Molten metal discharge nozzle

Abstract

Provided is a molten metal discharge nozzle which has a bore configuration capable of creating a low-energy loss and smooth (stabilized) molten metal flow to suppress the occurrence of an adhesion matter. In the molten metal discharge nozzle, a radius r(0) of an upper end (12) of a bore (11) thereof is 1.5 times or more a radius r(L) of a lower end (13) of the bore, and a cross-sectional shape of a bore wall surface 14 taken along an axis of the bore has no bend point. Further, a radius r(z) of the bore at a position downwardly away from the upper end of the bore by a distance z (where L is an axial length of the bore) is in a range between [[L/{(r(0)/r(L))1.5−1}+L]/[L{r(0)/r(L))1.5−1}+z]]1/1.5×r(L) and [[L/{(r(0)/r(L))6−1}+L]/[L/{(r(0)/r(L))6−1}+z]]1/6×r(L).

1 . A molten metal discharge nozzle having in an axial direction thereof a bore for allowing passage of molten metal, wherein:
 a radius r(0) of an upper end of the bore is 1.5 times or more a radius r(L) of a lower end of the bore;   a line indicative of a wall surface of the bore in a cross-section taken along an axis of the bore has no bend point;   a radius r(¼ L) of the bore at a position downwardly away from the upper end of the bore by a distance of ¼ L (where L is an axial length of the bore) is in a range between
 [[L/{(r(0)/r(L)) 1.5 −1}+L]/[L/{r((0)/r(L)) 1.5 −1}+¼ L]] 1/1.5 ×r(L) and 
 [[L/{(r(0)/r(L)) 6 −1}+L]/[L/{r((0)/r(L)) 6 −1}+¼ L]] 1/6 ×r(L); 
   a radius r(½ L) of the bore at a position downwardly away from the upper end of the bore by a distance of ½ L is in a range between
 [[L/{(r(0)/r(L)) 1.5 −1}+L]/[L/{r((0)/r(L)) 1.5 −1}+½ L]] 1/1.5 ×r(L) and 
 [[L/{(r(0)/r(L)) 6 −1}+L]/[L/{r((0)/r(L)) 6 −1}+½ L]] 1/6 r(L); and 
   a radius r(¾ L) of the bore at a position downwardly away from the upper end of the bore by a distance of ¾ L is in a range between
 [[L/{(r(0)/r(L)) 1.5 −1}+L]/[L/{r((0)/r(L)) 1.5 −1}+¾ L]] 1/1.5 ×r(L) and 
 [[L/{(r(0)/r(L)) 6 −1}+L]/[L/{r((0)/r(L)) 6 −1}+¾ L]] 1/6 r(L).