Daido Steel Co., Ltd.

Daido Tokushuko Kabushiki Kaisha

Mitsubishi Heavy Industries Limited

Other

Honda Motor Co., Ltd.

Ebara Corporation

Ihi Corporation

Tohoku University

Mitsubishi Hitachi Power Systems, Ltd.

Shigeki Ueta

Jun Sato

Hiroyuki Takabayashi

Takashi Nakano

Hideyuki Sakamoto

Shinya Imano

Toshiharu Noda

Michio Okabe

Mototsugu Osaki

Kohki Izumi

Kenji Sugiyama

Shin Nishimoto

Tetsuya Shimizu

Yoshikuni Kadoya

Ryuichi Yamamoto

Kenta Yamashita

Satoshi Takahashi

Kiyohito Ishida

Ryotaro Magoshi

Toshihiro Omori

Shuji Hamano

Keita Hinoshita

Shuji Narita

Hiroshi Yakuwa

Katsunari Oikawa

Manabu Noguchi

Hiroaki Nishida

Koichi Ishikawa

Yuta Tanaka

Takashi Ebata

Kota Sasaki

Michiharu Ogawa

Isao Nakanowatari

Takuma Okajima

Kei Matsuoka

Tomoki Shiota

Seiji Kurata

Takashi Tsuyumu

Kaoru Imaizumi

Akira Uchino

Ei Kimura

Yoshiyuki Sawada

Noritaka Takahata

Satoru Yusa

Koshiro Yamane

Ayumi Hori

Masahiro Hayashi

Mari Takahashi

The present invention relates to an Ni-based superalloy for hot forging, containing, in terms of % by mass, C: more than 0.001% and less than 0.100%, Cr: 11% or more and less than 19%, Co: more than 5% and less than 25%, Fe: 0.1% or more and less than 4.0%, Mo: more than 2.0% and less than 5.0%, W: more than 1.0% and less than 5.0%, Nb: 0.3% or more and less than 4.0%, Al: more than 3.0% and less than 5.0%, Ti: more than 1.0% and less than 3.0%, and Ta: 0.01% or more and less than 2.0%, with the balance being unavoidable impurities and Ni, in which the component composition satisfies the following two relationships: 3.5&#x2264;([Ti]+[Nb]+[Ta])/[Al]&#xd7;10&#x3c;6.5 and 9.5&#x2264;[Al]+[Ti]+[Nb]+[Ta]&#x3c;13.0.

Ni-based superalloy for hot forging

The present invention relates to a maraging steel containing, in terms of mass %, 0.10&#x2264;C&#x2264;0.35, 9.0&#x2264;Co&#x2264;20.0, 1.0&#x2264;(Mo+W/2)&#x2264;2.0, 1.0&#x2264;Cr&#x2264;4.0, a certain amount of Ni, a certain amount of Al, and V+Nb&#x2264;0.60, with the balance being Fe and inevitable impurities, in which in a case of V+Nb&#x2264;0.020, the amount of Ni is 6.0&#x2264;Ni&#x2264;9.4 and the amount of Al is 1.4&#x2264;Al&#x2264;2.0, and in a case of 0.020&#x3c;V+Nb&#x2264;0.60, the amount of Ni is 6.0&#x2264;Ni&#x2264;20.0 and the amount of Al is 0.50&#x2264;Al&#x2264;2.0.

Maraging steel

The present invention relates to a method for producing a precipitation strengthened Ni-based superalloy material having a predetermined composition, containing a blooming forging step of performing a forging at a temperature range of from Ts to Tm and performing an air cooling to form a billet having an average crystal grain size of #1 or more, an overaging thermal treatment step of heating and holding the billet at a temperature range of from Ts to Ts+50&#xb0; C. and slowly cooling it to a temperature of Ts or lower, and a crystal grain fining forging step of performing another forging at a temperature range of from Ts&#x2212;150&#xb0; C. to Ts and performing another air cooling, in which Ts is from 1,030&#xb0; C. to 1,100&#xb0; C., and an overall average crystal grain size is #8 or more after the crystal grain fining forging step.

Method for producing Ni-based superalloy material

The present invention relates to a maraging steel containing, in terms of mass %, 0.20&#x2264;C&#x2264;0.35, 9.0&#x2264;Co&#x2264;20.0, 1.0&#x2264;(Mo+W/2)&#x2264;2.0, 1.0&#x2264;Cr&#x2264;4.0, and a certain amount of Ni, with the balance being Fe and inevitable impurities, in which in a case where the contents of V and Nb satisfy V+Nb&#x2264;0.020 mass %, the amount of Ni is 6.0&#x2264;Ni&#x2264;9.4, and in which in a case where the contents of V and Nb satisfy 0.020 mass %&#x3c;V+Nb&#x2264;0.60 mass %, the amount of Ni is 6.0&#x2264;Ni&#x2264;16.0.

