PURPOSE: To improve heating efficiency and quality of steel plate by defining the concentration of oxygen in a combustion gas for heating an edge heater in the direct rolling of a cast billet with continuous casting.
CONSTITUTION: When a cast billet 19 which is cut after continuous casting is heated to a proper temperature for rolling, edges of the cast billet is heated by blowing coke gas, ain and oxygen gas which are made into a mixed gas with an introducing pipe 13 for a combustion gas from a burner 12 into edge heaters 11. At this time, oxygen quantity in the combustion gas is controlled with a control device 18 for oxygen gas quantity and is always made oxygen gas quantity in the combustion gas so as to be 23-30%. By this way, the edges of the cast billet 19 before rolling can be heated to the temperature at that stable rolling can be done and quality of the steel plate can be improved.
UCHINO KAORU
SHIROYAMA AKIRA
ISHIGUCHI YUKIO
