Ladle Metallurgy

Ladle metallurgy, also called ladle refining or secondary steelmaking, is the set of processes carried out on molten steel after it leaves a primary steelmaking furnace but before it is cast, using the ladle itself as a vessel for further heating, stirring, alloying and impurity removal rather than treating the ladle as a simple container for transport. Techniques such as ladle furnace reheating with electric arc electrodes, vacuum degassing to remove dissolved hydrogen and other gases, and inert-gas stirring to float out nonmetallic inclusions were developed and progressively combined through the middle decades of the twentieth century as steelmakers sought tighter control over a heat's final chemistry and cleanliness than a primary furnace alone could deliver. Ladle metallurgy is now a standard intermediate stage in virtually all modern steel production, letting mills produce the narrow, exacting compositions and very low impurity levels that automotive, pipeline and other demanding steel grades require.