SECONDARY COOLING METHOD FOR CONTINUOUSLY CAST SLAB

摘要

In a secondary cooling of a continuously cast slab by arranging three or more spray nozzle rows of plural spray nozzles in a widthwise direction of the slab and symmetrically with respect to a widthwise central line of the slab and supplying a cooling water and a compressed air to the spray nozzles, when a flow rate of the cooling water sprayed through the spray nozzle is less than a lower limit volumetric flow rate of a controllable range in the flow rate of the cooling water at the spray nozzle, the supplying of the cooling water is stopped sequentially from both sides of the three of more spray nozzle rows, while the compressed air is supplied to the spray nozzles stopping the supplying of the cooling water at a standard state volumetric flow rate of 5 times or higher with respect to an upper volumetric flow rate in a controllable range of the flow rate of the coolinmg water in these spray nozzles.