GENERAL DESCIRPTION OF CONTINUOUS CASTING PROCESS: -
Continuous Casting is a process of casting without interruption. Liquid steel form the converter is taken to the Argon Rising Unit. Argon is blown into the ladle. This homogenizes the temperature and composition of the molten steel. Aluminum may be added to it to reduce oxygen content. Ferro alloy are added are for trimming addition.
The molten steel in the ladle is then delivered to a reservoir above the continuous casting machine called a tundish. The flow of steel from the tundish into one or more open-ended, water-cooled copper mould is controlled by a stopper rod or a slide gate.
To initiate a cast, a dummy bar is inserted into the mould and sealed so that the initial flow of steel is contained in the mould and a solid skin is formed. After the mould has been filled to desired height, the dummy bar is gradually withdrawn at the same rate at which casting is done.
The initial liquid steel solidifies on a suitable attachment of the dummy bar so that the cast stand can be withdrawn through the machine. Solidification of a shell begins immediately at the surface of the copper mould and the casting speed is such that the shell thickness is capable of withstanding the pressure of the molten core upon exiting from the copper mould.
To prevent sticking of the frozen shell to the copper mould, the mould is oscillated during the casting operation and a lubricant is added to the mould, the strand is mechanically supported by rolls below the mould where secondary cooling is achieved by spraying cooling water or air mist onto the strand surface to complete the solidification process. After the stand has fully solidified, it is cut into desired length by cut off torch (normally an oxy-acetylene torch), which moves along with the stand. This final portion for disengagement and storage of the dummy bar.
MODIFIED SLAB CASTING MACHINE