Abstract: The present invention provides tough cast iron and cast iron semi-finished products excellent in workability without heat treatment requiring massive heat energy and long time and a method of production enabling these to be efficiently produced, that is, cast iron of ingredients of white cast iron where particles of spheroidal graphite or flattened graphite are dispersed, cast iron where the ingredients of the white cast iron satisfy, by wt %, (% C)?4.3?(% Si)÷3 and C?1.7% and where the particles of spheroidal graphite are dispersed at a density of 50 particles/mm2 or more, or cast iron where the particles of flattened graphite have a width of 0.4 mm or less and a length of 50 mm or less.

Abstract: A steel product for welding includes the following component: by mass %, C: 0.3% or less, Si: 0.5% or less, Mn: 0.3˜2%, P: 0.03% or less, S: 0.03% or less, Al: 0.3˜5%, O: 0.003˜0.01%, and N: 0.006% or less; wherein the balance is composed of Fe and inevitable impurities; wherein Al-containing oxides having a size of 0.005 to 0.05 ?m are dispersed in steel at a ratio of 1×106/mm2 or more.

Abstract: In a non-oriented electrical steel sheet, Si: not less than 1.0 mass % nor more than 3.5 mass %, Al: not less than 0.1 mass % nor more than 3.0 mass %, Ti: not less than 0.001 mass % nor more than 0.01 mass %, Bi: not less than 0.001 mass % nor more than 0.01 mass %, and so on are contained. (1) expression described below is satisfied when a Ti content (mass %) is represented as [Ti] and a Bi content (mass %) is represented as [Bi]. [Ti]?0.8×[Bi]+0.

Abstract: The present invention provides tough cast iron and cast iron semi-finished products excellent in workability without heat treatment requiring massive heat energy and long time and a method of production enabling these to be efficiently produced, that is, cast iron of ingredients of white cast iron where particles of spheroidal graphite or flattened graphite are dispersed, cast iron where the ingredients of the white cast iron satisfy, by wt %, (% C)?4.3-(% Si)÷3 and C?1.7% and where the particles of spheroidal graphite are dispersed at a density of 50 particles/mm2 or more, or cast iron where the particles of flattened graphite have a width of 0.4 mm or less and a length of 50 mm or less.

Abstract: A continuous casting device for steel of the present invention includes a casting mold for casting a molten steel, a submerged entry nozzle, an electromagnetic stirring device, and an electromagnetic brake device. Further, a curved portion which is curved toward the electromagnetic stirring device is formed at least at a position where the curved portion faces the submerged entry nozzle, on each of the long side walls. Moreover, the horizontal distance between a top of the curved portion and the submerged entry nozzle in plan view is equal to or more than 35 mm and less than 50 mm.

Abstract: A steel product for welding includes the following component: by mass %, C: 0.3% or less, Si: 0.5% or less, Mn: 0.3˜2%, P: 0.03% or less, S: 0.03% or less, Al: 0.3˜5%, O: 0.003˜0.01%, and N: 0.006% or less; wherein the balance is composed of Fe and inevitable impurities; wherein Al-containing oxides having a size of 0.005 to 0.05 ?m are dispersed in steel at a ratio of 1×106/mm2 or more.

Abstract: A high-strength steel sheet includes: 0.03 to 0.20% of C, 0.08 to 1.5% of Si, 0.5 to 3.0% of Mn, 0.05% or less of P, 0.0005% or more of S, 0.008 to 0.20% of acid-soluble Ti, 0.0005 to 0.01% of N, more than 0.01% of acid-soluble Al, and 0.001 to 0.04% of one or both of Ce and La in terms of mass %; and the balance including Fe and inevitable impurities. The ratio of (Ce+La)/acid-soluble Al is equal to or more than 0.1 and the ratio of (Ce+La)/S is in the range of 0.4 to 50 in a mass base, and the density of the number of inclusions, having a circle equivalent diameter of 2 ?m or less, which are present in the steel sheet is equal to or more than 15/mm2.

Abstract: A low-carbon steel slab producing method includes: adding Ti to a molten steel decarbonized to have a carbon concentration of 0.05 mass % or less, and subsequently adding at least one of La and Ce to adjust a constitution, and producing a smelted molten steel; and pouring the smelted molten steel into a casting mold via a tundish; wherein at least one of La and Ce in a total amount of 0.2 to 1.2 times an increased amount of oxygen in the smelted molten steel during contained in the tundish is added to the smelted molten steel in the tundish, so as to obtain a steel slab having inclusions which contain oxides of Ti and at least one of La and Ce as chief components, and so as to make a composition of each of the inclusions have a mass ratio of 0.1 to 0.7, in terms of (La2O3+Ce2O3)÷TiOn (n=1˜2).

Abstract: The present invention provides tough cast iron and cast iron semi-finished products excellent in workability without heat treatment requiring massive heat energy and long time and a method of production enabling these to be efficiently produced, that is, cast iron of ingredients of white cast iron where particles of spheroidal graphite or flattened graphite are dispersed, cast iron where the ingredients of the white cast iron satisfy, by wt %, (% C)?4.3?(% Si)÷3 and C?1.7% and where the particles of spheroidal graphite are dispersed at a density of 50 particles/mm2 or more, or cast iron where the particles of flattened graphite have a width of 0.4 mm or less and a length of 50 mm or less.

