Continuous casting method and continuous casting device

Abstract

Capture of a foreign matter into a solidified shell is effectively suppressed. A continuous casting method is a method which is carried out with use of a continuous casting device, and includes: a discharging step of discharging molten steel through a discharge hole; and a stirring step of stirring the molten steel so that a stirring region includes a whole line segment via which the discharge hole and a reached location are connected to each other, the reached location being a location on a surface of the molten steel in a mold which location is reached by the molten steel in a case where the molten steel discharged in the discharging step proceeds straight.

1 . A continuous casting method which is carried out with use of a continuous casting device,
 the continuous casting device including:   a mold which includes a first surface and a second surface, which intersects the first surface, so as to have a surrounding structure;   a submerged nozzle which has a discharge hole through which molten steel is discharged; and   a stirring device which forms a stirring region by stirring the molten steel in the mold,   the method comprising:   a discharging step of discharging, through the discharge hole located in the mold, the molten steel upward with respect to a horizontal direction and in a direction parallel to the first surface; and   a stirring step of stirring the molten steel so that the stirring region includes a whole line segment via which the discharge hole and a reached location are connected to each other, the reached location being a location on a surface of the molten steel in the mold or on the second surface which location is reached by the molten steel in a case where the molten steel discharged in the discharging step proceeds straight.   
     
     
         2 . The method as set forth in  claim 1 , wherein a flow velocity of the molten steel in the stirring region falls within a range of 0.20 m/s to 0.40 m/s. 
     
     
         3 . The method as set forth in  claim 1 , wherein the reached location is the location on the surface. 
     
     
         4 . The method as set forth in  claim 1 , wherein an impulse which the molten steel, discharged from the submerged nozzle, receives by a time when the molten steel reaches the surface is 0.4×107 G 2 /μΩ-m to 2.5×107 G 2 /μΩ-m. 
     
     
         5 . A continuous casting device comprising:
 a mold which includes a first surface and a second surface, which intersects the first surface, so as to have a surrounding structure;   a submerged nozzle which has a discharge hole located in the mold and from which molten steel is discharged in a direction parallel to the first surface through the discharge hole; and   a stirring device which forms a stirring region by stirring the molten steel in the mold,   the discharge hole being included in the stirring region and causing the molten steel to be discharged upward with respect to a horizontal direction,   the stirring device stirring the molten steel so that the stirring region includes a whole line segment via which the discharge hole and a reached location are connected to each other, the reached location being a location on a surface of the molten steel in the mold or on the second surface which location is reached by the molten steel in a case where the molten steel discharged through the discharge hole proceeds straight.   
     
     
         6 . The continuous casting device as set forth in  claim 5 , wherein a flow velocity of the molten steel in the stirring region falls within a range of 0.20 m/s to 0.40 m/s. 
     
     
         7 . The continuous casting device as set forth in  claim 5 , wherein the discharge hole causes the molten steel to be discharged upward at an angle of 5° to 30° with respect to a horizontal plane. 
     
     
         8 . The continuous casting device as set forth in  claim 5 , wherein an impulse which the molten steel, discharged from the submerged nozzle, receives by a time when the molten steel reaches the surface is 0.4×107 G 2 /μΩ-m to 2.5×107 G 2 /μΩ-m.