A heat treatment process for improving high-temperature stress-rupture properties of GH2909 alloy

Abstract

The application provides a heat treatment process for improving high-temperature stress-rupture property of GH2909 alloy, and relates to the technical field of high-temperature alloy heat treatment. The method comprises the following steps: pretreating the surface of an alloy part to obtain a surface-cleaned alloy part; then performing primary solid solution treatment and air cooling to room temperature; then performing high-temperature pretreatment and air cooling to room temperature; and finally performing primary aging treatment on the alloy part, and air cooling to obtain the alloy part with improved high-temperature stress-rupture property. The unique and efficient heat treatment of the GH2909 alloy through primary solid solution treatment + stabilization treatment + primary aging treatment can synergistically improve the plasticity and high-temperature stress-rupture property of the alloy; the method is simple and easy to operate, green and environmentally friendly, low in cost, short in process, high in efficiency, and beneficial to industrial large-scale production and popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-temperature alloy heat treatment, in particular to a heat treatment process for improving the high-temperature durability of GH2909 alloy. BACKGROUND

[0002] High-temperature alloys are a kind of metal materials developed according to the needs of aircraft jet engines, which can withstand complex stress under high-temperature oxidation and gas corrosion conditions of 600-1200℃ and can serve stably for a long time. High-temperature alloys are mainly used to manufacture hot end components of aircraft engines and gas turbines, and are also important materials for aerospace rocket engines, energy and chemical industries; in the prior art, high-temperature alloys can be divided into three categories according to the types of base elements: nickel-based, cobalt-based and iron-based high-temperature alloys, among which nickel-based alloys are most commonly used.

[0003] GH2909 alloy is a γ′ phase precipitation strengthened high-temperature alloy, and the microstructure after heat treatment is composed of γ solid solution, γ′ phase, Laves phase and ε phase. The strength of the alloy mainly comes from the number and size of γ′ phase precipitates. Generally, the alloy material with improved room temperature strength and stability can be obtained only after one solid solution treatment + two aging treatments or two solid solution treatments + two aging treatments; however, these methods consume a large amount of heat energy, the preparation process is long, and the strength and plasticity cannot be well improved.

[0004] For example, Chinese patent CN114277232A discloses a method and device for improving the strength of GH2909 alloy forgings, and the heat treatment method is two solid solution treatments + two aging treatments. The total treatment time is at least about 18h after not counting the temperature rising and falling time, the treatment cycle is long, the cost is high, the strength of the obtained material is low, the plasticity is reduced or increased, and the change rule is difficult to predict.

[0005] Chinese patent CN114807796A discloses a heat treatment process for improving the high-temperature plasticity of GH2909 alloy, and the heat treatment method is preliminary heat treatment + two-stage solid solution treatment. The total treatment time is at least about 18h after not counting the temperature rising and falling time. Although the two-stage solid solution treatment can improve the high-temperature plasticity of the alloy, the preparation process is time-consuming, the cooling speed is fast, and the effect of improving the plasticity is not good. SUMMARY

[0006] In order to solve the poor high temperature stress rupture performance of GH2909 alloy in the prior art, the complex two-step aging process, the complex two-step aging treatment process, the complex two-step solid solution treatment + two-step aging treatment process, the complex preliminary heat treatment + two-step solid solution treatment process, the long time-consuming process, the uncoordinated improvement of strength and plasticity, the irregular plasticity change rule and other technical problems, the present application provides a heat treatment process for improving the high temperature stress rupture performance of GH2909 alloy, and the technical scheme is as follows:

[0007] A heat treatment process for improving the high temperature stress rupture performance of GH2909 alloy, and the heat treatment process for improving the high temperature stress rupture performance of GH2909 alloy comprises the following steps:

[0008] S1, surface pretreatment: the surface of the GH2909 alloy part is pretreated to obtain a surface cleaned GH2909 alloy part;

[0009] S2, one solid solution treatment: the surface cleaned GH2909 alloy part in S1 is subjected to one solid solution treatment, and is air cooled to room temperature to obtain a solid solution treated GH2909 alloy part;

[0010] S3, stabilization heat treatment: the solid solution treated GH2909 alloy part in S2 is subjected to high temperature pretreatment, and is air cooled to room temperature to obtain a stabilization treated GH2909 alloy part;

[0011] S4, one aging treatment: the stabilization heat treated GH2909 alloy part in S3 is subjected to one aging treatment, and is air cooled to room temperature to obtain a GH2909 alloy with improved high temperature stress rupture performance.

[0012] Optionally, the GH2909 alloy in S1 is in a rod shape with a size of Φ170mm, φ220mm, Φ300mm, and a treatment state of standard long-term aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC); the tensile strength at room temperature is 1300-1330MPa, the standard deviation is 15-27MPa; the yield strength at room temperature is 965-1020MPa, the standard deviation is 19-35MPa; the elongation at room temperature is 14.7-18.2%, the standard deviation is 0.7-2.1%; the reduction of area at room temperature is 27-35%, the standard deviation is 2.7-5.9%; the hardness at room temperature is 370-380HB, the standard deviation is 2-7HB; the tensile strength at 650℃ is 975-1010MPa, the standard deviation is 15-25MPa; the yield strength at 650℃ is 827-870MPa, the standard deviation is 20-37MPa; the elongation at 650℃ is 15.5-17.4%, the standard deviation is 3.8-7.3%; the reduction of area at 650℃ is 28.0-43.5%, the standard deviation is 6.7-11.9%; the stress-rupture life at 650℃ and 510MPa is 57.7-67.4h, the standard deviation is 2.7-7.6h; the elongation after fracture at 650℃ and 510MPa is 12.4-20.8%, the standard deviation is 5.1-10.4%; the reduction of area after fracture at 650℃ and 510MPa is 29-41%, the standard deviation is 4.7-6.9%.

[0013] Optionally, the shape of GH2909 alloy in S1 is ring, the size is 500-600mm in outer diameter, 400-500mm in inner diameter, 70-100mm in height, chord sampling, and the treatment state is standard long-term aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC); the tensile strength at room temperature is 1300-1340MPa, the standard deviation is 15-27MPa; the yield strength at room temperature is 955-1031MPa, the standard deviation is 20-37MPa; the elongation at room temperature is 15.0-20.2%, the standard deviation is 0.7-2.3%; the reduction of area at room temperature is 27-38%, the standard deviation is 3.2-4.8%; the hardness at room temperature is 365-380HB, the standard deviation is 2-8HB; the tensile strength at 650℃ high temperature is 985-1015MPa, the standard deviation is 16-19MPa; the yield strength at 650℃ high temperature is 837-875MPa, the standard deviation is 25-37MPa; the elongation at 650℃ high temperature is 17.5-20.4%, the standard deviation is 3.8-6.5%; the reduction of area at 650℃ high temperature is 27.0-44.5%, the standard deviation is 6.7-10.7%; the stress-rupture life at 650℃ high temperature and 510MPa stress is 60-65.4h, the standard deviation is 2.7-4.6h; the elongation after fracture at 650℃ high temperature and 510MPa stress is 14.4-21.8%, the standard deviation is 5.1-7.8%; the reduction of area at 650℃ high temperature and 510MPa stress is 31-43%, the standard deviation is 4.7-5.7%.

