Rolls are
tailormade products and therefore need careful
production planning. Rolls are cast in chiller
mould with a controlled allowance for contraction
and machining. It is therefore necessary to have
a mould of the desired size. A new mould is required
to be made if oue is not available. After obtaining
a order from a customer and a drawing for the
reequired rolls, a method drawing for casting
is made, according to which the mould for casting
of the rolls is made. Melting of metal is carried
out in any of the several induction melting units
available as per requirement of metels. The melting
charges are selected as per required chemistry
of metal. Upon melting, samples are analyzed and
necessary adjustments for various alloying elements
made through additions of Ferro-alloys. Fracture
tests are made and temperature measured to control
the same through Immersion Pyrometeres. Metal
is poured in the moulds through geared ladles
of various capacities in pre-determined time to
ensure clean metal in the mould.
After casting, the mould in alowed
to cool for a pre-determined period of time before
removing the cast roll from the mould. Then the
cast roll is examined for casting defects and
dimensional deviations, before sending the same
for machining.
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