GH696 alloy cold-drawn bar and manufacturing method thereof

Abstract

The invention relates to a method for manufacturing a GH696 alloy high-performance cold-drawn material, and belongs to the technical field of metal processing. The GH696 alloy is an aging strengthening type high-temperature alloy and is mainly used for manufacturing fasteners, and a traditional production process of the GH696 alloy is difficult to meet the requirement that the tensile strength is larger than 1600 MPa in some special industries. Therefore, the invention provides a manufacturing method combining cold drawing deformation and heat treatment so as to improve the tensile strength of the alloy, and the specific manufacturing method comprises the following steps: firstly preparing a GH696 alloy bar, carrying out cold drawing after turning treatment, then carrying out aging heat treatment in a heat treatment furnace, and finally improving the material quality through straightening and polishing procedures. Experimental results show that the tensile strength of the cold-drawn material produced by the method is obviously superior to that of the cold-drawn material produced by a traditional method, and the problem of insufficient tensile strength in the prior art is solved. The manufacturing method provided by the invention provides effective technical support for popularization of the GH696 alloy in the high-strength application field.

Description

Technical Field

[0001] The invention belongs to the technical field of metal processing, and in particular relates to a GH696 alloy cold-drawn bar and a manufacturing method thereof. Background Art

[0002] GH696 alloy is a typical age-hardened high-temperature alloy, which is widely used in the field of fastener manufacturing under harsh environments such as high temperature and high pressure. This alloy has a wide range of applications in aerospace, power generation equipment, chemical equipment and other fields due to its excellent creep resistance, corrosion resistance and high thermal strength. GH696 alloy forms a microstructure with γ' phase as the main strengthening phase by adding alloying elements such as chromium, nickel, molybdenum and titanium. These precipitated phases significantly improve the mechanical properties of the material at high temperatures, allowing it to maintain high stability under high temperature and complex stress conditions.

[0003] The traditional GH696 alloy manufacturing process usually adopts vacuum induction + electroslag remelting + forging blanking + rolling into materials, and improves the material properties through subsequent solid solution + aging heat treatment. These production processes can produce alloy materials with a tensile strength of about 1200MPa, which meets the mechanical properties requirements of ordinary fasteners. However, with the rapid development of modern industry, especially in some fields with higher requirements for fastener strength, such as aircraft engines, nuclear power equipment and deep-sea operation equipment, the standardized GH696 alloy is difficult to meet the requirements of tensile strength exceeding 1600MPa. Therefore, how to further improve the strength of GH696 alloy on the basis of existing processes has become an urgent problem to be solved.

[0004] Traditional processes mainly rely on improving the strength of materials by adjusting the heat treatment system and microstructure control to improve alloy performance. However, while this method improves the strength of the alloy, it usually leads to a decrease in the plasticity and toughness of the material, making it difficult to strike a balance between high strength and good plasticity. In addition, conventional heat treatment methods have limited effect on improving the microstructure of the alloy, especially when the tensile strength needs to be greatly improved. Traditional heat treatment processes often fail to achieve sufficient strengthening effects. Therefore, it is difficult to further improve the mechanical properties of the GH696 alloy by heat treatment alone.

[0005] In order to solve the above problems, cold drawing deformation technology has gradually become an effective way to improve the strength of alloys. Cold drawing is a processing method that causes plastic deformation of materials through mechanical stretching, introduces dislocations, work hardening and other effects inside the alloy, and improves the strength of the material by changing the microstructure. Cold drawing deformation can not only effectively improve the tensile strength of the alloy, but also can be combined with heat treatment to make the alloy have certain plasticity and toughness during the strengthening process. In addition, cold drawing technology can also control different deformation amounts and perform personalized regulation on alloy materials of different specifications to adapt them to the needs of specific application scenarios.

[0006] Although cold drawing technology has shown significant effects in improving alloy strength, if the strength of GH696 alloy is improved by cold drawing alone, the plasticity and toughness of the material may decrease significantly, and the alloy material after cold drawing often has residual stress, which may affect its long-term performance. Therefore, the reasonable design of cold drawing process parameters and subsequent heat treatment procedures is the key to improving the overall performance of GH696 alloy. By combining appropriate heat treatment processes, some residual stress introduced during the cold drawing process can be eliminated, while promoting the further precipitation of strengthening phases in the alloy, further improving the mechanical properties of the alloy.

