Hitachi Metals, Ltd.

Hitachi, Ltd.

Sumitomo Precision Products Co., Ltd.

The Society of Japanese Aerospace Companies

Other

Agency of Industrial Science and Technology

Japan Atomic Energy Res. Institute

Rikizo Watanabe

Koji Sato

Toshihiro Uehara

Takehiro Ohno

Akira Misumi

Hakaru Sasaki

Ryoji Hirai

Shuichi Nakamura

Nobuhito Nakama

Toshio Fujita

Ryoichi Sasaki

Isao Masaoka

Shigeo Hattori

Susumu Isobe

Hisao Itow

Tatsuo Kondo

Yoshitaka Chiba

Toshiaki Nonomura

Yoshiki Masugata

Hajime Nakajima

Masami Shindo

Daiji Sakamoto

Hirokazu Tsuji

Ryohei Tanaka

Sadao Ohta

Yasuhiko Mori

Yositaka Chiba

Minoru Takuwa

Yoshimi Senda

Shigeaki Sato

Daizi Sakamoto

A high-strength low-thermal-expansion alloy consisting of, by weight, 0.06 to 0.50% C, 25 to 65% in total of one or both of 65% or less Co and less than 30% Ni, and balance of Fe as a main component, other optional elements and unavoidable impurities, and having a primary phase of austenite phase and martensite phase induced by working. A wire is made from the alloy.

High-strength and low-thermal-expansion alloy, wire of the alloy and method of manufacturing the alloy wire

A high strength, high toughness stainless steel consisting, by weight, of C more than 0.16% but less than 0.25%, Si not more than 2.0%, Mn not more than 1.0%, Ni not more than 2.0%, Cr from 11 to 15%, Mo not less than 0.5% but less than 3.0%, Co from 12 to 21%, at least one kind selected from the group consisting of V from 0.1 to 0.5% and Nb less than 0.1% which at least one kind is added as occasion demands, and the balance Fe and incidental impurities. This steel is produced by a method comprising the steps of: preparing a stainless steel having the composition of any one of the claims 1 to 4; subjecting the stainless steel to a solution heat treatment at a temperature of 950 to 1150.degree. C.; quenching the steel; subjecting the steel to a sub zero treatment at a temperature of -50.degree. to -100.degree. C.; and subjecting the steel to a tempering at a temperature of 120.degree. to 450.degree. C.

High strength and high toughness martensitic stainless steel and method

A high strength, high toughness stainless steel consisting, by weight, of C more than 0.16% but less than 0.25%, Si not more than 2.0%, Mn not more than 1.0%, Ni not more than 2.0%, Cr from 11 to 15%, Mo not less than 0.5% but less than 3.0%, Co from 12 to 21%, at least one kind selected from the group consisting of V from 0.1 to 0.5% and Nb less than 0.1% which at least one kind is added as occasion demands, and the balance Fe and incidental impurities. This steel is produced by a method comprising the steps of: preparing a stainless steel having the composition of any one of the claims 1 to 4; subjecting the stainless steel to a solution heat treatment at a temperature of 950.degree. to 1150.degree. C.; quenching the steel; subjecting the steel to a sub zero treatment at a temperature of -50 to -100.degree. C.; and subjecting the steel to a tempering at a temperature of 120.degree. to 450.degree. C.

Method of manufacturing high strength and high toughness stainless steel

A high strength lead frame material consists essentially, by weight, of 0.5 to 22% Co, 22 to 32.5% Ni, not more than 1.0% Mn and not more than 0.5% Si and the balance Fe and incidental impurities. The contents of Ni and Co are selected so that the Ni content is 27 to 32.5% when the Co content is less than 12%, and so that, when the Co content is not less than 12%, the Ni content and the Co content meet the condition of 66%.ltoreq.2Ni+Co.ltoreq.74%. The material has a multi-phase structure formed of austenitic phase, martensitic phase, and ferritic phase, the austenitic phase occupying not less than 50% of the structure. The method of producing the alloy of the invention comprises the steps of solid-solutioning the material of the above composition at a temperature not less than austenitizing completion temperature, cold-rolling the material at a rate of 40 6to 90% in reduction, and annealing the material at a temperature less than the austenitizing completion temperature.

