GB842095A - Method of welding workpieces, more particularly rails, by the intermediate aluminothermic casting process - Google Patents

Abstract

842,095. Casting composite articles. ELEK. TRO-THERMIT G.m.b.H. Aug. 15, 1956 [Aug. 16, 1955; Dec. 2, 1955; Feb. 9, 1956], No. 25007/56. Class 83 (1). [Also in Group XXIII] A method of welding workpieces, particularly rails, comprises casting aluminothermicallyproduced steel between the spaced ends of the workpieces enclosed in a prefabricated mould, said ends being preheated by flames, projected from above, down the mould riser. In one embodiment, Figs. 1, 3, mould ports 3a, 3b, 3c, which may be made by the CO 2 process, are bedded down in pliable cushioning 8, such as green sand, in metal box halves 5. An auxiliary box 17 may enclose the mould before its insertion in the cushioning 8. The outside of the mould may be coated with a water-repellant. The assembly is then clamped by a clamp 4 to the rails 1, 2, and the mould-joints sealed. The ends of the rails are then heated by a burner 9 introduced into the riser 10, and a pouring-pot 6 is moved into casting-position. The burner 9 is then removed while the aluminothermic reaction takes place in a crucible T, pouring being initiated by removal of a plug 13. Slag drains into a box 14. In a modification, Figs. 6 and 8, the mould-parts are clamped to the rails by a two-arm-clamp 4, Fig. 8, or 4a, 4b, Fig. 6. Refractory members 19, Fig. 9, engage in keyways in the mould above the rail-head, to close the gaps 23 between the mould and the tops of worn rails, while another refractory member 22, Fig. 11, may be positioned in the riser 10, after heating and removal of the burner, so as to leave only a small riser above the rail-head for subsequent removal.