There is provided a melting device including a melting cylinder that is heated to a predetermined temperature, melts a molding material supplied from a material supply port, and generates a molten material; an inert gas supply device configured to supply an inert gas onto a melting surface of the molten material and form an inert gas layer; and a low specific gravity gas supply device configured to supply a low specific gravity gas which is a gas having a different type from the inert gas and form a low specific gravity gas layer on the inert gas layer, wherein the low specific gravity gas layer has a lower specific gravity than the inert gas layer.

A device to generate and direct electric heat 10 for use over risers, drains, pathways and pour cups during solidification in which less than 2% plasma is utilized, comprising an outer shell 20 having one open heat delivery end 25, at least one lip 30 located at the open end 25, one closed end 35, at least one electric heating element 80 affixed within the closed 35 end and refractory material 60 surrounding the electric heating element 80. A method, employing the device 10, to improve the properties of cast alloys which comprises the heating and blanketing of a molten cast surface with an atmosphere of less than 2% plasma during solidification, the atmosphere of less than 2% plasma thereby controlling temperature during the solidification and shielding the molten cast surface from the affects of oxidation.

A device to generate and direct electric heat 10 for use over risers, drains, pathways and pour cups during solidification in which less than 2% plasma is utilized, comprising an outer shell 20 having one open heat delivery end 25, at least one lip 30 located at the open end 25, one closed end 35, at least one electric heating element 80 affixed within the closed 35 end and refractory material 60 surrounding the electric heating element 80. A method, employing the device 10, to improve the properties of cast alloys which comprises the heating and blanketing of a molten cast surface with an atmosphere of less than 2% plasma during solidification, the atmosphere of less than 2% plasma thereby controlling temperature during the solidification and shielding the molten cast surface from the affects of oxidation.

The present invention provides a method for casting a slab having a good cast surface. The method includes heating the surface of molten metal on a metal inlet side of a mold by a first heat source so that the following formulas: q0.87 and c11.762q+0.3095 are satisfied where c is a cycle time [sec] of turning movement of the first heat source, and q is an average amount of heat input [MW/m.sup.2] determined by accumulating an amount of heat input applied by at least the first heat source to the contact region between the upper surface of the slab on the metal inlet side and the mold, along the path of turning movement of the first heat source, and dividing the resultant accumulated value by the cycle time c.

The present invention provides a method for casting a slab having a good cast surface. The method includes heating the surface of molten metal on a metal inlet side of a mold by a first heat source so that the following formulas: q0.87 and c11.762q+0.3095 are satisfied where c is a cycle time [sec] of turning movement of the first heat source, and q is an average amount of heat input [MW/m.sup.2] determined by accumulating an amount of heat input applied by at least the first heat source to the contact region between the upper surface of the slab on the metal inlet side and the mold, along the path of turning movement of the first heat source, and dividing the resultant accumulated value by the cycle time c.

In order to provide a method for isolating a circuit and a thermal link, wherein the link has a very low resistance and is suitable for high currents, in particular very high short load currents, and also has a high degree of reliability, in particular under difficult conditions, such as thermal and mechanical loading which lasts for a relatively long time, for example, the invention proposes that, during the phase transition of the material of the fusible element (10) from the solid to the liquid state, the volume of the fusible element (10) increases and the pressure increases and, owing to the increase in volume and the increase in pressure, the fusible element (10) is dislodged so as to break the electrical connection.

In order to provide a method for isolating a circuit and a thermal link, wherein the link has a very low resistance and is suitable for high currents, in particular very high short load currents, and also has a high degree of reliability, in particular under difficult conditions, such as thermal and mechanical loading which lasts for a relatively long time, for example, the invention proposes that, during the phase transition of the material of the fusible element (10) from the solid to the liquid state, the volume of the fusible element (10) increases and the pressure increases and, owing to the increase in volume and the increase in pressure, the fusible element (10) is dislodged so as to break the electrical connection.

A method for continuous thin strip casting comprises: introducing molten steel through a long nozzle into a tundish from a ladle, the tundish is one strand tundish, and the molten steel flows below a weir, then passes a first dam and enters a channel with an induction heating device, and the heated molten steel then flows out from an outlet at the other side of the tundish to a nozzle also with an induction heating device for casting. The distances between the weirs of the tundish and the channel have optimal distance ranges. The present invention can improve the casting stability and the quality of the casting strip.

A method for continuous thin strip casting comprises: introducing molten steel through a long nozzle into a tundish from a ladle, the tundish is one strand tundish, and the molten steel flows below a weir, then passes a first dam and enters a channel with an induction heating device, and the heated molten steel then flows out from an outlet at the other side of the tundish to a nozzle also with an induction heating device for casting. The distances between the weirs of the tundish and the channel have optimal distance ranges. The present invention can improve the casting stability and the quality of the casting strip.

The present invention provides a method for casting a slab with good cast surface quality. The method includes pouring molten metal 8 into a mold 2 from one of the paired shorter sides of the mold 2 while allowing superheat T [ C.], which is a temperature difference obtained by subtracting the melting point Tm [ C.] of the raw material from the temperature Tin [ C.] of the molten material on the surface of the molten metal in the mold and at the pouring point of the molten metal, to satisfy the following Formula (1) and Formula (2):
0.0014T.sup.2 +0.0144T+699.45>800 Formula (1)
0.0008T.sup.2 +0.2472T+853.02<1250 Formula (2)