High temperature yield strength improvement process of gh4738 alloy forgings after vacuum brazing

Abstract

The invention discloses a process for improving the high-temperature yield strength of a GH4738 alloy forging after vacuum brazing, and belongs to the technical field of high-temperature alloy heat treatment. Including the following steps: Vacuum brazing treatment: at a pressure not greater than 10 ‑3 In a vacuum environment of Pa, heat up from room temperature to the brazing temperature of 1000-1080°C, keep it warm for 10-30min, and fill it with argon to cool it below 60°C; The time is 4±0.1h, then air-cooled to room temperature; the second stage of treatment temperature is 760±10°C, the holding time is 4±0.1h, and then air-cooled to room temperature. The invention improves the cooling rate of the alloy after vacuum brazing, shortens the aging treatment time, and obtains a finely dispersed gamma' strengthening phase, which has an unexpected effect in improving the high-temperature yield strength of the GH4738 alloy forging after brazing treatment. Among them, the yield strength at 540°C can reach 850MPa, which is 13.6% higher than that before process optimization; the yield strength at 760°C can reach 820MPa, which is 18.0% higher than that before process optimization.

Description

technical field [0001] The invention relates to a process for improving the high-temperature yield strength of a GH4738 alloy forging after vacuum brazing, and belongs to the technical field of high-temperature alloy heat treatment. Background technique [0002] Superalloys usually refer to a class of alloys formed by using Group VIII elements (iron, cobalt, nickel, etc.) as the base material and adding a large amount of strengthening elements. Superalloys can be used for a long time above 650 ° C, have good oxidation resistance, corrosion resistance, excellent tensile, durability, fatigue properties and long-term tissue stability and other comprehensive properties, and are currently widely used in hot-end components such as aero engines and gas turbines . Among many superalloy systems, nickel-based wrought superalloys are widely used in various high-performance engine hot-end rotating parts due to their good high-temperature forging properties and comprehensive properties....

AI Technical Summary

Problems solved by technology

[0007] In view of the above analysis, the present invention aims to provide a process for improving the high-temperature yield strength of GH4738 alloy forgings after vacuum brazing, so as to solve the problem that the existing vacuum brazing and aging treatment reduce the high-temperature yield strength of the alloy, and it is difficult to meet the technical requirements.

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