Abstract: Heat resistant spheroidal graphite cast iron having an improved high temperature tensile strength includes carbon (C) in a range of 3.2-3.4 wt %, silicon (Si) in a range of 4.3-4.8 wt %, manganese (Mn) in a range of 0.2-0.3 wt %, molybdenum (Mo) in a range of 0.8-1.0 wt %, vanadium (V) in a range of 0.4-0.6 wt %, chrome (Cr) in a range of 0.2-0.4 wt %, niobium (Nb) in a range of 0.2-0.4 wt %, inevitable impurities, and a remainder of iron (Fe) based on a total weight of the heat resistant spheroidal graphite cast iron. The heat resistant spheroidal graphite cast iron further includes barium (Ba) in a range of 0.0045-0.0075 wt %. A content ratio of chrome (Cr) and barium (Ba) (Cr/Ba) is in a range from about 26 to about 89.

Abstract: A spheroidal graphite cast iron for a component of an engine exhaust system includes carbon ranging from about 3.0 wt % to about 3.4 wt %, silicon ranging from about 4.2 wt % to about 4.5 wt %, manganese ranging from about 0.1 wt % to about 0.3 wt %, sulfur ranging from about 0.002 wt % to about 0.01 wt %, phosphorous in a range equal to or less than about 0.05 wt %, magnesium ranging from about 0.035 wt % to about 0.055 wt %, molybdenum ranging from about 0.9 wt % to about 1.2 wt %, nickel ranging from about 0.2 wt % to about 0.5 wt %, vanadium ranging from about 0.4 wt % to about 0.6 wt %, niobium ranging from about 0.1 wt % to about 0.4 wt %, cerium ranging from about 0.005 wt % to about 0.01 wt %, aluminum ranging from about 0.003 wt % to about 0.007 wt %, and a remainder of iron.

Abstract: The present disclosure relates to a manufacturing method of high-strength flake graphite cast iron, the high-strength flake graphite cast iron manufactured by the method, and an engine body including the cast iron, and more particularly, to flake graphite cast iron and a manufacturing method thereof, wherein the flake graphite cast iron has a uniform graphite shape and low probability of forming chill and has high tensile strength of at least 350 MPa and excellent workability and fluidity by controlling the content of manganese (Mn) and a trace of strontium (Sr), which are included in the cast iron, within a specific ratio.

Abstract: Heat resistant spheroidal graphite cast iron having an improved high temperature tensile strength includes carbon (C) in a range of 3.2-3.4 wt %, silicon (Si) in a range of 4.3-4.8 wt %, manganese (Mn) in a range of 0.2-0.3 wt %, molybdenum (Mo) in a range of 0.8-1.0 wt %, vanadium (V) in a range of 0.4-0.6 wt %, chrome (Cr) in a range of 0.2-0.4 wt %, niobium (Nb) in a range of 0.2-0.4 wt %, inevitable impurities, and a remainder of iron (Fe) based on a total weight of the heat resistant spheroidal graphite cast iron. The heat resistant spheroidal graphite cast iron further includes barium (Ba) in a range of 0.0045-0.0075 wt %. A content ratio of chrome (Cr) and barium (Ba) (Cr/Ba) is in a range from about 26 to about 89.

Abstract: A spheroidal graphite cast iron for a component of an engine exhaust system includes carbon ranging from about 3.0 wt % to about 3.4 wt %, silicon ranging from about 4.2 wt % to about 4.5 wt %, manganese ranging from about 0.1 wt % to about 0.3 wt %, sulfur ranging from about 0.002 wt % to about 0.01 wt %, phosphorous in a range equal to or less than about 0.05 wt %, magnesium ranging from about 0.035 wt % to about 0.055 wt %, molybdenum ranging from about 0.9 wt % to about 1.2 wt %, nickel ranging from about 0.2 wt % to about 0.5 wt %, vanadium ranging from about 0.4 wt % to about 0.6 wt %, niobium ranging from about 0.1 wt % to about 0.4 wt %, cerium ranging from about 0.005 wt % to about 0.01 wt %, aluminum ranging from about 0.003 wt % to about 0.007 wt %, and a remainder of iron.

Abstract: The present disclosure relates to a manufacturing method of high-strength flake graphite cast iron, the high-strength flake graphite cast iron manufactured by the method, and an engine body including the cast iron, and more particularly, to flake graphite cast iron and a manufacturing method thereof, wherein the flake graphite cast iron has a uniform graphite shape and low probability of forming chill and has high tensile strength of at least 350 MPa and excellent workability and fluidity by controlling the content of manganese (Mn) and a trace of strontium (Sr), which are included in the cast iron, within a specific ratio.

Abstract: A vibration control apparatus using a water tank, which is installed at the uppermost floor of a tall building, the water tank being formed at the inner wall surface thereof with horizontal protrusions. In order to improve a vibration attenuation rate in a horizontal direction within the water tank, the water tank is installed with vertical wire meshes therein, and the horizontal protrusions serve to improve a vibration attenuation rate in a vertical direction.