CN114318191A

CN114318191A - Homogenization treatment method of nickel-based superalloy GH4169G alloy

Info

Publication number: CN114318191A
Application number: CN202111419415.9A
Authority: CN
Inventors: 史新波; 亢梦珂; 郭会明; 曹国鑫; 付宝全
Original assignee: Xi'an Juneng High Temperature Alloy Material Technology Co ltd
Current assignee: Xi'an Juneng High Temperature Alloy Material Technology Co ltd
Priority date: 2021-11-26
Filing date: 2021-11-26
Publication date: 2022-04-12

Abstract

A homogenizing treatment process of a nickel-based superalloy GH4169G ingot comprises the following steps: step 1, charging at a temperature lower than 750 ℃, and preserving heat at 750 ℃ for 240 min; step 2, slowly heating to 1120 ℃, wherein the heating time is not less than 900min, and the heat preservation time is not less than 3000min at 1120 ℃; step 3, slowly heating to 1160 ℃, wherein the heating time is not less than 600min, and the heat preservation time at 1160 ℃ is not less than 2400 min; step 4, slowly heating to 1195 ℃, wherein the heating time is not less than 360min, and the heat preservation time at 1195 ℃ is not less than 6000 min; step 5, slowly cooling to 1120 ℃, wherein the cooling time is not less than 2800min, and the heat preservation time at 1120 ℃ is not less than 600 min; step 6, slowly cooling to 550 ℃, wherein the cooling time is not less than 1200min, and discharging from the furnace and air cooling; the method can effectively solve the problems of forging cracking and microcosmic component segregation caused by a brittle phase and a low-melting-point phase of the GH4169G alloy ingot, and lays a foundation for ingot cogging and forging.

Description

Homogenization treatment method of nickel-based superalloy GH4169G alloy

Technical Field

The invention belongs to the technical field of high-temperature alloy hot processing, and particularly relates to a homogenizing treatment process for a nickel-based high-temperature alloy GH4169G cast ingot.

Background

The GH4169G alloy is an advanced nickel-based high-temperature alloy formed by adopting a P, B microalloy composite strengthening method on the basis of the GH4169 alloy, and is mainly used for manufacturing parts such as an aircraft engine compressor blade disc, a shaft neck, a low-pressure turbine disc and the like. The GH4169G high-temperature alloy contains high easily-segregated element Nb and also contains a large amount of P, B grain boundary enriched elements, and a large amount of low-melting-point phase and brittle phase are precipitated in the ingot, so that homogenization treatment is required before forging and cogging in industrial production, and cracking of the ingot caused by the low-melting-point phase and the brittle phase is avoided.

The high-temperature alloy ingot is mainly prepared by eliminating a low-melting-point phase and a brittle phase by a homogenization diffusion annealing method and reducing the segregation of microcosmic components. The high-temperature alloy has more types of low-melting-point phases and brittle phases, has different redissolution temperatures, and can cause certain precipitated phases to be melted to generate holes if the homogenization setting is unreasonable, thereby causing ingot cracking when the ingot is cogging.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a homogenizing treatment process of a nickel-based superalloy GH4169G cast ingot, which adopts a multi-step long-time heat preservation method and ensures the homogenizing effect of the cast ingot through exemplified parameters; according to the invention, the brittle phase and the low-melting-point phase in the GH4169G alloy ingot are successfully eliminated by adopting 6 long-time heat preservation processes at different temperatures, so that the problem that the ingot is easy to crack when cogging is solved; meanwhile, the problem of uneven components between dendrite trunks and dendrites in the microscopic region is solved, and the stability of product quality is ensured.

In order to achieve the purpose, the invention adopts the technical scheme that: a homogenizing treatment process for a nickel-based superalloy GH4169G cast ingot, which comprises the following steps of firstly eliminating a brittle phase and a low-melting-point phase by heat preservation at 1120-1160 ℃, then diffusing elements in a cast-state micro region by heat preservation at 1195 ℃ for a long time, eliminating the appearance of cast-state dendrites, and reducing the segregation of microcosmic components, wherein the following steps are specifically included:

step 1, charging at a temperature lower than 750 ℃, and preserving heat at 750 ℃ for 240 min;

step 2, slowly heating to 1120 ℃, wherein the heating time is not less than 900min, and the heat preservation time is not less than 3000min at 1120 ℃;

step 3, slowly heating to 1160 ℃, wherein the heating time is not less than 600min, and the heat preservation time at 1160 ℃ is not less than 2400 min;

step 4, slowly heating to 1195 ℃, wherein the heating time is not less than 360min, and the heat preservation time at 1195 ℃ is not less than 6000 min;

step 5, slowly cooling to 1120 ℃, wherein the cooling time is not less than 2800min, and the heat preservation time at 1120 ℃ is not less than 600 min;

and 6, slowly cooling to 550 ℃, wherein the cooling time is not less than 1200min, and then discharging and air cooling.

The charging temperature in the step 1 is lower than 750 ℃, and then the temperature is kept at 750 ℃.

The heat preservation time of 1160 ℃ in the step 3 is more than 2400 min.

The heat preservation time of 1195 ℃ in the step 4 is more than 6000 min.

The invention has the beneficial effects that:

the homogenization process mainly adopts a gradual slow temperature rise and prolonged heat preservation mode to realize the re-dissolution of the brittle phase and the low-melting-point phase in the GH4169G alloy cast ingot, simultaneously alleviates the problem of micro dendrite segregation and lays a foundation for the subsequent bar forging.