Provided is a maraging steel excellent in fatigue characteristics, including, in terms of % by mass: C: &#x2264;0.015%, Ni: from 12.0 to 20.0%, Mo: from 3.0 to 6.0%, Co: from 5.0 to 13.0%, Al: from 0.01 to 0.3%, Ti: from 0.2 to 2.0%, O: &#x2264;0.0020%, N: &#x2264;0.0020%, and Zr: from 0.001 to 0.02%, with the balance being Fe and unavoidable impurities.

Maraging steel excellent in fatigue characteristics

The present invention relates to an Ni-based superalloy for hot forging, containing, in terms of % by mass, C: more than 0.001% and less than 0.100%, Cr: 11% or more and less than 19%, Co: more than 5% and less than 25%, Fe: 0.1% or more and less than 4.0%, Mo: more than 2.0% and less than 5.0%, W: more than 1.0% and less than 5.0%, Nb: 2.0% or more and less than 4.0%, Al: more than 3.0% and less than 5.0%, and Ti: more than 1.0% and less than 3.0%, with the balance being unavoidable impurities and Ni, in which the component composition satisfies the following two relationships: 3.5&#x2264;([Ti]+[Nb])/[Al]&#xd7;10&#x3c;6.5 and 9.5&#x2264;[Al]+[Ti]+[Nb]&#x3c;13.0.

The object of the present invention is to provide a heat-resistant steel for exhaust valves, having relatively small Ni content, high mechanical characteristics (for example, tensile strength, fatigue strength, wear resistance and hardness) at high temperature, and excellent oxidation resistance. The present invention provides a heat-resistant steel for exhaust valves, which includes: 0.45&#x2266;C&#x3c;0.60 mass %, 0.30&#x3c;N&#x3c;0.50 mass %, 19.0&#x2266;Cr&#x3c;23.0 mass %, 5.0&#x2266;Ni&#x3c;9.0 mass %, 8.5&#x2266;Mn&#x3c;10.0 mass %, 2.5&#x2266;Mo&#x3c;4.0 mass %, 0.01&#x2266;Si&#x3c;0.50 mass %, and 0.01&#x2266;Nb&#x3c;0.30 mass %, with the balance being Fe and unavoidable impurities, in which the steel satisfies 0.02&#x2266;Nb/C&#x3c;0.70 and satisfies 4.5&#x2266;Mo/C&#x3c;8.9.

Heat-resisting steel for exhaust valves

The present invention provides a hot-forgeable Ni-based superalloy excellent in high temperature strength, including, in terms of % by mass: C: more than 0.001% and less than 0.100%, Cr: 11.0% or more and less than 19.0%, Co: 0.5% or more and less than 22.0%, Fe: 0.5% or more and less than 10.0%, Si: less than 0.1%, Mo: more than 2.0% and less than 5.0%, W: more than 1.0% and less than 5.0%, Mo+&#xbd;W: 2.5% or more and less than 5.5%, S: 0.010% or less, Nb: 0.3% or more and less than 2.0%, Al: more than 3.00% and less than 6.50%, and Ti: 0.20% or more and less than 2.49%, with the balance being Ni and unavoidable impurities, in which (Ti/Al)&#xd7;10 is 0.2 or more and less than 4.0 in terms of atomic ratio, and in which Al+Ti+Nb is 8.5% or more and less than 13.0% in terms of atomic %.

Hot-forgeable Ni-based superalloy excellent in high temperature strength

The present invention provides a maraging steel containing: 0.10&#x2266;C&#x2266;0.30 mass %, 6.0&#x2266;Ni&#x2266;9.4 mass %, 11.0&#x2266;Co&#x2266;20.0 mass %, 1.0&#x2266;Mo&#x2266;6.0 mass %, 2.0&#x2266;Cr&#x2266;6.0 mass %, 0.5&#x2266;Al&#x2266;1.3 mass %, and Ti&#x2266;0.1 mass %, with the balance being Fe and unavoidable impurities, and satisfying 1.00&#x2266;A&#x2266;1.08, in which A is 0.95+0.35&#xd7;[C]&#x2212;0.0092&#xd7;[Ni]+0.011&#xd7;[Co]&#x2212;0.02&#xd7;[Cr]&#x2212;0.001&#xd7;[Mo], where [C] indicates a content (mass %) of C, [Ni] indicates a content (mass %) of Ni, [Co] indicates a content (mass %) of Co, [Cr] indicates a content (mass %) of Cr, and [Mo] indicates a content (mass %) of Mo, respectively. The maraging steel has a tensile strength of 2,300 MPa or more and is also excellent in the toughness/ductility and fatigue characteristics.

