阅读说明：本技术 一种制备功能梯度高温合金涡轮盘的方法 (Method for preparing functionally gradient high-temperature alloy turbine disc ) 是由 瞿宗宏 罗成 郑作赟 兰剑 赖运金 王庆相 梁书锦 张平祥 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种制备功能梯度高温合金涡轮盘的方法,包括：步骤1、制作用于装填合金粉末的涡轮盘包套；步骤2、将合金粉末装入包套,随后进行加热、振实和抽真空除气；步骤3、对包套进行封焊,然后将包套置于热等静压机中压制至全致密,得到涡轮盘毛坯；步骤4、对步骤3中压制完成后的涡轮盘毛坯进行机加工,去除双组织分界线以内的包套；步骤5、对经过步骤4机加工后带有包套的涡轮盘毛坯进行固溶处理和时效处理,得到功能梯度涡轮盘。通过设置包套获得功能梯度涡轮盘,成本低廉,操作简单方便。(The invention discloses a method for preparing a functionally gradient superalloy turbine disk, which comprises the following steps: step 1, manufacturing a turbine disc sheath for filling alloy powder; step 2, filling the alloy powder into a sheath, and then heating, tapping, vacuumizing and degassing; step 3, sealing and welding the sheath, and then placing the sheath in a hot isostatic pressing machine to be pressed to be fully compact to obtain a turbine disc blank; step 4, machining the turbine disc blank pressed in the step 3, and removing a sheath within a double-structure boundary; and 5, carrying out solid solution treatment and aging treatment on the turbine disc blank with the sheath machined in the step 4 to obtain the functionally graded turbine disc. The functional gradient turbine disc is obtained by arranging the sheath, so that the cost is low, and the operation is simple and convenient.)

1. A method for preparing a functionally gradient superalloy turbine disk is characterized by comprising the following steps:

step 1, manufacturing a turbine disc sheath for filling alloy powder;

step 2, filling the alloy powder into a sheath, and then heating, tapping, vacuumizing and degassing;

step 3, sealing and welding the sheath, and then placing the sheath in a hot isostatic pressing machine to be pressed to be fully compact to obtain a turbine disc blank;

step 4, machining the turbine disc blank pressed in the step 3, and removing a sheath within a double-structure boundary;

and 5, carrying out solid solution treatment and aging treatment on the turbine disc blank with the sheath machined in the step 4 to obtain the functionally graded turbine disc.

2. The method for preparing a functionally graded superalloy turbine disc as claimed in claim 1, wherein the sheath and the turbine disc in step 1 are similar in shape, the size of the sheath is increased by 15-20%, the sheath is made of low carbon steel or stainless steel, and the thickness of the sheath is 3-20 mm.

3. The method for preparing a functionally graded superalloy turbine disk according to claim 1, wherein the heating temperature in step 2 is 200-500 ℃ and the vacuum degree is less than 1 x 10^-3Pa, to remove gas between the powders; the vibration frequency of the tap is 5-20 Hz.

4. The method for preparing a functionally graded superalloy turbine disk according to claim 1, wherein the hot isostatic pressing in step 3 is conducted at a temperature of 1160-1200 ℃ and at 100-200 MPa for 1-6 hours.

5. The method for preparing a functionally gradient superalloy turbine disk according to claim 1, wherein the temperature during solid solution in the step 5 is 1050-1200 ℃ for 1-6 h, the temperature during aging is 760-870 ℃ for 5-32 h, and staged aging or one-time aging can be adopted.

Technical Field

The invention belongs to the technical field of alloy material processing, and relates to a method for preparing a functionally gradient high-temperature alloy turbine disc.

Background

The turbine disc is one of key parts at the hot end of the aircraft engine, generally works at 550-850 ℃, and with the improvement of the thrust-weight ratio of the aircraft engine, higher requirements are provided for the temperature bearing capacity and the performance stability of an alloy material. The disk center part of the turbine disk for the aeroengine has low working temperature, but needs enough tensile strength and fatigue resistance under the torsion action of a turbine shaft; the flange portion, close to the hot gas path, is subjected to high operating temperatures, so that it is necessary to ensure adequate endurance and creep properties, which require different microstructures in different regions of the turbine disk in order to obtain corresponding mechanical properties.

