In a continuous casting method for casting aluminum-deoxidized molten stainless steel 1 by using a continuous casting apparatus 100 in which a long nozzle 3 extending into a tundish 101 is provided at a ladle 2, the molten stainless steel 1 is poured into the tundish 101 through the long nozzle 3, while the spout 3a of the long nozzle 3 is being immersed in the molten stainless steel 1 that has been poured, and the molten stainless steel 1 in the tundish 101 is poured into a casting mold 105. A TD powder 5 is sprayed so that the powder covers the surface of the molten stainless steel 1 in the tundish 101, and nitrogen gas is supplied around the molten stainless steel 1. A calcium-containing material is added to the molten stainless steel 1 in a state other than a state of retention in the tundish 101.

Provided are a method for analyzing nitrogen in a metal sample, an apparatus for analyzing nitrogen in a metal sample, a method for adjusting nitrogen concentration in molten steel, and a method for manufacturing steel. The method includes: a melting process in which a metal sample containing a nitrogen component is melted in an argon gas atmosphere by performing impulse heating to gasify the nitrogen component; and an analyzing process in which nitrogen content in the metal sample is determined by analyzing nitrogen gas generated in the melting process and the argon gas by using a gas discharge optical emission method. By analyzing the nitrogen concentration of a sample taken from molten steel by using the analysis method described above, and by determining treatment conditions for adjusting nitrogen concentration on the basis of the nitrogen analysis value derived by the analysis, nitrogen concentration in molten steel is adjusted.

Provided are a method for analyzing nitrogen in a metal sample, an apparatus for analyzing nitrogen in a metal sample, a method for adjusting nitrogen concentration in molten steel, and a method for manufacturing steel. The method includes: a melting process in which a metal sample containing a nitrogen component is melted in an argon gas atmosphere by performing impulse heating to gasify the nitrogen component; and an analyzing process in which nitrogen content in the metal sample is determined by analyzing nitrogen gas generated in the melting process and the argon gas by using a gas discharge optical emission method. By analyzing the nitrogen concentration of a sample taken from molten steel by using the analysis method described above, and by determining treatment conditions for adjusting nitrogen concentration on the basis of the nitrogen analysis value derived by the analysis, nitrogen concentration in molten steel is adjusted.

A pivotable tundish (1) for continuous casting a metal alloy. The tundish includes a body (3) with a first chamber (5), a second chamber (7), a first passage (12) between the first chamber and the second chamber, and a second passage (16) between the second chamber and a mold (9). The first chamber is adapted to receive and hold a base metal constituting the base for forming the metal alloy by addition of alloying elements. The metal alloy is fed from the second chamber to the mold through the second passage. The second chamber further includes a first portion (30) and a second portion (32), and a third passage (36) between the first portion and the second portion. In the casting state the metal alloy is formed while casting by adding the alloying elements to the second portion of the second chamber.

A pivotable tundish (1) for continuous casting a metal alloy. The tundish includes a body (3) with a first chamber (5), a second chamber (7), a first passage (12) between the first chamber and the second chamber, and a second passage (16) between the second chamber and a mold (9). The first chamber is adapted to receive and hold a base metal constituting the base for forming the metal alloy by addition of alloying elements. The metal alloy is fed from the second chamber to the mold through the second passage. The second chamber further includes a first portion (30) and a second portion (32), and a third passage (36) between the first portion and the second portion. In the casting state the metal alloy is formed while casting by adding the alloying elements to the second portion of the second chamber.

In a continuous casting method for casting an aluminum-deoxidized molten stainless steel 1 by using a continuous casting apparatus 100 in which a long nozzle 3 extending into a tundish 101 is provided at a ladle 2, the molten stainless steel 1 is poured through the long nozzle 3 into the tundish 101, while immersing a spout 3a into the poured molten stainless steel 1, and the molten stainless steel 1 in the tundish 101 is poured into a casting mold 105. A TD powder 5 is sprayed so that the powder covers the surface of the molten stainless steel 1 in the tundish 101, a nitrogen gas is supplied around the molten stainless steel 1, and a calcium-containing material is added to the molten stainless steel 1 in the tundish 101. The surface of the molten stainless steel 1 after casting is ground.

In a continuous casting method for casting an aluminum-deoxidized molten stainless steel 1 by using a continuous casting apparatus 100 in which a long nozzle 3 extending into a tundish 101 is provided at a ladle 2, the molten stainless steel 1 is poured through the long nozzle 3 into the tundish 101, while immersing a spout 3a into the poured molten stainless steel 1, and the molten stainless steel 1 in the tundish 101 is poured into a casting mold 105. A TD powder 5 is sprayed so that the powder covers the surface of the molten stainless steel 1 in the tundish 101, a nitrogen gas is supplied around the molten stainless steel 1, and a calcium-containing material is added to the molten stainless steel 1 in the tundish 101. The surface of the molten stainless steel 1 after casting is ground.

Improved casting powders and improved casting slags enable production of steels having high aluminum contents of greater than or equal to 1% by weight and, in some cases, high manganese content of greater than or equal to 15% by weight. In some examples, such steels may also or alternatively include greater than or equal to 0.2% by weight titanium. The casting slag may result from a casting powder that comprises CaO and Al.sub.2O.sub.3 components essentially in the form of prefused calcium aluminate. Methods for casting steel, including methods for continuously casting steel, are also disclosed based on the use of the disclosed casting powders or casting slags.

Improved casting powders and improved casting slags enable production of steels having high aluminum contents of greater than or equal to 1% by weight and, in some cases, high manganese content of greater than or equal to 15% by weight. In some examples, such steels may also or alternatively include greater than or equal to 0.2% by weight titanium. The casting slag may result from a casting powder that comprises CaO and Al.sub.2O.sub.3 components essentially in the form of prefused calcium aluminate. Methods for casting steel, including methods for continuously casting steel, are also disclosed based on the use of the disclosed casting powders or casting slags.

In a continuous casting device 100 for casting a stainless steel billet 3c, a long nozzle 2 extending into a tundish 101 is provided at a ladle 1. A molten stainless steel 3 is poured through the long nozzle 2 into the tundish 101, and a spout 2a of the long nozzle 2 is immersed into the poured molten stainless steel 3. During pouring, an argon gas 4a is supplied around the molten stainless steel 3 in the tundish 101. Further, continuous casting 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 from the ladle 1 into the tundish 101 and poured from the tundish 101 into a casting mold 105. During casting, a nitrogen gas 4b is supplied instead of the argon gas 4a around the molten stainless steel 3 inside the tundish 101.