[0007] The existing GH696 alloy processing methods are still insufficient in improving material properties, especially when meeting the high-strength requirements of special industries. It is necessary to improve the tensile strength of GH696 alloy by improving the process, especially combining cold drawing deformation and heat treatment technology.

[0008] Therefore, the present invention aims to propose a new cold-drawn material manufacturing method, by combining cold drawing deformation and heat treatment, to improve the tensile strength of GH696 alloy, so as to meet the requirements of some special industries for tensile strength greater than 1600MPa. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a method for manufacturing GH696 alloy cold-drawn bars to solve the problem that the conventional manufacturing method in the prior art has insufficient alloy material strength and tensile strength and cannot meet the strict standards of material properties in certain special industries.

[0010] In order to solve the above technical problems, the present invention provides a method for manufacturing a GH696 alloy cold-drawn bar, comprising the following steps:

[0011] S1: preparing cold-drawn blank: polishing the surface of the hot-rolled GH696 alloy bar, and processing the cold-drawn head and transition section to obtain the cold-drawn blank;

[0012] S2: preparing lubricant: mixing lime, engine oil, graphite powder and water in proportion to prepare lubricant;

[0013] S3: Dipping into coating: dipping the cold-drawn blank obtained in step S1 into the lubricant obtained in step S2, so that a uniform coating is formed on the surface of the cold-drawn blank;

[0014] S4: cold drawing production: drawing the cold drawn blank with coating after the treatment in step S3 into a cold drawn material on a drawing machine, and the deformation amount of the cold drawn material diameter is 9%-10%;

[0015] S5: Aging heat treatment: The cold drawn material obtained in step S4 is kept at 700-800°C for 15-17 hours, then reduced to 600-650°C for 13-15 hours, and then cooled;

[0016] S6: Post-processing: The cold-drawn material after the heat treatment in step S5 is subjected to mechanical post-processing to obtain GH696 alloy cold-drawn bars.

[0017] A manufacturing method of a GH696 alloy cold-drawn bar in the present application has the following advantages compared with the prior art: the manufacturing method of the present invention changes the traditional heat treatment process in the prior art to a combination of cold drawing and aging heat treatment to achieve significant strengthening of the material. The cold drawing deformation and aging heat treatment in this process have a synergistic effect and form linkage, which significantly improves the strength of the GH696 alloy, especially under high temperature conditions, its tensile strength can reach more than 1600MPa. This technical principle provides a basis for improving material properties. During the cold drawing process, the grain refinement and dislocation density of the material increase, and by controlling the deformation amount of the cold-drawn material diameter, its tensile strength is further improved. Subsequently, the formation of the precipitated phase during the aging heat treatment further enhances the strength and durability of the material, thereby ensuring the reliability and stability of the material under harsh conditions.

[0018] In a possible implementation, in step S2, the method for manufacturing the lubricant includes: stirring lime and engine oil evenly, adding part of water and graphite powder and stirring until evenly mixed, adding water again while continuously stirring and adding the remaining raw materials.

[0019] Compared with the existing technology, the above technical solution can optimize the friction characteristics of the material during the cold drawing process through a reasonable lubricant formula, ensure the fluidity and stability of the cold-drawn blank during drawing, thereby reducing the surface defects and internal stress of the material and improving the quality of the cold-drawn material.

[0020] In a possible implementation, in step S2, the components of the lubricant are lime, engine oil, graphite powder and water, and the mass ratio thereof is (35-45):(4-6):(25-35):(160-180).

[0021] Compared with the prior art, the above technical solution can ensure that the ratio of the lubricant is adapted to the needs of different production conditions, enhance the controllability and stability of the cold drawing process, and thus improve the quality and performance of the finished product.

[0022] In a possible implementation, in the step S3, after the coating is formed, the step further includes curing the coating, wherein the curing method is sun exposure or drying.

[0023] Compared with the prior art, the above technical solution can enhance the adhesion of the coating through curing treatment, ensure the uniformity and stability of the coating on the surface of the cold-drawn blank, and reduce the friction loss in the subsequent drawing process.

[0024] In a possible implementation, in step S5, the aging heat treatment conditions are: keeping the cold drawn material at 750° C. for 16 hours, then reducing the temperature to 620° C. for 14 hours, and air cooling after exiting the furnace.

