Abstract: Method of producing Ta powder for tantalum solid electrolytic capacitor capable of stably providing CV value of more than 220 k and to provide the Ta powder and its Ta granulated powder. In method of producing Ta powder by vaporizing TaCl5 through heating and reducing with H2 gas, the reduction is performed under conditions that feeding rate of TaCl5 vapor passing through section area of reaction field of 1 cm2 for 1 minute is 0.05˜5.0 g/cm2·min and residence time of TaCl5 vapor in the reduction reaction field is 0.1˜5 seconds and reduction temperature of TaCl5 is 1100˜1600° C., whereby Ta powder including a single phase of ?-Ta of tetragonal system or mixed phase of ?-Ta and ?-Ta of cubic system and having average particle size of 30˜150 nm is obtained. Further, Ta granulated powder is obtained by granulating the Ta powder.

Abstract: It is to propose a method of producing super-micro powders of pure metal-alloy in which cheap materials can be used and the production is efficient. In the production method of pure metal super-micro powder by heating a starting material containing a metal chloride and reducing the resulting vapor of the metal chloride with hydrogen gas, an elementary metal constituting the metal chloride is added to the starting material containing the metal chloride and a metal chloride having a large valence among metal chlorides having two or more valence is used as the metal chloride. Also, in the production method of alloy super-micro powder, a metal chloride is used as one to (number of all alloying components—1) alloying components in the starting material and an elemental metal is used as the other alloying component.

Abstract: It is to propose a method of producing super-micro powders of pure metal-alloy in which cheap materials can be used and the production is efficient. In the production method of pure metal super-micro powder by heating a starting material containing a metal chloride and reducing the resulting vapor of the metal chloride with hydrogen gas, an elementary metal constituting the metal chloride is added to the starting material containing the metal chloride and a metal chloride having a large valence among metal chlorides having two or more valence is used as the metal chloride. Also, in the production method of alloy super-micro powder, a metal chloride is used as one to (number of all alloying components—1) alloying components in the starting material and an elemental metal is used as the other alloying component.

Abstract: A structure of a two-phase steel is controlled by subjecting a steel containing C: 0.05-0.80 mass % to a strain work in a true strain quantity of not less than 0.1 at a temperature zone of &agr;-phase or &ggr;-phase and then applying a magnetic field of 0.1-20 T thereto within a temperature range forming a two-phase zone of &agr;-phase and &ggr;-phase.

Abstract: A structure of a two-phase steel is controlled by subjecting a steel containing C: 0.05-0.80 mass % to a strain work in a true strain quantity of not less than 0.1 at a temperature zone of &agr;-phase or &ggr;-phase and then applying a magnetic field of 0.1-20T thereto within a temperature range forming a two-phase zone of &agr;-phase and &ggr;-phase.

Abstract: Magnetic heat treatment of steel, characterized by transforming steel containing about 0.01 to 2.0 mass % of carbon in a magnetic field having a gradient of about 0.1 T/cm or more and about 10 T/cm or less (absolute value) at the Curie point or lower, to effectively refine the microstructure by subjecting the steel to heat treatment in a strong magnetic field having a gradient, followed by advantageously improving the mechanical properties of the steel.