High strength lead frame material and method of producing the same

The improved superalloy that possesses all the characteristics required of the high-temperature structural material of high-temperature gas-cooled reactors (i.e., high-temperature strength, corrosion resistance, good productibility, good hot workability and resistance to embrittlement due to thermal aging) consists essentially of 16-28% Cr. 15-24% W (provided that Cr+W=39-44%), 0.01-0.1% Zr, 0.001-0.015% Y, 0.0005-0.01% B, up to 0.05% C, up to 0.1% Si, up to 0.1% Mn (provided that Si+Mn.gtoreq.0.1%), up to 0.1% Ti, up to 0.1% Al and up to 0.1% Nb (provided that Ti+Al.gtoreq.0.1% and Ti+Al+Nb.gtoreq.0.15%), with the balance being Ni and inevitable impurities and all percentages being on a weight basis.

Nickel-chromium-tungsten base superalloy

A method of forming a Ni-base superalloy suitable for use as the material for gas turbine disks or the like has a composition containing, by weight, 0.01 to 0.15% of C, 15 to 22% of Cr, 3 to 6% of Mo, 3 to 6% of W, 5 to 15% of Co, 1.0 to 1.9% of Al, 1.5 to 3.0% of Ti, 3.0 to 6.0% of Ta, 0.001 to 0.020% of B and the balance substantially Ni except inevitable impurities. This alloy is produced using the conventional ingot making and a hot working process including working at a reducing ratio greater than or equal to 10%, first above the .gamma. solvus temperature, and then during cooling to the recrystallization temperature and then subjected to direct aging without solid-solution treatment. As a result, the alloy exhibits excellent strength properties well comparable to those of expensive alloys produced by powder metallurgy process.

Method for producing a nickel-base superalloy

Alloys according to the present invention exhibit good resistance to erosion and stress corrosion cracking. The contents of individual components in these alloys as expressed in terms of wt. % are as follows:

Alloys having excellent erosion resistance and stress corrosion cracking

A heat-resistant ferritic cast steel having excellent thermal fatigue resistance, consisting, by weight, of 0.25 to 0.45% C, 0.3 to 2.0% Si, not more than 1.0% Mn, 17 to 22% Cr, at least one kind selected from the group consisting of not more than 6% Co and not more than 1.5% Ni, the amount of % Co+3 % Ni being in the range of 1 to 6%, 0.006 to 0.1% of at least one kind selected from the group consisting of Y and rare earth elements, and the balance Fe and incidental impurities, the ferritic cast steel being composed of a structure in which .alpha. ferrite and M.sub.23 C.sub.6 carbide are dispersed in .delta. ferrite. With this specific composition, even at high temperatures, there can be maintained the structure which has the .alpha. ferrite and the M.sub.23 C.sub.6 dispersed in the .delta. ferrite, with the result that there is obtained an excellent thermal fatigue resistance, and in this structure, the transformation under heating will not occur even at a temperature of about 1,000.degree. C. The steel of the present invention is particularly suited for a turbo rotor casing, an exhaust manifold, etc., of an automobile.

Heat-resistant ferritic cast steel having excellent thermal fatigue

A heat resistant steel for use as a material of engine valves, having a composition containing, not less than 0.01% and below 0.20% of carbon, from 0.05% to 1.0% of silicon, from 7.5% to 15.0% of manganese, from 2.0% to 20.0% in total of at least one of nickel and cobalt, from 15.0% to 25.0% of chromium, not more than 3.0% of molybdenum, above 2.0% and not more than 10.0% of tungsten, not less than 0.01% and below 0.50% of niobium, from 0.30% to 0.65% of nitrogen, not more than 0.02% of boron, and the balance incidental inclusions and iron. Cobalt content is determined to meet the condition of % Co=(Ni.+-.5)%. The heat resistant steel meets the conditions of: oxidation weight loss when held at 1000.degree. C. for 100 hours being not greater than 0.15 mg/cm.sup.2 /hour in atmosphere; tensile strength being not less than 20 kgf/mm.sup.2 at 900.degree. C. after a solution treatment at 1030.degree. to 1070.degree. C. and a subsequent aging treatment; and creep rupture life at 900.degree. C. under stress load of 6 kgf/mm.sup.2 being not less than 25 hours.

