Vacuum Diffusion Welding Die Welding Process

Wed Sep 07 17:19:05 CST 2022

1. a vacuum diffusion welding connection method of molybdenum-based superalloy, is characterized in that, comprises: Ni foil is put into part to be welded, the part is assembled; The assembled part is loaded into the vacuum brazing furnace, Pressurize the parts to the first pressure and start vacuuming until the degree of vacuum is less than or equal to 1×10-4Pa; heat the vacuum brazing furnace to the first temperature, and pressurize the parts to the second pressure; keep the pressure at the second pressure When the vacuum brazing furnace is heated to the second temperature; the preset duration of heat preservation; after the heat preservation is finished, the heating of the vacuum brazing furnace is stopped, and the furnace is cooled to 600 ° C, and the pressure is reduced to 0 MPa by the decompression rate of 1 MPa/min. , the parts are air-cooled to 20°C; the vacuum brazing furnace is heated to a first temperature, and the parts are pressurized to a second pressure, including: heating the vacuum brazing furnace to 900°C at a heating rate of 25°C/min , after reaching 900 ° C, the pressure is pressurized to 5MPa at a pressing rate of 0.3MPa/min, and the vacuum brazing furnace is kept at 900 ° C during this process; when the pressure is maintained at the second pressure, the vacuum brazing furnace is kept at the second pressure. Heating to the second temperature includes: when pressurized to 5MPa, heating the vacuum brazing furnace to 1100°C at a heating rate of 10°C/min, maintaining the temperature for 30min, and maintaining a pressure of 5MPa during this process. 2 . The method according to claim 1 , wherein the thickness of the Ni foil is determined according to the weld structure of the part and the size of the part. 3 . 3 . The method according to claim 1 , wherein the step of pressurizing the part to a first pressure to start vacuuming comprises: pressurizing the part to 2MPa at a preset rate to start vacuuming. 4 . 4. The method according to claim 1, wherein the gap between the Ni foil and the welding seam of the part after assembling is in the range of 0.005-0.01 mm. 5. method according to claim 1, is characterized in that, after molybdenum-based superalloy parts are air-cooled to 20 ℃, described method also comprises: X-ray flaw detection is carried out to the weld zone of parts, inside the weld of parts No cracks, incomplete penetration or fusion are allowed, and the maximum pore diameter is less than or equal to 0.2mm. 6. The method according to claim 1, characterized in that, before the Ni foil is put into the part to be welded and the part is assembled, the method further comprises: mechanically polishing the part to remove surface oxide; Ultrasonic cleaning of parts to remove oil stains on the surface of parts.