CN108588605B

CN108588605B - Heat treatment process of boron-containing nickel-based single crystal superalloy

Info

Publication number: CN108588605B
Application number: CN201810413777.9A
Authority: CN
Inventors: 余竹焕; 王盼航
Original assignee: Xian University of Science and Technology
Current assignee: Xian University of Science and Technology
Priority date: 2018-05-03
Filing date: 2018-05-03
Publication date: 2020-05-05
Anticipated expiration: 2038-05-03
Also published as: CN108588605A

Abstract

The invention discloses a heat treatment process of a boron-containing nickel-based single crystal superalloy, which comprises the following components in percentage by mass: 11.3 to 12.3 percent of Co, 4.4 to 5.3 percent of Cr, 5.71 to 6.6 percent of W, 1.01 to 1.04 percent of Mo, 4.8 to 5.2 percent of Re, 5.9 to 6.3 percent of Al, 7.8 to 8.1 percent of Ta, 0.05 to 0.09 percent of Hf, 0.08 to 0.09 percent of C, 0.008 to 0.016 percent of B and the balance of Ni; the process comprises the steps of smelting raw materials, then directionally solidifying to obtain a boron-containing nickel-based single crystal superalloy rod blank, and sequentially carrying out solid solution and aging treatment after warp cutting. According to the invention, a corresponding heat treatment process is prepared according to the component content of the boron-containing nickel-based single crystal superalloy, so that element segregation and eutectic structures are eliminated, and the creep resistance of the alloy is improved.

Description

Heat treatment process of boron-containing nickel-based single crystal superalloy

Technical Field

The invention belongs to the technical field of heat treatment of metal materials, and particularly relates to a heat treatment process of a boron-containing nickel-based single crystal superalloy.

Background

The nickel-based single crystal superalloy is widely used for hot end parts of aero-engines and gas turbines due to excellent high-temperature mechanical properties, and particularly has high temperature bearing capacity and excellent mechanical properties, so that the nickel-based single crystal superalloy becomes the best candidate material of advanced aero-turbine engine blades. Therefore, the development level of the nickel-based single crystal superalloy becomes one of the important marks for measuring the national aviation technological capability and even the comprehensive national force.

The crystal orientation of the nickel-based single crystal superalloy has three directions of [001], [010], [100], and the single crystal superalloy has obvious anisotropy, and the [001] oriented superalloy has higher high-temperature creep strength than the other two crystal orientations and always preferentially grows during the grain growth process, so the crystal orientation of the single crystal superalloy is usually selected as [001 ]. And the spiral crystal selection method is the most common method for preparing the nickel-based single crystal superalloy with the crystal orientation of [001 ].

Solute redistribution occurs in the solidification process of the alloy, so that the structure is seriously deviated from the equilibrium state structure, and the segregation phenomenon is generated, and the segregation phenomenon existing in the alloy can be effectively eliminated by carrying out proper heat treatment on the alloy. The heat treatment process is generally divided into solid solution treatment and aging treatment, wherein the solid solution treatment mainly has the function of completely or mostly solid dissolving coarse gamma ' phases and gamma/gamma ' eutectic crystals in the alloy, so that the uniformity of components and structures is improved, and uniform and fine gamma ' phases are precipitated in the subsequent cooling process; the aging treatment is to obtain a proper matrix phase gamma and a precipitation phase gamma ', the gamma ' phase is used as a main strengthening phase of the high-temperature alloy, and the shape, the size, the percentage content, the distribution and the like of the gamma ' phase have important influence on the mechanical properties of the single-crystal high-temperature alloy. The heat treatment process can adjust the form and distribution of the gamma' phase in the alloy, thereby influencing the mechanical property of the alloy. In recent years, with the development of nickel-based single crystal superalloy compositions, in order to improve the high temperature performance of the alloys, refractory elements in the alloys are increasing, which leads to the aggravation of dendrite segregation and eutectic segregation inside the alloys. The addition of elements such as Re significantly improves the high temperature strength of the alloy, but since Re is a strong negative segregation element, segregation of other elements is promoted, resulting in a decrease in the structural uniformity of the alloy. Therefore, the heat treatment process for the study of high alloyed superalloys is becoming more and more important and difficult.

