A Vacuum Brazing Repair Method for Cracks in Supersonic Regulators of Aeroengines

Abstract

The invention relates to a vacuum brazing repair method for cracks of aeroengine supersonic regulating plates. The method comprises the following steps: S1, polishing; S2, carrying out flaw detection; S3, cleaning; S4, filling alloy powder; S5, filling solders; S6, coating stop welding flux and drying; S7, carrying out vacuum brazing: firstly, performing vacuum pumping to be below 1.80*10<-2>Pa, then carrying out partial pressure of argon gas to be 50-100Pa, rising temperature to 600 to 650 DEG C, carrying out heat preservation for 10-15min, then performing vacuum pumping to be below 8.0*10<-2>Pa, rising temperature to 1150 to 1210 DEG C, carrying out heat preservation for 30-50min, performing brazing, cooling to the temperature of 800 to 900 DEG C along with a furnace, then filling argon and cooling to the temperature of 50 to 100 DEG C, and discharging from the furnace, and controlling the heating rates all at 5-10 DEG C / min in the whole temperature rising process; S8, restoring profiles. The vacuum brazing repair method for the cracks of the aeroengine supersonic regulating plates disclosed by the invention has the advantages that uniform heating can be carried out and welding cracks generated for large stress in the welding process are avoided, and the high-temperature strength of welded joints is measured to be up to 98% of the substrate strength after welding, so that the vacuum brazing repair method for the cracks of the aeroengine supersonic regulating plates can be widely applied to the repair for the cracks of the aeroengine supersonic regulating plates made of (B Zhe El 12y) nickel-base superalloy casting parts.

Description

technical field [0001] The invention relates to the field of aero-engine maintenance, in particular to a vacuum brazing repair method for cracks in an aero-engine supersonic regulating plate. Background technique [0002] The aero-engine supersonic regulator is an important hot-end part of the engine tail. A certain type of aero-engine supersonic regulator is made of nickel-based superalloy ВЖЛ12У. ВЖЛ12У is a high-aluminum, titanium, low-density nickel-based superalloy with high high-temperature strength, plasticity and good manufacturability. The supersonic regulator works in an environment of about 900°C for a long time. Due to the thermal stress, high pressure, and gas corrosion caused by the instantaneous high temperature and low temperature alternation, the blades are prone to thermal fatigue cracks and a large number of blades are scrapped. rate as high as 50%. The supersonic adjustment plate ВЖЛ12У alloy contains high aluminum and titanium content, and its weldabil...

AI Technical Summary

Problems solved by technology

The supersonic regulator works in an environment of about 900°C for a long time. Due to the thermal stress, high pressure, and gas corrosion caused by the instantaneous high temperature and low temperature alternation, the blades are prone to thermal fatigue cracks and a large number of blades are scrapped. rate up to 50%

Supersonic adjustment plate ВЖЛ12У alloy has high aluminum and titanium content, and its weldability is poor. When repairing with ordinary argon arc welding, the heat-affected zone is prone to welding cracks due to the large amount of heat input.

At present, there is no public report on the repair method of supersonic regulator crack at home and abroad, and there is no related report on the welding of ВЖЛ12У nickel-based superalloy. Therefore, there is a need for a repair method with high strength in the crack area and small heat input that will not cause cracking in the heat-affected zone. repair method