High-plasticity GH4141 alloy cold-drawn bar with uniform structure and preparation method of high-plasticity GH4141 alloy cold-drawn bar

Abstract

The invention relates to a high-plasticity GH4141 alloy cold-drawn bar with a uniform structure and a preparation method of the high-plasticity GH4141 alloy cold-drawn bar, belongs to the field of high-temperature alloy materials, and solves at least one of the problems that in the prior art, a GH4141 bar is poor in grain size uniformity, and a fastener is poor in performance stability, low in forming qualification rate and the like due to insufficient plasticity. The preparation method of the high-plasticity GH4141 alloy cold-drawn bar with the uniform structure comprises the steps that a hot-rolled GH4141 alloy bar blank is subjected to solution treatment, and then first-time cold drawing, first-time intermediate annealing treatment, second-time cold drawing, second-time intermediate annealing treatment, finished product cold drawing and finished product annealing treatment are sequentially carried out. According to the method, the plasticity is remarkably improved while the strength of the GH4141 alloy cold-drawn bar is guaranteed, and the upsetting qualification rate of a fastener and the product performance consistency are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloy materials technology, and in particular to a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity and its preparation method. Background Technology

[0002] GH4141 alloy is a typical precipitation-hardening Ni-Cr-Co based, difficult-to-deform superalloy. It exhibits high tensile, creep, and endurance strengths, as well as good fatigue resistance, corrosion resistance, and oxidation resistance within the temperature range of 650℃ to 900℃. It is widely used in the manufacture of high-temperature load-bearing components for aerospace engines, such as turbine disks, nozzles, guide vanes, combustion chamber liners, turbine rotors, and springs, requiring high strength below 870℃ and oxidation resistance below 980℃. In fastener applications, GH4141 alloy is currently the only mature and highest-temperature-resistant fastener material for aerospace engines that can be used under high-temperature and high-stress conditions of 750℃ to 850℃.

[0003] Traditionally, research and process optimization for GH4141 alloy have focused on improving its high-temperature tensile strength, creep rupture life, and fatigue resistance. Existing technologies typically achieve higher strength by adjusting the alloy composition and optimizing solution treatment and aging heat treatment regimes. However, these methods often emphasize the enhancement of a single property, neglecting the material's performance stability during subsequent use and its plasticity during fastener manufacturing.

[0004] In practical applications, especially in fastener manufacturing, GH4141 alloy cold-drawn bars commonly face problems such as uneven grain size and insufficient plasticity. This leads to cracking and inconsistent deformation during forming processes such as upsetting and stamping, severely affecting the forming pass rate and final performance stability of fasteners. Although existing processes can meet basic strength requirements, uneven microstructure and poor plasticity have become key bottlenecks restricting the reliability and mass application of GH4141 alloy high-end fasteners. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity, and a method for preparing the same, in order to solve at least one of the problems in the prior art, such as poor grain size uniformity of GH4141 bars, poor fastener performance stability due to insufficient plasticity, and low forming qualification rate.

[0006] The objective of this invention is achieved through the following technical solution: This invention provides a method for preparing cold-drawn GH4141 alloy bars with uniform microstructure and high plasticity, comprising the following steps: The hot-rolled GH4141 alloy billet is subjected to solution treatment, followed by a first cold drawing, a first intermediate annealing, a second cold drawing, a second intermediate annealing, a final cold drawing, and a final annealing. The solution treatment is heated at 1160~1180℃, and water cooling is used after the solution treatment. The first intermediate annealing, the second intermediate annealing, and the final annealing all employ water cooling.

[0007] Furthermore, after the solution treatment, the first intermediate annealing, the second intermediate annealing, and the finished product annealing, the time from when the billet or finished bar is removed from the furnace to when it is immersed in water is ≤10s; and / or, The heat preservation time of the solution treatment min is based on the diameter of the hot-rolled bar billet. mm is determined, and the calculation formula is: ; For 4~6; and / or, The solution treatment, the first intermediate annealing, the second intermediate annealing, and the finished product annealing are all carried out by charging the furnace at a warm temperature.

[0008] Furthermore, the deformation amount during the first cold drawing is 35-60%.

[0009] Furthermore, the heating temperature for the first intermediate annealing treatment is 1080~1120℃; and / or, The holding time of the first intermediate annealing treatment min is based on the diameter of the billet after the first cold drawing. mm is determined, and the calculation formula is: ; It ranges from 4 to 6.

[0010] Furthermore, the deformation amount of the second cold drawing is 16-22%.

[0011] Furthermore, the heating temperature for the second intermediate annealing treatment is 1080~1120℃; and / or, The heat preservation time of the second intermediate annealing treatment min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: ; It is 3~4.

[0012] Furthermore, the finished product is cold-drawn in one pass, with a deformation amount of 8-12%.

[0013] Furthermore, the heating temperature for the finished product annealing treatment is 1070~1090℃; and / or, The heat preservation time of the finished product annealing treatment min is based on the diameter of the finished cold-drawn bar blank. mm is determined, and the calculation formula is: ; It is 1.5~2.

[0014] This invention provides a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity, which is prepared by the aforementioned method.

[0015] Furthermore, the GH4141 alloy cold-drawn bar has a grain size difference of ≤2.0 grade, a room temperature tensile strength of 800~1270MPa, an elongation after fracture of ≥30%, and a reduction of area of ​​≥40%.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: (1) The preparation method of the present invention provides a new technical route, the core of which is: through the synergy of high-temperature solution pretreatment and multi-pass cold drawing-intermediate recrystallization annealing cycle (three cold and three annealing), the material microstructure and plasticity are actively controlled throughout the entire process. Specifically, unlike the traditional process of "hot rolling → solution treatment → single cold drawing" or relying on hot working microstructure control, the present invention adopts a "high-temperature solution treatment → three cold drawing → three intermediate annealing" cycle. Among them, increasing the solution temperature to 1160~1180℃ can cause the fine-grained microstructure after hot rolling to undergo moderate and uniform coarsening, fully dissolve unfavorable precipitated phases, reduce deformation resistance, provide an excellent plasticity foundation for subsequent multi-pass cold drawing, and avoid cold drawing cracking. Based on this, three cycles of "cold drawing-annealing" achieve grain refinement, microstructure homogenization, and plasticity recovery through staged recrystallization, ultimately obtaining cold-drawn bars with excellent strength and plasticity matching. While ensuring strength, plasticity is significantly improved, enabling the subsequent fastener upsetting to withstand greater deformation without cracking. This effectively improves the upsetting qualification rate and product performance consistency, solving the problems of low forming qualification rate and unstable performance caused by uneven microstructure and insufficient plasticity in existing technologies.

