Abstract: The invention relates to a cold expansion device (36) for work hardening a through bore (34) in a turbine engine part (32), comprising at least one chuck (38) supporting a burnisher (40) and a means (41) for pushing the chuck (38) in an axial direction, and is characterised in that it comprises at least: —a tubular guide (42) configured to guide the burnisher (40) to the bore (34), —a first magnetic attachment means (51) arranged at a free end (44) of the chuck (38), —the burnisher (40), comprising a work surface (46) and an end (48) comprising second magnetic attachment means (49) complementary to the first magnetic attachment means (51), and in that the axial pushing means (41) is configured to push the burnisher through the bore (34) until it emerges from stud bore.

Abstract: The invention relates to a cold expansion device (36) for work hardening a through bore (34) in a turbine engine part (32), comprising at least one chuck (38) supporting a burnisher (40) and a means (41) for pushing the chuck (38) in an axial direction, and is characterised in that it comprises at least: —a tubular guide (42) configured to guide the burnisher (40) to the bore (34), —a first magnetic attachment means (51) arranged at a free end (44) of the chuck (38), —the burnisher (40), comprising a work surface (46) and an end (48) comprising second magnetic attachment means (49) complementary to the first magnetic attachment means (51), and in that the axial pushing means (41) is configured to push the burnisher through the bore (34) until it emerges from stud bore.

Abstract: The present invention relates to a steel part for use in aeronautics, comprising a substrate, the substrate comprising at least carbon, cobalt, aluminium and nickel, and having an average atomic fraction of carbon between 0.09% and 0.17%, an average atomic fraction of cobalt between 15.5% and 18.5%, an average atomic fraction of aluminium less than 0.1%, an average atomic fraction of nickel between 7.2% and 9.8%, the part being case-hardened and also comprising a nitrided layer, the nitrided layer at least partially covering the substrate and having a thickness between 5 ?m to 180 ?m, preferably between 50 ?m and 150 ?m.