Mould powders
The primary functions of the mould flux are:
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To form a liquid slag pool which protects the surface of the steel from oxidation
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To provide thermal insulation which prevents the surface of the steel from freezing
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To lubricate the newly-formed shell
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To control the horizontal heat transfer between shell and mould
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To absorb inclusions from the steel
Powders are continuously added to the mould and form 4 layers over the steel surface:
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Raw powder layer (Contact atmosphere)
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Sintered layer
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Mushy layer (mixture of slag globules and carbon particles)
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A pool of liquid slag