[0014] Optionally, in S1, the GH2909 alloy has a shape of a square billet with a size of 100mm x 100mm x 100mm in outer diameter, and a treatment state of standard long-term double aging treatment 1 (720℃ x (8±0.5)h / FC→620℃ x (8±0.5)h / AC); the tensile strength at room temperature is 1310-1345MPa with a standard deviation of 14-20MPa; the yield strength at room temperature is 970-1040MPa with a standard deviation of 20-40MPa; the elongation at room temperature is 15.5-19.2% with a standard deviation of 0.6-2.4%; the reduction of area at room temperature is 26-35% with a standard deviation of 2.4-4.3%; the hardness at room temperature is 375-385HB with a standard deviation of 3-7HB; the tensile strength at 650℃ is 980-1020MPa with a standard deviation of 10-18MPa; the yield strength at 650℃ is 848-877MPa with a standard deviation of 25-29MPa; the elongation at 650℃ is 16.5-21.4% with a standard deviation of 3.8-7.1%; the reduction of area at 650℃ is 27.1-41.8% with a standard deviation of 6.7-9.7%; the stress-rupture life at 650℃ and 510MPa is 58.0-66.7h with a standard deviation of 1.9-4.1h; the elongation after fracture at 650℃ and 510MPa is 15.1-19.8% with a standard deviation of 2.7-6.7%; the reduction of area after fracture at 650℃ and 510MPa is 29-42% with a standard deviation of 4.8-6.2%.

[0015] Optionally, in S2, the temperature of the primary solid solution treatment is 970-1010℃, and the holding time is 60-70min; and then air cooling to room temperature at a rate of 50-80℃ / min.

[0016] Optionally, in S3, the temperature of the stabilization treatment is 810-840℃, and the holding time is 30-50min; and then air cooling to room temperature at a rate of 50-80℃ / min.

[0017] Optionally, in S4, the temperature of the primary aging treatment is 640-660℃, and the holding time is 6-8h; and then air cooling to room temperature at a rate of 50-80℃ / min.

[0018] Optionally, the GH2909 alloy in S3 is in a rod shape with a size of Φ170mm, Φ220mm or Φ300mm, and after one solid solution treatment + stabilization treatment + one aging treatment, the tensile strength at room temperature is 1350-1380MPa with a standard deviation of 10-17MPa, the yield strength at room temperature is 1020-1050MPa with a standard deviation of 9-14MPa, the elongation at room temperature is 17.9-23.2% with a standard deviation of 0.8-1.7%, the reduction of area at room temperature is 27-39% with a standard deviation of 2.9-4.8%, the hardness at room temperature is 370-385HB with a standard deviation of 3-8HB, the tensile strength at 650℃ is 1005-1025MPa with a standard deviation of 12-26MPa, the yield strength at 650℃ is 850-870MPa with a standard deviation of 14-27MPa, the elongation at 650℃ is 11.5-21.4% with a standard deviation of 2.3-5.7%, the reduction of area at 650℃ is 35.0-44.5% with a standard deviation of 2.7-4.9%, the stress-rupture life at 650℃ and 510MPa is 90.4-105.1h with a standard deviation of 2.1-3.4h, the elongation after fracture at 650℃ and 510MPa is 17.1-22.7% with a standard deviation of 2.7-5.1%, and the reduction of area after fracture at 650℃ and 510MPa is 37.0-47.5% with a standard deviation of 2.5-5.2%.

[0019] Optionally, the GH2909 alloy in S3 has a shape of a ring, a size of an outer diameter of 500-600 mm, an inner diameter of 400-500 mm, a height of 70-100 mm, and is sampled in a chord direction, and after one solid solution treatment + stabilization treatment + one aging treatment, the tensile strength at room temperature is 1340-1370 MPa, the standard deviation is 11-15 MPa; the yield strength at room temperature is 1025-1060 MPa, the standard deviation is 10-14 MPa; the elongation at room temperature is 18.8-24.5%, the standard deviation is 0.7-1.4%; the reduction of area at room temperature is 30-39%, the standard deviation is 2.7-4.2%; the hardness at room temperature is 370-385 HB, the standard deviation is 3-9 HB; the tensile strength at 650 ℃ is 1000-1020 MPa, the standard deviation is 12-20 MPa; the yield strength at 650 ℃ is 830-870 MPa, the standard deviation is 20-30 MPa; the elongation at 650 ℃ is 11.5-20.4%, the standard deviation is 3.7-5.1%; the reduction of area at 650 ℃ is 35.0-41.5%, the standard deviation is 2.7-3.8%; the stress rupture life at 650 ℃ and 510 MPa is 98.4-120.1 h, the standard deviation is 4.1-6.4 h; the elongation after fracture at 650 ℃ and 510 MPa is 18.2-28.7%, the standard deviation is 2.2-5.0%; the reduction of area after fracture at 650 ℃ and 510 MPa is 38.0-48.0%, the standard deviation is 2.3-6.2%.

[0020] Optionally, the shape of the GH2909 alloy in S3 is a square billet with a size of 100mm*100mm*100mm, and after one solid solution treatment + stabilization treatment + one aging treatment, the tensile strength at room temperature is 1200-1230MPa, the standard deviation is 15-28MPa; the yield strength at room temperature is 890-945MPa, the standard deviation is 19-35MPa; the elongation at room temperature is 14.7-18.2%, the standard deviation is 0.7-2.1%; the reduction of area at room temperature is 26-37%, the standard deviation is 2.7-5.9%; the hardness at room temperature is 360-365HB, the standard deviation is 2-7HB; the tensile strength at high temperature of 650 DEG C is 935-980MPa, the standard deviation is 15-25MPa; the yield strength at high temperature of 650 DEG C is 784-820MPa, the standard deviation is 20-40MPa; the elongation at high temperature of 650 DEG C is 15.5-29.4%, the standard deviation is 3.8-9.3%; the reduction of area at high temperature of 650 DEG C is 27.0-47.5%, the standard deviation is 6.7-11.9%; the stress rupture life under the condition of 510MPa stress at high temperature of 650 DEG C is 95.4-111.2h, the standard deviation is 5.1-6.8h; the elongation after fracture under the condition of 510MPa stress at high temperature of 650 DEG C is 17.5-24.7%, the standard deviation is 2.2-4.8%; the reduction of area after fracture under the condition of 510MPa stress at high temperature of 650 DEG C is 36.2-47.1%, the standard deviation is 2.2-6.9%.

[0021] Optionally, the microstructure of the GH2909 alloy part after vacuum brazing + one aging treatment is composed of 73.95-77.45% of γ solid solution, 14.71-15.43% of γ' phase, 4.06-5.36% of Laves phase, 1.21-1.89% of epsilon phase and 2.57-3.37% of G phase by volume fraction; (the γ solid solution is generally not studied, and the shape and size are not fixed) wherein the γ' phase is in the shape of fine spherical or cubic, and the average size is 18.84-19.72nm; the Laves phase is in the shape of spherical or short rod, the average long axis length is 1.45-1.84μm, and the average short axis length is 0.75-0.86μm; the epsilon phase is in the shape of needle, and the average length is 0.89-1.61μm; the G phase is in the shape of block or short rod, and the average size is 0.91-1.24μm.

