Abstract: To provide an apparatus for producing a metal powder and a method of producing a metal powder capable of obtaining a metal powder having a finer particle size of excellent quality. A supersonic combustion flame is intensively injected into a downwardly supplied molten metal, the intensive combustion flame is jetted directly downwardly as a focused jet flow, the focused jet flow thrusts into a turning water flow formed along an inner peripheral surface of a pulverization cooling cylinder whose axis line is inclined from a vertical direction, and an intensive position of the combustion flame is in an open space above the turning water flow.

Abstract: To provide an apparatus for producing a metal powder and a method of producing a metal powder capable of obtaining a metal powder having a finer particle size of excellent quality. A supersonic combustion flame is intensively injected into a downwardly supplied molten metal, the intensive combustion flame is jetted directly downwardly as a focused jet flow, the focused jet flow thrusts into a turning water flow formed along an inner peripheral surface of a pulverization cooling cylinder whose axis line is inclined from a vertical direction, and an intensive position of the combustion flame is in an open space above the turning water flow.

Abstract: Powder for grinding according to the present invention is powder for grinding that is manufactured according to the atomize method and serves as a medium for grinding a surface of a base substrate to form concave portions. The powder for grinding contains as its components at least one of Fe and Ni and W (tungsten) and a content of W is 30 to 55 wt % and a specific gravity thereof is equal to or higher than 8.5. Preferably, the powder for grinding further contains Cr at a content of 1 to 25 wt %. Preferably, the powder for grinding further contains B at a content of 0.5 to 4 wt %. It is possible to surely collect the powder for grinding making use of a difference between a specific gravity of the powder for grinding and a specific gravity of grinding wastes. The powder for grinding collected is suitable for being served for reuse at least once.

Abstract: A twin-drum continuous casting apparatus for casting a metal sheet (4) by supplying molten metal (3) to a pouring basin formed by a pair of cooling drums (1) rotating in opposite directions, and side gates (2), to cool the molten metal (3) by contact with surfaces of the cooling drums (1), thereby forming a solidified shell. The cooling drum (1) is formed from a drum body (11) having shaft portions at opposite end portions, and a drum sleeve (10) fitted on an outer peripheral portion of the drum body (11). Also, means is provided for preventing various adverse influences due to differences in thermal expansion of constituent members of the drum body (11) during casting. Thus, the reliability of the apparatus is increased, and the quality of casting is improved.

Abstract: A twin-drum continuous casting apparatus for casting a metal sheet (4) by supplying molten metal (3) to a pouring basin formed by a pair of cooling drums (1) rotating in opposite directions, and side gates (2), to cool the molten metal (3) by contact with surfaces of the cooling drums (1), thereby forming a solidified shell. The cooling drum (1) is formed from a drum body (11) having shaft portions at opposite end portions, and a drum sleeve (10) fitted on an outer peripheral portion of the drum body (11). Also, means is provided for preventing various adverse influences due to differences in thermal expansion of constituent members of the drum body (11) during casting. Thus, the reliability of the apparatus is increased, and the quality of casting is improved.

Abstract: A cast iron pipe surface-modified for preventing corrosion and a method of modifying the pipe surface for corrosion prevention. A corrosion preventive coating is formed on the surface of the iron material of the pipe. The corrosion preventive coating is made up of an aluminum alloy containing not less than 5 wt % but not more than 25 wt % of Mn, the remainder being Al, the aluminum alloy being such that the manganese is present as a supersaturated solid solution in an aluminum phase. The corrosion preventive coating is formed by thermally spraying a quenched aluminum alloy of the above noted composition onto the surface of the iron material of the pipe.

