Hitachi Metals, Ltd.

Kiyoshi Suehara

Toru Iwanaga

Yutaka Morita

Masahide Kawabata

Masafumi Kokubo

Hideaki Nagayoshi

Fumio Obata

Hisashi Yasuda

Toshiki Yoshida

Kouhei Imanishi

Hidenori Takahashi

A casting apparatus for producing a casting by pouring a metal melt into a gas-permeable casting mold by gravity, comprising: a gas-permeable casting mold comprising a cavity including a sprue composed of a tubular portion and a cup portion having a larger diameter than that of the tubular portion to receive the metal melt, a runner constituting a flow path of the metal melt supplied through the sprue, and a product-forming cavity to be filled with the metal melt sent through the runner; a means for pouring the metal melt into the sprue by gravity; a gas-blowing unit comprising a gas-ejecting member to be connected to the sprue; and a mechanism for moving the gas-ejecting member; the gas-ejecting-member-moving mechanism placing the gas-ejecting member at a position just above the tubular portion and not interfering with gravity pouring of the metal melt, and moving it downward for connection to the tubular portion; the gas-blowing unit having blowing a gas to fill the product-forming cavity with the metal melt.

Casting apparatus and method for producing castings using it

A casting apparatus for producing castings using molds each having a sprue, comprising a mold-conveying means for conveying molds each containing a melt poured through the sprue; nozzles each having a gas-introducing opening attachable to and detachable from the sprue; nozzle-attaching/detaching means each moving each nozzle to attach and detach the gas-introducing opening to and from the sprue; moving means for moving the nozzle-attaching/detaching means, such that the nozzle-attaching/detaching means moves following a mold conveyed by the mold-conveying means, while keeping the connection of the gas-introducing opening to the sprue by the nozzle-attaching/detaching means; and a gas supply means connected to each nozzle for supplying a gas to the gas-introducing opening.

Casting apparatus and casting method

The spheroidal graphite cast iron member having a surface layer portion mostly composed of a ferrite phase and having a thickness of at least 1 mm, and an inner portion composed of a pearlite phase and a ferrite phase, the surface layer portion having a ferritization ratio of 70% or more which is larger than that of the inner portion by at least about 15% is produced by (a) pouring a spheroidal graphite cast melt into a casting mold; (b) removing the casting mold by shake-out after the completion of solidification of the melt, while substantially the entire portion of the resulting cast iron product is still at a temperature of its A.sub.1 transformation point or higher; (c) when the temperature difference between the surface layer portion and the inner portion has become 40.degree.-60.degree. C., introducing the cast iron product into a uniform-temperature furnace kept at 750.degree.-900.degree. C., where the cast iron product is held for such a time period as to produce the surface layer portion having a ferritization ratio of 70% or more which is larger than that of the inner portion by at least about 15%; and (d) transferring the cast iron product into a cooling furnace to cool the cast iron product at a cooling speed of 15.degree.-100.degree. C./min.

Spheroidal graphite cast iron member having improved mechanical strength

Growing community of inventors

Moka, Japan

Kiyoshi Suehara