Hitachi Powdered Metals Co., Ltd.

Other

Nissan Motor Company Limited

Honda Giken Kogyo Kabushiki Kaisha

Koichiro Hayashi

Hideaki Kawata

Yoshimasa Aoki

Koichi Aonuma

Katsunao Chikahata

Akira Fujiki

Kunio Maki

Kei Ishii

Katsuaki Sato

Yutaka Ikenoue

Atsushi Ehira

Toru Tsuboi

Makoto Kano

Tsutomu Saka

Masaki Toriumi

Hiroki Fujitsuka

Yoshio Okada

Tomonori Miyazawa

Shin Nomura

Michiharu Mogami

Hideki Muramatsu

Sadayuki Abo

Koji Koyanagi

Ryoji Satoh

Kouichi Aonuma

Seigo Sato

Alloy powder for forming a hard phase for a valve seat material having excellent high temperature wear resistance. The overall composition is consisted of Mo: 48 to 60 mass %, Cr: 3 to 12 mass % and Si: 1 to 5 mass %, and the balance of Co and inevitable impurities.

Alloy powder for forming hard phase and ferriferous mixed powder using the same, and manufacturing method for wear resistant sintered alloy and wear resistant sintered alloy

Valve guides made of ferrous sintered alloy for internal combustion engines have improved durability of the valve stem without soft nitriding process. The valve guides include Cu: 8 to 20 mass %, C: 0.8 to 1.5 mass %, and at least one of MnS, WS, and MoS: 0.5 to 2 mass % and the balance of Fe, the valve guides have many pores, have a metal structure in which the copper phase dispersed in an iron pearlite matrix exists, and have a structure in which metal sulfides are dispersed between particles between the matrix and the copper phase.

Valve guide for internal combustion engine made from iron base sintered alloy

A turbo component for a turbocharger in which heat resistance, corrosion resistance, and wear resistance is superior, and in which the cost is further lowered, is provided. In the turbo component, the overall composition is, in ratio by mass, Cr: 23.8 to 44.3%, Mo: 1.0 to 3.0%, Si: 1.0 to 3.0%, P: 0.1 to 1.0%, C: 1.0 to 3.0%, and the balance of Fe and inevitable impurities, and carbide is dispersed in the matrix at a density ratio of 95% or more.

Turbo component for turbocharger

A valve seat is provided in which wear resistance can be ensured by optimizing the matrix structure without dispersing of expensive hard particles, and therefore the machinability can be improved and the holding down of cost can be achieved. The valve seat exhibits a metallographic structure consisting of only bainite single phase or only a mixed phase of bainite and martensite, has an area ratio of bainite and martensite in cross section of 100:0 to 50:50, and has a matrix hardness of 250 to 850 Hv.

Valve seat for internal combustion engines

Disclosed is a sintered alloy material for valve guides, containing: 1.5% to 4% by mass of carbon; 1% to 20% by mass of copper; 0.1% to 2% by mass of tin; 0.01% or more than 0.01% and less than 0.1% by mass of phosphorus; and an iron base. The metallographic structure of the sintered alloy material has a matrix phase composed mainly of pearlite, and a free carbon phase being dispersed in the matrix phase.

Material for valve guides

A wear resistant sintered member exhibits superior wear resistance at the same level as those of the conventional materials without using a Co-based hard phase is provided. A first hard phase comprising Mo silicide particles dispersed in an Fe-based alloy matrix of the first hard phase and a second hard phase comprising a ferrite phase or a mixed phase of ferrite and austenite having a higher Cr concentration than the Fe-based alloy matrix surrounding a core consisting of Cr carbide particles, are diffused in an Fe-based alloy matrix, the Mo silicide particles are contained in the first hard phase in an amount of 3 to 25 % by area, and the Cr carbide particles are contained in the second hard phase in an amount of 3 to 30 % by area.

Wear resistant sintered member

The invention relates to an iron-based high-temperature wear-resistant sintered alloy. This alloy contains 3.74-13.36 wt % W, 0.39-5.58 wt % V, 0.2-5.78 wt % Cr, 0.1-0.6 wt % Si, 0.39-1.99 wt % Mn, 0.21-1.18 wt % S, and up to 2.16 wt % C. This alloy includes 20-80 wt % of a first phase and 80-20 wt % of a second phase, each distributed therein, in the form of spots. The first phase contains 3-7 wt % W, up to 1 wt % Cr, 0.1-0.6 wt % Si, 0.2-1 wt % Mn, 0.1-0.6 wt % S, and up to 2.2 wt % C. The first phase may contain 0.5-1.5 wt % V, and in this case the vanadium content of the alloy becomes 0.79-5.88 wt %. The second phase contains 7-15 wt % W, 2-7 wt % V, 1-7 wt % Cr, 0.1-0.6 wt % Si, 0.2-1 wt % Mn, 0.1-0.6 wt % S, and up to 2.2 wt % of C. Each phase contains 0.3-1.6 wt % MnS and a carbide of at least tungsten, which are dispersed therein. The second phase further contains 10-20 areal % tungsten carbide (particle diameter: &gE;1 &mgr;m) dispersed therein. The alloy further contains 0.3-16 wt % MnS grains dispersed in grain boundaries and/or pores. The alloy is greatly improved in wear resistance, while suppressing damage to mating part in contact with the alloy.

