Process for manufacturing or repairing a monobloc bladed disc

A monobloc bladed disc and a process for manufacturing or repairing a monobloc bladed disc, where the process includes forming, on a protruding projection belonging to a disc and extending from an upstream end to a downstream end along a protruding projection chord, a welded joint surface intended to allow a subsequent stage of fitting a blade by linear friction welding onto the protruding projection of the disc. The forming the welded joint surface is carried out in such a way that it includes at least two butt-jointed plane portions arranged in sequence along the protruding projection chord.