Kobe Steel, Ltd.

Kabushiki Kaisha Kobe Seiko Sho

Masaki Shimamoto

Tomoko Sugimura

Takehiro Tsuchida

Shingo Yoshida

Takao Harada

Shoichi Kikuchi

Koichi Sakamoto

Hiroshi Yaguchi

Hitoshi Ishida

Hidenori Nako

Mutsuhisa Nagahama

Tomokazu Masuda

Masaki Kaizuka

Yosuke Shindo

Shun Izutani

Shogo Murakami

Tetsunao Ikeda

Hirohisa Watanabe

Yoshitomi Okazaki

Hitoshi Hatano

Tetsushi Deura

Shigenobu Namba

Sei Kimura

Akira Ibano

Koichi Akazawa

Yushi Sawada

Hiroaki Kawamoto

Taiji Hatakeyama

Motohiro Horiguchi

Shinsuke Masuda

Naoki Mukai

Kazuhiro Fukuda

Yui Hosono

Yukinobu Natsume

Akihiro Owaki

Takashi Sugitani

Shinsuke Sato

The reduced iron manufacturing method of the present invention includes preparing an agglomerate by agglomerating a mixture containing an iron oxide-containing substance and a carbonaceous reducing agent, and preparing reduced iron by heating the agglomerate to reduce iron oxide in the agglomerate, characterized in that Expression (I) as follows is satisfied:&#x2264;51&#x2003;&#x2003;(I)where Ois the mass percentage of oxygen contained in the iron oxide in the agglomerate, Cis the mass percentage of total fixed carbon contained in the agglomerate, and Xis the mass percentage of particles having a particle diameter of 105 &#x3bc;m or less with respect to the total mass of particles configuring the carbonaceous reducing agent.

Reduced iron manufacturing method

A Ni based alloy flux cored wire including a Ni based alloy as a sheath is provided, wherein the sheath contains predetermined ranges of Ni, Cr, Mo, Ti, Al, and Mg relative to the total mass of the sheath, control is made to ensure predetermined C and Si, the composition of the whole wire, which is the sum total of the sheath components and flux components enveloped in the sheath, contains predetermined ranges of Ni, Cr, Mo, Mn, W, Fe, Ti, Al, and Mg relative to the total mass of the wire, and control is made to ensure predetermined C, Si, Nb, P, and S.

Ni based alloy flux cored wire

Bearing steel material according to the present invention has: a properly adjusted chemical composition; an average chemical composition of oxide-inclusions which comprises 10 to 45% of CaO, 20 to 45% of AlO, 30 to 50% of SiO, up to 15% (exclusive of 0) of MnO, and 3 to 10% of MgO, with the balance being unavoidable impurities; a maximum major axis diameter of the oxide inclusions in a longitudinal section of the steel material of 20 &#x3bc;m or less; and a spheroidal cementite structure.

Bearing steel material with excellent rolling contact fatigue properties and a bearing part

A bearing steel material which contains 0.8-1.1 mass % C, 0.15-0.8 mass % Si, 0.1-1.0 mass % Mn, 1.3-1.8 mass % Cr, up to 0.05 mass % P (0 mass % is excluded), up to 0.015 mass % S (0 mass % excluded), 0.0002-0.005 mass % Al, 0.0002-0.0020 mass % Ca, 0.0005-0.010 mass % Ti, up to 0.0080 mass % N (0 mass % is excluded), and up to 0.0025 mass % O (0 mass % is excluded). The steel material contains oxide inclusions which have an average composition that comprises, in terms of mass %, 20-50% CaO, 20-50% AlO, 20-70% SiO, and 3-10% TiO.

Bearing steel material with excellent rolling fatigue property and bearing part

Provided is a steel for machine structural use which has excellent machinability (particularly, with respect to tool life) for both intermittent cutting with a high-speed steel tool and continuous cutting with a cemented carbide tool while maintaining strength properties required of the steel for machine structural use. Specifically, the steel for machine structural use contains C: 0.05-0.9 mass %, Si: 0.03-2 mass %, Mn: 0.2-1.8 mass %, P: 0.03 mass % or less, S: 0.03 mass % or less, Al: 0.1-0.5 mass %, N: 0.002-0.017 mass %, and O: 0.003 mass % or less, and contains one or more selected from a group consisting of Ti: 0.05 mass % or less (excluding 0 mass %) and B: 0.008 mass % or less (excluding 0 mass %), with the remainder being iron and unavoidable impurities, and satisfies all of the following inequalities (1)-(3) below: (1): [N]&#x2212;0.3[Ti]&#x2212;1.4[B]&#x3c;(0.0004/[Al])&#x2212;0.002; (2): [Ti]&#x2212;[N]/0.3&#x3c;0.005; and (3): [B]&#x2212;([N]&#x2212;0.3[Ti])/1.4&#x3c;0.003 when [Ti]&#x2212;[N]/0.3&#x3c;0 and [B]&#x3c;0.003 when [Ti]&#x2212;[N]/0.3&#x2267;0.

Steel for machine structural use

An object of the present invention is to provide a Ni base alloy solid wire for welding, which has excellent cracking resistance to ductility dip cracking in weld metal, can increase the tensile strength of the weld metal to not less than the tensile strength of the base material, and has excellent weldability. The present invention provides a solid wire which has a composition containing Cr: 27.0 to 31.5 mass %, Ti: 0.50 to 0.90 mass %, Nb: 0.40 to 0.70 mass %, Ta: 0.10 to 0.30 mass %, C: 0.010 to 0.030 mass %, and Fe: 5.0 to 11.0 mass %, and is regulated to Al: 0.10 mass % or less, N: 0.020 mass % or less, Zr 0.005 mass % or less, P:0.010 mass % or less, S: 0.0050 mass % or less, Si: 0.50 mass % or less, and Mn: 1.00 mass % or less, with the balance including Ni and inevitable impurities.

Ni base alloy solid wire for welding

The present invention provides a steel for machine and structural use which is capable of maintaining mechanical characteristics such as strength by reducing a S content as well as of exhibiting excellent machinability (particularly tool life) in intermittent cutting (such as hobbing) with the high speed tool, and a method useful for producing the steel for machine and structural use. The steel for machine and structural use according to the invention secures 0.002% or more of solute N in the steel and has a chemical composition which is appropriately adjusted and satisfies a relationship of the following expression (1): (0.1&#xd7;[Cr]+[Al])/[O]&#x2267;150 . . . (1), in which [Cr], [Al], and [0] represent a Cr content (mass %), an Al content (mass %), and an O content (mass %), respectively.

Steel for machine and structural use having excellent machinability and process for producing the same

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Kobe, Japan

Masaki Shimamoto