Horizontal continuous casting of metals

Abstract

A mould for horizontal casting of molten metal comprising a mould body forming an open-ended mould cavity having an inlet end and an outlet end. An annular permeable wall member is mounted in the mould body adjacent the inlet end of the mould cavity with an inner face thereof forming an interior face of the mould. A refractory transition plate is mounted at the inlet end of the mould cavity, this transition plate providing a mould inlet opening having a cross-section less than that of the mould cavity. This provides an annular shoulder at the inlet end of the cavity. Means are provided for feeding molten aluminum through the inlet opening. Separate conduits are also provided for feeding a gas into the shoulder and via the permeable wall means for providing a layer of gas between the metal and the inner face of the mould. A gas that is more reactive with molten aluminum is fed into the shoulder and a less reactive gas is fed via the permeable wall. The reactions with the molten aluminum create a skin or shell on the aluminum which provides smooth passage through the mould and allows for more rapid secondary cooling of the emerging ingot.

1 - 32 . (canceled)  
   
   
       33 . A mould for casting of a molten metal comprising a mould body forming an open ended mould cavity having an inlet end and an outlet end, said mould cavity including a permeable wall portion forming an interior face of the mould, feed means for feeding molten metal through the mould cavity to form a metal ingot, conduits for feeding gas and a lubricant through said permeable wall portion and into contact with metal adjacent the interior face of the mould, and means for controlling the amount of lubricant being fed to the mould cavity comprising detectors located to measure the electrical resistance between the mould cavity wall and molten metal present in the mould during casting, said electrical resistance being indicative of the amount of lubricant in contact with the metal.  
   
   
       34 . A cast aluminum or aluminum alloy billet obtained by continuous casting, said cast billet having a uniform as cast microstructure with an average inter-dendritic arm spacing of less than 10 microns.  
   
   
       35 . A cast billet as in  claim 34  having a surface roughness (R z ) of less than 50 microns over at least 50% of the circumferential area.