PURPOSE: To produce a cast piece excellent in the surface conditions free of shrinkage cavity and segregation inside by pressing the upper portion of the cast piece with a roller before it is solidified through a solidification from the bottom to the top.
CONSTITUTION: A molten metal poured into an ingot mold from a tundish 1 is solidified from the bottom and both sides to form a gutter-shaped solidified shell 4. After withdrawn, this shell is colled with a forced coller only at the bottom so that the molten metal retained in the shell 4 is solidified toward the top from the bottom of the cast piece. With such an arrangement, impurities are concentrated into the molten metal at the top of the cast piece. While the molten metal at the top is left, a reduction roll 6 is immersed into the metal and reduces the tip of the solidified layer in such a manner as to check further flowing thereof. In this manner, the molten metal having the impurities concentrated is removed from the top of the cast piece thereby smoothing the top surface of the cast piece.
HORIGUCHI JIYOU
NIIYAMA EISUKE
KODAMA HIDEYO