[0017] (2) In some preferred embodiments, by controlling the time from the time the bar is taken out of the furnace to the time it is put into the water to not exceed 10 seconds, the precipitation of harmful phases and abnormal grain growth in the high-temperature stage can be effectively suppressed, thereby obtaining a finer and more stable microstructure; the solid solution holding time calculation formula based on the diameter of the bar billet is adopted to ensure that bars of different specifications can be fully homogenized and avoid structural defects; the implementation of the warm charging process can prevent the material from generating precipitates during the heating process, thereby causing cracking, and significantly improving process stability and batch consistency.

[0018] (3) In some preferred embodiments, the large deformation cold drawing process of 35-60% can fully break the grain structure after solution treatment, accumulate sufficient deformation energy, and provide sufficient driving force for complete recrystallization in the subsequent intermediate annealing process. It is a key control step to achieve grain refinement and uniform structure.

[0019] (4) In some preferred embodiments, an intermediate annealing temperature range of 1080-1120°C is set to ensure sufficient recrystallization while avoiding excessive grain growth; a holding time calculation method based on diameter is adopted to ensure that bars of different specifications can complete the full recrystallization process, effectively restore the plasticity of the material, and provide a good microstructure for the next cold drawing process.

[0020] (5) In some preferred embodiments, a medium deformation amount of 16-22% is used for cold drawing, which further optimizes the uniformity of the microstructure on the basis of already refined grains. This maintains a moderate work hardening effect and avoids the generation of microcracks that may be caused by excessive deformation, thus achieving a good balance between strength and plasticity.

[0021] (6) In some preferred embodiments, the second intermediate annealing adopts a temperature range of 1080-1120°C and a holding time based on the diameter calculation, which can effectively eliminate the work hardening generated by the previous cold drawing, promote further homogenization of the grains, and reserve sufficient plastic deformation capacity for the finished product cold drawing process.

[0022] (7) In some preferred embodiments, the finished product cold drawing adopts a single-pass small deformation process of 8-12%, which is conducive to the precise control of the final product size. At the same time, it introduces uniform and moderate work hardening, which can not only meet the strength index required by the product, but also minimize surface defects and performance fluctuations.

[0023] (8) In some preferred embodiments, the finished product annealing temperature of 1070-1090℃ and the holding time calculated based on the diameter can effectively eliminate the residual stress generated by the cold drawing of the finished product, stabilize the microstructure and mechanical properties of the material, and ensure that the final product has good strength-plasticity matching and stable performance.

[0024] (9) The GH4141 alloy cold-drawn bars obtained by the preparation method provided in the embodiments of the present invention have high microstructure uniformity, excellent plasticity, and good strength. Specifically, after standard heat treatment, the grain size difference of the GH4141 alloy cold-drawn bars is ≤2.0 grade; the room temperature tensile strength is 800~1270MPa; the elongation after fracture is ≥30%; and the reduction of area is ≥40%. Further, the grain size difference is ≤1.5 grade; the elongation after fracture is ≥39.5%; and the reduction of area is ≥50%.

[0025] Regarding performance consistency, the intra-batch coefficient of variation (Cv value) of room temperature tensile strength of existing GH4141 alloy fasteners is generally greater than 8%. The cold-drawn bars produced by the method of this invention, under the same heat treatment conditions, have an intra-batch coefficient of variation (Cv value) of room temperature tensile strength ≤2%; furthermore, the intra-batch coefficient of variation (Cv value) of room temperature tensile strength of the cold-drawn bars produced by the method of this invention is ≤1.6%, significantly improving performance stability.

[0026] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0027] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 The image shows the grain structure morphology of the uniform, high-plasticity GH4141 alloy cold-drawn bar provided in this embodiment of the invention after standard heat treatment, as captured by a metallographic microscope. Figure 2 Macroscopic photograph of a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity provided in an embodiment of the present invention. Detailed Implementation

[0028] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0029] GH4141 alloy is a typical precipitation-hardening Ni-Cr-Co based hard-deformable superalloy with high Al and Ti content; for example, the total mass fraction of Al+Ti is 4.85%, and the mass fraction of C is 0.06~0.12%. After standard heat treatment, the microstructure, excluding the γ matrix, shows the main strengthening phase, Ni3(Al,Ti) type γ′ phase, spherically dispersed within the grains; Ti-rich MC-type carbides are randomly distributed in blocky form in the matrix and at grain boundaries; and fine M6C and M… 23 C6-type carbides precipitate continuously in a chain-like manner at the grain boundaries.

[0030] Based on the above analysis of the microstructure characteristics of GH4141 alloy, the difficulties in improving its microstructure uniformity and plasticity are: improper morphology and distribution of γ′ phase and grain boundary carbides can easily induce cracks during deformation; the alloy has high deformation resistance and is prone to mixed grains and local coarse grains during processing; and improper matching of cold working and heat treatment processes can easily lead to deterioration of microstructure and properties.

[0031] To address the problems of low upsetting yield and poor performance stability of fasteners caused by poor microstructure uniformity and insufficient plasticity in existing technologies, this invention proposes a systematic process route of "solution treatment → three cold drawing → three annealing". By controlling the process parameters at each stage, the aim is to synergistically optimize the recrystallization behavior, precipitate evolution and grain boundary state of the material, thereby obtaining GH4141 alloy cold-drawn bars with uniform microstructure and high plasticity. This effectively solves the bottleneck problem of poor forming yield and performance consistency of GH4141 material in fastener manufacturing.