High-temperature wear-resistant sintered alloy

The present invention provides a sintered material having high mechanical strength and superior wear resistance, and to a process of manufacture therefor. A sintered alloy having superior wear resistance has an overall composition consisting of, in percent by weight, Ni in an amount of 6.0 to 25.0%, Cr in an amount of 0.6 to 8.75%, C in an amount of 0.54 to 2.24%, and balance consisting of Fe, the sintered alloy exhibiting a metallographic structure in which the following hard phase is dispersed in a mixed structure of martensite and austenite, the hard phase comprising a core consisting of Cr carbide and a ferrite phase diffused Cr, or a mixed phase of ferrite and austenite diffused Cr, surrounding the core, and an area ratio of austenite in the mixed structure in the metallographic structure ranging from 5 to 30%.

Sintered alloy having superior wear resistance

A sintered alloy having superb wear resistance comprising: composite phases dispersed in a matrix of the sintered alloy; the composite phase consisting of; a particle group in which Cr carbide particles and Cr sulfide particles exist in a mixed condition; and a ferrite phase or a mixture phase of ferrite and austenite surrounding the particle group as a core.

Sintered alloy having superb wear resistance and process for producing the same

Disclosed is a valve guide which is manufactured by a sintered alloy and used for an engine, and more particularly, to a valve guide which has high wear resistance and can prevent appearance of scuffing on a surface of a valve stem associated with the valve guide, and to a process for manufacturing the valve guide. The valve guide comprises an inner surface sliding with a valve stem, the inner surface finished by machining and exposing pores. Area-ratio of the pores with respect to the inner surface is 2.7 to 10.7%, and at least one pore having pore size of not less than 80 .mu.m exists per 1 mm.sup.2 of the inner surface.

Valve guide and process for manufacturing thereof

A sintered alloy having superb wear resistance consisting, percent by weight of, as a whole, Ni in the amount of 1.35 to 19.61%, Cr in the amount of 0.9 to 11.05%, Mo in the amount of 1.44 to 9.09%, Co in the amount of 3.6 to 20.05%, V in the amount of 0.018 to 0.26%, Si in the amount of 0.1 to 0.75%, C in the amount of 0.35 to 1.5%, and the balance of Fe, and the sintered alloy exhibiting a metallographic structure in which the following hard phases are dispersed in a mixed structure of martensite, sorbite, and austenite: a first hard phase comprising, a hard phase as a core mainly consisting of Mo suicide, and a diffused phase including diffused Co surrounding the hard phase; and a second hard phase comprising, a hard phase as a core consisting of Cr carbide, and a mixed phase of ferrite and austenite surrounding the hard phase.

Sintered alloy having superb wear resistance and process for producing

The invention relates to a sintered alloy. This sintered alloy includes 3-13.4 wt % of W, 0.4-5.6 wt % or 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. The sintered alloy includes first and second phase which are distributed therein, in a form of spots, respectively. The second phase is in an amount of from 20 to 80 wt %, based on the total weight of the first and second phases. The first phase contains 3-7 wt % of W, 0.5-1.5 wt % of optional V, up to 1 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. The second phase contains 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. When the manganese contents of the first and second phases and the total of the sintered alloy are respectively in a range of from 0.2 to 1.0 wt %, sulfur is respectively contained therein in an amount of from 0.1 to 0.6 wt %. The sintered alloy has wear-resistant at high temperature and good compatibility without damaging mating part that is in contact with the sintered alloy.

The present invention provides a valve seat having a suitable degree of wear resistance, which can be produced without recourse to expensive elements represented by cobalt and at a cost lower than ever before. This valve seat is formed of a wear-resistant sintered alloy having a general composition consisting essentially of, in weight ratio, 0.736 to 5.79% of nickel, 0.12 to 6.25% of chromium, 0.294 to 0.965% of molybdenum, and 0.508 to 2.0% of carbon with the balance being iron, and inevitable impurities, and having a micro structure wherein a bainite matrix structure or a mixed bainite and sorbite matrix structure includes a nucleus having a hard phase composed mainly of chromium carbide, and a ferrite surrounding said nucleus and having a high chromium concentration and a martensite surrounding said ferrite are dispersed.

Wear-resistant sintered alloy, and its production method

The invention provides a valve seat having a suitable degree of wear resistance, which can be produced without recourse to expensive elements represented by cobalt and at a cost lower than ever before. This valve seat is formed of a wear-resistant sintered alloy having a general composition consisting essentially of, in weight ratio, 0.736 to 9.65% of nickel, 0.736 to 2.895% of copper, 0.294 to 0.965% of molybdenum, 0.12 to 6.25% of chromium, and 0.508 to 2.0% of carbon with the balance being iron, and inevitable impurities, and having a metallic structure in which there are dispersed (1) a martensite, (2) a bainite having a nucleus of sorbite and/or upper bainite and surrounding said nucleus, (3) an austenite having a high nickel concentration, and (4) a hard phase surrounding with a ferrite having a high chromium concentration and composed mainly of a chromium carbide.

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Matsudo, Japan

Koichiro Hayashi