The temperature of the solution heat treatment is generally between the full solution temperature of the gamma' phase and the initial melting temperature of the alloy, and the solution heat treatment of the alloy at higher temperature can promote the sufficient diffusion of alloy elements and make the alloy structure more uniform. In order to raise the solution treatment temperature of the nickel-based single crystal superalloy, researchers removed grain boundary strengthening elements such as C, B, Hf at the beginning, and the liquidus and solidus temperatures of the alloy were both greatly raised. However, small-angle grain boundaries appearing in the alloy are difficult to effectively eliminate in the preparation process, and researches find that the creep property of the high-temperature alloy is reduced due to the existence of the small-angle grain boundary defects. In order to solve the problem, researchers reintroduce grain boundary strengthening elements such as C, B, Hf into the high-temperature alloy to strengthen the weak link.

Disclosure of Invention

The invention aims to solve the technical problem of providing a heat treatment process of boron-containing nickel-based single crystal superalloy aiming at the defects of the prior art. The process promotes the dissolution of gamma' phase with a coarse structure in the boron-containing nickel-based single crystal superalloy, obviously eliminates element segregation and eutectic structures in the boron-containing nickel-based single crystal superalloy structure, improves the uniformity of the alloy structure, eliminates the influence of crystal boundary strengthening elements on the alloy, and improves the creep resistance of the alloy.

In order to solve the technical problem, the invention provides a heat treatment process of a boron-containing nickel-based single crystal superalloy, which is characterized by comprising the following components in percentage by mass: 11.3 to 12.3 percent of Co, 4.4 to 5.3 percent of Cr, 5.71 to 6.6 percent of W, 1.01 to 1.04 percent of Mo, 4.8 to 5.2 percent of Re, 5.9 to 6.3 percent of Al, 7.8 to 8.1 percent of Ta, 0.05 to 0.09 percent of Hf, 0.08 to 0.09 percent of C, 0.008 to 0.016 percent of B and the balance of Ni; the heat treatment process comprises the following steps:

adding nickel particles, cobalt particles, chromium particles, tungsten particles, molybdenum particles, rhenium particles, aluminum particles, tantalum particles, hafnium particles, carbon powder and boron powder into a vacuum induction furnace for smelting, then carrying out directional solidification by adopting a liquid metal cooling method, and preparing a boron-containing nickel-based single crystal high-temperature alloy bar blank oriented to [001] by adopting a spiral crystal selection method; the temperature gradient of the directional solidification is 150K/cm;

step two, performing linear cutting on the boron-containing nickel-based single crystal superalloy rod blank obtained in the step one to obtain a boron-containing nickel-based single crystal superalloy rod;

step three, carrying out solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the temperature of the solution treatment is 1280-1315 ℃, and the time is 15-47 h;

step four, carrying out aging treatment on the boron-containing nickel-based single crystal high-temperature alloy rod subjected to solution treatment in the step three to obtain a heat-treated boron-containing nickel-based single crystal high-temperature alloy rod; the aging treatment comprises the following specific processes: firstly, the mixture is processed for 4 to 6 hours at 1050 to 1100 ℃ and then processed for 20 to 24 hours at 870 ℃.

The heat treatment process of the boron-containing nickel-based single crystal superalloy is characterized in that the diameter of the boron-containing nickel-based single crystal superalloy rod in the second step is 12mm, and the length of the boron-containing nickel-based single crystal superalloy rod is 5 mm.

The heat treatment process of the boron-containing nickel-based single crystal superalloy is characterized in that the solution treatment in the third step is a secondary solution treatment, and the specific process of the secondary solution treatment is as follows: firstly, the mixture is processed for 8 hours at 1285-1310 ℃ and then processed for 15 hours at 1290-1315 ℃.

