VERTICAL TYPE CONTINUOUS CASTING METHOD OF LARGE CROSS SECTION CAST SLAB FOR THICK STEEL PLATE

摘要

PPROBLEM TO BE SOLVED: To provide a vertical type continuous casting method with which the grain diameter of equiaxed crystal generated at the center part of a large section cast slab for thick steel plate having ≥380 mm thickness of the cast slab, is made fine to attain improvement in the toughness. PSOLUTION: When the large section cast slab for thick steel plate having ≥380 mm thickness of the cast slab, is cast at ≤0.2 m/min casting speed with the vertical type continuous caster, the position of an immersion nozzle 2 for pouring molten steel into a mold 1 is shifted to the center of the mold and set to the substantial center part to the thickness of the cast slab to cast the molten steel. In this way, the molten steel pouring flow is uniformly collided with the standard surface side and the shifting surface side and the many nuclei of the equiaxed crystals are generated and the grain diameters of the equiaxed crystals are made fine and the toughness can be improved. PCOPYRIGHT: (C)2007,JPO&INPIT