A moulding assembly for aluminothermic welding of metal rails includes at least one mould part configured to come into contact with at least one other mould part and rails to be welded to form a mould cavity in which the ends of the metal rails to be welded are arranged and into which a molten metal is cast to weld the metal rails, wherein each mould part comprises includes a seating configured to be placed in contact least one of the rails, the seating including a groove into which a sealing product made of intumescent material is applied.

The present invention relates to a moulding assembly for aluminothermic welding of metal rails (30), comprising at least one mould part (1, 50) configured to come into contact with at least one other mould part (1, 50) and rails (30) to be welded in order to form a mould cavity (102) in which the ends (31) of the metal rails to be welded are arranged and into which a molten metal is cast in order to weld the metal rails (30), the moulding assembly being characterised in that each mould part (1, 50) comprises a seating (13) configured to be placed in contact with at least one of said rails (30), said seating (13) comprising a groove (60) into which a sealing product (40) made of intumescent material is applied.

Method for the aluminothermic welding of rails, involving the steps of: triggering an aluminothermic reaction in a crucible, pouring the metal resulting from said reaction into the mold so as to fill the molding cavity from the rail flange, after filling the cavity, triggering a second aluminothermic reaction above the rail head, and pouring the metal resulting from said reaction into the cavity in the region of the rail head. The mold used in the method is designed to fit over the ends of two rails to form a molding cavity comprising a crucible positioned above the rail head region so that it can be fed with molten metal of the cavity via a secondary passage.

Method for the aluminothermic welding of rails, involving the steps of: triggering an aluminothermic reaction in a crucible, pouring the metal resulting from said reaction into the mold so as to fill the molding cavity from the rail flange, after filling the cavity, triggering a second aluminothermic reaction above the rail head, and pouring the metal resulting from said reaction into the cavity in the region of the rail head. The mold used in the method is designed to fit over the ends of two rails to form a molding cavity comprising a crucible positioned above the rail head region so that it can be fed with molten metal of the cavity via a secondary passage.