The heat treatment process of the boron-containing nickel-based single crystal superalloy is characterized in that equipment adopted for the solution treatment in the third step and the aging treatment in the fourth step are SX2-9-17TP high-temperature box furnaces, the maximum temperature rise rate of the SX2-9-17TP high-temperature box furnaces is 10 ℃/min, and the temperature control precision is +/-1 ℃.

Compared with the prior art, the invention has the following advantages:

1. the heat treatment process acts on the boron-containing nickel-based single crystal superalloy with specific components and content, obviously eliminates element segregation and eutectic structures in the boron-containing nickel-based single crystal superalloy structure, improves the uniformity of the alloy structure, reduces the influence of crystal boundary strengthening elements on the alloy, and improves the creep resistance of the alloy.

2. The heat treatment process of the invention promotes the dissolution of the gamma ' phase with a coarse structure in the boron-containing nickel-based single crystal superalloy, effectively eliminates secondary dendrite segregation and eutectic structures generated in the solidification process of the alloy, and along with the increase of the time of solution treatment, the more uniform the size of the gamma ' phase in the alloy is, the eutectic is gradually reduced, the size of carbide is reduced, the morphology of the carbide is changed from a Chinese character shape to a block shape and a rod shape, and the finally obtained main strengthening phase gamma ' phase has regular morphology and uniform size, thereby improving the creep resistance, structural stability and durability of the boron-containing nickel-based single crystal superalloy.

3. The secondary solution treatment breaks through the temperature limitation of single-stage solution treatment by adopting two sections of solution strengthening with different temperatures and time, improves the solid solubility of the gamma' phase, avoids the coarseness and overburning of alloy grains caused by overhigh solution temperature and overlong time, provides more strengthening phases for subsequent aging treatment, and further improves the mechanical property of the boron-containing nickel-based single crystal superalloy.

4. The heat treatment process optimizes the tissue structure of the boron-containing nickel-based single crystal superalloy, the appearance of the gamma' phase in the boron-containing nickel-based single crystal superalloy after heat treatment is converted into a regular cube shape, the size range is 300 nm-500 nm, the volume fraction is 60% at most, and the mechanical property of the boron-containing nickel-based single crystal superalloy is greatly improved.

The invention is explained in more detail below with reference to the figures and examples.

Drawings

FIG. 1 is a dendritic structural morphology of a boron-containing nickel-based single crystal superalloy rod obtained in example 1 of the present invention.

FIG. 2 is a shape and size diagram of an intercrystalline gamma' phase of a boron-containing nickel-based single crystal superalloy rod obtained in example 1 of the present invention.

FIG. 3 is a graph of the dendritic dry gamma' -phase morphology and size of the boron-containing nickel-based single crystal superalloy rod obtained in example 1 of the present invention.

FIG. 4 is a carbide morphology diagram of a boron-containing nickel-based single crystal superalloy rod obtained in example 1 of the present invention.

FIG. 5 is an EDC chart of carbides of boron-containing Ni-based single crystal superalloy rods obtained in example 1 of the present invention.

FIG. 6 is a microstructure of a heat-treated boron-containing nickel-based single crystal superalloy rod obtained in example 1 of the present invention.

FIG. 7 is a gamma prime phase morphology size graph of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in example 1 of the present invention.

FIG. 8 is a carbide morphology map of a boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in example 1 of the present invention.

FIG. 9 is an EDC chart of carbides of the heat-treated boron-containing nickel-based single crystal superalloy rods obtained in example 1 of the present invention.

FIG. 10 is a microstructure of a heat-treated boron-containing nickel-based single crystal superalloy rod obtained in example 5 of the present invention.

FIG. 11 is a gamma prime phase morphology size plot of a heat treated boron containing nickel based single crystal superalloy rod obtained in example 5 of the present invention.

FIG. 12 is a microstructure of a heat-treated boron-containing nickel-based single crystal superalloy rod obtained in example 6 of the present invention.