[0022] The technical principle of the application is:

[0023] The heat treatment process of the application does not focus on the heating rate and the cooling rate of the process, the heating rate is selected to ensure the normal use of the heating furnace, a lower heating power is selected, about 10-30 DEG C / min; the cooling rate is selected in the form of air cooling, since the air cooling rate is a range of values, and the specific value cannot be selected artificially, the value is only an empirical value according to the size of the alloy part; the focus of the application is on the selection of the temperature and the holding time of the stabilization treatment and the primary aging treatment: the temperature of the stabilization treatment is 810-840 DEG C, according to the CCT curve of the alloy precipitated phase, the precipitation temperature range of the epsilon phase is between 700-900 DEG C, the precipitation temperature of the G phase is between 680-850 DEG C, and the temperature close to the peak temperature of the G phase is selected as the stabilization treatment temperature; the holding time is selected to be 30-50 min, according to the CCT curve of the alloy, although the precipitation temperature of the epsilon phase and the G phase is coincident, the epsilon phase has a slow kinetics process, and needs to be kept for about 1 h before precipitation, while the G phase is precipitated before the epsilon phase. The temperature of the primary aging treatment is 640-660 DEG C, and the holding time is 6-8 h, according to the CCT curve of the alloy, the precipitation temperature of the main strengthening phase gamma prime of the alloy is 600-720 DEG C, a lower temperature close to the precipitation limit is selected for aging, which can ensure the dense precipitation of the gamma prime phase to approach saturation, and also will not be excessively large, which ensures the stability of the alloy strength.

[0024] Compared with the prior art, the above technical solution has at least the following beneficial effects:

[0025] The above scheme provides a heat treatment process for improving the high-temperature endurance performance of GH2909 alloy, which can solve the technical problems of poor high-temperature endurance performance of GH2909 alloy, complex process, long process time, irregular high-temperature plasticity change and the like in the prior art.

[0026] The application replaces the twice solid solution treatment and twice aging treatment, the preliminary heat treatment and two-stage solid solution treatment, shortens the process flow, reduces the process cost, and improves the process efficiency.

[0027] The heat treatment adopts the stabilization treatment + primary aging process, and replaces the relatively longer double aging process in the case of the same two-step process. By setting the stabilization treatment in the solid solution and aging temperature range, the G phase is precipitated at the grain boundary of the alloy in this stage, which plays a role in pinning the grain boundary together with the fine Laves phase at the grain boundary. In addition, the heat treatment process ensures the dense precipitation of the gamma prime phase in the alloy matrix, and the size is small and does not excessively grow. After the heat treatment, there is a suitable amount of G phase strengthening the grain boundary at the grain boundary, and the distribution of the gamma prime phase in the grain is dense, which has unexpected effects on improving the high-temperature endurance performance of the alloy under the premise of ensuring the strength of the alloy.

[0028] The multi-group durability detection result of the present application shows that, compared with the traditional solid solution + double aging process, the average high-temperature durability of the alloy after being treated by the method of the present application can reach more than 90h, which is increased by more than 40% compared with before process optimization.

[0029] In summary, compared with other traditional methods, the method of the present application can synergistically improve the plasticity and high-temperature durability of the alloy by once solid solution treatment + stabilization treatment + once aging treatment of the specially designed high-efficiency heat treatment of the GH2909 alloy; the method is simple and easy to operate, green and environmentally friendly, low in cost, short in process, high in efficiency, and beneficial to industrial large-scale production and promotion. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0031] Figure 1 is a microstructure diagram of alloy grain and grain boundary of the GH2909 alloy after the heat treatment process for improving high-temperature durability in embodiment 1 of the present application;

[0032] Figure 2 is a microstructure diagram of alloy grain and grain boundary of the alloy after the traditional twice solid solution + double aging heat treatment process in the comparative example 1 of the present application. DETAILED DESCRIPTION

[0033] The technical solutions in the present application will be described below with reference to the drawings.

[0034] In the embodiments of the present application, the words such as "example", "for example" are used to represent as an example, illustration or description. Any embodiment or design scheme described as "example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present application, the meaning expressed by "and / or" can be both, or can be one of the two.

[0035] In the embodiments of the present application, "image" and "picture" can be used interchangeably at times. It should be pointed out that when the distinction is not emphasized, the meanings expressed are consistent.

[0036] In the embodiments of the present application, sometimes the subscript such as W1 can be written in the form of non-subscript such as W1. When the distinction is not emphasized, the meanings expressed are consistent.

[0037] To make the technical problems, technical solutions and advantages to be solved by the present application clearer, the following will be described in detail in conjunction with the drawings and specific embodiments.

[0038] A heat treatment process for improving high-temperature stress-rupture properties of GH2909 alloy, the heat treatment process for improving high-temperature stress-rupture properties of GH2909 alloy comprises the following steps:

[0039] S1, surface pretreatment: pretreating the surface of the GH2909 alloy part to obtain a surface-cleaned GH2909 alloy part;

[0040] S2, primary solid solution treatment: performing primary solid solution treatment on the surface-cleaned GH2909 alloy part of S1, and air cooling to room temperature to obtain a GH2909 alloy part after solid solution treatment;

[0041] S3, stabilization heat treatment: performing high-temperature pretreatment on the GH2909 alloy part after solid solution treatment of S2, and air cooling to room temperature to obtain a GH2909 alloy part after stabilization treatment;

[0042] S4, primary aging treatment: performing primary aging treatment on the GH2909 alloy part after stabilization heat treatment of S3, and air cooling to room temperature to obtain a GH2909 alloy with improved high-temperature stress-rupture properties.

[0043] In particular, the GH2909 alloy in S1 is in the shape of a rod with a size of Φ170 mm, Φ220 mm, Φ300 mm, and a treatment state of standard long-term double aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC); the tensile strength at room temperature is 1300-1330 MPa, and the standard deviation is 15-27 MPa; the yield strength at room temperature is 965-1020 MPa, and the standard deviation is 19-35 MPa; the elongation at room temperature is 14.7-18.2%, and the standard deviation is 0.7-2.1%; the reduction of area at room temperature is 27-35%, and the standard deviation is 2.7-5.9%; the hardness at room temperature is 370-380 HB, and the standard deviation is 2-7 HB; the tensile strength at 650℃ high temperature is 975-1010 MPa, and the standard deviation is 15-25 MPa; the yield strength at 650℃ high temperature is 827-870 MPa, and the standard deviation is 20-37 MPa; the elongation at 650℃ high temperature is 15.5-17.4%, and the standard deviation is 3.8-7.3%; the reduction of area at 650℃ high temperature is 28.0-43.5%, and the standard deviation is 6.7-11.9%; the stress-rupture life at 650℃ high temperature and 510 MPa stress is 57.7-67.4 h, and the standard deviation is 2.7-7.6 h; the elongation after fracture at 650℃ high temperature and 510 MPa stress is 12.4-20.8%, and the standard deviation is 5.1-10.4%; the reduction of area after fracture at 650℃ high temperature and 510 MPa stress is 29-41%, and the standard deviation is 4.7-6.9%.

[0044] In particular, the shape of GH2909 alloy in S1 is ring, the size is 500-600mm in outer diameter, 400-500mm in inner diameter, 70-100mm in height, chord sampling, and the treatment state is standard long-term aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC); the tensile strength at room temperature is 1300-1340MPa, the standard deviation is 15-27MPa; the yield strength at room temperature is 955-1031MPa, the standard deviation is 20-37MPa; the elongation at room temperature is 15.0-20.2%, the standard deviation is 0.7-2.3%; the reduction of area at room temperature is 27-38%, the standard deviation is 3.2-4.8%; the hardness at room temperature is 365-380HB, the standard deviation is 2-8HB; the tensile strength at 650℃ high temperature is 985-1015MPa, the standard deviation is 16-19MPa; the yield strength at 650℃ high temperature is 837-875MPa, the standard deviation is 25-37MPa; the elongation at 650℃ high temperature is 17.5-20.4%, the standard deviation is 3.8-6.5%; the reduction of area at 650℃ high temperature is 27.0-44.5%, the standard deviation is 6.7-10.7%; the stress-rupture life at 650℃ high temperature and 510MPa stress is 60-65.4h, the standard deviation is 2.7-4.6h; the elongation after fracture at 650℃ high temperature and 510MPa stress is 14.4-21.8%, the standard deviation is 5.1-7.8%; the reduction of area at 650℃ high temperature and 510MPa stress is 31-43%, the standard deviation is 4.7-5.7%.