[0032] In a first aspect, the present invention provides a method for preparing a cold-drawn bar of GH4141 alloy with uniform microstructure and high plasticity, comprising the following steps: The hot-rolled GH4141 alloy billet is subjected to solution treatment, followed by a first cold drawing, a first intermediate annealing, a second cold drawing, a second intermediate annealing, a final cold drawing, and a final annealing. The solution treatment is heated at 1160~1180℃, and water cooling is used after the solution treatment. The first intermediate annealing, the second intermediate annealing, and the final annealing all employ water cooling.

[0033] Compared with the prior art, the present invention provides a new technical route, the core of which is: through the synergy of "high temperature solution pretreatment (1160~1180℃) and multi-pass cold drawing-intermediate recrystallization annealing cycle (three cold and three annealing)", the whole process of material microstructure evolution and plasticity reserve can be actively controlled in the cold drawing forming stage.

[0034] Specifically, in terms of process routes, existing technologies mostly use hot working processes (such as forging and rolling) to complete the billet forming and microstructure control, or achieve the final shape through a simplified process of "hot rolling → solution treatment → single cold drawing". This invention, however, uniquely adopts a synergistic path of "high-temperature solution treatment (1160~1180℃) → three cold drawing → three intermediate annealing". The core advantage of raising the solution treatment temperature to 1160~1180℃ is that the high temperature promotes a moderate and uniform coarsening of the fine-grained microstructure formed after hot rolling. This process not only more fully dissolves unfavorable grain boundary precipitates, but also significantly reduces the initial deformation resistance and work hardening tendency of the material, thus providing a superior plasticity reserve for subsequent multi-pass cold drawing, fundamentally avoiding the risk of cold drawing cracks caused by excessive material hardness and insufficient plasticity. Based on this, the systematic "cold drawing-annealing" cycle, through three complete intermediate recrystallization annealing processes during cold forming, achieves a phased and iterative reconstruction of grain structure, dislocation density and precipitate morphology. Ultimately, while ensuring precise dimensional forming, cold-drawn bars with uniform grain size and excellent strength-plasticity matching are obtained.

[0035] The cold-drawn bar material obtained by the preparation method significantly improves plasticity while ensuring service strength, thus enabling it to withstand greater deformation and less prone to cracking during subsequent fastener upsetting. This effectively improves the upsetting qualification rate and product performance consistency, and solves the industry bottleneck of low forming qualification rate and unstable performance caused by uneven structure and insufficient plasticity in the existing technology.

[0036] Specifically, after the solution treatment, the first intermediate annealing treatment, the second intermediate annealing treatment, and the finished product annealing treatment, the time from the billet or finished bar being taken out of the furnace to being immersed in water is ≤10s.

[0037] It should be noted that the advantages of rapid water cooling after solution treatment and each annealing by controlling the water immersion time (e.g., not exceeding 10 seconds) are: it can quickly suppress the precipitation of the γ′ phase, whose chemical formula is Ni3 (Al, Ti), and avoid the hardening of the material due to the precipitation of the γ′ phase, thereby significantly improving the plasticity reserve of the material. This is conducive to obtaining cold-drawn bars with uniform structure and excellent plasticity while ensuring strength.

[0038] Specifically, the heat treatment holding time min is based on the diameter of the hot-rolled bar billet. mm is determined, and the calculation formula is: ; It ranges from 4 to 6. The unit is min. The unit is mm.

[0039] For example, The values ​​are 4.0, 4.5, 4.7, 5.0, 5.2, 5.5, and 6.0; the preferred values ​​are 4.5 to 5.5.

[0040] It should be noted that, in conjunction with a solution treatment temperature of 1160~1180℃, an appropriate solution treatment holding time can ensure that the γ′ strengthening phase is fully dissolved and the alloying elements diffuse uniformly, thereby obtaining a matrix with homogeneous composition and structure. This avoids microstructure inhomogeneity caused by too short a time, or excessive grain coarsening and precipitation of harmful phases caused by too long a time, thus laying a uniform and plastic microstructure foundation for subsequent multi-pass cold drawing.

[0041] Specifically, the solution treatment, first intermediate annealing, second intermediate annealing, and finished product annealing are all performed using a preheated furnace charging method. The advantages of this control method are: it avoids the billet remaining in the medium-low temperature range for extended periods during the heating process, thereby effectively suppressing the precipitation of the γ′ phase and reducing the risk of cracking during heat treatment or subsequent processing; simultaneously, it allows for more precise control of the actual holding time at the target temperature, ensuring consistency between recrystallization behavior and the evolution of the precipitated phase, further improving the uniformity and performance stability of the microstructure of each batch of bars. For example, in the solution treatment and third annealing processes, the furnace charge is laid flat at the bottom of the heat treatment furnace.

[0042] In one embodiment, a hyperbolic straightener is used to straighten the solution-treated billet; a peeling machine is used to peel the straightened billet to a diameter of 10-18 mm for subsequent first cold drawing process.

[0043] Specifically, the preparation of the hot-rolled GH4141 alloy billet (hereinafter referred to as hot-rolled billet) includes the following steps: placing the initial billet in a heating furnace with a furnace temperature not exceeding 600°C, and then heating the initial billet (for example, at a heating rate of 3~5°C / min) to 1120~1160°C for heat preservation treatment; and hot-rolling the initial billet after heat preservation treatment to obtain the hot-rolled billet.

[0044] For example, the initial billet is heated to 1120°C, 1125°C, 1130°C, 1135°C, 1140°C, 1150°C, or 1160°C, preferably 1120°C to 1140°C.

[0045] Specifically, in the preparation process of the hot-rolled bar billet, the heat treatment time t 热 min is based on the diameter D of the initial bar blank. 初 mm is determined, and the calculation formula is: ; The value is 0.8~2.5. The final rolling temperature of the hot rolling is ≥950℃. t 热 The unit is min, D 初 The unit is mm.

[0046] For example, The values ​​are 0.8, 1.0, 1.2, 1.5, 1.7, 2.0, and 2.5; preferably 1.0 to 2.0.

[0047] In one embodiment, the diameter of the initial billet is 28-35 mm; the hot rolling is a single-pass hot rolling; and the diameter of the hot-rolled billet obtained after hot rolling is 12-20 mm.

