PURPOSE: To reduce the time and man-hour from the preparation of a casting mold to the end of casting and to obtain precision casting dies for multiple kinds and small-quantity production by working directly a boron nitride ingot to form the casting mold and casting the dies under specific conditions.
CONSTITUTION: The boron niride ingot is machined by allowing for the shrinkage of the cast steel which is a die material to form a drag. The drag is installed in a calcination furnace where the drag is gradually heated and the moisture is gradually evaporated away therefrom. The drag is taken out of the calcination furnace while the drag temp. is 500W900°C and a carbon dioxide cope provided with an exothermic sleeve is installed thereto and is clamped. A molten steel having cast steel components is poured into the mold to cast the die. The temp. in the casting stage of the casting mold varies with the shape of the die. The molten steel is liable to solidify and a mis-run arises when the temp. is below 500°C. The molten steel solidifies at a low rate and an increase in the amt. of a riser is necessitated, thus the yield is decreased if the temp. exceeds 900°C.
HAMADA HIKARI
YOSHIKAWA SHIYOUICHI
| JPS4940124A | 1974-04-15 | |||
| JPS4843649A | 1973-06-23 | |||
| JPS5623348A | 1981-03-05 |