[0045] In particular, the shape of the GH2909 alloy in S1 is a square billet with a size of 100 mm x 100 mm x 100 mm in outer diameter, and the treatment state is a standard long-term double aging treatment 1 (720℃ x (8±0.5)h / FC→620℃ x (8±0.5)h / AC); the tensile strength at room temperature is 1310-1345 MPa, and the standard deviation is 14-20 MPa; the yield strength at room temperature is 970-1040 MPa, and the standard deviation is 20-40 MPa; the elongation at room temperature is 15.5-19.2%, and the standard deviation is 0.6-2.4%; the reduction of area at room temperature is 26-35%, and the standard deviation is 2.4-4.3%; the hardness at room temperature is 375-385 HB, and the standard deviation is 3-7 HB; the tensile strength at high temperature of 650℃ is 980-1020 MPa, and the standard deviation is 10-18 MPa; the yield strength at high temperature of 650℃ is 848-877 MPa, and the standard deviation is 25-29 MPa; the elongation at high temperature of 650℃ is 16.5-21.4%, and the standard deviation is 3.8-7.1%; the reduction of area at high temperature of 650℃ is 27.1-41.8%, and the standard deviation is 6.7-9.7%; the stress-rupture life at high temperature of 650℃ and a stress of 510 MPa is 58.0-66.7h, and the standard deviation is 1.9-4.1h; the elongation after fracture at high temperature of 650℃ and a stress of 510 MPa is 15.1-19.8%, and the standard deviation is 2.7-6.7%; the reduction of area after fracture at high temperature of 650℃ and a stress of 510 MPa is 29-42%, and the standard deviation is 4.8-6.2%.

[0046] In particular, the temperature of the primary solid solution treatment in S2 is 970-1010℃, and the holding time is 60-70 min; and then air cooling to room temperature at a rate of 50-80℃ / min.

[0047] In particular, the temperature of the stabilization treatment in S3 is 810-840℃, and the holding time is 30-50 min; and then air cooling to room temperature at a rate of 50-80℃ / min.

[0048] In particular, the temperature of the primary aging treatment in S4 is 640-660℃, and the holding time is 6-8h; and then air cooling to room temperature at a rate of 50-80℃ / min.

[0049] In particular, the GH2909 alloy in S3 has a shape of a rod, a size of Φ170mm, Φ220mm, Φ300mm, and after once solid solution treatment + stabilization treatment + once aging treatment; the tensile strength at room temperature is 1350-1380MPa, the standard deviation is 10-17MPa; the yield strength at room temperature is 1020-1050MPa, the standard deviation is 9-14MPa; the elongation at room temperature is 17.9-23.2%, the standard deviation is 0.8-1.7%; the reduction of area at room temperature is 27-39%, the standard deviation is 2.9-4.8%; the hardness at room temperature is 370-385HB, the standard deviation is 3-8HB; the tensile strength at 650℃ high temperature is 1005-1025MPa, the standard deviation is 12-26MPa; the yield strength at 650℃ high temperature is 850-870MPa, the standard deviation is 14-27MPa; the elongation at 650℃ high temperature is 11.5-21.4%, the standard deviation is 2.3-5.7%; the reduction of area at 650℃ high temperature is 35.0-44.5%, the standard deviation is 2.7-4.9%; the stress rupture life at 650℃ high temperature and 510MPa stress is 90.4-105.1h, the standard deviation is 2.1-3.4h; the elongation after fracture at 650℃ high temperature and 510MPa stress is 17.1-22.7%, the standard deviation is 2.7-5.1%; the reduction of area at 650℃ high temperature and 510MPa stress is 37.0-47.5%, the standard deviation is 2.5-5.2%.

[0050] In particular, the shape of the GH2909 alloy in S3 is ring, the size is 500-600mm in outer diameter, 400-500mm in inner diameter, 70-100mm in height, chord sampling, after once solid solution treatment + stabilization treatment + once aging treatment; the tensile strength at room temperature is 1340-1370MPa, the standard deviation is 11-15MPa; the yield strength at room temperature is 1025-1060MPa, the standard deviation is 10-14MPa; the elongation at room temperature is 18.8-24.5%, the standard deviation is 0.7-1.4%; the reduction of area at room temperature is 30-39%, the standard deviation is 2.7-4.2%; the hardness at room temperature is 370-385HB, the standard deviation is 3-9HB; the tensile strength at 650℃ high temperature is 1000-1020MPa, the standard deviation is 12-20MPa; the yield strength at 650℃ high temperature is 830-870MPa, the standard deviation is 20-30MPa; the elongation at 650℃ high temperature is 11.5-20.4%, the standard deviation is 3.7-5.1%; the reduction of area at 650℃ high temperature is 35.0-41.5%, the standard deviation is 2.7-3.8%; the stress rupture life at 650℃ high temperature under 510MPa stress is 98.4-120.1h, the standard deviation is 4.1-6.4h; the elongation after fracture at 650℃ high temperature under 510MPa stress is 18.2-28.7%, the standard deviation is 2.2-5.0%; the reduction of area at 650℃ high temperature under 510MPa stress is 38.0-48.0%, the standard deviation is 2.3-6.2%.

[0051] In particular, the shape of the GH2909 alloy in S3 is a square billet with a size of 100 mm x 100 mm x 100 mm, and after one solid solution treatment + stabilization treatment + one aging treatment; the tensile strength at room temperature is 1200-1230 MPa, and the standard deviation is 15-28 MPa; the yield strength at room temperature is 890-945 MPa, and the standard deviation is 19-35 MPa; the elongation at room temperature is 14.7-18.2%, and the standard deviation is 0.7-2.1%; the reduction of area at room temperature is 26-37%, and the standard deviation is 2.7-5.9%; the hardness at room temperature is 360-365 HB, and the standard deviation is 2-7 HB; the tensile strength at high temperature of 650°C is 935-980 MPa, and the standard deviation is 15-25 MPa; the yield strength at high temperature of 650°C is 784-820 MPa, and the standard deviation is 20-40 MPa; the elongation at high temperature of 650°C is 15.5-29.4%, and the standard deviation is 3.8-9.3%; the reduction of area at high temperature of 650°C is 27.0-47.5%, and the standard deviation is 6.7-11.9%; the stress-rupture life at high temperature of 650°C and stress of 510 MPa is 95.4-111.2 h, and the standard deviation is 5.1-6.8 h; the elongation after fracture at high temperature of 650°C and stress of 510 MPa is 17.5-24.7%, and the standard deviation is 2.2-4.8%; the reduction of area after fracture at high temperature of 650°C and stress of 510 MPa is 36.2-47.1%, and the standard deviation is 2.2-6.9%.

[0052] In particular, the microstructure of the GH2909 alloy part after vacuum brazing + one aging treatment is composed of 73.95-77.45% by volume of γ solid solution, 14.71-15.43% by volume of γ' phase, 4.06-5.36% by volume of Laves phase, 1.21-1.89% by volume of ε phase, and 2.57-3.37% by volume of G phase; (the γ solid solution is generally not studied, and the shape and size are not fixed) wherein the γ' phase is in the shape of fine spherical or cubic, and the average size is 18.84-19.72 nm; the Laves phase is in the shape of spherical or short rod, and the average long axis length is 1.45-1.84 μm, and the average short axis length is 0.75-0.86 μm; the ε phase is in the shape of needle, and the average length is 0.89-1.61 μm; and the G phase is in the shape of block or short rod, and the average size is 0.91-1.24 μm.