Abstract: A quench solidification method, wherein a steel cast strip having a mean grain size 50 ?m or more is prepared and then the steel cast strip is rolled to produce a non-oriented electrical steel sheet having high magnetic flux density in both L and C directions. However the magnetic flux density reduces when the cold reduction rate exceeds 70%. To avoid this problem the non-oriented electrical steel sheet is manufactured with a ratio of at least 4 of the integrated intensity of the {100} plane for a given sample of steel to the integrated intensity of {100} plane for a “random” sample in which crystal grains have random orientations; and a cold reduction rate of the cold-rolling is between 70% and 85%. The superheating degree of the molten steel can be 70° C. or more.

Abstract: A cooling drum for metal cast strip by continuous casting has dimples 40 to 200 ?m in average depth and 0.5 to 3 mm in diameter of circle equivalent formed on a plated peripheral surface of the cooling drum, adjacent to each other at rims of the dimples; and a film, containing oxides of at least one member selected from the group consisting of Ni—W, Ni—Co—W, Cr, Ni—Fe and Ni—Al, is formed on the peripheral surface.

Abstract: The present invention provides tough cast iron and cast iron semi-finished products excellent in workability without heat treatment requiring massive heat energy and long time and a method of production enabling these to be efficiently produced, that is, cast iron of ingredients of white cast iron where particles of spheroidal graphite or flattened graphite are dispersed, cast iron where the ingredients of the white cast iron satisfy, by wt %, (% C)?4.3?(% Si)÷3 and C?1.7% and where the particles of spheroidal graphite are dispersed at a density of 50 particles/mm2 or more, or cast iron where the particles of flattened graphite have a width of 0.4 mm or less and a length of 50 mm or less.

Abstract: Dimples, preferably 40 to 200 ?m in average depth and 0.5 to 3 mm in diameter of circle equivalent, are formed on the peripheral surface of a cooling drum, adjacent to each other at the rims of the dimples; and fine humps (preferably, fine humps 1 to 50 ?m in height and 5 to 200 ?m in diameter of circle equivalent on the surfaces of the dimples and/or fine humps 1 to 50 ?m in height and 30 to 200 ?m in diameter of circle equivalent at the rims of the dimples), fine holes (preferably, fine holes 5 ?m or more in depth and 10 to 200 ?m in diameter of circle equivalent), or fine unevenness (preferably, fine unevenness 1 to 50 ?m in average depth and 10 to 200 ?m in diameter of circle equivalent) are formed at the rims and/or on the indented surfaces of said dimples.

Abstract: Dimples, preferably 40 to 200 ?m in average depth and 0.5 to 3 mm in diameter of circle equivalent, are formed on the peripheral surface of a cooling drum, adjacent to each other at the rims of the dimples; and fine humps (preferably, fine humps 1 to 50 ?m in height and 5 to 200 ?m in diameter of circle equivalent on the surfaces of the dimples and/or fine humps 1 to 50 ?m in height and 30 to 200 ?m in diameter of circle equivalent at the rims of the dimples), fine holes (preferably, fine holes 5 ?m or more in depth and 10 to 200 ?m in diameter of circle equivalent), or fine unevenness (preferably, fine unevenness 1 to 50 ?m in average depth and 10 to 200 ?m in diameter of circle equivalent) are formed at the rims and/or on the indented surfaces of said dimples.

Abstract: A quench solidification method, wherein a steel cast strip having a mean grain size 50 &mgr;m or more is prepared and then the steel cast strip is rolled to produce a non-oriented electrical steel sheet having high magnetic flux density in both L and C directions. However the magnetic flux density reduces when the cold reduction rate exceeds 70%. To avoid this problem the non-oriented electrical steel sheet is manufactured with a ratio of at least 4 of the integrated intensity of the {100} plane for a given sample of steel to the integrated intensity of {100} plane for a “random” sample in which crystal grains have random orientations; and a cold reduction rate of the cold-rolling is between 70% and 85%. The superheating degree of the molten steel can be 70° C. or more.

Abstract: Dimples, preferably 40 to 200 &mgr;m in average depth and 0.5 to 3 mm in diameter of circle equivalent, are formed on the peripheral surface of a cooling drum, adjacent to each other at the rims of the dimples; and fine humps (preferably, fine humps 1 to 50 &mgr;m in height and 5 to 200 &mgr;m in diameter of circle equivalent on the surfaces of the dimples and/or fine humps 1 to 50 &mgr;m in height and 30 to 200 &mgr;m in diameter of circle equivalent at the rims of the dimples), fine holes (preferably, fine holes 5 &mgr;m or more in depth and 10 to 200 &mgr;m in diameter of circle equivalent), or fine unevenness (preferably, fine unevenness 1 to 50 &mgr;m in average depth and 10 to 200 &mgr;m in diameter of circle equivalent) are formed at the rims and/or on the indented surfaces of said dimples.