Abstract: A Mo source powder is added to and mixed with an iron-based powder containing 1.0% by mass or less of prealloyed Mn to yield a powder mixture containing 0.2 to 10.0% by mass of Mo, the resulting powder mixture is subjected to heat treatment in a reducing atmosphere to thereby yield an alloyed steel powder containing Mo as a powder partially diffused and bonded to a surface of the iron-based powder particles. The prepared alloyed steel powder for powder metallurgy has satisfactory compactability. The use of this alloyed steel powder can produce a sintered powder metal body (an intermediate material after compaction and preliminary sintering in re-compaction of sintered powder materials process) for highly strong sintered member.

Abstract: The surface of the body of powder additive for use in powder metallurgy is coated with an organic binder, thereby obtaining powder additive to cause adhesion of the powder additive to the surface of iron-based powder by the organic binder, thereby providing a powder additive with no segregation of components and excellent flowability and compression, and an iron-based powder mixture manufactured by mixing the powder additive and the iron-based powder.

Abstract: A sintered iron-based powder metal body with lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density.

Abstract: The surface of the body of powder additive for use in powder metallurgy is coated with an organic binder, thereby obtaining powder additive to cause adhesion of the powder additive to the surface of iron-based powder by the organic binder, thereby providing a powder additive with no segregation of components and excellent flowability and compression, and an iron-based powder mixture manufactured by mixing the powder additive and the iron-based powder.

Abstract: On the basis of mass percentage of a mixture, 1-5% of Ni powder, 0.5-3% of Cu powder, and 0.2-0.9% of graphite powder are mixed into an alloy steel powder containing 0.5-3 mass % of prealloyed Ni, more than 0.7 to 4 mass % of prealloyed Mo, and the balance being Fe and unavoidable impurities. The alloy steel powder may contain 0.2-0.7 mass % of prealloyed Cu in addition to Ni and Mo.

Abstract: A high density iron based forged part such as a mechanical part is produced by a method comprising the following steps in the sequence set forth: (a) preparing iron based powder mixture containing iron based metal powder and graphite powder; (b) preliminarily compacting the iron based powder mixture to form a preliminary compact; (c) sintering the preliminary compact in a non-oxidizing atmosphere whose nitrogen partial pressure is 30 kPa or less, at a temperature of 950° C. or more and of 1300° C. or less to form a forming material; and (d) forging the forming material by closed die forging or enclosed die forging to produce a high density forged part.

Abstract: A Mo source powder is added to and mixed with an iron-based powder containing 1.0% by mass or less of prealloyed Mn to yield a powder mixture containing 0.2 to 10.0% by mass of Mo, the resulting powder mixture is subjected to heat treatment in a reducing atmosphere to thereby yield an alloyed steel powder containing Mo as a powder partially diffused and bonded to a surface of the iron-based powder particles. The prepared alloyed steel powder for powder metallurgy has satisfactory compactability. The use of this alloyed steel powder can produce a sintered powder metal body (an intermediate material after compaction and preliminary sintering in re-compaction of sintered powder materials process) for highly strong sintered member.

Abstract: An sintered iron-based powder metal body with outstandingly lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density, the method comprising mixing,

Abstract: A magnetite-iron based composite powder includes magnetite with a ratio of X-ray diffraction intensity to that of &agr;-Fe of about 0.001 to about 50 and has an average primary particle size of about 0.1 to about 10 &mgr;m. The composite powder can highly dehalogenate organic halogen compounds and exhibits satisfactory absorption power of high frequency electromagnetic waves after molding. An ultrafine nonferrous inorganic compound powder may adhere to the surface of the composite powder, or at least the composite powder may adhere to the surfaces of small particles of a nonferrous inorganic compound to thereby yield a composite powder composition. The composite powder can be produced by partial reduction of a material powder containing a hematite based powder or by complete reduction and subsequent partial oxidation of the material powder.

Abstract: A Mo source powder is added to and mixed with an iron-based powder containing 1.0% by mass or less of prealloyed Mn to yield a powder mixture containing 0.2 to 10.0% by mass of Mo, the resulting powder mixture is subjected to heat treatment in a reducing atmosphere to thereby yield an alloyed steel powder containing Mo as a powder partially diffused and bonded to a surface of the iron-based powder particles. The prepared alloyed steel powder for powder metallurgy has satisfactory compactability. The use of this alloyed steel powder can produce a sintered powder metal body (an intermediate material after compaction and preliminary sintering in re-compaction of sintered powder materials process) for highly strong sintered member.

Abstract: An sintered iron-based powder metal body with outstandingly lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density, the method comprising mixing, an iron-based metal powder containing at most about 0.05% of carbon, at most about 0.3% of oxygen, at most about 0.010% of nitrogen, with at least about 0.03% and at most about 0.5% of graphite powder and a lubricant, preliminarily compacting the mixture into a preform, the density of which is about 7.3 Mg/m3 or more, and preliminarily sintering the preform in a non-oxidizing atmosphere in which a partial pressure of nitrogen is about 30 kPa or less at a temperature of about 1000° C. or higher and about 1300° C. or lower, thereby forming a sintered iron-based powder metal body with outstandingly lower re-compacting load and having high deformability, the density of which is about 7.

