Hitachi Metals, Ltd.

Lin Wang

Toru Iwanaga

Yoshimasa Fujii

Masahide Kawabata

Kentaro Fukumoto

Hiroyuki Watanabe

A method for producing a casting using a gas-permeable casting mold comprising a cavity composed of a production cavity and a flow path, the flow path comprising a sprue through which a gravity-poured melt flows downward, and a runner connecting the production cavity to the sprue, comprising gravity-pouring a metal melt in a volume smaller than that of the entire cavity and larger than that of the production cavity into the gas-permeable casting mold; supplying a gas through the sprue to push the metal melt in the flow path, thereby pushing the metal melt upward in the production cavity, so that the production cavity is filled with the metal melt; in a hypothetical equilibrium state in which a hypothetical liquid fills the production cavity by the supplied gas, setting the volume of the metal melt to be poured to be equal to the volume of the hypothetical liquid, such that the surface height hs of the hypothetical liquid remaining in the flow path after filling the production cavity, the height hof the lowest ceiling portion of the runner, and the height hof a point at which a ceiling of the runner is connected to the sprue, meet the relation of h&#x3e;hs&#x3e;h

Production method of castings and gas-permeable casting mold

A method for producing a casting by pouring a metal melt by gravity into a gas-permeable casting mold having a cavity comprising at least a sprue, a runner and a product-forming cavity, comprises pouring a metal melt into a desired cavity portion including the product-forming cavity through the sprue, the melt being in a volume smaller than the volume of an entire cavity of the gas-permeable casting mold and substantially equal to the volume of the desired cavity portion; supplying a gas to the desired cavity portion through the sprue before the desired cavity portion is filled with the poured melt, so that the melt fills the desired cavity portion and solidifies; the gas being supplied from a gas-blowing nozzle fit into the sprue.

Method for producing castings, casting apparatus, and gas-blowing nozzle used in casting apparatus

A spheroidal graphite cast iron having (a) a composition comprising by mass 3.4-4% of C, 1.9-2.8% of Si, 0.02-0.06% of Mg, 0.2-1% of Mn, 0.2-2% of Cu, 0-0.1% of Sn, 0.85-3% of (Mn+Cu+10&#xd7;Sn), 0.05% or less of P, and 0.02% or less of S, the balance being Fe and inevitable impurities, and (b) a duplex matrix structure comprising by area 2-40% of fine ferrite phases and 60-98% of fine pearlite phases, the maximum length of the ferrite phases being 300 &#x3bc;m or less, and (c) the pearlite phases being formed around graphite particles dispersed in the duplex matrix structure.

Spheroidal graphite cast iron having excellent strength and toughness and its production method

A method for producing a casting by pouring a metal melt by gravity into a gas-permeable casting moldhaving a cavity comprising at least a sprue, a runnerand a product-forming cavity, comprising pouring a metal melt into a desired cavity portionincluding the product-forming cavity through the sprue, the melt being in a volume substantially equal to the volume of the desired cavity portion; supplying a gasto the desired cavity portion through the sprue before the desired cavity portion is filled with the poured melt, so that the melt fills the desired cavity portion; and cooling a portion of the melt in contact with the gas directly or indirectly by watersupplied from outside the gas-permeable casting mold, simultaneously with, during or after supplying the gas, thereby solidifying the melt.

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Moka, Japan

Lin Wang