Sumitomo Metal Industries, Inc.

Mitsubishi Jukogyo Kabushiki Kaisha

Other

Shimano Inc.

Yasutaka Okada

Akio Ikeda

Takeo Kudo

Kunihiko Yoshikawa

Hiroo Ohtani

Taishi Moroishi

Kunio Kondo

Masaaki Igarashi

Toshio Yonezawa

Hiroo Nagano

Koji Watari

Kazuo Yamanaka

Yasuhide Fujioka

Hiroshi Susukida

Takao Minami

Kichiro Onimura

Nobuya Sasaguri

Seiji Tanimoto

Shiro Mukai

Daisuke Nago

Tsuyoshi Sakashita

Masahide Umino

Masaru Nishiguchi

Shinji Tsuge

Tomoaki Sera

Tatsuro Kunitake

Mamoru Inoue

Katsuji Kawaguchi

Noritake Yamaguchi

Takaaki Matsuda

Kazuo Tsumura

Iwao Saito

Masahiro Nishio

Tsuyashi Sakashita

Method of producing tool steels

The present invention is directed to a steel product for machine structural use having excellent machinability and to a structural steel part for machinery manufactured from the steel product. More particularly, the invention is directed to a steel product for machine structural use having excellent machinability, particularly bringing about excellent &ldquo;drill life&rdquo; and exhibiting excellent &ldquo;chip disposability&rdquo; in the course of drilling, as well as to a structural steel part for machinery manufactured from the steel product. The steel product for machine structural use has a chemical composition comprising, in mass percent, C: 0.05% to 0.55%; Si: 0.50% to 2.5%; Mn: 0.01% to 2.00%; P: not greater than 0.035%; S: 0.005% to 0.2%; N: not greater than 0.0150%; elements to be added as needed: Cu, Ni, Cr, Mo, V, Nb, Ti, B, Al, Bi, Ca, Pb, Te, Nd, and Se; &minus;23C&plus;Si(5&minus;2Si)&minus;4Mn&plus;104S&minus;3Cr&minus;9V&plus;10&gE;0; 3.2C&plus;0.8Mn&plus;5.2S&plus;0.5Cr&minus;120N&plus;2.6Pb&plus;4.1Bi&minus;0.001&agr; &plus;0.13&agr;&gE;3.0; and balance: Fe and incidental impurities; percentage of ferrite in microstructure being 10% to 80%; and Hv hardness being 160 to 350. In the above expressions, &agr; represents the area percentage in % of a ferrite phase in the microstructure. The structural steel part for machinery can be manufactured relatively easily from the steel product for machine structural use through machining.

Machine structural steel product

Stainless steel for a disc brake rotor

Seamless steel pipe manufacturing method and equipment

The present invention is directed to steel products which exhibit excellent machinability and are suitable for steel stocks of structural steel parts for a variety of machinery, such as transportation machinery including automobiles, machinery for industrial use, construction machinery, and the like; as well as to a variety of machined structual steel parts for machinery such as crankshafts, connecting rods, gears, and the like. The steel products of the present invention are endowed with excellent machinability and have the following composition based on % by weight: C: 0.05% to 0.6%; S: 0.002% to 0.2%; Ti: 0.04% to 1.0%; N: 0.008% or less; Nd: 0% to 0.1%; Se: 0% to 0.5%; Te: 0% to 0.05%; Ca: 0% to 0.01%; Pb: 0% to 0.5%; and Bi: 0% to 0.4%; wherein the maximum diameter of titanium carbosulfide contained in the steel is not greater than 10 .mu.m, and its amount expressed in the index of cleanliness of the steel is equal to or more than 0.05%. The machined parts, according to the present inventions are manufactured by subjecting the steel products of the invention to a machining process, and are useful as structural steel parts for a variety of machinery, such as transportation machinery including automobiles, machinery for industrial use, construction machinery, and the like.