[0048] For example, the diameter of the initial bar billet is 28mm, 30mm, 31mm, 32mm, 34mm, or 35mm. The diameter of the hot-rolled bar billet is 12mm, 14mm, 16mm, 18mm, or 20mm.

[0049] After solution treatment, a three-cycle cold drawing-annealing process is performed. Unlike existing cold drawing processes that commonly use a small deformation amount (e.g., 8%~10%) in a single cycle, this invention innovatively adopts a graded decreasing deformation strategy based on the excellent plasticity established by higher temperature solution treatment: the first cold drawing uses a large deformation amount (35~60%), aiming to fully break the initial structure and accumulate sufficient deformation energy to provide the core driving force and nucleation point for complete recrystallization in the subsequent intermediate annealing; the second cold drawing uses a medium deformation amount (16~22%), further optimizing the uniformity of the structure based on the already refined grains and balancing work hardening and plasticity reserves; the final (finished product) cold drawing uses a small deformation amount (8~12%), the main purpose of which is to achieve precise control of the final dimensions and introduce uniform and controllable final work hardening.

[0050] The core advantage of this "large-medium-small" deformation path lies in its high synergy with the "solution-cold drawing-annealing" cycle, ensuring that the deformation amount in each pass most effectively drives the recrystallization and microstructure optimization in the next stage. Large deformation induces deep recrystallization to refine grains, medium deformation optimizes microstructure uniformity, and small deformation completes precision dimensionalization and strengthening, ultimately achieving a better balance between strength, plasticity, and microstructure uniformity.

[0051] Specifically, the deformation amount in the first cold drawing is 35-60%. In the first cold drawing, the deformation amount per pass is controlled to be 6-12%.

[0052] For example, the deformation amount of the first cold drawing is 35%, 40%, 45%, 50%, 55%, or 60%; preferably 40% to 55%.

[0053] For example, in the first cold drawing, the deformation amount of each pass is controlled to be 6%, 8%, 10%, and 12%.

[0054] Specifically, the heating temperature for the first intermediate annealing treatment is 1080~1120℃.

[0055] Specifically, the holding time for the first intermediate annealing treatment min is based on the diameter of the billet after the first cold drawing. mm is determined, and the calculation formula is: ; It ranges from 4 to 6.

[0056] For example, the heating temperature for the first intermediate annealing treatment is 1080°C, 1090°C, 1100°C, 1105°C, 1110°C, 1115°C, or 1120°C; preferably 1100°C to 1120°C.

[0057] For example, The values ​​are 4.0, 4.2, 4.5, 4.7, 5.0, 5.5, and 6.0; the preferred values ​​are 4.5 to 5.5.

[0058] Specifically, the deformation amount in the second cold drawing is 16-22%. In the second cold drawing, the deformation amount per pass is controlled to be 8-12%.

[0059] For example, the deformation amount of the second cold drawing is 16%, 17%, 18%, 19%, 20%, 21%, or 22%; preferably 18-21%.

[0060] For example, in the second cold drawing, the deformation amount of each pass is controlled to be 8%, 9%, 10%, 11%, or 12%; preferably 9 to 11%.

[0061] Specifically, the heating temperature for the second intermediate annealing process is 1080~1120℃.

[0062] Specifically, the holding time for the second intermediate annealing treatment min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: ; It is 3~4.

[0063] For example, the heating temperature for the second intermediate annealing treatment is 1080°C, 1090°C, 1100°C, 1105°C, 1110°C, 1115°C, or 1120°C; preferably 1100°C to 1120°C.

[0064] For example, The values ​​are 3.0, 3.2, 3.4, 3.5, 3.6, 3.7, 3.8, and 4.0; the preferred values ​​are 3.4 to 3.8.

[0065] Specifically, the finished product is cold-drawn in one pass, with a deformation amount of 8-12%.

[0066] Specifically, the heating temperature for the annealing treatment of the finished product is 1070~1090℃.

[0067] Specifically, the holding time for the finished product annealing treatment min is based on the diameter of the finished cold-drawn bar blank. mm is determined, and the calculation formula is: ; It is 1.5~2.

[0068] For example, the heating temperature for annealing the finished product is 1070℃, 1075℃, 1078℃, 1080℃, 1082℃, 1085℃, or 1090℃; preferably 1075~1085℃.

[0069] For example, The values ​​are 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0; the preferred values ​​are 1.6 to 1.9.

[0070] Specifically, after the finished product annealing process is completed, the finished cold-drawn bar stock (hereinafter referred to as the finished bar stock) is subjected to a finished product straightening and polishing process. Specifically, hyperbolic tumbling straightening is adopted, and the straightening is carried out in two stages to control the total straightening deformation to be 1~2%. After that, it is polished to meet the diameter and tolerance requirements. The surface roughness Ra of the polished bar stock is ≤2.6μm.

[0071] In one embodiment, the diameter of the finished bar (i.e., the uniformly structured, highly ductile GH4141 alloy cold-drawn bar) is 4-12 mm; for example, the diameter of the uniformly structured, highly ductile GH4141 alloy cold-drawn bar is 4 mm, 5 mm, 6 mm, 8 mm, 10 mm, or 12 mm.

[0072] In a second aspect, the present invention provides a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity, which is prepared by the preparation method described in the first aspect.

[0073] Specifically, the GH4141 alloy cold-drawn bars, after standard heat treatment, have a grain size difference of ≤2.0 grade, a room temperature tensile strength (delivery condition) of 800~1270MPa, an elongation after fracture of ≥30%, and a reduction of area of ​​≥40%.

[0074] Specifically, the uniformly structured, high-plasticity GH4141 alloy cold-drawn bar exhibits high performance stability. After standard heat treatment, the room temperature tensile strength Cv value of the uniformly structured, high-plasticity GH4141 alloy cold-drawn bar is ≤2%.

[0075] In this invention, the GH4141 alloy cold-drawn bar comprises the following components by mass fraction: C: 0.06~0.12%, Cr: 18~20%, Co: 10~12%, Mo: 9.0~10.5%, Al: 1.4~1.6%, Ti: 3.0~3.3%, B: 0.003~0.010%, Zr: 0.005~0.07%, Fe: 0.01~5.0%, Si: 0.001~0.5%, Mn: 0.001~0.1%, Cu: 0.0005~0.5%, with Ni as the balance.