FIG. 13 is a gamma prime phase morphology size graph of the boron-containing nickel-based single crystal superalloy rods after heat treatment obtained in example 6 of the present invention.

Detailed Description

The method for observing the microstructure of the boron-containing nickel-based single crystal superalloy in the embodiment 1, the embodiment 5 and the embodiment 6 of the invention is as follows: (1) pretreatment: sequentially grinding the boron-containing nickel-based single crystal high-temperature alloy by adopting metallographic abrasive paper of No. 800, No. 1000, No. 1200, No. 1500 and No. 2000 step by step, then polishing by adopting a diamond polishing agent with the diamond particle size of 1 mu m, cleaning by water and ethanol, and drying by a blower; (2) shallow layer corrosion: adopts HNO with the mass concentration of 68 percent₃Solution, HF solution with mass concentration of 40% and C with mass concentration of 99%₃H₈O₃Corroding the pretreated boron-containing nickel-based single crystal superalloy for 9s by using a shallow corrosion solution prepared according to the volume ratio of 1:2:3, observing the gamma' phase and eutectic microstructure of the boron-containing nickel-based single crystal superalloy, cleaning the corroded boron-containing nickel-based single crystal superalloy by using ethanol, blow-drying by using a blower, and observing primary and secondary dendritic crystal appearances amplified by 50 times by using an optical microscope (model DM-4000M, Leica, Germany); (3) adopting HCl solution with mass concentration of 68% and H with mass concentration of 30%₂O₂Corroding the pretreated boron-containing nickel-based single crystal high-temperature alloy for 40min by using deep corrosive liquid prepared by the solution according to the volume ratio of 7:3, observing the carbide and eutectic structure which are magnified 3000 times by using a scanning electron microscope (ZeissSIGMA, Germany), dotting on the carbide, and performing EDS analysis, thereby determining the chemical components of the carbide, and judging whether the carbide of the alloy is converted after heat treatment according to the element content analysis result of the EDS.

Example 1

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 11.3 percent of Co, 4.4 percent of Cr, 5.71 percent of W, 1.01 percent of Mo, 4.8 percent of Re, 5.9 percent of Al, 7.8 percent of Ta, 0.05 percent of Hf, 0.08 percent of C, 0.008 percent of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1177.4g of nickel particles, 226g of cobalt particles, 88g of chromium particles, 114.2g of tungsten particles, 20.2g of molybdenum particles, 96g of rhenium particles, 118g of aluminum particles, 156g of tantalum particles, 1g of hafnium particles, 1.6g of carbon powder and 1.6g of boron powder into a vacuum induction furnace for smelting, then adopting a liquid metal cooling method for directional solidification, and adopting a spiral crystal selection method for preparing a boron-containing nickel-based single crystal superalloy rod blank with the orientation of [001 ]; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step two, performing linear cutting on the boron-containing nickel-based single crystal superalloy rod blank obtained in the step one to obtain a boron-containing nickel-based single crystal superalloy rod; the diameter of the boron-containing nickel-based single crystal superalloy rod is 12mm, and the length of the boron-containing nickel-based single crystal superalloy rod is 5 mm;

step three, carrying out secondary solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the secondary solution treatment comprises the following specific processes: firstly treating at 1310 ℃ for 8h, and then treating at 1315 ℃ for 15 h; the equipment for the secondary solution treatment is a SX2-9-17TP type high-temperature box furnace, the maximum temperature rise rate of the high-temperature box furnace can reach 10 ℃/min, and the temperature control precision is +/-1 ℃;

step four, carrying out aging treatment on the boron-containing nickel-based single crystal high-temperature alloy rod subjected to solution treatment in the step three to obtain a heat-treated boron-containing nickel-based single crystal high-temperature alloy rod; the aging treatment comprises the following specific processes: firstly, processing at 1100 ℃ for 4h, and then processing at 870 ℃ for 24 h; the aging treatment equipment is a SX2-9-17TP type high-temperature box furnace, the maximum temperature rise rate of the high-temperature box furnace can reach 10 ℃/min, and the temperature control precision is +/-1 ℃.

