Area of Invention
Materials technology and manufacturing processes

Description of Invention
Bottom pour casting method in which solidification is controlled to permit casting of long ingots without center porosity

Technology Synopsis
Conventional practice in bottom pour casting of ingots is to promote solidification of the ingot from bottom to top. However, the thermal gradients at the time the ingot mold is filled conflict with this pattern of solidification in that the coldest metal is at the top of the mold and the hottest metal is at the bottom. This condition invariably creates inadequate feeding of liquid metal which produces unwanted porosity in the solidified product. Subsequent hot working requires heavy cross-sectional reduction to 'heal' the porosity and produce salable product. A bottom pouring method and apparatus have been invented which control the thermal gradients in a way that assures that adequate feeding of hot metal is provided as the ingot solidifies from top to bottom, thus eliminating solidification shrinkage and piping.

Patent Protection
U. S. Patents 6,435,257 B2 and 6,457,512 B1 for Bottom Pouring Fully Dense Long Ingots

Potential Commercial Applications
This technology is particularly beneficial for the production of specialty steel bar and rod in that primary breakdown of the ingot into intermediate sized billets can be eliminated. Fully dense long ingots can be rolled directly to bar and rod product, thus reducing manufacturing costs.

Status of Invention
Technology has been demonstrated by CTC. Licensee could implement the technology using its own technical support team or access the technical capabilities of CTC on a negotiable fee basis.