Abstract: The invention provides a method of producing metal powders which is less likely permit variations in cooling rate, ensures rapid solidification at a great cooling rate and readily gives fine particles, and a production apparatus for the method. The method comprises injecting a cooling liquid into a cooling tubular body (1) along an inner peripheral surface thereof to form a cooling liquid layer (9) moving toward a cooling liquid discharge end of the tubular body (1) while swirling along the inner peripheral surface of the tubular body (1); supplying a molten metal (25) to a space (23) inside the cooling liquid layer (9); applying a gas jet (26) as directed toward the cooling liquid layer (9) to the molten metal (25) to divide the molten metal and supply the divided molten metal to the cooling liquid layer (9); and discharging the cooling liquid containing a metal powder solidified in the liquid layer (9) from the cooling liquid discharge end of the tubular body (1) to outside.

Abstract: A cooling liquid is injected into and supplied to a cooling tubular body along its inner periphery to form a cooling liquid layer flowing down the inner peripheral surface of the body while revolving. A molten metal is then injected into the cooling liquid layer from the inner peripheral side thereof to divide, rapidly cool and solidify the stream of molten metal with the cooling liquid layer and obtain a metal powder. Since the metal powder is continuously obtained upon flowing down the tubular body along with the cooling liquid, the liquid can be continuously removed from the powder by suitable means, and the power can be subsequently dried continuously.

Abstract: A cooling liquid is injected into and supplied to a cooling tubular body along its inner periphery to form a cooling liquid layer flowing down the inner peripheral surface of the body while revolving. A molten metal is then injected into the cooling liquid layer from the inner peripheral side thereof to divide, rapidly cool and solidify the stream of molten metal with the cooling liquid layer and obtain a metal powder. Since the metal powder is continuously obtained upon flowing down the tubular body along with the cooling liquid, the liquid can be continuously removed from the powder by suitable means, and the power can be subsequently dried continuously.

Abstract: A chill preventing arrangement is used in a metal mold employed in centrifugal casting. The metal mold is provided, at its spigot portion, with an end plate which has a central opening smaller in diameter than the internal diameter of the metal mold main body and which includes a metallic base plate, an intermediate layer of metallic alloy formed by flame or plasma spraying on a surface of the metallic base plate contacting the molten metal for casting, and a coating of ceramic material more than 0.7 mm thick formed on the intermediate layer by flame or plasma spraying for preventing chill formation at the corresponding end portions of tubular castings.

Abstract: An applicator nozzle for applying a coating solution onto the molding surface of a metal mold for use in centrifugal casting. The applicator nozzle mounted on an applicator lance is provided, at its one end facing the molding surface, with a plurality of small nozzle openings which are arranged at a predetermined pitch to each other in the direction of movement of the lance into the metal mold, through which nozzle openings, a solution of coating material is emitted in solid rod-like form in such an amount as to be sufficient to complete mold coating in one way of the nozzle into the metal mold, thus producing mold coating free from an undesirable spiral pattern.

Abstract: An applicator nozzle for applying a coating solution onto the molding surface of a metal mold for use in centrifugal casting. The applicator nozzle mounted on an applicator lance is provided, at its one end facing the molding surface, with a plurality of small nozzle openings which are arranged at a predetermined pitch to each other in the direction of movement of the lance into the metal mold, through which nozzle openings, a solution of coating material is emitted in solid rod-like form in such an amount as to be sufficient to complete mold coating in one way of the nozzle into the metal mold, thus producing mold coating free from an undesirable spiral pattern.

Abstract: A method for making a disposable model for a precision investment casting, which comprises casting a naphthalene or para-dichlorobenzene-containing modeling material into a pattern mold at a temperature of 150.degree. C or less, preferably 80 to 150.degree. C and further preferably at a casting speed of 5 to 0.1 kg/second; the modeling material being optionally admixed with a resin selected from the group consisting of polystyrene, polyethylene, polyvinyl acetate and a mixture thereof as a reinforcing material or comprising a mixture of naphthalene or paradichlorobenzene (preferably 80 to 30% by weight), a wax (preferably 20 to 70% by weight) and the resin as mentioned above (preferably 0.5 to 15% by weight on the basis of the whole weight of the modeling material).