|
It is important to reduce to a minimum the amount and
position of pipe cavitation and to locate it where it
will be least harmful in the solidified Ingot. To achieve
this, it is necessary to limit the chilled area of the
ingot to the final body shape required and supply an
additional quantity of metal to compensate for the liquid
and solidification shrinkage within the chilled volume,
delivered as required by gravitation and atmospheric
forces. This extra metal, known as the feeder head, must
be placed above the ingot chill area and be of a volume
in excess of that required to satisfy the total shrinkage
of metal by a satisfactory safety margin.
LITEFAX refractory, highly insulating tiles maintain
the ingot head in a liquid state until the whole of
the body metal of the ingot has solidified. The feeder
head should then contain all unacceptable segregation
of such elements as sulphur, phosphorus and carbon. |