Fig. 1 is a dendritic structure morphology diagram of the boron-containing nickel-based single crystal superalloy rod obtained in the embodiment, and it can be seen from fig. 1 that the structure of the boron-containing nickel-based single crystal superalloy rod of the embodiment is a relatively thick dendritic crystal with obvious segregation, and through measurement, the primary dendritic crystal spacing of the structure is 350 μm, the secondary dendritic crystal spacing of the structure is 80 μm, the structure of the alloy is not only a fine γ ' precipitation phase distributed in a γ matrix, but also a small amount of white massive γ/γ ' eutectic exists among the dendritic crystals and is unevenly distributed among the dendritic crystals, and the average volume fraction of the γ/γ ' eutectic in the alloy structure is 1.2%.

Fig. 2 is a graph showing the shape and size of the gamma 'phase between dendrites of the boron-containing nickel-based single crystal superalloy rod obtained in this embodiment, and it can be seen from fig. 2 that the shape and size of the gamma' phase in the boron-containing nickel-based single crystal superalloy rod obtained in this embodiment are irregularly distributed, and the size range of the gamma 'phase of dendrites is 228nm to 247nm, and the size range of the gamma' phase between dendrites is 360nm to 379nm, and the shape and size irregular distribution of the gamma 'phase can reduce the high temperature mechanical properties of the alloy, so that an appropriate heat treatment process needs to be performed on the alloy to adjust the size and shape of the gamma' phase, thereby improving the high temperature mechanical properties of the alloy.

Fig. 3 is a size diagram of a dendrite dry γ' phase morphology of the boron-containing nickel-based single crystal superalloy rod obtained in this embodiment, and it can be seen from fig. 3 that the morphology of carbides in the boron-containing nickel-based single crystal superalloy rod obtained in this embodiment is relatively dispersed and mainly consists of blocky, acicular, Chinese character-shaped, and the like.

FIG. 4 is a carbide morphology diagram of the boron-containing nickel-based single crystal superalloy rod obtained in the present example, FIG. 5 is a carbide EDC diagram of FIG. 4, and when FIG. 4 and FIG. 5 are combined, it can be seen that the mass percent of Ta element in the boron-containing nickel-based single crystal superalloy rod of the present example is 71.18%, which indicates that the carbide is MC type carbide, which has a high melting point and is generally formed at the initial stage of solidification as a strengthening phase in the alloy.

Fig. 6 is a microstructure diagram of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in this embodiment, and it can be seen from fig. 6 that harmful structures such as eutectic and the like do not appear in the microstructure of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in this embodiment, and primary fusion holes appear in a partial region, which indicates that the heat treatment process and parameters of this embodiment are suitable.

Fig. 7 is a graph showing the shape and size of the γ ' phase of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment, and it can be seen from fig. 7 that the shape and size of the γ ' phase of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment are approximately cubic, and the size of the γ ' phase measured by Image pro plus software is 350nm to 420 nm.

Comparing fig. 7 and fig. 2, it can be seen that the size of the γ 'phase in fig. 7 is more uniform than that in fig. 2, which illustrates that the heat treatment process of this embodiment significantly increases the regularization of the γ' phase in the boron-containing nickel-based single crystal superalloy rod, the diffusion of elements in the alloy is more sufficient, and the segregation phenomenon is significantly improved.

Fig. 8 is a morphology graph of carbides of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment, and it can be seen from fig. 8 that the morphology of carbides of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment is in a granular distribution.

FIG. 9 is an EDC chart of the carbide in FIG. 8. it can be seen from FIG. 9 that the contents of Cr, Co and other elements are in an ascending state, which shows that the type of the carbide in the boron-containing nickel-based single crystal superalloy rod obtained in the present example after heat treatment has started to transform, and the analysis from the thermodynamic energy perspective shows that the alloy gradually transforms to a lower energy state, so that the morphology of the carbide is transformed to a more stable granular shape, and the type of the carbide is transformed from MC type to M type₆C or M₂₃C₆And (4) molding.

