Allmanna Svenska Elektriska Aktiebolaget

Uddeholms Aktiebolag

Karl-Erik Oberg

Lars-Gunnar Norberg

Kare Folgero

Bengt Fredriksson

Conny Andersson

Bengt Fredrikson

Lars Anders Eriksson

Steinar Steinarson

Birger Hedberg

Kare M Folgero

A metal melt casting apparatus comprises a vessel for containing the melt and having a wall portion having a downwardly pointing melt tapping hole, the vessel tilting so that this wall portion can be raised and lowered. A fountain has a top for receiving the melt when registered with said tapping hole and a bottom for connection with the bottom of a mold. A gas-tight elastically deflectible sealing means interconnects the tapping hole and the fountain top when the mentioned wall portion is lowered thereon by tilting of the vessel. The sealing means is made in the form of two parts which elastically flexibly engage when the converter wall with the tapping hole is lowered on the top of the fountain, one part being connected to the wall and the other part being connected to the fountain. The sealing means is provided with a gas passage so that the tapping metal stream may be subject to evacuation for degassing or surrounded by an inert gas.

Melt casting apparatus

In a process for reducing the carbon content of an iron, cobalt or nickel based alloy containing carbon and at least 10% by weight chromium by introducing into the molten alloy, through at least one inner section of a tuyere which comprises at least two concentric tubes, essentially pure steam or steam and any inert gas belonging to the group consisting of nitrogen, argon, helium, neon and xenon, blockage of gas inlet is avoided by passing a gas mixture containing between 5 and 30% by volume of gaseous oxygen through an outermost section of the tuyere.

Decarburization of a metal melt

A metal-refining converter comprises an elongated vessel for containing a melt to be refined and which tilts so that it can be positioned upright or horizontal. This vessel has an upper end having a charging opening provided with a removable gas-tight cover and a lower end provided with a channel-type inductor, and the vessel has a closable tap hole in its side which is downward when the vessel is horizontal. The vessel is charged with the melt to be refined, via its charging opening. With the vessel upright, the vessel is provided with means for injecting refining material into the melt while it is heated by the inductor. After the refining period, the vessel is tilted to its horizontal position, the vessel having an internal contour such that a space is formed over the melt, the gas-tight cover being applied at that time. Non-oxidizing gas is injected into the vessel and with the inductor continuing to heat the melt, the latter is tapped via the tap hole. Control of the gas pressure within the vessel and of the electric power applied to the inductor, permits tapping to be effected, for example, via bottom pouring into ingot molds, at a constant rate and temperature. With these two normally varying factors under complete control, high-quality castings are obtained.

Apparatus and method for refining metal

A metallurgical furnace has a wall contacted by molten metal and having a nozzle opening below the level of the metal, a nozzle positioned in this opening forms a passage for injecting a blast into the metal, and this nozzle has means for liquid-cooling the outer end of its blast passage to freeze the molten metal when flowing backwardly through the nozzle's passage in the event of a blast failure. In such an event, the frozen or solidified metal forms a stopper for the nozzle's passage.

Metallurgical furnace having a blast injection nozzle

A method of treating molten metal in a converter having an induction heater the heating space of which opens into the lowermost portion of the converter compartment comprises injecting a mixture of a solid treating material in powder form with a carrier gas through a sidewall of the converter at a level only slightly above the bottom wall of the converter compartment. A tuyere through which the gas-powder mixture is injected is directed slightly downward and toward the region where the heating space of the induction heater opens into the converter compartment.

Method for treating a metal melt

A process is provided for directly reducing a metal oxide to metal in a molten metal which comprises providing a body of molten metal in a converter provided with means for introducing molten metal and means for introducing metal oxide into the body of the molten metal by introducing molten metal therein, introducing said metal oxide as a powder suspended in a carrier gas, separately from said molten metal, into the body of the molten metal such that the molten metal introduced is hotter than the suspended powder and is distributed by said suspension to other parts of the mass of molten metal where the reduction can take place at the desired temperature. Preferably the molten metal is introduced into the converter via a channel in liquid communication with the converter, the channel opening into the converter at a level below the operating level of the molten metal, said metal being melted in a separate heating zone such that a temperature gradient is established between said zone and the contents of the converter, said zone having a refractory lining which is thinner than the lining of the converter, and the suspended metal oxide is injected into the body of the molten metal via a tuyere extending through the wall of the converter and terminating in the vessel at a distance from the channel, such that the suspended metal oxide does not pass through the heating zone.

Growing community of inventors

Hagfors, Sweden

Karl-Erik Oberg