Patent ID: 6857465

Claim:
A process for producing a continuously cast primary product, having a thickness of the primary product D>100 mm and a width of the primary product B=2700 mm to 3500 mm at a casting rate v c <2 m/min in a continuous-casting plant, comprising: introducing molten material of the primary product via a submerged nozzle into a mold, wherein the mold is formed with opposite wide side walls and opposite narrow side walls, allowing the primary product to partially solidify in the mold to have a liquid core and a solidified strand shell, continuously withdrawing the primary product from the permanent mold and permitting it to cool, causing the molten material of the primary product to leave the submerged nozzle through opposite outlet openings with a momentum which is directed toward the narrow side walls of the mold, and for causing a defined width:thickness ratio of the primary product, as a function of the ratio of the velocity of the molten material in the core cross section of the submerged nozzle (v k ) to the casting rate (v c ), by selecting design values for the width (b) of the submerged nozzle and the height (h) of the lateral outlet opening of the submerged nozzle such that a uniform strand shell is formed in the casting direction and peripheral direction along the wide side walls and narrow side walls of the mold and wherein the submerged nozzle in relation to the mold satisfies the following conditions h B = 9 5 ⁢ ψ + 1 5 ⁢ D B and b h = 1.9 - 2.0 and a numerical ratio ψ, which sets the relationship of the velocity of the molten material in the core cross section of the submerged nozzle (v k ) to the casting rate (v c ), is determined according to the following condition ψ = 0.1 ⁢ ⁢ ( B D ) - 0.7 in which: B=width of the primary product (mm) D=thickness of the primary product (mm) b=width of the submerged nozzle (mm) h=height of the lateral outlet opening of the submerged nozzle (mm) ψ=numerical ratio (no dimensions).