Nippon Steel Corporation

Mitsubishi Jukogyo Kabushiki Kaisha

Other

Masahiro Ohgami

Yasushi Hasegawa

Hisashi Naoi

Fujimitsu Masuyama

Masayuki Abe

Jun Maki

Toshio Fujita

Kazuhisa Kusumi

Hiroyuki Mimura

Toshio Fujii

Nobuo Mizuhashi

Toshiyuki Ogata

Shuichi Funaki

Shinya Nakajima

Norihiro Fujita

Tetsuya Magatani

Naoki Takasugi

Osamu Takeda

A method is proved for hot pressing hot rolled steel sheet, cold rolled steel sheet, Al-based plated steel sheet or Zn-based plated steel sheet, where the hot pressed sheet can exhibit a strength of at least about 1200 Mpa, and my be prevented from exhibiting hydrogen embrittlement. The steel sheet may include between about 0.05 to 0.5 wt % C, and/or it may be plated with an Al-based or Zn-based plating material. The steel sheet may be heating to a temperature greater than an Actemperature and not more than about 1100&#xb0; C. before pressing. An atmosphere can be provided during heating which contains not more than about 6 vol % of hydrogen and a dew point of not more than about 10&#xb0; C. The exemplary methods may be used to form high strength parts which may be used, e.g., in automobiles.

Hot pressing method for high strength member using steel sheet and hot pressed parts

The present invention provides an electric resistance welded steel pipe for a hollow stabilizer excellent in workability, which steel pipe contains, in mass, 0.20 to 0.35% of C, 0.10 to 0.50% of Si, 0.30 to 1.00% of Mn, 0.01 to 0.10% of Al, 0.10 to 1.00% of Cr, 0.005 to 1.00% of Mo, 0.001 to 0.02% of Ti, 0.0005 to 0.0050% of B and 0.0010 to 0.0100% of N, satisfying the expression N/14&#x3c;Ti/47.9, the balance consisting of Fe and unavoidable impurities and further has an ideal critical diameter (Di) being 1.0 (in) or more, an n-value in the axial direction of the steel pipe being 0.12 or more, a difference in hardness between the electric resistance welded seam portion and the base steel being Hv 30 or less, an average grain size of ferrite being 3 to 40 &#x3bc;m, an area percentage of the ferritic crystal grains having the aspect ratios of 0.5 to 3.0 being 90% or more in the entire ferrite phase, and having an average grain size of 20 &#x3bc;m or less in the second phase.

Electric resistance-welded steel pipe for hollow stabilizer

High strength, ferritic heat-resistant steel having improved resistance

Martensitic heat-resisting steel excellent in HAZ-softening resistance

A high-nitrogen ferritic heat-resisting steel with high vanadium content comprises, in weight percent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.005-1.00% Mo, 0.20-1.50% W, 0.30-2.00% V, and 0.10-0.50% N and being controlled to include less than 0.020% Nb, the balance being Fe and unavoidable impurities. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the resulting melt in an atmosphere controlled to have a total pressure of not less than 2.77 bar and a nitrogen partial pressure of not less than 1.0 bar, with the relationship between the nitrogen partial pressure p and the total pressure P being

High-nitrogen ferritic heat-resisting steel with high vanadium content

A high-nitrogen ferritic heat-resisting steel with high niobium content comprises, in weight per cent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.005-1.00% Mo, 0.20-1.50% W, 0.05-1.00% V, over 0.12 up to 2.00% Nb and 0.10-0.50%N, the balance being Fe and unavoidable impurities. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the resulting melt in an atmosphere controlled to have a total pressure of not less than 2.5 bar and a nitrogen partial pressure of not less than 1.0 bar, with the relationship between the nitrogen partial pressure p and the total pressure P being

High-nitrogen ferritic heat-resisting steel with high niobium content

Growing community of inventors

Kanagawa-ken, Japan

Masahiro Ohgami