[0025] Compared with the existing technology, the above technical solution can optimize the formation of precipitation phase by accurately controlling the aging heat treatment conditions, improve the tensile strength and heat resistance of GH696 alloy, and thus meet the application requirements under high temperature conditions.

[0026] In a possible implementation, in step S6, the mechanical post-processing includes straightening and polishing;

[0027] The straightening treatment comprises: cutting off the cold-drawn head and the transition section of the cold-drawn material after the aging heat treatment, and then straightening it on a straightening machine;

[0028] The polishing treatment includes: polishing the cold-drawn material after the straightening treatment with a sanding machine to remove the surface oxide scale.

[0029] Compared with the existing technology, the adoption of the above technical solution can ensure the uniformity of the cold-drawn material in the final product form and appearance quality, thereby improving its competitiveness in the market.

[0030] In a possible implementation, in step S6, the mechanical post-processing further includes a step of sampling and preparing the cold-drawn material and then conducting a tensile strength test, including: cutting a section of rod at one end of the cold-drawn material, making a room temperature tensile specimen, and breaking the specimen on a universal testing machine to measure the tensile strength.

[0031] Compared with the existing technology, the above technical solution can provide reliable tensile strength data support, making the quality control in the production process more scientific and accurate.

[0032] Another technical problem to be solved by the present invention is to provide a method for manufacturing GH696 alloy cold-drawn bars to solve the trade-off problem between strength and toughness in conventional manufacturing methods in the prior art, especially the insufficient mechanical properties under high temperature environment.

[0033] In order to solve the above technical problems, the present invention provides a GH696 alloy cold-drawn bar, which is prepared by the above manufacturing method, and the chemical composition range of the bar includes: C: 0.040-0.050%, Mn: 0.025-0.035%, Si: 0.004-0.006%, S: 0.0008-0.0012%, P: 0.0020-0.0030%, Cr: 11.20-11.35%, Ni: 22.90-23.00%, Mo: 1.25-1.35%, Al: 0.55-0.60%, Ti: 2.85-2.95%, B: 0.005-0.007%, Fe: 60.70-60.85%, and the remainder is inevitable impurities, and the tensile strength of the GH696 alloy cold-drawn bar is greater than 1600MPa.

[0034] A GH696 alloy cold-drawn bar in the present application has the following advantages compared with the prior art: by optimizing the alloy formula, the strength and toughness of the material are significantly improved. Specifically, the alloy composition design of the present invention not only pays attention to the appropriate content of each element, but also fully considers the interaction between the elements, so that a uniform and refined microstructure can be formed during cold drawing and aging heat treatment, thereby improving the comprehensive mechanical properties of the material. The direct technical principle is to improve the dislocation density and microstructural stability of the material through cold drawing deformation, and combine the formation of precipitated phases during aging heat treatment to achieve a significant enhancement of material performance. This method ensures that the GH696 alloy can stably perform its performance in a high temperature environment and meet the requirement of a tensile strength greater than 1600MPa. The technical problems mentioned in the background technology section have been effectively solved, ensuring the reliability and stability of the GH696 alloy in harsh application environments.

[0035] In a possible embodiment, the chemical composition range of the rod includes: C: 0.045%, Mn: 0.029%, Si: 0.005%, S: 0.001%, P: 0.0025%, Cr: 11.27%, Ni: 22.95%, Mo: 1.30%, Al: 0.57%, Ti:

[0036] 2.89%, B: 0.006%, Fe: 60.78%.

[0037] Compared with the existing technology, the above technical solution further optimizes the chemical composition of the bar, and can achieve high performance of GH696 alloy cold-drawn bars through the optimization of alloy formula and the innovative cold drawing and aging heat treatment method. The direct technical effect is to significantly improve the tensile strength of the material to more than 1600MPa, ensuring its application requirements in complex environments such as high temperature and high pressure. DETAILED DESCRIPTION

[0038] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0039] The invention discloses a method for manufacturing a GH696 alloy cold-drawn bar, comprising the following steps:

[0040] S1: preparing cold-drawn blank: polishing the surface of the hot-rolled GH696 alloy bar, and processing the cold-drawn head and transition section to obtain the cold-drawn blank;

