GB691875A - A method of and a device for extruding metals, particularly easily oxidising metals - Google Patents

Abstract

691,875. Extruding. HIRSCH KUPFERUND MESSINGWERK GES. Dec. 22, 1950 [Oct. 1, 1948; Oct. 1, 1948], No. 31221/50. Class 83 (iv). In a method of extruding metals, scale forma. tion is avoided by preventing the access of air to the extruded metal until it has cooled down to a temperature at which oxidation cannot take place. In one example, short extruded lengths are discharged from a die 2, Fig. 1, into a tube 5 containing a protective gas supplied through inlet and outlet pipes 6, 7 and which may be below atmospheric pressure. After cooling, the lengths are removed through a sealing door 8. In another example the work is discharged through a pipe 5, Fig. 2, containing steam, and then passes through a tube 16 containing cooling water moving in the same direction as the work. The tube 5 is enclosed at one end by a chamber 11 containing steam and which acts as a sump for preventing water from reaching the die as a result of condensation of steam or backward flow from the pipe 16, a gap 18 and holes 19 being provided for draining purposes. Inert gas or steam may be passed into the pipe 5 through a pipe 21 and a heater may be provided in the chamber 11 for producing steam when starting from cold. The discharge pipe 16 is surrounded by a pressure chamber 12 supplied with cooling water from a pipe 14, the water passing into the pipe 16 through an annular jet 15. A number of tubes &c. may be simultaneously extruded through parallel discharge tubes arranged in common steam and pressure chambers.