Abstract: An iron-based alloy powder for powder metallurgy contains 2.0 mass % to 5.0 mass % of Cu, the balance being Fe and incidental impurities. From 1/10 to 8/10 of the Cu is diffusion bonded in powder-form to the surfaces of iron powder that serves as a raw material for the iron-based alloy powder, and the remainder of the Cu is contained in this iron powder as a pre-alloy. The iron-based alloy powder has superior compressibility to conventional Cu pre-alloyed iron-based alloy powders and enables production of a high strength sinter-forged member even when sintered at a lower temperature than conventional iron-based alloy powders containing mixed Cu powder.

Abstract: An iron-ion supply material capable of efficiently supplying iron ions to plants is provided. An iron-ion supply material that acts as an iron-ion supply source for supplying iron ions contributing to plant growth comprises an iron powder having an iron content of 80% by mass or more, wherein 50% by mass or more of the whole iron powder has a particle size of 100 ?m or more and 10 mm or less.

Abstract: An Fe—Mo—Cu—C-based alloy steel powder for powder metallurgy has a chemical composition containing Mo: 0.2 mass % to 1.5 mass %, Cu: 0.5 mass % to 4.0 mass %, and C: 0.1 mass % to 1.0 mass %, with a balance being Fe and incidental impurities, wherein an iron-based powder has a mean particle size of 30 ?m to 120 ?m, and a Cu powder has a mean particle size of 25 ?m or less. Despite the alloy steel powder for powder metallurgy having a chemical composition not containing Ni, a part produced by sintering a press formed part of the powder and further carburizing-quenching-tempering the sintered part has mechanical properties of at least as high tensile strength, toughness, and sintered density as a Ni-added part.

Abstract: A method of producing a mixed powder for powder metallurgy comprises: mixing an iron-based powder with a Mo-containing powder and a Cu-containing powder, to obtain a raw material mixed powder; heat-treating the raw material mixed powder to cause Mo and Cu to diffusionally adhere to a surface of the iron-based powder, to obtain a partially diffusion-alloyed steel powder; and mixing the partially diffusion-alloyed steel powder with a graphite powder, to obtain a mixed powder for powder metallurgy, wherein the iron-based powder has an average particle size of 30 ?m to 120 ?m, a cuprous oxide powder is used as the Cu-containing powder, and the mixed powder for powder metallurgy has a chemical composition containing Mo: 0.2 mass % to 1.5 mass %, Cu: 0.5 mass % to 4.0 mass %, and C: 0.1 mass % to 1.0 mass %, with a balance being Fe and incidental impurities.

Abstract: An iron-ion supply material capable of efficiently supplying iron ions to plants is provided. An iron-ion supply material that acts as an iron-ion supply source for supplying iron ions contributing to plant growth comprises an iron powder having an iron content of 80% by mass or more, wherein 50% by mass or more of the whole iron powder has a particle size of 100 ?m or more and 10 mm or less.

Abstract: An iron-based alloy powder for powder metallurgy contains 2.0 mass % to 5.0 mass % of Cu, the balance being Fe and incidental impurities. From 1/10 to 8/10 of the Cu is diffusion bonded in powder-form to the surfaces of iron powder that serves as a raw material for the iron-based alloy powder, and the remainder of the Cu is contained in this iron powder as a pre-alloy. The iron-based alloy powder has superior compressibility to conventional Cu pre-alloyed iron-based alloy powders and enables production of a high strength sinter-forged member even when sintered at a lower temperature than conventional iron-based alloy powders containing mixed Cu powder.

Abstract: An Fe—Mo—Cu—C-based alloy steel powder for powder metallurgy has a chemical composition containing Mo: 0.2 mass % to 1.5 mass %, Cu: 0.5 mass % to 4.0 mass %, and C: 0.1 mass % to 1.0 mass %, with a balance being Fe and incidental impurities, wherein an iron-based powder has a mean particle size of 30 ?m to 120 ?m, and a Cu powder has a mean particle size of 25 ?m or less. Despite the alloy steel powder for powder metallurgy having a chemical composition not containing Ni, a part produced by sintering a press formed part of the powder and further carburizing-quenching-tempering the sintered part has mechanical properties of at least as high tensile strength, toughness, and sintered density as a Ni-added part.

Abstract: A method for manufacturing sponge iron and an apparatus for charging in the method are disclosed. Iron oxide powder and reducing-agent powder are charged such that alternating layers of the iron oxide powder and the reducing-agent powder are formed and such that each of the layers is in the form of a helix, and then a reduction treatment is performed. The method has not only high reaction efficiency of a gas, high quality, and high productivity, but also the advantage for a production adjustment because the amount of charge can be adjusted without the limitation of a reduction time. The molar ratio of the carbon content in the reducing agent to the oxygen content in the iron oxide in the reaction container is preferably 1.1 or more.

Abstract: A method for manufacturing sponge iron includes heating iron oxide together with a solid reducing agent to reduce the iron oxide into sponge iron, wherein the iron oxide includes a mixture of powdered hematite and powdered iron ore or a mixture of powdered hematite and powdered mill scale, the powdered hematite has a specific surface area of 2.0 m2/g or more, and the content of the powdered hematite is 5-45% by mass with respect to the total quantity of iron oxide.

Abstract: In order to improve machinability of a sintered compact, a phosphate compound of an alkali earth metal (calcium phosphate compound or the like) is mixed with an iron-based powder, or an alkali earth metal fluoride (calcium fluoride, or the like) is further mixed with the iron-based powder. Alternatively, the alkali earth metal fluoride, together with a graphite powder, is preferably fixed to recesses of the iron-based powder.

Abstract: A method for manufacturing sponge iron includes heating iron oxide together with a solid reducing agent to reduce the iron oxide into sponge iron, wherein the iron oxide includes a mixture of powdered hematite and powdered iron ore or a mixture of powdered hematite and powdered mill scale, the powdered hematite has a specific surface area of 2.0 m2/g or more, and the content of the powdered hematite is 5-45% by mass with respect to the total quantity of iron oxide.

Abstract: In order to improve machinability of a sintered compact, a phosphate compound of an alkali earth metal (calcium phosphate compound or the like) is mixed with an iron-based powder, or an alkali earth metal fluoride (calcium fluoride, or the like) is further mixed with the iron-based powder. Alternatively, the alkali earth metal fluoride, together with a graphite powder, is preferably fixed to recesses of the iron-based powder.

Abstract: An iron-based powder mixture for powder metallurgy essentially consists of a melted mixture, as a binder, which includes about 0.1% to about 1.0% by weight of a powder of at least one organic compound selected from stearic acid, oleic acid amide, and stearic acid amide, and about 0.1% to about 1.0% by weight of a powder of stearic acid bisamide; and the balance which is an iron-based powder, to the surface of which adhered about 0.1% to about 3.0% by weight of an alloying powder and/or a powder for improving machinability. Disclosed also is a method of producing the mixture.

Abstract: An iron-based powder mixture for powder metallurgy essentially consists of a melted mixture, as a binder, which includes about 0.1% to about 1.0% by weight of a powder of at least one organic compound selected from stearic acid, oleic acid amide, and stearic acid amide, and about 0.1% to about 1.0% by weight of a powder of stearic acid bisamide; and the balance which is an iron-based powder, to the surface of which adhered about 0.1% to about 3.0% by weight of an alloying powder and/or a powder for improving machinability. Disclosed also is a method of producing the mixture.