Patent ID: 7891406

Claim:
Ingot mold for casting ultra thin (20-50 mm) steel slabs, with casting speed between 6 and 16 m/min, thus defining a longitudinal plane of symmetry (X) and a cross-sectional plane of symmetry (Y), reciprocally orthogonal, comprising a through cavity with an entrance section and an exit section of the steel slab, the cavity surface consisting of two first walls arranged reciprocally facing two opposite sides of the longitudinal plane of symmetry (X) and two second narrow, flat, rectangular walls located parallel to the cross-sectional plane of symmetry (Y), wherein the first and second walls form four longitudinal corners, wherein the first walls have a concave central zone, with concavity facing the longitudinal plane of symmetry, portions of wall rectilinear to its ends and intermediate convex connecting portions, with convexity facing the longitudinal plane of symmetry (X), in which the connecting portions(S) and the concave central zone determine inflection points (P′) and where the straight portions of wall (R) as well as the connecting portions (S) determine connecting points (P) wherein a ratio between a length (d)/(l) is between 10 and 60% and a ratio (h)/(f) is between 10% and 60% wherein (d) is a length of the connecting portion measured in projection view on the longitudinal plane of symmetry (X), length (l) is a distance between two symmetrical connecting points relative to the cross-sectional plane of symmetry (Y), measured in projection view on the plane of symmetry (X), (h) is a distance between the connecting point P and the inflection point P′ measured in projection view on the cross-sectional plane of symmetry Y; (f) is a distance between point P′ and the tangent to the concave zone in the maximum point of concavity (P″) measured in projection view on the plane of symmetry Y and wherein a variation of the radii of curvature in the concave zone results in an inclination of the first walls relative to the longitudinal plane of symmetry (X), of from 0 to 7 degrees and wherein (l) has a value between 750 and 1500 mm and (f) is between 15 and 100 mm at the entrance section.