Example 2

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 11.5% of Co, 4.6% of Cr, 6.0% of W, 1.015% of Mo, 4.9% of Re, 6.04% of Al6.04%, 7.85% of Ta, 0.06% of Hf, 0.083% of C, 0.01% of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1158.84g of nickel particles, 230g of cobalt particles, 92g of chromium particles, 120g of tungsten particles, 20.3g of molybdenum particles, 98g of rhenium particles, 120.8g of aluminum particles, 157g of tantalum particles, 1.2g of hafnium particles, 1.66g of carbon powder and 0.2g of boron powder into a vacuum induction furnace for smelting, then carrying out directional solidification by adopting a liquid metal cooling method, and preparing a boron-containing nickel-based single crystal high-temperature alloy bar blank with the orientation of [001] by adopting a spiral crystal selection method; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, carrying out three-stage solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the specific process of the third-stage solution treatment is as follows: firstly, processing at 1295 ℃ for 8h, then processing at 1300 ℃ for 15h, and then processing at 1305 ℃ for 24 h;

step four, carrying out aging treatment on the boron-containing nickel-based single crystal high-temperature alloy rod subjected to solution treatment in the step three to obtain a heat-treated boron-containing nickel-based single crystal high-temperature alloy rod; the aging treatment comprises the following specific processes: the treatment was carried out at 1080 ℃ for 6h and then at 870 ℃ for 20 h.

Example 3

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 11.6 percent of Co, 4.7 percent of Cr, 6.0 percent of W, 1.02 percent of Mo, 4.95 percent of Re, 6.05 percent of Al, 7.9 percent of Ta, 0.065 percent of Hf, 0.084 percent of C, 0.011 percent of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1152.4g of nickel particles, 232g of cobalt particles, 94g of chromium particles, 120g of tungsten particles, 20.4g of molybdenum particles, 99g of rhenium particles, 121g of aluminum particles, 158g of tantalum particles, 1.3g of hafnium particles, 1.68g of carbon powder and 0.22g of boron powder into a vacuum induction furnace for smelting, then adopting a liquid metal cooling method for directional solidification, and adopting a spiral crystal selection method for preparing a boron-containing nickel-based single crystal superalloy rod blank oriented to [001 ]; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, carrying out secondary solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the secondary solution treatment comprises the following specific processes: firstly, processing at 1295 ℃ for 8h, and then processing at 1300 ℃ for 15 h;

Example 4

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 11.7% of Co, 4.8% of Cr, 6.2% of W, 1.03% of Mo, 5.0% of Re, 6.1% of Al, 8.0% of Ta, 0.07% of Hf, 0.085% of C, 0.012% of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1140.06g of nickel particles, 234g of cobalt particles, 96g of chromium particles, 124g of tungsten particles, 20.6g of molybdenum particles, 100g of rhenium particles, 122g of aluminum particles, 160g of tantalum particles, 1.4g of hafnium particles, 1.7g of carbon powder and 0.24g of boron powder into a vacuum induction furnace for smelting, then adopting a liquid metal cooling method for directional solidification, and adopting a spiral crystal selection method for preparing a boron-containing nickel-based single crystal superalloy rod blank with the orientation of [001 ]; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, performing primary solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the temperature of the first-stage solution treatment is 1295 ℃ and the time is 15 hours;

