2. Refractory casting systems

The degradation of molding sands in contact with moving liquid steel does not generally occur under the effect of high dynamic forces, but as a result of repeated thermal shocks, received in the absence of an established and stable static pressure along the conduits that are the filling systems.

This degradation is all the more marked as the casting time of a large part is long by definition. This is why steel foundries of large parts build complete attack systems from elements (ferrules, nozzles or pots) made of silico-aluminous refractory (at Al ₂ O ₃ : 30% approx.), which they obtain commercially (figures and ).