[0053] Example 1

[0054] The application discloses a heat treatment process for improving high-temperature stress-rupture property of GH2909 alloy, wherein the GH2909 alloy is in a rod shape with a size of 170 mm, and the content of each element is as follows: C 0.01%, Si 0.40%, Co 13.48%, Ni 38.06%, Ti 1.64%, Nb 4.88%, Al 0.031%, Mo 0.04%, and the balance is Fe and inevitable impurities; the heat treatment process for improving high-temperature stress-rupture property of the GH2909 alloy comprises the following steps:

[0055] S1, surface pretreatment: the surface of the GH2909 alloy part is pretreated to remove the surface oxide layer or oil stain, and finally cleaned and dried to obtain a GH2909 alloy part with a clean surface; the GH2909 alloy part is in a rod shape with a size of 170 mm, and is in a standard long-time double aging treatment 1 (720 DEG C x (8+ / -0.5) h / FC→620 DEG C x (8+ / -0.5) h / AC), and the sampling size is 10 mm, and the performance is shown in Table 1:

[0056] Table 1

[0057]

[0058]

[0059] S2, primary solid solution treatment: the GH2909 alloy part with a clean surface in S1 is subjected to primary solid solution treatment, the temperature of the primary solid solution treatment is 980 DEG C, and the holding time is 65 min; and then air cooling to room temperature at a rate of 65 DEG C / min to obtain the GH2909 alloy part after solid solution treatment;

[0060] S3, stabilization treatment: the GH2909 alloy part after the solid solution treatment in S2 is subjected to stabilization treatment, the temperature of the stabilization treatment is 840 DEG C, and the holding time is 30 min; and then air cooling to room temperature at a rate of 65 DEG C / min to obtain the GH2909 alloy part after the stabilization treatment;

[0061] S4, primary aging treatment: the GH2909 alloy part after the stabilization treatment is subjected to primary aging treatment, the temperature of the primary aging treatment is 640 DEG C, and the holding time is 6.5 h; and then air cooling to room temperature at a rate of 65 DEG C / min to obtain the GH2909 alloy part with improved high-temperature stress-rupture property.

[0062] The GH2909 alloy part in the embodiment is in a rod shape with a size of 170 mm, and the sampling size is 10 mm, and the performance after the primary solid solution treatment, the stabilization treatment and the primary aging treatment is shown in Table 2:

[0063] Table 2

[0064]

[0065] like Figure 1 As shown, the microstructure of the GH2909 alloy with improved high-temperature creep performance in this example consists of 76.81% γ solid solution, 14.77% γ′ phase, 4.37% Laves phase, 1.27% ε phase, and 2.78% G phase by volume. (γ solid solution is generally not studied, and its shape and size are not fixed.) Among them, the γ′ phase is shaped as fine spherical or cubic, with an average size of 18.89 nm; the Laves phase is shaped as spherical or short rod-shaped, with an average major axis length of 1.51 μm and an average minor axis length of 0.77 μm; the ε phase is shaped as needle-like, with an average length of 1.12 μm; and the G phase is shaped as blocky or short rod-shaped, with an average size of 0.97 μm.

[0066] Comparative Example 1

[0067] A heat treatment process for improving the high-temperature creep rupture performance of GH2909 alloy is disclosed. The GH2909 alloy used is in rod shape with a diameter of φ170mm. The elemental composition, by mass percentage, is: C 0.01%, Si 0.40%, Co 13.48%, Ni 38.06%, Ti 1.64%, Nb 4.88%, Al 0.031%, Mo 0.04%, with the balance being Fe and unavoidable impurities. The heat treatment process for improving the high-temperature creep rupture performance of the GH2909 alloy comprises the following steps:

[0068] S1. Surface Pretreatment: The surface of the GH2909 alloy part is pretreated to remove the surface oxide layer or oil stains. Finally, it is cleaned and dried to obtain a clean GH2909 alloy part. The GH2909 alloy part is rod-shaped with a size of Φ170mm. The treatment state is standard long-term double aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC). The sampling size is Φ10mm. The performance is shown in Table 3 below.

[0069] Table 3

[0070]

[0071]

[0072] S2. First solution treatment: The GH2909 alloy parts with cleaned surface from S1 are subjected to a first solution treatment at a temperature of 990℃ and a holding time of 70min. After that, they are air-cooled to room temperature at a rate of 65℃ / min to obtain the solution-treated GH2909 alloy parts.

[0073] S3. Two-time aging treatment: The GH2909 alloy after the S2 solution treatment is subjected to two-time aging treatments. The temperature of the two aging treatments is 720℃ and held for 8 hours. Then, it is cooled in the furnace to 620℃ and held for 8 hours. It is then taken out and air-cooled to room temperature at a rate of 65℃ / min to obtain the GH2909 alloy after standard double-aging heat treatment 1.

[0074] The 70mm×50mm×50mm GH2909 alloy component used in this comparative example, after one solution treatment and two aging treatments, is rod-shaped with a dimension of Φ170mm and a sampling size of Φ10mm. The mechanical properties of the GH2909 alloy after standard solution treatment and double aging treatment are shown in Table 4 below:

[0075] Table 4

[0076]

[0077] like Figure 2 As shown, the microstructure of the GH2909 alloy in Comparative Example 1 consists of 73.81% γ solid solution, 20.41% γ′ phase, 4.48% Laves phase, 1.11% ε phase, and 0.19% G phase by volume. (γ solid solution is generally not studied, and its shape and size are not fixed.) Among them, the γ′ phase is cubic in shape with an average size of 29.83 nm; the Laves phase is spherical or short rod-shaped with an average major axis length of 1.63 μm and an average minor axis length of 0.87 μm; the ε phase is acicular with an average length of 1.54 μm; and the G phase is blocky or short rod-shaped with an average size of 0.59 μm.

[0078] and Figure 1 Compared to the heat treatment process shown in the embodiment, the distribution of alloy grains and grain boundary precipitates after heat treatment is different. Figure 2 The process of Comparative Example 1 showed that after processing, the distribution of G phase at the grain boundaries of the alloy was less, or even absent.

[0079] A comparison of the high-temperature creep rupture life values ​​between Comparative Example 1 and Example 1 shows that the GH2909 alloy treated with the process described in this invention achieves a creep rupture life of up to 90 hours, which is a significant improvement over the high-temperature creep rupture performance after traditional standard aging treatment. Specifically, the creep rupture life is increased by more than 25 hours compared to before optimization, representing an improvement of over 40%. This overcomes the technical barrier of low high-temperature creep rupture performance of the GH2909 alloy in actual production.