Example 5

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 11.8% of Co, 4.9% of Cr, 6.3% of W, 1.035% of Mo, 5.05% of Re, 6.15% of Al, 8.05% of Ta, 0.08% of Hf, 0.086% of C, 0.013% of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1130.72g of nickel particles, 236g of cobalt particles, 98g of chromium particles, 126g of tungsten particles, 20.7g of molybdenum particles, 101g of rhenium particles, 123g of aluminum particles, 161g of tantalum particles, 1.6g of hafnium particles, 1.72g of carbon powder and 0.26g of boron powder into a vacuum induction furnace for smelting, then adopting a liquid metal cooling method for directional solidification, and adopting a spiral crystal selection method for preparing a boron-containing nickel-based single crystal superalloy rod blank with the orientation of [001 ]; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, carrying out secondary solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the secondary solution treatment comprises the following specific processes: firstly, processing at 1280 ℃ for 8h, and then processing at 1285 ℃ for 15 h;

step four, carrying out aging treatment on the boron-containing nickel-based single crystal high-temperature alloy rod subjected to solution treatment in the step three to obtain a heat-treated boron-containing nickel-based single crystal high-temperature alloy rod; the aging treatment comprises the following specific processes: the treatment was carried out at 1080 ℃ for 6h and then at 870 ℃ for 24 h.

Fig. 10 is a microstructure diagram of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment, and it can be seen from fig. 10 that the structure of the alloy after heat treatment becomes uniform and no harmful phase such as eutectic occurs, which illustrates that the heat treatment process of the present embodiment makes the diffusion of elements in the boron-containing nickel-based single crystal superalloy rod very sufficient, and eliminates the element segregation and eutectic structure.

Fig. 11 is a size diagram of the γ 'phase of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in this embodiment, and it can be seen from fig. 11 that the size of the γ' phase in the boron-containing nickel-based single crystal superalloy rod after heat treatment is relatively uniform and the morphology of the γ 'phase is a regular cube, and the size of the γ' phase measured by Image pro plus software is 380nm, and the volume fraction is as high as 61.2%.

Example 6

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 11.9 percent of Co, 5.0 percent of Cr, 6.4 percent of W, 1.036 percent of Mo, 5.1 percent of Re, 6.16 percent of Al, 8.06 percent of Ta, 0.085 percent of Hf, 0.087 percent of C, 0.014 percent of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1123.16g of nickel particles, 238g of cobalt particles, 100g of chromium particles, 128g of tungsten particles, 20.72g of molybdenum particles, 102g of rhenium particles, 123.2g of aluminum particles, 161.2g of tantalum particles, 1.7g of hafnium particles, 1.74g of carbon powder and 0.28g of boron powder into a vacuum induction furnace for smelting, then carrying out directional solidification by adopting a liquid metal cooling method, and preparing a boron-containing nickel-based single crystal high-temperature alloy bar blank with the orientation of [001] by adopting a spiral crystal selection method; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, carrying out secondary solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the secondary solution treatment comprises the following specific processes: firstly, processing at 1285 ℃ for 8h, and then processing at 1290 ℃ for 15 h;

Fig. 12 is a microstructure diagram of the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment, and it can be seen from fig. 12 that the structure of the boron-containing nickel-based single crystal superalloy rod after heat treatment in the present embodiment is relatively uniform and does not have harmful phases such as eutectic, which illustrates that the heat treatment process in the present embodiment makes the elements in the boron-containing nickel-based single crystal superalloy rod diffuse very sufficiently, and eliminates the element segregation and the eutectic structure.

Fig. 13 is a graph showing the shape and size of the γ ' phase in the boron-containing nickel-based single crystal superalloy rod after heat treatment obtained in the present embodiment, and it can be seen from fig. 13 that the size of the γ ' phase in the boron-containing nickel-based single crystal superalloy rod after heat treatment of the present embodiment is more uniform, and the shape shows a regular cube, and the size of the γ ' phase is 420nm and the volume fraction is about 53% measured by Image pro plus software.