Abstract: In a preliminary molding step 1, a metallic powder mixture 7 obtained by blending an iron-based metal powder 7a with graphite 7b such that the graphite is present in an amount of preferably not less than 0.1% by weight, more preferably not less than 0.3% by weight, is compacted into a preform 8 having a density of not less than 7.3 g/cm3. In a provisional sintering step 2, the preform 8 is provisionally sintered at a predetermined temperature to form a metallic powder-molded body 9 having a structure in which the graphite remains along a grain boundary of the metal powder. In a re-compaction step 3, the metallic powder-molded body 9 is re-compacted into a re-compacted body 10. In a re-sintering step 4, the re-compacted body 10 is re-sintered to obtain a sintered body 11. In a heat treatment step 5, the sintered body 11 is heat-treated to obtain a heat-treated sintered body 11.

Abstract: In a preliminary molding step 1, a metallic powder mixture 7 obtained by blending an iron-based metal powder 7a with graphite 7b such that the graphite is present in an amount of preferably not less than 0.1% by weight, more preferably not less than 0.3% by weight, is compacted into a preform 8 having a density of not less than 7.3 g/cm3. In a provisional sintering step 2, the preform 8 is provisionally sintered at a predetermined temperature to form a metallic powder-molded body 9 having a structure in which the graphite remains along a grain boundary of the metal powder. In a re-compaction step 3, the metallic powder-molded body 9 is re-compacted into a re-compacted body 10. In a re-sintering step 4, the re-compacted body 10 is re-sintered to obtain a sintered body 11. In a heat treatment step 5, the sintered body 11 is heat-treated to obtain a heat-treated sintered body 11.

Abstract: An sintered iron-based powder metal body with outstandingly lower re-compacting load and having a high density and a method of manufacturing an iron-based sintered component with fewer pores of a sharp shape and having high strength and high density, the method comprising mixing,

Abstract: A Mo source powder is added to and mixed with an iron-based powder containing 1.0% by mass or less of prealloyed Mn to yield a powder mixture containing 0.2 to 10.0% by mass of Mo, the resulting powder mixture is subjected to heat treatment in a reducing atmosphere to thereby yield an alloyed steel powder containing Mo as a powder partially diffused and bonded to a surface of the iron-based powder particles. The prepared alloyed steel powder for powder metallurgy has satisfactory compactability. The use of this alloyed steel powder can produce a sintered powder metal body (an intermediate material after compaction and preliminary sintering in re-compaction of sintered powder materials process) for highly strong sintered member.

Abstract: A process for producing a high-density iron-based green compact is provided that can form a green compact with a high density. Also provided is a process for producing a sintered compact from the green compact. A specified combination lubricant is applied to the surface of a die for compacting by electrical charging, wherein the combination lubricant includes a first lubricant having a melting point that is higher than a preset compacting temperature, and a second lubricant having a melting point that is lower than a compacting temperature. A heated iron-based powder mixture is filled into the die, followed by compacting, whereby a green compact is formed. The green compact can be sintered to provide a sintered compact.

Abstract: A manufacturing method for high-density iron-based powder compacts is disclosed. The temperature of the die is adjusted at ordinary temperature or at a predetermined temperature by preheating. A lubricant for die lubrication prepared by mixing at least two different lubricants having melting points higher than a predetermined temperature of the compaction pressure is sprayed at the upper part of the die and is introduced into the die and adhered by electrification to the surface of the die. The resulting die is filled with an iron-based mixed powder including a lubricant and molding is performed at ordinary temperature or at a temperature raised by heating.

Abstract: The invention has for its object the provision alloy steel powders for Cr-based high strength sintered bodies having high tensile strength, fatigue strength and toughness which are adapted for use in parts for motor vehicles and parts for OA apparatus.The composition of the alloy steel powder comprises, by wt %, not larger than 0.1% of C, not larger than 0.08% of Mn, 0.5-3% of Cr, 0.1-2% of Mo, not larger than 0.01% of S, not larger than 0.01% of P, not larger than 0.2% of O, optionally one or more of 0.2.about.2.5% Ni, 0.5.about.2.5% Cu and the balance being inevitable impurities and Fe. The sintered body has substantially the same composition provided that the content of C alone is limited to 0.2-1.2%.The manufacturing method comprises molding the above alloy steel powder, sintering the resulting green compact at a temperature of 1100.degree.-1300.degree. C. and immediately cooling at a cooling rate of 10.degree.-200.degree. C./minute.

Abstract: Alloy steel powders capable of obtaining high strength in a sintered state and having excellent compacting compressibility and methods of manufacturing a sintered body. The alloy steel powder comprises, by wt %, about 0.5-2% of Cr, not greater than about 0.08% of Mn, about 0.1-0.6% of Mo, about 0.05-0.5% of V, not greater than about 0.015 of S, not greater than about 0.2% of O, and the balance being Fe and incidental impurities. The alloy steel powder is compacted and sintered at a temperature of about 1100.degree.-1300.degree. C. and then cooled at a cooling rate no higher than about 1.degree. C./s in a temperature range of from about 800.degree. C. to 400.degree. C. The alloy steel powder can contain Nb and/or Ti and one or more of Co, W and B. Additionally, Ni powder and/or Cu powder may be adhered and dispersed onto the surface of the alloy steel powder.