The preparation of the double-structure double-performance functionally-graded turbine disc mainly adopts a method for controlling grain growth, controls the solid solution temperature of different parts of the turbine disc in the heat treatment process by designing a complex heat insulation device, and ensures that the disc edge obtains coarse grains and the wheel center obtains fine grains, and the methods are shown in US patent Nos. 4820358 and US patent No. 5312497. Russian patent RU 245115 discloses a functional gradient turbine disk with dual-structure and dual-performance, wherein the complex sheath and powder filling device are designed, so that high-temperature alloy powder with different granularities and different grades is filled in the disk edge and the disk center. These methods are complicated and costly to implement, and are not conducive to mass production.

Disclosure of Invention

The invention provides a method for preparing a functionally graded high-temperature alloy turbine disc, which is characterized in that a sheath is arranged to perform solution treatment on a turbine disc blank to obtain the functionally graded turbine disc.

In order to achieve the purpose, the technical scheme adopted by the invention is that the method for preparing the functionally gradient superalloy turbine disk is implemented according to the following steps:

step 1, manufacturing a turbine disc sheath for filling alloy powder;

step 2, filling the alloy powder into a sheath, and then heating, tapping, vacuumizing and degassing;

step 3, sealing and welding the sheath, and then placing the sheath in a hot isostatic pressing machine to be pressed to be fully compact to obtain a turbine disc blank;

step 4, machining the turbine disc blank pressed in the step 3, and removing a sheath within a double-structure boundary;

and 5, carrying out solid solution treatment and aging treatment on the turbine disc blank with the sheath machined in the step 4 to obtain the functionally graded turbine disc.

In the step 1, the shape of the sheath is similar to that of the turbine disc, and the size of the sheath is increased by 15-20%; the sheath is made of low-carbon steel or stainless steel and has a thickness of 3-20 mm.

The heating temperature in the step 2 is 200-500 ℃, and the vacuum degree is lower than 1 multiplied by 10^-3Pa to remove gas between the powders; the vibration frequency of the tap is 5-20 Hz.

And 3, performing hot isostatic pressing at the temperature of 1160-1200 ℃ under 100-200 MPa for 1-6 h.

And (5) preserving heat for 1-6 h at 1050-1200 ℃ during solid solution in the step 5, preserving heat for 5-32 h at 760-870 ℃ during aging treatment, and performing grading aging or one-time aging.

The invention has the beneficial effects that:

1. the functionally gradient turbine disk is obtained by arranging the sheath, so that the cost is low, and the operation is simple and convenient.

2. The steel covering sleeve of the disc edge forms an oxide layer on the surface when the high-temperature solution treatment is carried out at 1050-1200 ℃, the thermal conductivity of the oxides is 5-10W/(m.DEG C) at the temperature of over 1000 ℃, and the thermal conductivity of a nickel-based high-temperature alloy matrix formed by alloy powder is more than 30W/(m.DEG C). Therefore, the residual sheath has heat insulation effect on the nickel-based superalloy substrate, so that the cooling speed of the disc edge is lower than that of the disc center in the cooling process after solid solution. When the cooling speed is high, nucleation and precipitation of a main strengthening phase gamma ' phase in the high-temperature alloy are facilitated, so that a small-size gamma ' phase is obtained at the center of the disc, a large-size gamma ' phase is obtained at the edge of the disc, and the double-structure double-performance turbine disc with the functional gradient is obtained.

Drawings

FIG. 1 is a schematic illustration of a cooling process after solutionizing a turbine disk according to the present disclosure;

FIG. 2 is a phase γ' of the microstructure of the rim of a turbine disk of the present invention;

FIG. 3 is a phase γ' in the microstructure of the disk core of the turbine disk of the present invention.

Detailed Description

The present invention will be described in detail with reference to the following embodiments.