METHOD AND DEVICE FOR PRODUCING CONTINUOUSLY CAST STEEL SLABS

摘要

Continuously cast products (12) are often provided with surface defects such as oscillation marks (17) and other non-homogeneous structures in the cast state thereof during production in a casting die (11) of a continuous casting plant (10). Defects which render a strip useless for superior applications also frequently occur on the strip surface during subsequent milling of the slab (12") into a strip. The aim of the invention is to minimize said defects and provide the rolling mill with a slab (12") having a desired preliminary profile and an improved near-surface structure. Said aim is achieved by arranging a reducing roll stand (30) in the area of the bending rolls or straightening driver rolls (24) within the continuous casting plant (10). Said reducing roll stand (30) allows the cast billet (12) to be deformed in a specific manner at an early point in time while still having a high temperature and providing a high energy yield after being completely hardened such that the depth of the existing oscillation marks (17) on the cast billet surface (16) is reduced, the finely crystalline edge layer (18) is enlarged as a result of the energy being released which is introduced into the reducing billet (12') during said deformation process, and increased recrystallization occurs and the grains in the deformed edge zone (19) of the slab (12") are refined during the subsequent thermal treatment in a holding furnace (40).