[0076] It is understood that the "deformation amount" mentioned in this invention refers to the percentage reduction in the cross-sectional area of ​​the bar during the cold drawing process, and the deformation amount (%) = ; This represents the cross-sectional area of ​​the bar stock before cold drawing. This represents the cross-sectional area of ​​the cold-drawn bar.

[0077] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and comparative examples.

[0078] Example 1: This embodiment provides a method for preparing a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity. The GH4141 alloy cold-drawn bar comprises the following components (mass fraction / %): C: 0.088, Cr: 18.91, Co: 11.15, Mo: 9.88, Al: 1.57, Ti: 3.11, B: 0.0048, Zr: 0.029, Fe: 1.41, Si: 0.084, Mn: 0.0093, Cu: 0.0008, and Ni as the balance.

[0079] The preparation method includes the following steps: S0. Preparation of hot-rolled bar billets: Using GH4141 alloy initial billets with a diameter of 30mm as raw materials, the billets were placed in a heating furnace at a temperature of 500℃ and heated to 1130℃ at a heating rate of 4℃ / min for a holding time t. 热 min is based on the initial billet's D 初 The value in mm (30mm) is determined by the following formula: =2×30=60min. After heat preservation treatment, hot rolling is carried out at a final rolling temperature of 1000℃. After one hot rolling, a hot-rolled bar billet with a diameter of 12mm is obtained.

[0080] S1. Pretreatment of billets before cold drawing: solution treatment, straightening and peeling; S11, Solution treatment: The hot-rolled billet is subjected to solution treatment in a preheated furnace at a heating temperature of 1170°C. min is based on the diameter of the hot-rolled bar billet. The value in mm (12mm) is determined by the following formula: =5×12=60min. After solution treatment, water cooling is used, and the time from when the billet is taken out of the furnace to when it is put into the water is 8s.

[0081] S12. The solution-treated billet is straightened using a hyperbolic straightening machine; the straightened billet is peeled to a diameter of 10 mm using a peeling machine.

[0082] S2. Cold drawing of billet in one step: The stripped billet underwent its first cold drawing, with a total deformation of 54%. The deformation per pass was controlled at 11%→10%→10%→11%→11%→12%→9%. The billet diameter after the first cold drawing was 6.8 mm.

[0083] S3. Intermediate Annealing Treatment of Cold-Drawn Billets: The billets after the first cold drawing undergo a first intermediate annealing treatment. This is done using a preheated furnace charging method, with the furnace charge laid flat at the bottom of the heat treatment furnace. The heating temperature is 1110℃, and the holding time is [not specified]. min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (6.8mm), and the calculation formula is as follows: =5×6.8mm=34min. After the first intermediate annealing, water cooling was used, and the time from when the billet was taken out of the furnace to when it was put into the water was 8s.

[0084] S4. Secondary cold drawing of billet: The billet after the first intermediate annealing was subjected to a second cold drawing, with a total deformation of 20%, and the deformation per pass successively increasing from 11% to 10%. The diameter of the billet after the second cold drawing was 6.1 mm.

[0085] S5. Secondary cold-drawn billet intermediate annealing treatment: The billets after the second cold drawing undergo a second intermediate annealing treatment using a heated furnace method. The furnace charge is laid flat at the bottom of the heat treatment furnace, and the heating temperature is 1100℃ with a holding time of [missing information]. min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =3.6 × 6.1 = 22 min. After annealing, water cooling is used, and the time from when the billet is taken out of the furnace to when it is put into the water is 8 seconds.

[0086] S6. Cold drawing of finished bar stock: The billet after the second intermediate annealing was cold-drawn in one pass with a deformation of 12%. The diameter of the finished cold-drawn billet was 5.7 mm.

[0087] S7. Annealing treatment of finished bar stock: The finished cold-drawn billets undergo annealing treatment using a heated furnace method. The furnace charge is laid flat at the bottom of the heat treatment furnace, and the heating temperature is 1080℃ with a holding time of [missing information]. min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (5.7mm), and the calculation formula is as follows: =1.75×5.7=10min. After annealing, water cooling is used, and the time from when the bar is taken out of the furnace to when it is put into the water is 8s.

[0088] S8. Straightening and polishing of finished bars: The finished annealed bars are straightened using hyperbolic tumbling straightening, performed in two stages to control the total straightening deformation to 1-2%. Following this, a grinding process is performed to meet the diameter and tolerance requirements. The surface roughness Ra of the ground bar is ≤2.6μm, ultimately yielding a high-ductility GH4141 alloy cold-drawn bar with a uniform microstructure and a diameter of 5.5mm and a tolerance of (-0.08, 0)mm.

[0089] Example 2 This embodiment provides a method for preparing a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity. The GH4141 alloy cold-drawn bar comprises the following components (mass fraction / %): C: 0.083, Cr: 18.91, Co: 11.00, Mo: 9.86, Al: 1.56, Ti: 3.10, B: 0.0054, Zr: 0.032, Fe: 1.47, Si: 0.13, Mn: 0.0080, Cu: 0.0008, and Ni as the balance.

[0090] The preparation method includes the following steps: S0. Preparation of hot-rolled bar billets: Using GH4141 alloy initial billets with a diameter of 32mm as raw materials, the billets were placed in a heating furnace at a temperature of 500℃ and heated to 1130℃ at a heating rate of 4℃ / min for a holding time t. 热 min is based on the initial billet's D 初 The value in mm (32mm) is determined by the following formula: =2×32= 64min. After heat preservation treatment, hot rolling is carried out at a final rolling temperature of 1000℃. After one hot rolling, a hot-rolled bar billet with a diameter of 20mm is obtained.

[0091] S1. Pretreatment of billets before cold drawing: solution treatment, straightening and peeling; S11, Solution treatment: The hot-rolled billet is subjected to solution treatment in a preheated furnace at a heating temperature of 1170°C. min is based on the diameter of the hot-rolled bar billet. The value in mm (20mm) is determined by the following formula: =5×20=100min. After solution treatment, water cooling is used, and the time from when the billet is taken out of the furnace to when it is put into the water is 8s.

