Abstract: Techniques are disclosed for reducing macrosegregation in cast metals. Techniques include providing an eductor nozzle capable of increasing mixing in the fluid region of an ingot being cast. Techniques also include providing a non-contacting flow control device to mix and/or apply pressure to the molten metal that is being introduced to the mold cavity. The non-contacting flow control device can be permanent magnet or electromagnet based. Techniques additionally can include actively cooling and mixing the molten metal before introducing the molten metal to the mold cavity.

Abstract: The present invention relates to a device for degassing molten steel, comprising an evacuation vessel (2), a pouring ladle (3), an inlet nozzle (4) with a gas purging device (5) arranged therein, and a discharge nozzle (1), wherein at its lower edge (9), in a radial direction in relation to the central longitudinal axis (6) of the discharge nozzle (1), the discharge nozzle (1) has at least one bore (7).

Abstract: A method, for the conveyance of molten metal from one place to another, in a high-temperature molten metal pool in a metal-melting furnace or out of said molten metal pool, employing an at least partially-inclined elongated conveying conduit and gas feed means for feeding inert gas into the lower end of the conveying conduit and thereby inducing a flow of molten metal in and through said conveying conduit, is disclosed, along with suitable apparatus for carrying out the said method wherein the parts or elements coming into contact with the high-temperature molten metal pool are of a suitable refractory material. According to the present invention, the inert gas is fed into the conveying conduit at a supersonic velocity, thereby simultaneously effecting a degassing of the molten metal while it is being conveyed.

Abstract: Method for decarburisation of steel in a vacuum treatment chamber consisting of an upper part (4) in the shape of a bell, of an intermediate ring (5) and of a lower part (6) in which the bath of metal to be treated (2) is located and which is equipped with two legs (7, 8) which are immersed in the steel ladle (9) containing all the metal (10) to be treated, characterised in that oxygen is blown horizontally over the bath of metal to be treated (2), at the level of the intermediate ring (5), substantially at the centre of the latter.Vacuum steel-treatment chamber in which at least two horizontal tuyeres (11, 12) are provided in the intermediate ring (5) of the said chamber, substantially in the centre of the latter.

Abstract: Disclosed is a method of refining of a high purity steel capable of effectively lowering impurities in molten steel into respective ultra-low ranges. In secondary refining for molten steel after a molten iron prerefining process and a converting process, a reducing agent and a flux are added on the bath surface within a ladle containing the molten steel decarburized in a converter so that the composition of slag on the bath surface is adjusted in such a manner that the total concentration of FeO and MnO becomes 5 wt % or less, and subsequently, impurities in the molten steel are effectively lowered into respective ultra-low ranges using a RH vacuum degassing unit.

Abstract: A process and apparatus for the vacuum treatment of metals. In a tightly sealed vacuum treatment vessel, molten metal is preferably divided, on the surface, into a generally circular sector and a generally ring-shaped sector surrounding the generally circular sector. Preferably, each sector of the molten metal is exposed to different vacuum pressures during vacuum treatment, wherein a generally lower vacuum pressure is applied to the ring-shaped sector than to the circular sector. The two sectors are preferably separated to an immersion depth, in the molten bath, of between 10 and about 20 cm, as measured starting from the ring-shaped sector.