Example 7

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 12.0% of Co, 5.1% of Cr, 6.5% of W, 1.037% of Mo, 5.15% of Re, 6.2% of Al, 8.07% of Ta, 0.087% of Hf, 0.088% of C, 0.015% of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1115.06g of nickel particles, 240g of cobalt particles, 102g of chromium particles, 130g of tungsten particles, 20.74g of molybdenum particles, 103g of rhenium particles, 124g of aluminum particles, 161.4g of tantalum particles, 1.74g of hafnium particles, 1.76g of carbon powder and 0.3g of boron powder into a vacuum induction furnace for smelting, then carrying out directional solidification by adopting a liquid metal cooling method, and preparing a boron-containing nickel-based single crystal high-temperature alloy bar blank with the orientation of [001] by adopting a spiral crystal selection method; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, carrying out three-stage solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the specific process of the third-stage solution treatment is as follows: firstly treating at 1285 ℃ for 8h, then treating at 1290 ℃ for 15h, and then treating at 1295 ℃ for 24 h;

Example 8

The heat treatment process of the boron-containing nickel-based single crystal superalloy of the embodiment comprises the following components in percentage by mass: 12.3 percent of Co, 5.3 percent of Cr, 6.6 percent of W, 1.04 percent of Mo, 5.2 percent of Re, 6.3 percent of Al, 8.1 percent of Ta, 0.09 percent of Hf, 0.09 percent of C, 0.016 percent of B and the balance of Ni; the heat treatment process comprises the following steps:

adding 1099.28g of nickel particles, 246g of cobalt particles, 106g of chromium particles, 132g of tungsten particles, 20.8g of molybdenum particles, 104g of rhenium particles, 126g of aluminum particles, 162g of tantalum particles, 1.8g of hafnium particles, 1.8g of carbon powder and 0.32g of boron powder into a vacuum induction furnace for smelting, then adopting a liquid metal cooling method for directional solidification, and adopting a spiral crystal selection method for preparing a boron-containing nickel-based single crystal superalloy rod blank with the orientation of [001 ]; the temperature gradient of the directional solidification is 150K/cm, and the drawing speed is 100 mu m/s;

step three, carrying out three-stage solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the specific process of the third-stage solution treatment is as follows: firstly treating at 1280 ℃ for 8h, then treating at 1285 ℃ for 15h, and then treating at 1290 ℃ for 24 h;

step four, carrying out aging treatment on the boron-containing nickel-based single crystal high-temperature alloy rod subjected to solution treatment in the step three to obtain a heat-treated boron-containing nickel-based single crystal high-temperature alloy rod; the aging treatment comprises the following specific processes: the treatment was carried out at 1050 ℃ for 5h and then at 870 ℃ for 23 h.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the technical essence of the invention are still within the protection scope of the technical solution of the invention.

Claims

1. The heat treatment process of the boron-containing nickel-based single crystal superalloy is characterized in that the boron-containing nickel-based single crystal superalloy consists of the following components in percentage by mass: 11.3 to 12.3 percent of Co, 4.4 to 5.3 percent of Cr, 5.71 to 6.6 percent of W, 1.01 to 1.04 percent of Mo, 4.8 to 5.2 percent of Re, 5.9 to 6.3 percent of Al, 7.8 to 8.1 percent of Ta, 0.05 to 0.09 percent of Hf0, 0.08 to 0.09 percent of C, 0.008 to 0.016 percent of B and the balance of Ni; the heat treatment process comprises the following steps:

step three, carrying out solution treatment on the boron-containing nickel-based single crystal superalloy rod obtained in the step two; the solid solution treatment is secondary solid solution treatment, and the specific process of the secondary solid solution treatment is as follows: firstly, processing for 8h at 1285-1310 ℃, and then processing for 15h at 1290-1315 ℃;

2. The heat treatment process of the boron-containing nickel-based single crystal superalloy according to claim 1, wherein the diameter of the boron-containing nickel-based single crystal superalloy rod in the second step is 12mm, and the length of the boron-containing nickel-based single crystal superalloy rod is 5 mm.

3. The heat treatment process of the boron-containing nickel-based single crystal superalloy as claimed in claim 1, wherein the equipment adopted for the solution treatment in the third step and the aging treatment in the fourth step is an SX2-9-17TP high temperature box furnace, the maximum temperature rise rate of the SX2-9-17TP high temperature box furnace is 10 ℃/min, and the temperature control precision is +/-1 ℃.