Heat resistant steel for use as material of engine valve

A ferritic heat resisting steel usable as the material of parts of steam and gas turbines of a power generating plant. Co content and Mo content are increased as compared with known alloy steels of the same kind. For instance, the alloy steel has a composition containing, by weight, 0.05 to 0.20% C, 0.05 to 1.5% Mn, 0.05 to 1.0% Ni, 9.0 to 13.0% Cr, 0.05 to less than 0.50% Mo, 2.0 to 3.5% W, 0.05 to 0.30% V, 0.01 to 0.20% Nb, 2.1 to 10.0% Co, 0.01 to 0.1% N, and the balance substantially Fe and incidental impurities, with Si as an impurity limited to be not more than 0.15%.

Ferritic heat resisting steel having superior high-temperature strength

A high strength lead frame material consists, by weight, of 0.5 to 22% Co, 22 to 32.5% Ni, not more than 1.0% Mn and not more than 0.5% Si and the balance Fe and incidental impurities. The contents of Ni and Co are selected so that the Ni content is 27 to 32.5% when the Co content is less than 12%, and so that, when the Co content is not less than 12%, the Ni content and the Co content meet the condition of 66%.ltoreq. 2Ni+Co.ltoreq.74%. The material has a two-phase structure formed of austenitic phase and martensitic phase, the austenitic phase occupying not less than 50% of the structure.

A member adapted for use under a stress in an atmosphere of a temperature below the creep temperature and made from an Ni base alloy having a high resistance to stress corrosion cracking. The Ni alloy consists essentially of, by weight, 15 to 25% of Cr, 1 to 8% of Mo, 0.4 to 2% of Al, 0.7 to 3% of Ti, 0.7 to 4.5% of Nb and the balance Ni, and has an austenite matrix in which precipitated is at least one of .gamma.' phase and .gamma.' phase. The member can suitably used as parts which are subjected to pure water in nuclear reactor.

Member made of nickel base alloy having high resistance to stress

This invention relates to a heat resistant single-crystal nickel-base super alloy that possesses microstructural stability and excellent creep rupture strength and oxidation resistance. This alloy is composed of 4-9% chromium, 4-6.5% aluminum, 5-8.5% wolfram, 5-8.5% tantalum, 3-6% molybdenum, 0.01-0.30% hafnium, 0.02-4% cobalt by weight, and the balance of nickel and incidental elements and meets the conditional expression wolfram+tantalum&lt;16%. The preferable chemcial composition of this alloy is approximately 6.4% chromium, approximately 5.1% aluminum, approximately 7.3% wolfram, 7.3% tantalum, approximately 4.3% molybdenum, approximately 0.1% hafnium, approximately 1% cobalt by weight, and the balance of nickel and incidental elements.

Heat resistant single crystal nickel-base super alloy

The alloys of this invention illustrate good property on erosion resistance. The compositions of these alloys are C: more than 0.09 wt. % and less than 1.7 wt. %, Si: 2.5 wt. % or less, Mn: 10-25 wt. %, Cr: 6-20 wt. %, V: more than 4 wt. % and less than 7 wt. % , N: 0.1 wt. % or less, and Fe: the rest. Optional small content is Ni and /or Mo.

Alloys having excellent erosion resistance

A single-crystal Ni-based super-heat-resistant alloy consisting essentially of, by weight percentage, 4 to 10% of Cr, 4 to 6.5% of Al, 4 to 10% of W, 4 to 9% of Ta, 1.5 to 6% of Mo, and the balance substantially Ni and impurities; or the alloy containing not greater than 12% of Co in addition to the above composition; wherein the contents of W, Ta and Mo are selected to meet the following condition: 1/2.W+1/2.Ta+Mo=9.5% to 13.5%.

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Yasugi, Japan

Rikizo Watanabe