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Click on different parts of the machine to find out about the continuous
Ladles carry molten metal to the tundish, which continuously pours
the liquid into the mould, where it solidifies. The structure of the
tundish gives a constant pouring rate into the mould. The temperature
at which the metal is delivered to the tundish is important. If it is
too hot the solid shell formed by the mould will not be thick enough
and a breakout will occur during secondary cooling. Too cold, and the
metal may freeze in the tundish.
Molten metal is poured from the tundish into the mould, which oscillates
rapidly up and down, to release the metal as it solidifies inwards from
the edges under primary cooling from the mould walls, which may be water
cooled. A powder lubricant is used to prevent the metal from sticking
to the mould, and to remove impurities (slag). An outer shell of solid
passes from the bottom of the mould, surrounding a 'mushy zone', with
the centre remaining liquid.
The solid shell is passed through rollers to take it to a horizontal
path. If the curvature is too great, or the solid shell too thin, a
break out of molten metal through the solid shell could occur at this
point. The speed of the rollers is matched to the pouring rate to keep
the level of the liquid in the mould constant. Secondary cooling by
a water spray thickens the solid shell, and eventually completes solidification.
A torch cutter is used to slice the metal into billets, bloom, or slabs
(depending on the machine), which are further processed to make other
intermediate metallic forms used in manufacturing.