[0092] S12. The solution-treated billet is straightened using a hyperbolic straightening machine; the straightened billet is peeled to a diameter of 18mm using a peeling machine.

[0093] S2. Cold drawing of billet in one step: The stripped billet underwent its first cold drawing, with a total deformation of 41.2%. The deformation amounts in each pass were as follows: 9% → 8% → 7% → 6% → 8% → 7% → 6%. The diameter of the billet after the first cold drawing was 13.8 mm.

[0094] S3. Intermediate Annealing Treatment of Cold-Drawn Billets: The billets after the first cold drawing undergo a first intermediate annealing treatment. This is done using a preheated furnace charging method, with the furnace charge laid flat at the bottom of the heat treatment furnace. The heating temperature is 1110℃, and the holding time is [not specified]. min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (13.8mm), and the calculation formula is as follows: =5×13.8mm=69min. After the first intermediate annealing, water cooling was used, and the time from when the billet was taken out of the furnace to when it was put into the water was 8s.

[0095] S4. Secondary cold drawing of billet: The billet after the first intermediate annealing was subjected to a second cold drawing, with a total deformation of 20%, and the deformation per pass successively increasing from 11% to 10%. The diameter of the billet after the second cold drawing was 12.3 mm.

[0096] S5. Secondary cold-drawn billet intermediate annealing treatment: The billets after the second cold drawing undergo a second intermediate annealing treatment using a heated furnace method. The furnace charge is laid flat at the bottom of the heat treatment furnace, and the heating temperature is 1100℃ with a holding time of [missing information]. min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =3.6×12.3=44min. After annealing, water cooling is used, and the time from when the billet is taken out of the furnace to when it is put into the water is 8s.

[0097] S6. Cold drawing of finished bar stock: The billet after the second intermediate annealing was cold-drawn in one pass with a deformation of 11%. The diameter of the finished cold-drawn billet was 11.6 mm.

[0098] S7. Annealing treatment of finished bar stock: The finished cold-drawn billets undergo annealing treatment using a heated furnace method. The furnace charge is laid flat at the bottom of the heat treatment furnace, and the heating temperature is 1080℃ with a holding time of [missing information]. min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (11.6mm), and the calculation formula is as follows: =1.6×11.6=18.5min. After annealing, water cooling is used, and the time from when the bar is taken out of the furnace to when it is put into the water is 8s.

[0099] S8. Straightening and polishing of finished bars: The finished annealed bars are straightened using hyperbolic roll straightening in two stages, with the total straightening deformation controlled at 1-2%. Following this, a grinding process is performed to meet the diameter and tolerance requirements. The surface roughness Ra of the ground bar is ≤2.6μm, ultimately yielding a high-ductility GH4141 alloy cold-drawn bar with a uniform microstructure and a diameter of 11.4mm and a tolerance of (-0.08, 0)mm.

[0100] Example 3 This embodiment is the same as Embodiment 1, except that: S11, the heating temperature for the solution treatment is 1160℃, and the solution treatment... min is based on the diameter of the hot-rolled bar billet. The value in mm (12mm) is determined by the following formula: =4.0×12=48min.

[0101] Example 4 This embodiment is the same as Embodiment 1, except that: S11, the heating temperature for the solution treatment is 1180℃, and the solution treatment... min is based on the diameter of the hot-rolled bar billet. The value in mm (12mm) is determined by the following formula: =6.0×12=72min.

[0102] Example 5 This embodiment is the same as Embodiment 1, except that: S3, the heating temperature is 1080℃, and the holding time is... min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (6.8mm), and the calculation formula is as follows: =4.0×6.8 =27.2min.

[0103] Example 6 This embodiment is the same as Embodiment 1, except that: S3, the heating temperature is 1120℃, and the holding time is... min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (6.8mm), and the calculation formula is as follows: =6.0×6.8 =40.8min.

[0104] Example 7 This embodiment is the same as Embodiment 1, except that: S5, the heating temperature is 1080℃, and the holding time is... min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =3×6.1=18.3min.

[0105] Example 8 This embodiment is the same as Embodiment 1, except that: S5, the heating temperature is 1120℃, and the holding time is... min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =4×6.1=24.4min.

[0106] Example 9 This embodiment is the same as Embodiment 1, except that: S7, the heating temperature is 1070℃, and the holding time is... min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (5.7mm), and the calculation formula is as follows: =1.5×5.7=8.6min.

[0107] Example 10 This embodiment is the same as Embodiment 1, except that: S7, the heating temperature is 1090℃, and the holding time... min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (5.7mm), and the calculation formula is as follows: =2.0×5.7=11.4min.

[0108] Example 11 This embodiment is the same as Embodiment 1, except that: S2. Cold drawing of billet in one step: The stripped billet (10mm in diameter) was subjected to a first cold drawing, with a total deformation of 36%, and the deformation per pass was controlled at 11%→10%→10%→11%. After the first cold drawing, the billet diameter was 8mm.

[0109] S3. Intermediate annealing treatment of cold-drawn billet in one step: Insulation time min is based on the diameter of the billet after the first cold drawing. The value in mm (8mm) is determined by the following formula: =4×8mm=32min.

[0110] S4. Secondary cold drawing of billet: The billet after the first intermediate annealing was subjected to a second cold drawing, with a total deformation of 16.3% and a per-pass deformation of 9% → 8%. The diameter of the billet after the second cold drawing was 7.3 mm.

[0111] S5. Secondary cold-drawn billet intermediate annealing treatment: Insulation time min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =4×7.3=29min.

[0112] S6. Cold drawing of finished bar stock: The billet after the second intermediate annealing was cold-drawn in one pass with a deformation of 8%. The diameter of the finished billet after cold drawing was 7 mm.

[0113] S7. Annealing treatment of finished bar stock: Insulation time min is based on the diameter of the finished cold-drawn bar blank. The value of mm (7mm) is determined by the following formula: =2×7=14min.

[0114] S8. Straightening and polishing of finished bars: The final product is a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity, with a diameter of 6.8 mm and a tolerance of (-0.08, 0) mm.

