The present invention provides a casting method and cast product of spherical graphite cast iron, in which, even with a small modulus, there is no chill, the spherical graphite in the tissue is further made ultrafine, the dispersion of the particle diameter is small, and the number of the particles is several times that of the conventional one in the as cast state where heat treatment is not carried out.

A casting method of a spherical graphite cast iron comprised from, a melting process, a spheroidizing treatment process, an inoculation process, and a casting process, in which the original molten metal after the inoculation process is poured and filled up to a product space through a gate of a metal mold; wherein the original molten metal before being filled up to the product space is controlled to a semi-solidification temperature range. An amount of nitrogen at the time of melting of the (cast iron?) is controlled to 0.9 ppm (mass) or less. The casting process is carried out by controlling the pouring temperature and the heat removal amount from the molten metal so that the temperature of the raw material when passing through the gate becomes a substantially constant temperature between an eutectic temperature and a liquidus temperature.

A ductile iron composition including, by weight: about 3.1% to about 3.6% C; about 3.5% to about 4.0% Si; about 0.035% to about 0.050% Mg; about 0.001% to about 0.004% Ce; up to about 0.005% Sb; about 0.008% to about 0.016% S; up to about 0.04% P; up to about 0.3% Mn; and balance iron and incidental impurities;
The ductile iron composition includes a ratio of Sb/Ce greater than or equal to about 1.25, has a ferritic microstructure and graphite nodules, and greater than about 65% of the graphite nodules having a highly spherical geometry. A method and apparatus for forming a ductile iron composition are also disclosed.

The present invention provides a die-cast product producing method and a spheroidizing agent of a spherical graphite cast iron with ultrafine spherical graphite by simple method and good reproducibility.

The present invention provides a sand mold producing method and a spheroidizing agent capable of producing an ultrafine spherical graphite cast iron with good reproducibility even in a sand mold thin walled spherical graphite cast iron, which has solidification cooling conditions equivalent to those of a metal mold.

The present invention provides a producing method of a die-cast product of a spherical graphite cast iron using a spheroidizing agent, in which a C amount is 0.5 mass % or more, a total nitrogen amount N is 150 ppm (by mass) or less, and a nitrogen amount generated during melting is 15 ppm (by mass) or less, in a producing method of a sand mold cast product of a thin walled spherical graphite cast iron having a melting process, a spheroidizing process, an inoculation process, and a casting process.

The invention provides a method for increasing the quality of graphite balls. The method comprises melting molten iron in an electric furnace, increasing the sulfur content in the molten iron during the melting process, and adding rare earth in the electric furnace or in a nodularizing ladle; after the molten iron is completely melted, pouring the molten iron into the nodularizing ladle and nodularizing; and after nodularization, adding ferromanganese to a transfer ladle. In the present invention, sulfur is added to molten iron in advance, and rare earth is added to a nodularizing ladle previously, so that a large number of dispersed rare earth sulfide particles are formed in the molten iron during the nodularization process. Rare earth sulfide particles serve as the nuclei of graphite crystallization to increase the number of graphite balls, and improve the roundness of graphite balls.

An inoculant for the manufacture of cast iron with spheroidal graphite is disclosed, the inoculant has a particulate ferrosilicon alloy having between 40 and 80% by weight of Si; 0.02-8% by weight of Ca; 0-5% by weight of Sr; 0-12% by weight of Ba; 0-15% by weight of rare earth metal; 0-5% by weight of Mg; 0.05-5% by weight of Al; 0-10% by weight of Mn; 0-10% by weight of Ti; 0-10 by weight of Zr; the balance being Fe and incidental impurities in the ordinary amount, wherein the inoculant additionally contains, by weight, based on the total weight of inoculant: 0.1 to 15% of particulate Bi.sub.2S.sub.3, and optionally between 0.1 and 15% of particulate Bi.sub.2O.sub.3, and/or between 0.1 and 15% of particulate Sb.sub.2O.sub.3, and/or between 0.1 and 15% of particulate Sb.sub.2S.sub.3, and/or between 0.1 and 5% of particulate Fe.sub.3O.sub.4, Fe.sub.2O.sub.3, FeO, or a mixture thereof, and/or between 0.1 and 5% of one or more of particulate FeS, FeS.sub.2, Fe.sub.3S.sub.4, or a mixture thereof, a method for producing such inoculant and use of such inoculant.

A method for treating molten iron includes applying a metal treatment agent to molten iron; and stirring the molten iron using a rotary device comprising a rotor head. The rotary device can be resistant to corrosion and thermal shock, and thereby permit efficient application of metal treatment agents.

A rotary device and methods for treating molten metal, a tubular sleeve for said rotary device and the use of said rotary device in the treatment of molten metal. The rotary device comprises: a tubular sleeve comprising a rotor head at one end, the rotor head comprising a gas outlet for dispersing gas into molten metal; and a hollow shaft extending inside the tubular sleeve such that at least a portion of the hollow shaft is enclosed by the tubular sleeve, wherein the hollow shaft is fluidly connected to the gas outlet of the rotor head, the tubular sleeve is formed from a refractory material that is resistant to corrosion and thermal shock, and the hollow shaft is formed from a material comprising graphite. A first method comprises: applying a layer of synthetic slag material onto an exposed surface of the molten metal; and stirring the molten metal using a rotary device comprising a rotor head, such that the molten metal flows past the layer of synthetic slag material. A second method comprises: applying a metal treatment agent to molten metal; stirring the molten metal using a rotary device comprising a rotor head; and discharging gas into the molten metal through the rotor head.

The present invention relates to a particulate inoculant for treating liquid cast-iron, comprising, on the one hand, support particles made of a fusible material in the liquid cast-iron, and on the other hand, surface particles made of a material that promotes the germination and the growth of graphite, disposed and distributed in a discontinuous manner at the surface of the support particles, the surface particles presenting a grain size distribution such that their diameter d50 is smaller than or equal to one-tenth of the diameter d50 of the support particles.

An inoculant for manufacturing cast iron with lamellar, compacted or spheroidal graphite is disclosed. The inoculant has a particulate ferrosilicon alloy 40 and 80% by weight of silicon, 0.5 and 5% by weight of calcium and/or strontium and/or barium, 0 and 10% by weight of rare earths, 0 and 5% by weight of magnesium, less than 5% by weight of aluminium, 0 and 10% by weight of manganese and/or zirconium, and the balance being iron, wherein the inoculant additionally contains 0.1 to 10% by weight of particulate bismuth oxide particles and optionally 0.1 and 10% by weight of one or more particulate metal sulphides and/or one or more particulate iron oxides, where the particulate bismuth oxide is mixed or blended with the ferrosilicon particles, or is simultaneously added to cast iron together with the particulate ferrosilicon particles.

An inoculant for the manufacture of cast iron with lamellar, compacted or spheroidal graphite is disclosed. The inoculant has a particulate ferrosilicon alloy having about 40 to 80 wt % silicon, about 0.1 to 10 wt % calcium, 0 and 10% by weight of rare earths, for example cerium and/or lanthanum, and up to 5 wt % aluminium the balance being iron and incidental impurities in the ordinary amount, wherein the inoculant additionally has 0.1 to 10 wt %, based on the total weight of inoculant, antimony oxide where said antimony oxide is in particulate form and is mixed or blended with the ferrosilicon alloy particles, or is simultaneously added to cast iron together with the particulate ferrosilicon alloy particles.