A spheroidal graphite cast iron meeting N.sub.(5-)≥250, N.sub.5-20)/N.sub.(5-)≥0.6, and N.sub.(30-)/N.sub.(5-)≤0.2, wherein N.sub.(5-) represents the number (/mm.sup.2) of graphite particles having equivalent-circle diameters of 5 μm or more, N.sub.(5-20) represents the number (/mm.sup.2) of graphite particles having equivalent-circle diameters of 5 μm or more and less than 20 μm, and N.sub.(30-) represents the number (/mm.sup.2) of graphite particles having equivalent-circle diameters of 30 μm or more, among graphite particles observed in an arbitrary cross section of at least 1 mm.sup.2.

A casing component is configured to form part of a flow path in a turbine. The casing component includes a base made of nodular cast iron, and a repaired region in the base. The repaired region includes a butter layer applied on the base and a fill layer applied on the butter layer.

Additive for the thermochemical treatment of molten iron in order to separate, distribute, agglomerate, precipitate, spheroidize and/or crystallize combined, solvated and/or colloidal carbon present in molten iron in the liquid state into graphite in its hexagonal diamond or Lonsdaleite form, in order to produce ductile, nodular, spheroidal, vermicular, coral, spheroidized or grey iron with superior mechanical properties, iron with high metal yield and zero contraction during casting; the additive comprises two or more elements in the metallic state selected from the S-block of periods 2 to 7 of the periodic table of elements; and two or more elements in the metallic state selected from F-block of periods 6 to 7 of the periodic table of elements. The additive makes it possible to produce cast iron parts with Type I and II spheroidal graphite in hexagonal diamond or Lonsdaleite form as per the ASTM-A247 standard.

Additive for the thermochemical treatment of molten iron in order to separate, distribute, agglomerate, precipitate, spheroidize and/or crystallize combined, solvated and/or colloidal carbon present in molten iron in the liquid state into graphite in its hexagonal diamond or Lonsdaleite form, in order to produce ductile, nodular, spheroidal, vermicular, coral, spheroidized or grey iron with superior mechanical properties, iron with high metal yield and zero contraction during casting; the additive comprises two or more elements in the metallic state selected from the S-block of periods 2 to 7 of the periodic table of elements; and two or more elements in the metallic state selected from F-block of periods 6 to 7 of the periodic table of elements. The additive makes it possible to produce cast iron parts with Type I and II spheroidal graphite in hexagonal diamond or Lonsdaleite form as per the ASTM-A247 standard.

A diesel engine piston is cast in one piece and consists of almost fully pearlitic cast iron with spheroidal graphite as the piston material. Such a piston is used for “light vehicle” diesel engines, “heavy duty” diesel engines and “large bore” diesel engines.

A spheroidal graphite cast iron having a chemical composition of: C: 3.0% to 4.0%, Si: 2.0% to 2.4%, Cu: 0.20% to 0.50%, Mn: 0.15% to 0.35%, S: 0.005% to 0.030%, Mg: 0.03% to 0.06%, each by mass, and the balance being Fe and inevitable impurities, where Mn and Cu are contained at 0.45% to 0.75% in total; and a structure in which a ferrite layer encloses spheroidal graphite crystallized out in a matrix of pearlite. Part of the pearlite is extended from the matrix side to the spheroidal graphite side to divide the ferrite layer at one or more areas.

A spheroidal graphite cast iron having a chemical composition of: C: 3.0% to 4.0%, Si: 2.0% to 2.4%, Cu: 0.20% to 0.50%, Mn: 0.15% to 0.35%, S: 0.005% to 0.030%, Mg: 0.03% to 0.06%, each by mass, and the balance being Fe and inevitable impurities, where Mn and Cu are contained at 0.45% to 0.75% in total; and a structure in which a ferrite layer encloses spheroidal graphite crystallized out in a matrix of pearlite. Part of the pearlite is extended from the matrix side to the spheroidal graphite side to divide the ferrite layer at one or more areas.

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.

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.

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.