PRODUCTION OF CONTINUOUSLY CAST INGOT HAVING GOOD SURFACE CHARACTERISTIC

摘要

PURPOSE:To prevent the surface flawing of a continuously cast ingot or the generation of the surface flaw during rolling of the ingot in a continuous casting device for a steel by oscillating grids for supporting the ingot provided right under a casting mold at a high speed. CONSTITUTION:The molten steel 2 poured into the casting mold 1 of the continuous casting device is extracted of heat from the mold walls and is drawn while a solidified shell 3 is formed. the ingot right under the mold is directly cooled by the sprays from cooling medium spraying nozzles 5 while the surfaces thereof are supported by the supporting grids 4. The solidification progresses in such a manner. The grids 4 are oscillated at the high speed of about 50Hz and are intermittently brought into contact with the ingot to support the ingot to the extent of preventing bulging thereby preventing the decrease of the cooling rate as a result of shielding the spray cooling. The generation of the surface flaw owing to the formation of th coarse austenite grains in the surface layer part of the ingot and the generation of the surface flaw during hot rolling are thus prevented.