[0080] Comparative Example 2

[0081] The application discloses a heat treatment process for improving high-temperature stress-rupture property of GH2909, wherein the GH2909 alloy is in a rod shape with a size of 170 mm, and the content of each element is as follows in percentage by mass: C 0.01%, Si 0.40%, Co 13.48%, Ni 38.06%, Ti 1.64%, Nb 4.88%, Al 0.031%, Mo 0.04%, and the balance of Fe and inevitable impurities; the heat treatment process for improving high-temperature stress-rupture property of the GH2909 alloy comprises the following steps:

[0082] S1, surface pretreatment: the surface of the GH2909 alloy part is pretreated to remove the surface oxide layer or oil stain, and finally cleaned and dried to obtain a GH2909 alloy part with a clean surface; the GH2909 alloy part is in a rod shape with a size of 170 mm, and is in a standard long-time double aging treatment 1 (720 DEG C x (8+ / -0.5) h / FC→620 DEG C x (8+ / -0.5) h / AC), and the sampling size is 10, and the performance is shown in Table 5:

[0083] Table 5

[0084]

[0085] S2, primary solid solution treatment: the GH2909 alloy part with a clean surface in S1 is subjected to primary solid solution treatment, the temperature of the primary solid solution treatment is 980 DEG C, and the holding time is 65 min; and then air-cooled to room temperature at a rate of 65 DEG C / min to obtain the GH2909 alloy part after the primary solid solution treatment;

[0086] S3, secondary solid solution treatment: the GH2909 alloy part after the primary solid solution treatment in S2 is subjected to secondary solid solution treatment, the temperature of the secondary solid solution treatment is 980 DEG C, and the holding time is 65 min; and then taken out and air-cooled to room temperature at a rate of 65 DEG C / min to obtain the GH2909 alloy part after the secondary solid solution treatment;

[0087] S4, double aging treatment: the GH2909 alloy part after the secondary solid solution treatment in S2 is subjected to double aging treatment, the temperature of the double aging treatment is 720 DEG C, and the holding time is 8 h; and then furnace-cooled to 620 DEG C and held for 8 h; and then taken out and air-cooled to room temperature at a rate of 65 DEG C / min to obtain the GH2909 alloy part after the standard double aging treatment 1.

[0088] The GH2909 alloy part in the comparative example is in a rod shape with a size of 170 mm, and the sampling size is 10; after the double solid solution and double aging treatment, the mechanical properties of the GH2909 alloy are shown in Table 6:

[0089] Table 6

[0090]

[0091]

[0092] The microstructure of the GH2909 alloy of Comparative Example 2 consists of 73.81% of γ solid solution in volume fraction, 20.16% of γ' phase in volume fraction, 4.91% of Laves phase in volume fraction, 1.06% of ε phase in volume fraction and 0.16% of G phase in volume fraction; (the γ solid solution is generally not studied, and the shape and size are not fixed) wherein the shape of the γ' phase is or cubic, and the average size is 29.76 nm; the shape of the Laves phase is spherical or short rod-shaped, the average long axis length is 1.21 μm, and the average short axis length is 0.77 μm; the shape of the ε phase is needle-shaped, and the average length is 1.40 μm; the shape of the G phase is blocky or short rod-shaped, and the average size is 0.55 μm

[0093] Comparative Example 1 is Example 1, which optimizes the aging treatment method in Comparative Example 1, adopts stable treatment matching one-time low-temperature aging treatment, instead of standard double-aging heat treatment, and shortens the total heat treatment time; Comparative Example 1 and Comparative Example 2, Example 1 optimizes the solid solution and aging heat treatment method in Comparative Example 2, adopts one-time solid solution instead of twice solid solution, and adopts stable treatment matching one-time aging treatment instead of standard double-aging treatment. Compared with Comparative Examples 1-2, Example 1 optimizes the process while making the alloy grain boundary precipitate more G phase, which together with the fine Laves phase pins the grain boundary, plays a role in strengthening the grain boundary, thereby improving the plasticity of the material and improving the high-temperature durability of the alloy.

[0094] Under the premise of meeting the actual production, the present application proposes a heat treatment process suitable for GH2909 alloy, which simplifies the traditional standard aging process. The process of stable treatment matching one-time aging improves the high-temperature durability of the alloy, optimizes the process and improves the service life of the alloy.

[0095] Compared with the traditional standard heat treatment process, the heat treatment described in the present application adopts one-time aging process, instead of the relatively complex two-step aging process, and shortens the aging time. Through stable treatment, G phase precipitates at the alloy grain boundary in this stage, and together with the fine Laves phase at the grain boundary, it plays a role in pinning the grain boundary. In addition, this heat treatment process ensures that the γ' phase in the alloy matrix precipitates densely and the size is small and does not overgrow. After this heat treatment, there is an appropriate amount of G phase at the grain boundary to strengthen the grain boundary, and the γ' phase distribution in the grain interior is dense, which has an unexpected effect on improving the high-temperature durability of the alloy under the premise of ensuring the strength of the alloy. Multiple sets of durability test results show that after being treated by the method described in the present application, the average high-temperature durability of the alloy can reach more than 90 h, and compared with the traditional heat treatment process, the performance improvement is more than 40%.

[0096] Example 2

[0097] A heat treatment process for improving high temperature stress rupture properties of GH2909 alloy, the used GH2909 alloy is in a rod shape, the size is φ220mm, and the element composition is recorded in percentage by mass as follows: C 0.022%, Si 0.26%, Co 14.08%, Ni 37.66%, Ti 1.67%, Nb 5.09%, Al 0.12%, Mo 0.50%, and the balance is Fe and inevitable impurities; the heat treatment process for improving high temperature stress rupture properties of the GH2909 alloy comprises the following steps:

[0098] S1, surface pretreatment: the surface of the GH2909 alloy part is pretreated to remove the surface oxide layer or oil stain, and finally cleaned and dried to obtain a GH2909 alloy part with a clean surface; the GH2909 alloy part is in a rod shape, the size is Φ220, the treatment state is standard long-term double aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC), the sampling size is Φ10, and the performance is shown in Table 7:

[0099] Table 7

[0100]

[0101]

[0102] S2, primary solid solution treatment: the GH2909 alloy part with a clean surface in S1 is subjected to primary solid solution treatment, the temperature of the primary solid solution treatment is 1000℃, and the holding time is 60min; and then air-cooled to room temperature at a rate of 65℃ / min to obtain the GH2909 alloy part after solid solution treatment;

[0103] S3, stabilization treatment: the GH2909 alloy part after solid solution treatment in S2 is subjected to stabilization treatment, the temperature of the stabilization treatment is 830℃, and the holding time is 35min; and then air-cooled to room temperature at a rate of 65℃ / min to obtain the GH2909 alloy part after stabilization treatment;

[0104] S4, primary aging treatment: the GH2909 alloy part after solid solution treatment in S3 is subjected to primary aging treatment, the temperature of the primary aging treatment is 640℃, and the holding time is 6.5h; and then air-cooled to room temperature at a rate of 65℃ / min to obtain the GH2909 alloy part with improved high temperature stress rupture properties.

[0105] The GH2909 alloy part in this embodiment is in a rod shape, the size is Φ220mm, the sampling size is Φ10mm, and after primary solid solution treatment + stabilization treatment + primary aging treatment, the performance is shown in Table 8:

[0106] Table 8

[0107]

[0108]

[0109] The microstructure of the GH2909 alloy with improved high-temperature stress-rupture property in the example consists of 77.19% by volume of γ solid solution, 14.34% by volume of γ' phase, 4.29% by volume of Laves phase, 1.21% by volume of ε phase and 2.97% by volume of G phase; wherein the γ' phase is in the shape of fine globular or cubic shape with an average size of 18.94 nm; the Laves phase is in the shape of globular or short rod shape with an average long axis length of 1.61 μm and an average short axis length of 0.81 μm; the ε phase is in the shape of needle with an average length of 1.21 μm; and the G phase is in the shape of block or short rod shape with an average size of 1.18 μm.