Steel products excellent in machinability and machined steel parts

The manufacturing method of the present invention comprises steps (1) through (8) which are sequentially arranged, and the steps or equipment from the production of billets to end products are connected in the same single continuous manufacturing line:

Method and facility for manufacturing seamless steel pipe

A high tensile strength, low yield ratio steel member has a steel composition consisting essentially of, by weight:

High strength steel member with a low yield ratio

Method of manufacturing high strength steel member with a low yield ratio

A precipitation-hardening-type Ni-base alloy exhibiting improved resistance to stress corrosion cracking in a sour gas atmosphere containing elemental sulfur at high temperatures is disclosed. The alloy consists essentially of, by weight %;

Precipitation-hardening-type Ni-base alloy exhibiting improved corrosion

A precipitation-hardening-type Ni-base alloy exhibiting improved resistance to stress corrosion cracking in a sour gas atmosphere containing elemental sulfur at high temperatures is disclosed. The alloy comprises essentially, by weight %;

Precipitation-hardening-type ni-base alloy exhibiting improved corrosion

The present invention is concerned with a high-strength Ni-based alloy excellent in resistance to stress corrosion cracking in high-temperature high-pressure water, characterized by consisting essentially of, in terms of weight ratio, 0.08% or less of C, 0.15% or less of Si, 0.1 to 1% of Mn, 15% or less of Fe, 20 to 30% of Cr, 3.5% or less of Ti, 2% or less of Al, 7% or less of Nb and the balance of Ni, having at least one of a .gamma.' phase and a .gamma.' phase in a .gamma. base, and semicontinuously predominantly precipitating M.sub.23 C.sub.6 in grain boundaries; a method for preparing this high-strength Ni-based alloy by heating and maintaining the alloy having the identical composition at 980.degree. to 1,200.degree. C., cooling it, and subjecting it once or more to an aging treatment of additionally heating and maintaining it at 550.degree. to 850.degree. C.; a method for preparing the aforesaid alloy by heating and maintaining the alloy having the identical composition at 980.degree. to 1,200.degree. C., cooling it, subjecting it to a cold working at a 10% or more reduction of area, and subjecting it once or more to an aging treatment of additionally heating and maintaining it at 550.degree. to 850.degree. C.; and a method for preparing the aforesaid alloy by subjecting the alloy having the identical composition to a hot working at 850.degree. to 1,250.degree. C. at a draft percentage of 20% or more, heating and maintaining the alloy at 980.degree. to 1,200.degree. C., cooling it, and subjecting it once or more to an aging treatment of additionally heating and maintaining it at 550.degree. to 850.degree. C.

Ni-based alloy and method for preparing same

A nickel-chromium alloy excellent in a stress corrosion cracking resistance which is obtained by carrying out an annealing treatment under specific conditions, said alloy having the following composition:

Nickel-chromium alloy in stress corrosion cracking resistance

A method for a thermal treatment of a nickel based alloy, characterized in that said nickel based alloy for a material which will be subjected to a high-temperature and high-pressure water or vapor comprises, in terms of % by weight, 58% or more of Ni, 25 to 35% of Cr, 0.003% or less of B, 0.012 to 0.035% of C, 1% or less of Mn, 0.5% or less of Si, 0.015% or less of P, 0.015% or less of S, and the residue of Fe and usual impurities; in a first thermal treatment process, said nickel based alloy is heated and retained at a temperature of T.degree. C. to (T+100).degree.C. and is cooled at a cooling rate of a furnace cooling rate or more; and in a second thermal treatment process, said nickel based alloy is then retained at a temperature of 600.degree. to 750.degree. C. and at a temperature within a sensitization recovery range for a period of 0.1 to 100 hours and is cooled at a cooling rate of said furnace cooling rate or more.

Method for thermal treatment of nickel based alloy materials

A precipitation-hardening Ni-base alloy exhibiting improved resistance to corrosion under a corrosive environment containing at least one of hydrogen sulfide, carbon dioxide and chloride ions and method of producing the same are disclosed. The alloy is of the .gamma.'-phase, or (.gamma.'+.gamma.')-phase precipitation hardening type in which Ti is restricted to less than 0.40% and is comprised of:

Precipitation-hardening nickel-base alloy and method of producing same

A process for manufacturing high strength deep well casing, tubing, and drill pipes, which have improved resistance to stress corrosion cracking is disclosed. The process comprises the steps of preparing an alloy composition which is:

Process for making high strength deep well casing and tubing having

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Nara, Japan

Yasutaka Okada