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Secondary steel making
Photo of ingot being cast
Ingot being cast from a ladle
Once steel of the correct specification has been made, it is ready for casting. This a way of giving the metal the basic shape that the customer wants. In the past, it was usual to cast the molten steel from a ladle into moulds called ingots.The steel was then shaped after it had solidified in the mould. This required re-heating the ingot to soften it and then rolling in a steel mill.
Continuous Casting
The modern steel industry uses continuous casting, which is more efficient. This technique allows molten steel from the ladle to be cast directly into the basic shape that the customer wants. By adjusting the water-cooled moulds in the continuous caster, steel sections can be produced in the three basic shapes shown on the right: slabs, blooms and billets.

Graphic of slabs, blooms and billets
Part of graphic of continuous casting rollersPart of graphic of continuous casting rollersPart of graphic of continuous casting rollersPart of graphic of continuous casting rollersPart of graphic of continuous casting rollers
Part of graphic of continuous casting rollersPart of graphic of continuous casting rollers
Part of graphic of continuous casting rollersPart of graphic of continuous casting rollersPart of graphic of continuous casting rollers
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Continuos casting of billets seen from above
Question 14

Between the ladle and the water cooled mould is a tundish. This acts as a kind of reservoir for the molten metal. Why do you think this casting reservoir of liquid metal is held in the tundish?

Question 15
Replacing ingot casting by continuous casting of steel has:

(a) reduced energy consumption
(b) increased productivity in the steel industry.

Explain why continuous casting has benefited the industry in these ways.