PURPOSE: To obtain the cast iron having good mechanical characteristics, particularly in fatigue resistance by subjecting a thin casting of spheroidal graphite cast iron to knock-out, thereafter immediately subjecting it to heat treatment at a prescribed temp. for a short time and executing cooling at a regulated cooling rate.
CONSTITUTION: The molten metal having the compsn. of spheroidal graphite cast iron is poured into a mold and knock out is executed at the time when the almost whole of the casting is so far in the state of the A3 transformation point or above; the casting is immediately charged to the soaking area in a continuous furnace held to the tem. of the A3 transformation point or above. Then, in order to decompose cementite in the matrix, the casting is held for ≤30min, is thereafter transferred to the cooling area in the above furnace and is cooled it the cooling rate of attaining the ferritization of the matrix. In this way, the cast iron in which fine voids are not present substantially between the graphite grains and the ferrite matrix can be obtd.
NAGAYOSHI HIDEAKI
NAKANO EIJI
| JPS5789423A | 1982-06-03 | |||
| JPS62164819A | 1987-07-21 | |||
| JPS62256914A | 1987-11-09 | |||
| JPS5665963A | 1981-06-04 |