1. Liquid metal processing

1.1 Crucible melting

This technique, discovered in the 18th century, has survived to the present day. It does not allow for a refining operation to remove impurities such as sulfur or phosphorus. The crucible is reductive, but acidic, consisting of a mixture of graphite and siliceous earth. This calls for a rigorous choice of raw materials, which, if the melting process is well managed, ensures a much-appreciated consistency of quality.

The charge consists of Swedish iron, alloying elements and cast iron. The difficulty lies in adjusting...