Mould cap for avoiding shrinkage pipe in cast ingot - has radiation-intercepting diaphragm and infrared reflector for returning emitted radiation

摘要

A cap for an open top mould includes a diaphragm for intercepting radiation emitted from the top surface of the liq. metal in the mould and to re-emit radiation back to the surface. A reflector or series of baffles return radiation emitted from the top of the diaphragm. Used as ingot casting. The formation of shrinkage pipe is inhibited in the casting of large metal parts. Metal yield is improved by reducing oxidn. and other chemical effects which occur on exposure of metal to the atmos. during casting and solidification. A roughing vacuum can be created within the mould structure to eliminate convective heat losses from the top of the ingots. The regions adjacent the top of the ingot may be heated with electrodes.