[0110] Example 3

[0111] A heat treatment process for improving high-temperature stress-rupture property of a GH2909 alloy, wherein the GH2909 alloy is in the shape of a ring with a size of an outer diameter of 600 mm, an inner diameter of 500 mm and a height of 80 mm, and the element composition is recorded in terms of mass percentage as follows: C 0.01%, Si 0.38%, Co 13.42%, Ni 37.64%, Ti 1.55%, Nb 4.68%, Al 0.039%, Mo 0.03%, and the balance being Fe and inevitable impurities; and the heat treatment process for improving high-temperature stress-rupture property of the GH2909 alloy comprises the following steps:

[0112] S1, surface pretreatment: the surface of the GH2909 alloy part is pretreated to remove the surface oxidation layer or oil stains, and finally cleaned and dried to obtain a GH2909 alloy part with a clean surface; the GH2909 alloy part is in the shape of a ring with a size of an outer diameter of 600 mm, an inner diameter of 500 mm and a height of 80 mm, and in a standard long-time double aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC) state, and the sampling size is Φ10, and the performance is shown in Table 9 as follows:

[0113] Table 9

[0114]

[0115]

[0116] S2, once solid solution treatment: the GH2909 alloy part with a clean surface in S1 is subjected to once solid solution treatment, the temperature of the once solid solution treatment is 1000 DEG C, the holding time is 60 min; then air cooling to room temperature, the air cooling rate is 65 DEG C / min, to obtain the GH2909 alloy part after solid solution treatment;

[0117] S3, stabilization treatment: the GH2909 alloy part after solid solution treatment in S2 is subjected to stabilization treatment, the temperature of the stabilization treatment is 820 DEG C, the holding time is 40 min; then air cooling to room temperature, the air cooling rate is 65 DEG C / min, to obtain the GH2909 alloy part after stabilization treatment;

[0118] S4, once aging treatment: the GH2909 alloy after stabilization treatment in S3 is subjected to once aging treatment, the temperature of the once aging treatment is 645 DEG C, the holding time is 7h; then air cooling to room temperature, the air cooling rate is 65 DEG C / min, to obtain the GH2909 alloy part with improved high temperature stress rupture property.

[0119] The shape of the GH2909 alloy part in the embodiment is a ring, the size is an outer diameter of 600 mm, an inner diameter of 500 mm, and a height of 80 mm, the sampling size is Φ10 mm, and after once solid solution treatment + stabilization treatment + once aging treatment, the performance is shown in the following table 10:

[0120] Table 10

[0121]

[0122]

[0123] The microstructure of the GH2909 alloy with improved high temperature stress rupture property in the embodiment is composed of 77.04% of γ solid solution, 14.51% of γ' phase, 4.57% of Laves phase, 1.01% of epsilon phase and 2.87% of G phase in volume fraction; wherein, the shape of the γ' phase is fine spherical or cubic, and the average size is 18.89 nm; the shape of the Laves phase is spherical or short rod, the average long axis length is 1.55 μm, and the average short axis length is 0.82 μm; the shape of the epsilon phase is needle-like, and the average length is 1.19 μm; the shape of the G phase is blocky or short rod, and the average size is 1.27 μm.

[0124] In the above scheme, the present application proposes a heat treatment process for improving the high temperature stress rupture property of GH2909 alloy, which can solve the technical problems of poor high temperature stress rupture property of GH2909 alloy, complex process, long process time, irregular high temperature plasticity change and the like in the prior art.

[0125] The present application replaces twice solid solution treatment and twice aging treatment, preliminary heat treatment and two-stage solid solution treatment by one solid solution treatment + stabilization treatment + one aging treatment, shortens the process flow, reduces the process cost, and improves the process efficiency.

[0126] The heat treatment adopts stabilization treatment + one aging process, and replaces the relatively longer double aging process in the same two-step process. By setting the stabilization treatment in the solid solution and aging temperature range, the G phase is precipitated at the alloy grain boundary in this stage, which plays a role of pinning the grain boundary together with the fine Laves phase at the grain boundary. In addition, the heat treatment process ensures the dense precipitation of the gamma prime phase in the alloy matrix, and the size is small and does not overgrow. After the heat treatment, the grain boundary is strengthened by the appropriate G phase, and the distribution of the gamma prime phase in the grain is dense, which has unexpected effect on improving the high-temperature durability of the alloy under the premise of ensuring the strength of the alloy.

[0127] The multiple group durability detection results show that, compared with the traditional solid solution + double aging process, the average high-temperature durability of the alloy after being treated by the method of the present application can reach more than 90h, which is more than 40% higher than before the process optimization.

[0128] In summary, compared with other traditional methods, the method of the present application performs unique and efficient heat treatment on GH2909 alloy by one solid solution treatment + stabilization treatment + one aging treatment, which synergistically improves the plasticity and high-temperature durability of the alloy. The method is simple, easy to operate, green, low in cost, short in process flow, high in efficiency, and conducive to large-scale industrial production and promotion.

[0129] It should be understood that the term "and / or" herein merely describes the association relationship of the associated objects, and means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone, wherein A and B can be singular or plural. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects, but can also represent an "and / or" relationship, which can be understood according to the context before and after.

[0130] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or the like means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b, or c can mean a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

[0131] It should be understood that the size of the sequence number of each process described above does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the application.

[0132] The above description is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A heat treatment process for improving high temperature stress rupture properties of GH2909 alloy, characterized in that, The heat treatment process for improving the high-temperature stress-rupture property of the GH2909 alloy comprises the following steps: S1, surface pretreatment: the surface of the GH2909 alloy part is pretreated to remove the surface oxide layer or oil stain, and finally cleaned and dried to obtain a surface-cleaned GH2909 alloy part; S2, primary solid solution treatment: the surface-cleaned GH2909 alloy part in S1 is subjected to primary solid solution treatment at a temperature of 970-1010℃ for 60-70min, and then air-cooled to room temperature at a rate of 50-80℃ / min to obtain a solid-solution-treated GH2909 alloy part; S3, stabilization heat treatment: the solid-solution-treated GH2909 alloy part in S2 is subjected to stabilization treatment at a temperature of 810-840℃ for 30-50min, and then air-cooled to room temperature at a rate of 50-80℃ / min to obtain a stabilization-treated GH2909 alloy part; S4, primary aging treatment: the stabilization-treated GH2909 alloy part in S3 is subjected to primary aging treatment at a temperature of 640-660℃ for 6-8h, and then air-cooled to room temperature at a rate of 50-80℃ / min to obtain a GH2909 alloy with improved high-temperature stress-rupture property.

2. The GH2909 alloy high temperature stress rupture performance enhancing thermal treatment process of claim 1, wherein, In S1, the GH2909 alloy has a rod shape with a size of Φ170mm, Φ220mm or Φ300mm, and a treatment state of standard long-term double aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC); the tensile strength at room temperature is 1300-1330MPa with a standard deviation of 15-27MPa; the yield strength at room temperature is 965-1020MPa with a standard deviation of 19-35MPa; the elongation at room temperature is 14.7-18.2% with a standard deviation of 0.7-2.1%; the reduction of area at room temperature is 27-35% with a standard deviation of 2.7-5.9%; the hardness at room temperature is 370-380HB with a standard deviation of 2-7HB; the tensile strength at 650℃ high temperature is 975-1010MPa with a standard deviation of 15-25MPa; the yield strength at 650℃ high temperature is 827-870MPa with a standard deviation of 20-37MPa; the elongation at 650℃ high temperature is 15.5-17.4% with a standard deviation of 3.8-7.3%; the reduction of area at 650℃ high temperature is 28.0-43.5% with a standard deviation of 6.7-11.9%; the stress-rupture life at 650℃ high temperature and 510MPa stress is 57.7-67.4h with a standard deviation of 2.7-7.6h; the elongation after rupture at 650℃ high temperature and 510MPa stress is 12.4-20.8% with a standard deviation of 5.1-10.4%; and the reduction of area after rupture at 650℃ high temperature and 510MPa stress is 29-41% with a standard deviation of 4.7-6.9%.

