NOZZLE FOR DISCHARGING MOLTEN METAL

摘要

In order to make it possible to suppress turbulence in a flow of a molten metal passing through an inner bore by a simple structure, a nozzle for discharging a molten metal is provided wherein a wall surface of the inner bore has a sectional shape, taken along an axis of the inner bore, which includes in a part or the entirety of the sectional shape a curve represented by log(r(z))=(1/n)xlog((Hc+L)/(Hc+z))+log(r(L))(6=n=1.5) wherein the nozzle length is (L), the head height obtained by calculation is (Hc), and the radius of the inner bore at a position located downward at a distance (z) from an upper end of the nozzle is r(z), and wherein in a graph represented by an abscissa (X axis) representing the distance (z) and the ordinate (Y axis) along which the pressure of the molten metal at the center of the inner bore in a section in the horizontal direction at the distance z is plotted, an approximated line of the graph does not include portions having a negative constant and a positive constant simultaneously, and when the line is assumed to be represented by an approximation by a linear regression, the absolute value of a correlation coefficient thereof is not less than 0.95.