[0041] S2: preparing lubricant: mixing lime, engine oil, graphite powder and water in proportion to prepare lubricant;

[0042] S3: Dipping into coating: dipping the cold-drawn blank obtained in step S1 into the lubricant obtained in step S2, so that a uniform coating is formed on the surface of the cold-drawn blank;

[0043] S4: cold drawing production: drawing the cold drawn blank with coating after the treatment in step S3 into a cold drawn material on a drawing machine, and the deformation amount of the cold drawn material diameter is 9%-10%;

[0044] S5: Aging heat treatment: The cold drawn material obtained in step S4 is kept at 700-800°C for 15-17 hours, then reduced to 600-650°C for 13-15 hours, and then cooled;

[0045] S6: Post-processing: The cold-drawn material after the heat treatment in step S5 is subjected to mechanical post-processing to obtain GH696 alloy cold-drawn bars.

[0046] As a preferred solution, in step S2, the method for manufacturing the lubricant includes: stirring lime and engine oil evenly, adding part of water and graphite powder and stirring until evenly mixed, adding water again while continuously stirring and adding the remaining raw materials.

[0047] As a preferred solution, in step S2, the components of the lubricant are lime, engine oil, graphite powder and water, and the mass ratio thereof is (35-45):(4-6):(25-35):(160-180).

[0048] As a preferred solution, in the step S3, after the coating is formed, the coating is further cured by sun exposure or drying.

[0049] As a preferred solution, in step S5, the conditions for the aging heat treatment are: keeping the cold drawn material at 750°C for 16 hours, then reducing the temperature to 620°C for 14 hours, and air cooling after exiting the furnace.

[0050] As a preferred solution, in step S6, the mechanical post-processing includes straightening and polishing;

[0051] The straightening treatment comprises: cutting off the cold-drawn head and the transition section of the cold-drawn material after the aging heat treatment, and then straightening it on a straightening machine;

[0052] The polishing treatment includes: polishing the cold-drawn material after the straightening treatment with a sanding machine to remove the surface oxide scale.

[0053] As a preferred solution, in step S6, the mechanical post-processing also includes the step of sampling and preparing the cold-drawn material and then conducting a tensile strength test, including: cutting a section of rod at one end of the cold-drawn material, making a room temperature tensile specimen, and breaking it on a universal testing machine to measure the tensile strength.

[0054] The present invention also provides a GH696 alloy cold-drawn bar, characterized in that the GH696 alloy cold-drawn bar is prepared by the above-mentioned manufacturing method, and the chemical composition range of the bar includes: C: 0.040-0.050%, Mn: 0.025-0.035%, Si: 0.004-0.006%, S: 0.0008-0.0012%, P: 0.0020-0.0030%, Cr: 11.20-11.35%, Ni: 22.90-23.00%, Mo: 1.25-1.35%, Al: 0.55-0.60%, Ti: 2.85-2.95%, B: 0.005-0.007%, Fe: 60.70-60.85%, the remainder is inevitable impurities, and the tensile strength of the GH696 alloy cold-drawn bar is greater than 1600MPa.

[0055] As a preferred solution, the chemical composition range of the rod includes: C: 0.045%, Mn: 0.029%, Si: 0.005%, S: 0.001%, P: 0.0025%, Cr: 11.27%, Ni: 22.95%, Mo: 1.30%, Al: 0.57%, Ti: 2.89%, B: 0.006%, Fe: 60.78%.

[0056] The following provides examples combining specific preparation methods and specific formulations to further expand and explain the above technical solutions of the present invention:

[0057] Embodiment 1:

[0058] Embodiment 1 provides a GH696 alloy cold-drawn bar and a manufacturing method thereof, the manufacturing method comprising:

[0059] S1: Prepare cold-drawn blank: The surface of the hot-rolled GH696 alloy bar is polished, and a cold-drawn head and a transition section are processed to obtain a cold-drawn blank, the diameter of which is polished from Φ45mm to Φ42mm, and a cold-drawn head of Φ36×200mm and a transition section of 100mm are processed at one end of the bar.

[0060] S2: Making a lubricant: Mix lime, engine oil, graphite powder and water in proportion to make a lubricant. Specifically, stir the lime, engine oil, graphite powder and water evenly to ensure that the desired lubricant is obtained after the mixture is evenly mixed. The mass ratio of lime, engine oil, graphite powder and water is 40:5:30:170.