3. The GH2909 alloy high temperature stress rupture performance enhancing thermal treatment process of claim 1, wherein, The shape of GH2909 alloy in S1 is ring, the size is 500-600mm in outer diameter, 400-500mm in inner diameter, 70-100mm in height, chord sampling, and the treatment state is standard long-term aging treatment 1 (720℃×(8±0.5)h / FC→620℃×(8±0.5)h / AC); the tensile strength at room temperature is 1300-1340MPa, the standard deviation is 15-27MPa; the yield strength at room temperature is 955-1031MPa, the standard deviation is 20-37MPa; the elongation at room temperature is 15.0-20.2%, the standard deviation is 0.7-2.3%; the reduction of area at room temperature is 27-38%, the standard deviation is 3.2-4.8%; the hardness at room temperature is 365-380HB, the standard deviation is 2-8HB; the tensile strength at 650℃ is 985-1015MPa, the standard deviation is 16-19MPa; the yield strength at 650℃ is 837-875MPa, the standard deviation is 25-37MPa; the elongation at 650℃ is 17.5-20.4%, the standard deviation is 3.8-6.5%; the reduction of area at 650℃ is 27.0-44.5%, the standard deviation is 6.7-10.7%; the stress-rupture life at 650℃ and 510MPa is 60-65.4h, the standard deviation is 2.7-4.6h; the elongation after fracture at 650℃ and 510MPa is 14.4-21.8%, the standard deviation is 5.1-7.8%; the reduction of area at 650℃ and 510MPa is 31-43%, the standard deviation is 4.7-5.7%.

4. The GH2909 alloy high temperature stress rupture performance enhancing thermal treatment process of claim 1, wherein, The shape of GH2909 alloy in S1 is square billet with size of 100mmx100mmx100mm, and the treatment state is standard long-term aging treatment 1 (720℃x(8±0.5)h / FC→620℃x(8±0.5)h / AC); the tensile strength at room temperature is 1310-1345MPa, and the standard deviation is 14-20MPa; the yield strength at room temperature is 970-1040MPa, and the standard deviation is 20-40MPa; the elongation at room temperature is 15.5-19.2%, and the standard deviation is 0.6-2.4%; the reduction of area at room temperature is 26-35%, and the standard deviation is 2.4-4.3%; the hardness at room temperature is 375-385HB, and the standard deviation is 3-7HB; the tensile strength at 650℃ is 980-1020MPa, and the standard deviation is 10-18MPa; the yield strength at 650℃ is 848-877MPa, and the standard deviation is 25-29MPa; the elongation at 650℃ is 16.5-21.4%, and the standard deviation is 3.8-7.1%; the reduction of area at 650℃ is 27.1-41.8%, and the standard deviation is 6.7-9.7%; the stress-rupture life at 650℃ and 510MPa is 58.0-66.7h, and the standard deviation is 1.9-4.1h; the elongation after fracture at 650℃ and 510MPa is 15.1-19.8%, and the standard deviation is 2.7-6.7%; the reduction of area after fracture at 650℃ and 510MPa is 29-42%, and the standard deviation is 4.8-6.2%.

5. The GH2909 alloy high temperature stress rupture performance enhancing thermal treatment process of claim 2, wherein, The shape of GH2909 alloy in S3 is bar, the size is Φ170mm, Φ220mm, Φ300mm, after once solid solution treatment + stabilization treatment + once aging treatment; the tensile strength at room temperature is 1350-1380MPa, the standard deviation is 10-17MPa; the yield strength at room temperature is 1020-1050MPa, the standard deviation is 9-14MPa; the elongation at room temperature is 17.9-23.2%, the standard deviation is 0.8-1.7%; the reduction of area at room temperature is 27-39%, the standard deviation is 2.9-4.8%; the hardness at room temperature is 370-385HB, the standard deviation is 3-8HB; the tensile strength at 650℃ high temperature is 1005-1025MPa, the standard deviation is 12-26MPa; the yield strength at 650℃ high temperature is 850-870MPa, the standard deviation is 14-27MPa; the elongation at 650℃ high temperature is 11.5-21.4%, the standard deviation is 2.3-5.7%; the reduction of area at 650℃ high temperature is 35.0-44.5%, the standard deviation is 2.7-4.9%; the stress rupture life at 650℃ high temperature and 510MPa stress is 90.4-105.1h, the standard deviation is 2.1-3.4h; the elongation after fracture at 650℃ high temperature and 510MPa stress is 17.1-22.7%, the standard deviation is 2.7-5.1%; the reduction of area at 650℃ high temperature and 510MPa stress is 37.0-47.5%, the standard deviation is 2.5-5.2%.

6. The GH2909 alloy high temperature stress rupture performance enhancing thermal treatment process of claim 3, wherein, The shape of GH2909 alloy in S3 is ring, the size is 500-600mm in outer diameter, 400-500mm in inner diameter, 70-100mm in height, chord sampling, after once solid solution treatment + stabilization treatment + once aging treatment; the tensile strength at room temperature is 1340-1370MPa, the standard deviation is 11-15MPa; the yield strength at room temperature is 1025-1060MPa, the standard deviation is 10-14MPa; the elongation at room temperature is 18.8-24.5%, the standard deviation is 0.7-1.4%; the reduction of area at room temperature is 30-39%, the standard deviation is 2.7-4.2%; the hardness at room temperature is 370-385HB, the standard deviation is 3-9HB; the tensile strength at 650℃ high temperature is 1000-1020MPa, the standard deviation is 12-20MPa; the yield strength at 650℃ high temperature is 830-870MPa, the standard deviation is 20-30MPa; the elongation at 650℃ high temperature is 11.5-20.4%, the standard deviation is 3.7-5.1%; the reduction of area at 650℃ high temperature is 35.0-41.5%, the standard deviation is 2.7-3.8%; the stress rupture life at 650℃ high temperature and 510MPa stress is 98.4-120.1h, the standard deviation is 4.1-6.4h; the elongation after fracture at 650℃ high temperature and 510MPa stress is 18.2-28.7%, the standard deviation is 2.2-5.0%; the reduction of area at 650℃ high temperature and 510MPa stress is 38.0-48.0%, the standard deviation is 2.3-6.2%.

7. The GH2909 alloy high temperature stress rupture performance enhancing thermal treatment process of claim 4, wherein, The shape of the GH2909 alloy in S3 is a square billet with a size of 100mm*100mm*100mm, and after one solid solution treatment + stabilization treatment + one aging treatment, the tensile strength at room temperature is 1200-1230MPa, the standard deviation is 15-28MPa; the yield strength at room temperature is 890-945MPa, the standard deviation is 19-35MPa; the elongation at room temperature is 14.7-18.2%, the standard deviation is 0.7-2.1%; the reduction of area at room temperature is 26-37%, the standard deviation is 2.7-5.9%; the hardness at room temperature is 360-365HB, the standard deviation is 2-7HB; the tensile strength at 650℃ is 935-980MPa, the standard deviation is 15-25MPa; the yield strength at 650℃ is 784-820MPa, the standard deviation is 20-40MPa; the elongation at 650℃ is 15.5-29.4%, the standard deviation is 3.8-9.3%; the reduction of area at 650℃ is 27.0-47.5%, the standard deviation is 6.7-11.9%; the stress rupture life at 650℃ and 510MPa is 95.4-111.2h, the standard deviation is 5.1-6.8h; the elongation after fracture at 650℃ and 510MPa is 17.5-24.7%, the standard deviation is 2.2-4.8%; the reduction of area after fracture at 650℃ and 510MPa is 36.2-47.1%, the standard deviation is 2.2-6.9%.

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