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 includes 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; where the original molten metal is controlled to a semi-solidification temperature range, before being filled up to the product space.

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 includes 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; where the original molten metal is controlled to a semi-solidification temperature range, before being filled up to the product space.

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.

The present disclosure provides a method for controlling an amount of silicon added to ductile cast iron, a method for casting ductile cast iron, and a cast product, which relate to the technical fields of metallurgical and cast iron alloys. The method for controlling an amount of silicon added to ductile cast iron includes smelting ductile cast iron using scrap steel as a raw material. After the scrap steel is melted into molten iron, a copper alloy is added so that the molten iron has a copper equivalent of 0.8% to 1.0%, wherein the copper equivalent is controlled by formula (II). Then, ferrosilicon is added so that the content of silicon added to the molten iron satisfies formula (I).

The present disclosure provides a method for controlling an amount of silicon added to ductile cast iron, a method for casting ductile cast iron, and a cast product, which relate to the technical fields of metallurgical and cast iron alloys. The method for controlling an amount of silicon added to ductile cast iron includes smelting ductile cast iron using scrap steel as a raw material. After the scrap steel is melted into molten iron, a copper alloy is added so that the molten iron has a copper equivalent of 0.8% to 1.0%, wherein the copper equivalent is controlled by formula (II). Then, ferrosilicon is added so that the content of silicon added to the molten iron satisfies formula (I).

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 relates to the technological field of cast iron alloys for automotive and similar applications. Problem to be solved: Presently, structural parts of internal combustion engines are made of gray cast iron alloys that rarely have a tensile strength limit range greater than 350 MPa or vermicular cast iron alloys that do not remain stable at high temperatures. Solution of the problem: It is disclosed a vermicular cast iron alloy that, due to the addition of amounts of Molybdenum, Copper and Tin, with Hot Resistance Factor from 0.5 to 1.7% (HRF=3(% Mo)+1(% Sn)+0.25(% Cu)) achieves a tensile strength limit of 500 to 550 MPa at room temperature and up to 300 C., and a tensile strength limit of 430 to 450 MPa at 400 C.

A spheroidal graphite cast iron comprising, in mass percentage: 2.8% or more and 3.3% or less of carbon; 2.5% or more and 4.0% or less of silicon; 0.32% or more and 0.40% or less of manganese; 0.020% or more and 0.030% or less of phosphorus; 0.020% or more and 0.035% or less of sulfur; 0.030% or more and 0.050% or less of magnesium; 0.010% or more and 0.050% or less in total of lanthanum and cerium; and 0.0020% or more and 0.0050% or less of calcium, with the balance being iron and inevitable impurities.

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.