Aircraft engine shaft comprising a maraging steel having a tensile strength of 2300MPa or more

The present invention aim at providing a steel for steam turbine blades which is excellent in terms of strength and toughness. The steel of the present invention has a composition which contains, in terms of % by mass, 0.02-0.10% of C, up to 0.25% of Si, 0.001-0.10% of Mn, up to 0.010% of P, up to 0.010% of S, 8.5-10.0% of Ni, 10.5-13.0% of Cr, 2.0-2.5% of Mo, 0.001-0.010% of N, 1.15-1.50% of Al, less than 0.10% of Cu, up to 0.20% of Ti, and the remainder being incidental impurities and Fe, and which satisfies 6.0&#x2266;Ni/Al&#x2266;8.0, 9.0&#x2266;Nieq&#x2266;11.0 and 17.0&#x2266;Creq&#x2266;19.0, in whichNieq=[Ni]+0.11[Mn]&#x2212;0.0086([Mn])+0.44[Cu]+18.4[N]+24.5[C]Creq=[Cr]+1.21[Mo]+0.48[Si]+2.2[Ti]+2.48[A1].

Steel for steam turbine blade with excellent strength and toughness

The present invention relates to a high-hardness hardfacing alloy powder, containing: 0.5&#x3c;C&#x2266;3.0 mass %, 0.5&#x2266;Si&#x2266;5.0 mass %, 10.0&#x2266;Cr&#x2266;30.0 mass %, and 16.0&#x3c;Mo&#x2266;40.0 mass %, with the balance being Co and unavoidable impurities, wherein a total amount of Mo and Cr satisfies 40.0&#x2266;Mo+Cr&#x2266;70.0 mass %. The high-hardness hardfacing alloy powder according to the present invention may further contain at least one element selected from the group consisting of: Ca&#x2266;0.03 mass %, P&#x2266;0.03 mass %, Ni&#x2266;5.0 mass % and Fe&#x2266;5.0 mass %. The high-hardness hardfacing alloy powder according to the present invention can be employed for build-up welding of a face part of a valve used in various internal combustion engines, automotive engines, steam turbines, heat exchangers, heating furnaces and the like.

High-hardness hardfacing alloy powder

The present invention provides a nonmagnetic high-hardness alloy having a Ni-based alloy composition containing; by weight %, C of 0.1% or less: Si of 2.0% or less; Mn of 2.0% or less; P of 0.03% or less; S of 0.01% or less; Cr of 30 to 45%; Al of 1.5 to 5.0%; and a balance of unavoidable impurities and Ni, the nonmagnetic high-hardness alloy being subjected to cold or warm plastic working and then ageing treatment, and a method for producing the nonmagnetic high-hardness alloy.

Nonmagnetic high-hardness alloy

The present invention relates to a low thermal expansion Ni-base superalloy containing, in terms of mass %, C: 0.15% or less; Si: 1% or less; Mn: 1% or less; Cr: 5% or more but less than 20%; at least one of Mo, W and Re, in which Mo+&#xbd;(W+Re) is 5% or more but less than 20%; W: 10% or less; Al: 0.1 to 2.5%; Ti: 0.10 to 0.95%; Nb+&#xbd;Ta: 1.5% or less; B: 0.001 to 0.02%; Zr: 0.001 to 0.2%; Fe: 4.0% or less; and a balance of inevitable impurities and Ni, in which the total amount of Al, Ti, Nb and Ta is 2.0 to 6.5% in terms of atomic %. The low thermal expansion Ni-base superalloy of the present invention has a thermal expansion coefficient almost equal to that of 12 Cr ferritic steel, excellent high temperature strength, excellent corrosion and oxidation resistance, good hot-workability, and excellent weldability.

Low thermal expansion Ni-base superalloy

A method for producing a low thermal expansion Ni-base superalloy including the steps of subjecting the alloy to a solution heat treatment under the condition of at a temperature of 1000 to 1200&#xb0; C. and subjecting the alloy to either a carbide stabilizing treatment for making aggregated carbides on grain boundaries and stabilizing the carbides under the conditions of at a temperature of not less than 850&#xb0; C. and less than 1000&#xb0; C. and for 1 to 50 hours, or a carbide stabilizing treatment for making aggregated carbides on grain boundaries and stabilizing the carbides by cooling from the temperature in the solution heat treatment to 850&#xb0; C. at a cooling rate of 100&#xb0; C. or less per hour. The method also including the steps of subjecting the alloy to a first aging treatment for precipitating y' phase under the conditions of at a temperature of 720 to 900&#xb0; C. and for 1 to 50 hours, and subjecting the alloy to a second aging treatment for precipitating AB phase under the conditions of at a temperature of 550 to 700&#xb0; C. and for 5 to 100 hours.

Method for producing low thermal expansion Ni-base superalloy

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Nagoya, Japan

Shigeki Ueta