to 1.0&#xd7;10oxides/m, and an average grain diameter of the oxides is 500 nm or less.

High-strength hot-dip galvanized steel sheet excellent in impact resistance property and manufacturing method thereof, and high-strength alloyed hot-dip galvanized steel sheet and manufacturing method thereof

Provided are: a galvannealed steel sheet, improved in the adhesiveness of a plated layer with a base steel sheet, as a galvannealed steel sheet, prepared by using a high-strength steel sheet as a base material; and a method for producing the galvannealed steel sheet. A galvannealed layer is formed on the base steel sheet including a high-strength steel having a predetermined composition. The average amount of Fe in the galvannealed layer is 8.0 to 12.0%. The absolute value of a difference (&#x394;Fe) between the amount of Fe in the vicinity of an interface with the base steel sheet and the amount of Fe in the vicinity of the external surface of the plated layer in the plated layer is 0.0 to 3.0%.

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Tokyo, Japan

Takeshi Yasui