[0061] S3: coating operation: immersing the cold-drawn blank obtained in step S1 into the lubricant obtained in step S2, so that a uniform coating is formed on the surface of the cold-drawn blank, and then sun-drying or drying is performed to solidify the coating.

[0062] S4: producing cold-drawn material: the cold-drawn blank with coating after the treatment in step S3 is drawn into a cold-drawn material on a drawing machine, and the diameter is reduced from Φ42 mm to Φ38 mm.

[0063] S5: Aging heat treatment: The cold drawn material obtained in step S4 is placed in a heating furnace, heated to 750°C and kept at this temperature for 16 hours, then cooled to 620°C and kept at this temperature for 14 hours, and then taken out of the furnace and air-cooled.

[0064] S6: Post-processing: The cold-drawn material after the heat treatment in step S5 is subjected to mechanical post-processing, including cutting off the cold-drawn head and transition section and then straightening it on a straightening machine to ensure its straightness.

[0065] Polishing: Use a belt sander to polish and remove the surface oxide to ensure a smooth surface.

[0066] Sampling and sample preparation: Cut a 200mm long sample from one end of the bar and make a Φ10mm room temperature tensile specimen.

[0067] Test tensile strength: The prepared Φ10mm room temperature tensile specimen was subjected to a breaking test on a universal testing machine, and the tensile strength was measured to be 1642MPa.

[0068] The composition of the GH696 alloy cold-drawn bar prepared in Example 1 includes:

[0069] C: 0.045%, Mn: 0.029%, Si: 0.005%, S: 0.001%, P: 0.0025%, Cr: 11.27%, Ni: 22.95%, Mo: 1.30%, Al: 0.57%, Ti: 2.89%, B: 0.006%, Fe: 60.78%.

[0070] Embodiment 2:

[0071] Embodiment 2 provides a GH696 alloy cold-drawn bar and a manufacturing method thereof, the manufacturing method comprising:

[0072] S1: Prepare cold-drawn blank: The surface of the hot-rolled GH696 alloy bar is polished, and a cold-drawn head and a transition section are processed to obtain a cold-drawn blank, the diameter of which is polished from Φ45mm to Φ42mm, and a cold-drawn head of Φ36×200mm and a transition section of 100mm are processed at one end of the bar.

[0073] S2: Making a lubricant: Mix lime, engine oil, graphite powder and water in proportion to make a lubricant. Specifically, stir the lime, engine oil, graphite powder and water evenly to ensure that the desired lubricant is obtained after the mixture is evenly mixed. The mass ratio of lime, engine oil, graphite powder and water is 35:4:25:160.

[0074] S3: coating operation: immersing the cold-drawn blank obtained in step S1 into the lubricant obtained in step S2, so that a uniform coating is formed on the surface of the cold-drawn blank, and then sun-drying or drying is performed to solidify the coating.

[0075] S4: producing cold-drawn material: the cold-drawn blank with coating after the treatment in step S3 is drawn into a cold-drawn material on a drawing machine, and the diameter is reduced from Φ42 mm to Φ38 mm.

[0076] S5: Aging heat treatment: The cold drawn material obtained in step S4 is kept at 700° C. for 15 hours, then reduced to 600° C. for 13-15 hours, and then naturally cooled.

[0077] S6: Post-processing: The cold-drawn material after the heat treatment in step S5 is subjected to mechanical post-processing, including cutting off the cold-drawn head and transition section and then straightening it on a straightening machine to ensure its straightness.

[0078] Polishing: Use a belt sander to polish and remove the surface oxide to ensure a smooth surface.

[0079] Sampling and sample preparation: Cut a 200mm long sample from one end of the bar and make a Φ10mm room temperature tensile specimen.

[0080] Test tensile strength: The prepared Φ10mm room temperature tensile specimen was subjected to a breaking test on a universal testing machine, and the tensile strength was measured to be 1642MPa.

[0081] The composition of the GH696 alloy cold-drawn bar prepared in Example 2 includes:

[0082] C: 0.040%, Mn: 0.025%, Si: 0.004%, S: 0.0008%, P: 0.0020%, Cr: 11.20%, Ni: 22.90%, Mo: 1.25%, Al: 0.55-0.60%, Ti: 2.85-2.95%, B: 0.005%, and the balance is Fe and inevitable impurities.

