| 摘要 |
PURPOSE:To realize high performance by controlling the following conditions: a spouting condition to spout a molten metal at a uniform velocity; a material of a roll for molten-metal cooling use; a surface roughness of the roll; the number of revolutions of the roll; a gap between a nozzle and the surface of the roll; an angle of inclination of the nozzle; an atmospheric gas inside a chamber. CONSTITUTION:The following conditions shall be set: regarding a differential pressure to control a spouting velocity of a molten metal, an initial differential pressure of 0.3 to 0.5kg/cm<2>; a middle differential pressure of 0.05 to 0.2kg/cm<2>; after the middle differential pressure has reached this differential pressure, the differential pressure is increased continuously to 0.2 to 0.4kg/cm<2>; a spouting angle of the molten metal is 2 to 10 deg. with reference to a perpendicular line; a distance at which the molten metal comes into contact with a roll is within a range of 0 to 12mm from the center of the roll to the side of its direction of rotation; a gap between the surface of the roll and a nozzle is 8 to 30mm; a shifting velocity of a flake on the surface of the roll is 20 to 30m/sec; a ratio of a volume velocity of a spout to a velocity of rotation of the roll is within a range of 0.06 to 0.10; a degree of vacuum inside a chamber before a spouting operation is 100 to 450mmHg; an atmospheric gas is a mixed gas of Ar and He; its mixture ratio is at Ar (50 to 70%) : He (30 to 50%). Thereby, it is possible to manufacture a flake whose magnetic characteristic is excellent and whose yield is good. |