The advantages of the invention are embodied in the following aspects:

1) the process is adopted for homogenization, the brittle phase and the low-melting-point phase of the GH4169G alloy are completely dissolved, and the problem of cogging and cracking of the cast ingot is solved;

2) the process of the invention is adopted for homogenization, the problem of segregation of components between dendrite trunk and dendrite trunk of the GH4169G alloy ingot is reduced, and the component uniformity of the finished bar is ensured.

Drawings

FIG. 1 is the microstructure morphology of GH4169G ingot of phi 508mm ingot type before homogenization treatment by the process of the present invention, illustrating the presence of a large amount of brittle and low melting phase, in the form of distinct dendrites.

FIG. 2 is the microstructure morphology of GH4169G ingot of phi 508mm ingot type after homogenization treatment using the process of the present invention, illustrating the absence of brittle and low melting phases, and the absence of dendritic morphology.

Detailed description of the preferred embodiment

The present invention will be described in further detail with reference to specific examples.

Hereinafter, the homogenization treatment process of the invention is described by combining GH4169G alloy ingots of different ingot types.

Example 1:

GH4169G cast ingot formed by vacuum consumable smelting has specification of phi 406mm, homogenizing equipment is a natural gas furnace, and the furnace temperature precision is required to be +/-5 ℃. The homogenization process of the cast ingot is divided into 6 steps in total, and comprises the following steps in sequence:

step 1, charging the ingot at 700 ℃, and then setting the temperature at 750 ℃ for heat preservation for 120 min;

step 2, slowly heating to 1120 ℃, wherein the heating time is 900min, and the heat preservation time at 1120 ℃ is 3000 min;

step 3, slowly heating to 1160 ℃, wherein the heating time is 600min, and the heat preservation time at 1160 ℃ is 2400 min;

step 4, slowly heating to 1195 ℃, wherein the heating time is 360min, and the heat preservation time at 1195 ℃ is 6000 min;

step 5, slowly cooling to 1120 ℃, wherein the cooling time is 2800min, and the heat preservation time at 1120 ℃ is 600 min;

and 6, slowly cooling to 550 ℃ for 1200min, and then discharging and air cooling.

Example 2:

GH4169G cast ingot formed by vacuum consumable smelting, the product specification phi is 450mm, the homogenizing device is a natural gas furnace, and the furnace temperature precision is required to be +/-5 ℃. The homogenization process of the cast ingot is divided into 6 steps in total, and comprises the following steps in sequence:

step 1, charging the ingot at 650 ℃, and then setting the temperature at 750 ℃ for heat preservation for 180 min;

step 2, slowly heating to 1120 ℃, wherein the heating time is 1020min, and the heat preservation time at 1120 ℃ is 3060 min;

step 3, slowly heating to 1160 ℃, wherein the heating time is 720min, and the heat preservation time at 1160 ℃ is 2520 min;

step 4, slowly heating to 1195 ℃, wherein the heating time is 480min, and the heat preservation time at 1195 ℃ is 6120 min;

step 5, slowly cooling to 1120 ℃, wherein the cooling time is 2920min, and the heat preservation time at 1120 ℃ is 720 min;

and 6, slowly cooling to 550 ℃ for 1500min, and then discharging from the furnace for air cooling.

Example 3:

GH4169G cast ingot formed by vacuum consumable smelting, the product specification is phi 508mm, the homogenizing equipment is a natural gas furnace, and the furnace temperature precision is required to be +/-5 ℃. The homogenization process of the cast ingot is divided into 6 steps in total, and comprises the following steps in sequence:

step 1, charging the ingot at 500 ℃, and then setting the temperature at 750 ℃ for 240 min;

step 2, slowly heating to 1120 ℃, wherein the heating time is 1080min, and the heat preservation time at 1120 ℃ is 3140 min;

step 3, slowly heating to 1160 ℃, wherein the heating time is 780min, and the heat preservation time at 1160 ℃ is 2580 min;

step 4, slowly heating to 1195 ℃, wherein the heating time is 540min, and the heat preservation time at 1195 ℃ is 6200 min;

step 5, slowly cooling to 1120 ℃, wherein the cooling time is 2980min, and the heat preservation time at 1120 ℃ is 780 min;

and 6, slowly cooling to 550 ℃ for 1800min, and then discharging from the furnace and air cooling.

The above example can completely dissolve the brittle phase and the low melting point in the GH4169G ingot, and simultaneously eliminate the dendritic crystal morphology, so as to successfully achieve the purpose of homogenization treatment.

In conclusion, the homogenizing treatment method of the GH4169G alloy cast ingot provided by the invention achieves a better treatment effect.

Claims

1. A homogenizing treatment process for a nickel-based superalloy GH4169G cast ingot is characterized by being realized in a slow temperature rise and multi-step heat preservation mode, and specifically comprises the following steps:

step 1, charging the finished product ingot at a temperature lower than 750 ℃, and preserving heat at 750 ℃ for 120-240 min;

step 3, on the basis of the step 2, slowly heating to 1160 ℃, wherein the heating time is not less than 600min, and the heat preservation time at 1160 ℃ is not less than 2400 min;

step 4, on the basis of the step 3, slowly heating to 1195 ℃, wherein the heating time is not less than 360min, and the heat preservation time at 1195 ℃ is not less than 6000 min;

2. The process of the homogenization treatment of the nickel-base superalloy GH4169G ingot according to claim 1, wherein the heat preservation time of 1160 ℃ in the step 3 is larger than 2400 min.

3. The homogenizing treatment process of the nickel-base superalloy GH4169G ingot according to claim 1, wherein the holding time of 1195 ℃ in the step 4 is more than 6000 min.