Patent ID: 6367671
Filing Date: 2002-04-09
Classification: B22D

Abstract:
A stopper rod for use in the casting of molten metal comprising an elongated body including a lower end, an upper end, a longitudinal axis extending between the lower and upper ends, an inner surface open to the upper end and defining a borehole along the longitudinal axis, the borehole having an enlarged portion comprising an annular sealing surface spaced away from upper end, and a fastener within the borehole spaced further from the upper end than the annular sealing surface and adapted to secure the elongated body to a metal rod, the elongated body comprising least two different refractory materials including:a) an impermeable material having a specific permeability lower than 5.10âˆ’17m2, and substantially surrounding the annular sealing surface, whereby gas leakage through the annular sealing surface is substantially prevented; and b) a corrosion-resistant material contacting the molten metal.