For continuously casting an ingot of titanium or titanium alloy, molten titanium or titanium alloy is poured into a top opening of a bottomless mold with a circular cross-sectional shape, the solidified molten metal in the mold is pulled downward from the mold, a plurality of plasma torches disposed on an upper side of molten metal in the mold such that their centers are located directly vertically above the molten metal in the mold, are operated to generate plasma arcs that heat the molten metal in the mold, and the plasma torches are moved in a horizontal direction above a melt surface of the molten metal in the mold, along a trajectory located directly vertically above the molten metal in the mold, while keeping a mutual distance between the respective plasma torches such that the plasma torches do not interfere with each other.

For continuously casting an ingot of titanium or titanium alloy, molten titanium or titanium alloy is poured into a top opening of a bottomless mold with a circular cross-sectional shape, the solidified molten metal in the mold is pulled downward from the mold, a plurality of plasma torches disposed on an upper side of molten metal in the mold such that their centers are located directly vertically above the molten metal in the mold, are operated to generate plasma arcs that heat the molten metal in the mold, and the plasma torches are moved in a horizontal direction above a melt surface of the molten metal in the mold, along a trajectory located directly vertically above the molten metal in the mold, while keeping a mutual distance between the respective plasma torches such that the plasma torches do not interfere with each other.

A steel product having, by weight, less than 0.25% carbon, between 0.20 and 2.0% manganese, between 0.05 and 0.50% silicon, aluminum 0.008% or less by weight, and at least one element selected from the group consisting of titanium between about 0.01% and about 0.20%, niobium between about 0.01% and about 0.20%, molybdenum between about 0.05% and about 0.50%, and vanadium between about 0.01% and about 0.20%, and having a microstructure comprised of a majority bainite, and fine oxide particles of silicon and iron distributed through the steel microstructure of average precipitate size less than 50 nanometers. The yield strength of the steel product may be at least 55 ksi (380 MPa) or the tensile strength of at least 500 MPa, or both. The steel product may have total elongation of at least 6% or 10%, and thickness less than 3.0 mm.

A steel product having, by weight, less than 0.25% carbon, between 0.20 and 2.0% manganese, between 0.05 and 0.50% silicon, aluminum 0.008% or less by weight, and at least one element selected from the group consisting of titanium between about 0.01% and about 0.20%, niobium between about 0.01% and about 0.20%, molybdenum between about 0.05% and about 0.50%, and vanadium between about 0.01% and about 0.20%, and having a microstructure comprised of a majority bainite, and fine oxide particles of silicon and iron distributed through the steel microstructure of average precipitate size less than 50 nanometers. The yield strength of the steel product may be at least 55 ksi (380 MPa) or the tensile strength of at least 500 MPa, or both. The steel product may have total elongation of at least 6% or 10%, and thickness less than 3.0 mm.

There is provided a method of manufacturing a high nitrogen duplex stainless steel sheet through a twin roll strip casting process without the occurrence of surface swelling on the high nitrogen duplex stainless steel sheet.

There is provided a method of manufacturing a high nitrogen duplex stainless steel sheet through a twin roll strip casting process without the occurrence of surface swelling on the high nitrogen duplex stainless steel sheet.

In a continuous casting apparatus 100 for casting a stainless steel billet 3c, a long nozzle 2 extending into a tundish 101 is provided at a ladle 1 for pouring a molten stainless steel 3 in the ladle 1 into the tundish 101. Further, a nitrogen gas 4 is supplied as a seal gas around the molten stainless steel 3 in the tundish 101, and continuous casting of the stainless steel billet 3c is performed, in which, while immersing the spout 2a of the long nozzle 2 into the molten stainless steel 3 in the tundish 101, the molten stainless steel 3 is poured through the long nozzle 2 into the tundish 101 and the molten stainless steel 3 in the tundish 101 is poured into a casting mold 105.

In a continuous casting apparatus 100 for casting a stainless steel billet 3c, a long nozzle 2 extending into a tundish 101 is provided at a ladle 1 for pouring a molten stainless steel 3 in the ladle 1 into the tundish 101. Further, a nitrogen gas 4 is supplied as a seal gas around the molten stainless steel 3 in the tundish 101, and continuous casting of the stainless steel billet 3c is performed, in which, while immersing the spout 2a of the long nozzle 2 into the molten stainless steel 3 in the tundish 101, the molten stainless steel 3 is poured through the long nozzle 2 into the tundish 101 and the molten stainless steel 3 in the tundish 101 is poured into a casting mold 105.

A purifying device for removing impurities from liquid metal present in a vessel includes a baffle including a first surface and a second surface disposed opposite the first surface. A vent channel is formed between the first surface and the second surface, the vent channel having a proximal end and a distal end opposite the proximal end, the vent channel configured to receive a stream of gas at the proximal end and vent at least some of the stream of gas at the distal end. At least one first vent hole is arranged on the first surface and extending into the vent channel, and at least one second vent hole arranged on the second surface and extending into the vent channel. A passage for liquid metal flow is disposed within the baffle, the passage having a proximal surface and a distal surface, where the distal surface is disposed adjacent to the proximal end of the vent channel.

A purifying device for removing impurities from liquid metal present in a vessel includes a baffle including a first surface and a second surface disposed opposite the first surface. A vent channel is formed between the first surface and the second surface, the vent channel having a proximal end and a distal end opposite the proximal end, the vent channel configured to receive a stream of gas at the proximal end and vent at least some of the stream of gas at the distal end. At least one first vent hole is arranged on the first surface and extending into the vent channel, and at least one second vent hole arranged on the second surface and extending into the vent channel. A passage for liquid metal flow is disposed within the baffle, the passage having a proximal surface and a distal surface, where the distal surface is disposed adjacent to the proximal end of the vent channel.