GB1014003A - Improvements in or relating to continuous casting of steel wire - Google Patents

Abstract

<PICT:1014003/C6-C7/1> A process of continuously casting steel wire comprises subjecting a molten steel bath in a degassed state to a gas pressure to drive it upwardly through a die extending into the bath and leading to a cooling die through which the metal passes and solidifies. The electrically heated crucible 2 is filled through the opening 7 while a reducing gas such as argon is introduced through a pipe 12. After filling the chamber is evacuated through pipe 13 until degassing is completed. The degassing may be improved by creating a sub-atmospheric pressure in the crucible before filling or by bubbling argon through the melt via an inlet 18 and die 15. Deoxidation may be effected by entraining deoxidants e.g. fine magnesium powder in the argon gas. C or alloying ingridients such as W, Ta, V, Ni, Cr, Mn may be similarly added. When starting casting, a cock 20 in the metal outlet pipe is closed and argon gas is supplied to the crucible through the pipe 12 and the inlet 18, to pressurize the container. Then the admission of argon through the inlet 18 is stopped, causing the metal to rise rapidly in the die 15 leading to a copper cooling tube 16 where the metal solidifies and opens the valve 20, passing through to the tube 21. The tube 16 may be cooled by water, an organic product such as tetrachlorodiphenyl or a low melting point liquid metal such as sodium or potassium. A lubricant such as liquid sodium and a coolant such as hydrogen, cracked ammonia, or liquefied alloy of sodium and potassium may be introduced into the clearance space caused by shrinkage of the metal due to solidification in the tube 16. That portion of the tube beneath the cover 6 may be electrically heated so that solidification is effected only beyond the cover. At the outlet of the valve 20 heat treatment may be applied to the wire.