[0115] Example 12 This embodiment is the same as Embodiment 1, except that: S2. Cold drawing of billet in one step: The stripped billet (10mm in diameter) was subjected to a first cold drawing with a total deformation rate of 60%. The deformation amount per pass was controlled at 12%→11%→11%→10%→10%→9%→7%→6%. The diameter of the billet after the first cold drawing was 6.3mm.

[0116] S3. Intermediate annealing treatment of cold-drawn billet in one step: Insulation time min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (6.3mm), and the calculation formula is as follows: =6×6.3mm=37.8min.

[0117] S4. Secondary cold drawing of billet: The billet after the first intermediate annealing was subjected to a second cold drawing, with a total deformation of 21%, and the deformation per pass successively increasing from 12% to 10%. The diameter of the billet after the second cold drawing was 5.6 mm.

[0118] S5. Secondary cold-drawn billet intermediate annealing treatment: Insulation time min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =3×5.6=16.8min.

[0119] S6. Cold drawing of finished bar stock: The billet after the second intermediate annealing was cold-drawn in one pass with a deformation of 12%. The diameter of the finished cold-drawn billet was 5.3 mm.

[0120] S7. Annealing treatment of finished bar stock: Warm time min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (5.3mm), and the calculation formula is as follows: =1.5×5.3=8min.

[0121] S8. Straightening and polishing of finished bars: The final product is a cold-drawn GH4141 alloy bar with uniform microstructure and high plasticity, with a diameter of 5.1 mm and a tolerance of (-0.08, 0) mm.

[0122] Comparative Example 1 This comparative example is the same as Example 1, except that the heating temperature for the S11 solution treatment is 1120°C.

[0123] Comparative Example 2 This comparative example is the same as Example 1, except that the heating temperature for the S11 solution treatment is 1200°C.

[0124] Comparative Example 3 This comparative example is the same as Example 1, except that the heating temperature for the S11 solution treatment is 1120°C. min is based on the diameter of the hot-rolled bar billet. The value in mm (12mm) is determined by the following formula: =7×12=84min.

[0125] Comparative Example 4 This comparative example is the same as Example 1, except that the heating temperature for the S11 solution treatment is 1200℃. min is based on the diameter of the hot-rolled bar billet. The value in mm (12mm) is determined by the following formula: =3×12=36min.

[0126] Comparative Example 5 This comparative example is the same as Example 1, except that S3 (first intermediate annealing) is omitted, and S4 (second cold drawing) is performed directly after the first cold drawing in S2.

[0127] Comparative Example 6 This comparative example is the same as Example 1, except that S5 (second intermediate annealing) is omitted, and S6 (finished product cold drawing) is performed directly after the second cold drawing in S4.

[0128] Comparative Example 7 This comparative example is the same as Example 1, except that S7 (finished product annealing) is omitted, and S8 straightening and polishing are performed directly after the finished product is cold-drawn in S6.

[0129] Comparative Example 8 This comparative example is the same as Example 1, except that: S0. Preparation of hot-rolled bar billets: Using GH4141 alloy initial billets with a diameter of 20mm as raw materials, the billets were placed in a heating furnace at a temperature of 500℃ and heated to 1130℃ at a heating rate of 4℃ / min for a holding time t. 热 min is based on the initial billet's D 初 The value in mm (20mm) is determined by the following formula: =2×20=40min. After heat preservation treatment, hot rolling is carried out at a final rolling temperature of 1000℃. After one hot rolling, a hot-rolled bar billet with a diameter of 9mm is obtained.

[0130] S1. Pretreatment of billets before cold drawing: solution treatment, straightening and peeling; S11, Solution treatment: The hot-rolled billet is subjected to solution treatment in a preheated furnace at a heating temperature of 1170°C. min is based on the diameter of the hot-rolled bar billet. The value in mm (9mm) is determined by the following formula: =5×9=45min. After solution treatment, water cooling is used, and the time from when the billet is taken out of the furnace to when it is put into the water is 8s.

[0131] S12. The solution-treated billet is straightened using a hyperbolic straightening machine; the straightened billet is peeled to a diameter of 7mm using a peeling machine.

[0132] S2. Cold drawing of billet in one step: The bar blank with a diameter of 7 mm after peeling was subjected to a first cold drawing with a total deformation of 10%, which was completed in a single pass with a deformation of 10% per pass. After the first cold drawing, the diameter of the bar blank was approximately 6.6 mm.

[0133] S3. Intermediate Annealing Treatment of Cold-Drawn Billets: The billets after the first cold drawing undergo a first intermediate annealing treatment. This is done using a preheated furnace charging method, with the furnace charge laid flat at the bottom of the heat treatment furnace. The heating temperature is 1110℃, and the holding time is [not specified]. min is based on the diameter of the billet after the first cold drawing. mm is determined, and the calculation formula is: =5×6.6mm=33min. After the first intermediate annealing treatment, water cooling was used, and the time from when the billet was taken out of the furnace to when it was put into the water was 8s.

[0134] S4. Secondary cold drawing of billet: The billet after the first intermediate annealing was subjected to a second cold drawing, with a total deformation of 10%, completed in a single pass with a 10% deformation per pass. The diameter of the billet after the second cold drawing was 6.30 mm.

[0135] S5. Secondary cold-drawn billet intermediate annealing treatment: The billets after the second cold drawing undergo a second intermediate annealing treatment using a heated furnace method. The furnace charge is laid flat at the bottom of the heat treatment furnace, and the heating temperature is 1100℃ with a holding time of [missing information]. min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =3.6 × 6.3 = 22.7 min. After annealing, water cooling is used, and the time from when the billet is taken out of the furnace to when it is put into the water is 8 seconds.

[0136] S6. Cold drawing of finished bar stock: The billet after the second intermediate annealing was cold-drawn in one pass with a deformation of 10%. The diameter of the finished cold-drawn billet was 6.0 mm.

[0137] S7. Annealing treatment of finished bar stock: The finished cold-drawn billets undergo annealing treatment using a heated furnace method. The furnace charge is laid flat at the bottom of the heat treatment furnace, and the heating temperature is 1080℃ with a holding time of [missing information]. min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (6.0mm), and the calculation formula is as follows: =1.75×6.0=10.5min. After annealing, water cooling is used, and the time from when the bar is taken out of the furnace to when it is put into the water is 8s.

[0138] S8. Straightening and polishing of finished bars: The finished annealed bars are straightened using hyperbolic tumbling straightening, performed in two stages, with the total straightening deformation controlled at 1-2%. Following this, a grinding process is performed to meet the diameter and tolerance requirements. The surface roughness Ra of the ground bar is ≤2.6μm, ultimately yielding a high-ductility GH4141 alloy cold-drawn bar with a uniform microstructure and a diameter of 5.8mm and a tolerance of (-0.08, 0)mm.

[0139] Comparative Example 9 This comparative example is the same as Example 1, except that air cooling (room temperature air cooling) is used instead of water cooling after S11 (solution treatment), S3 (first intermediate annealing treatment), S5 (second intermediate annealing treatment) and S7 (finished product annealing treatment).

[0140] Comparative Example 10 This comparative example is the same as Example 1, except that the heating temperature of S3 (first intermediate annealing treatment) is 1050°C and the holding time is [not specified]. min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (6.8mm), and the calculation formula is as follows: =8×6.8mm=54.4min; The heating temperature for S5 (second intermediate annealing) is 1050℃, and the holding time is... min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =5.0×6.1=30.5min.

[0141] The heating temperature for S7 (finished product annealing) is 1050℃, and the holding time is... min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (5.7mm), and the calculation formula is as follows: =3.0×5.7=17.1min.

[0142] Comparative Example 11 This comparative example is the same as Example 1, except that the heating temperature of S3 (first intermediate annealing treatment) is 1150°C and the holding time is [not specified]. min is based on the diameter of the billet after the first cold drawing. The value is determined in mm (6.8mm), and the calculation formula is as follows: =2×6.8mm=13.6min; The heating temperature for S5 (second intermediate annealing) is 1150℃, and the holding time is... min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: =2.0×6.1=12.2min.

[0143] The heating temperature for S7 (finished product annealing) is 1100℃, and the holding time is... min is based on the diameter of the finished cold-drawn bar blank. The value is determined in mm (5.7mm), and the calculation formula is as follows: =1.0×5.7=5.7min.

[0144] Comparative Example 12 This comparative example is the same as Example 1, except that in S11, S3, S5 and S7, the time from when the billet or bar is taken out of the furnace to when it is put into the water is 12 seconds.

[0145] Comparative Example 13 This comparative example is the same as Example 1, except that in S11, S3, S5 and S7, a non-temperature-to-the-furnace charging method is used. Specifically, the billet or bar is charged into the furnace when the furnace temperature is below 500°C and then heated to the target temperature with the furnace.

[0146] After standard heat treatment, the GH4141 alloy cold-drawn bars obtained in the above embodiments and comparative examples were measured for grain size difference, elongation after fracture, reduction of area, room temperature tensile strength, and room temperature tensile strength Cv value. The Cv value was obtained by randomly selecting 10 bars from the same batch of delivered state and measuring them after standard heat treatment, as detailed in Table 1.

[0147] The "standard heat treatment" refers to taking a cold-drawn bar of GH4141 alloy, cutting a sample, and subjecting it to 1120℃×30min, oil cooling + 900℃×4h, and air cooling.

[0148] Table 1 Test results of the examples and comparative examples

[0149] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a cold-drawn bar of GH4141 alloy with uniform microstructure and high plasticity, characterized in that, Includes the following steps: The hot-rolled GH4141 alloy billet is subjected to solution treatment, followed by a first cold drawing, a first intermediate annealing, a second cold drawing, a second intermediate annealing, a final cold drawing, and a final annealing. The solution treatment is heated at 1160~1180℃, and water cooling is used after the solution treatment. The first intermediate annealing, the second intermediate annealing, and the final annealing all employ water cooling.

2. The preparation method according to claim 1, characterized in that, After the solution treatment, the first intermediate annealing, the second intermediate annealing, and the finished product annealing, the time from when the billet or finished bar is removed from the furnace to when it is immersed in water is ≤10s; and / or, The heat preservation time of the solution treatment min is based on the diameter of the hot-rolled bar billet. mm is determined, and the calculation formula is: ; For 4~6; and / or, The solution treatment, the first intermediate annealing, the second intermediate annealing, and the finished product annealing are all carried out by charging the furnace at a warm temperature.

3. The preparation method according to claim 1, characterized in that, The deformation amount during the first cold drawing is 35-60%.

4. The preparation method according to claim 1, characterized in that, The heating temperature for the first intermediate annealing treatment is 1080~1120℃; and / or, The holding time of the first intermediate annealing treatment min is based on the diameter of the billet after the first cold drawing. mm is determined, and the calculation formula is: ; It ranges from 4 to 6.

5. The preparation method according to claim 1, characterized in that, The deformation amount during the second cold drawing is 16-22%.

6. The preparation method according to claim 1, characterized in that, The heating temperature for the second intermediate annealing treatment is 1080~1120℃; and / or, The heat preservation time of the second intermediate annealing treatment min is based on the diameter of the billet after the second cold drawing. mm is determined, and the calculation formula is: ; It is 3~4.

7. The preparation method according to claim 1, characterized in that, The finished product is cold-drawn in one pass, with a deformation of 8-12%.

8. The preparation method according to claim 1, characterized in that, The annealing temperature of the finished product is 1070~1090℃; and / or, The heat preservation time of the finished product annealing treatment min is based on the diameter of the finished cold-drawn bar blank. mm is determined, and the calculation formula is: ; It is 1.5~2.

9. A cold-drawn bar of GH4141 alloy with uniform microstructure and high plasticity, characterized in that, It is prepared by any one of claims 1 to 8.

10. The uniformly structured, highly ductile GH4141 alloy cold-drawn bar according to claim 9, characterized in that, The GH4141 alloy cold-drawn bars have a grain size difference of ≤2.0 grade, a room temperature tensile strength of 800~1270MPa, an elongation after fracture of ≥30%, and a reduction of area of ​​≥40%.

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