[0083] Embodiment 3:

[0084] Embodiment 3 provides a GH696 alloy cold-drawn bar and a manufacturing method thereof, the manufacturing method comprising:

[0085] S1: Prepare cold-drawn blank: The surface of the hot-rolled GH696 alloy bar is polished, and a cold-drawn head and a transition section are processed to obtain a cold-drawn blank, the diameter of which is polished from Φ45mm to Φ42mm, and a cold-drawn head of Φ36×200mm and a transition section of 100mm are processed at one end of the bar.

[0086] S2: Making a lubricant: Mix lime, engine oil, graphite powder and water in proportion to make a lubricant. Specifically, stir the lime, engine oil, graphite powder and water evenly to ensure that the desired lubricant is obtained after the mixture is evenly mixed. The mass ratio of lime, engine oil, graphite powder and water is 45:6:35:180.

[0087] S3: coating operation: immersing the cold-drawn blank obtained in step S1 into the lubricant obtained in step S2, so that a uniform coating is formed on the surface of the cold-drawn blank, and then sun-drying or drying is performed to solidify the coating.

[0088] S4: producing cold-drawn material: the cold-drawn blank with coating after the treatment in step S3 is drawn into a cold-drawn material on a drawing machine, and the diameter is reduced from Φ42 mm to Φ38 mm.

[0089] S5: Aging heat treatment: The cold drawn material obtained in step S4 is kept at 800° C. for 17 hours, then reduced to 650° C. for 15 hours, and then naturally cooled.

[0090] S6: Post-processing: The cold-drawn material after the heat treatment in step S5 is subjected to mechanical post-processing, including cutting off the cold-drawn head and transition section and then straightening it on a straightening machine to ensure its straightness.

[0091] Polishing: Use a belt sander to polish and remove the surface oxide to ensure a smooth surface.

[0092] Sampling and sample preparation: Cut a 200mm long sample from one end of the bar and make a Φ10mm room temperature tensile specimen.

[0093] Test tensile strength: The prepared Φ10mm room temperature tensile specimen was subjected to a breaking test on a universal testing machine, and the tensile strength was measured to be 1642MPa.

[0094] The composition of the GH696 alloy cold-drawn bar prepared in Example 3 includes:

[0095] C: 0.050%, Mn: 0.035%, Si: 0.006%, S: 0.0012%, P: 0.0030%, Cr: 11.35%, Ni: 23.00%, Mo: 1.35%, Al: 0.60%, Ti: 2.95%, B: 0.007%, and the balance is Fe and inevitable impurities.

[0096] The cold-drawn material (deformation of 9.5%) from the Φ42 mm hot-rolled polished rod cold-drawn to Φ38 mm in step S4 of the preparation process of Example 1 was subjected to room temperature tensile test. The test standards and results are shown in Table 1:

[0097] Table 1

[0098]

[0099] For comparison, the room temperature tensile strength of a Φ42mm hot-rolled polished bar cold-drawn to Φ40mm (deformation of 4.76%) is shown in Table 2 below:

[0100] Table 2

[0101]

[0102] Repeat the above steps, and use Φ42mm hot-rolled polished rod to cold-draw Φ39mm (deformation is 7.14%) to measure the room temperature tensile strength as shown in Table 3 below:

[0103] Table 3

[0104]

[0105] The above comparison with Example 1 of the present invention further proves that the present invention further improves the room temperature tensile strength of the rod by controlling the deformation amount of the diameter of the cold drawn material to 9%-10%.

[0106] According to the above embodiment, it is further explained that the present invention provides a GH696 alloy cold-drawn bar and a manufacturing method thereof, and the manufacturing method mainly combines cold-drawn deformation with aging heat treatment technology to significantly improve the tensile strength of the GH696 alloy. Specifically, the cold-drawing process introduces plastic deformation through mechanical stretching, and by reasonably controlling the deformation amount of its diameter to 9%-10%, the dislocation density of the material and the stability of the microstructure are increased, thereby improving the strength of the alloy. Subsequently, by performing aging heat treatment at a high temperature of 700-800°C, the formation of the precipitated phase further strengthens the material, ensuring its mechanical properties and reliability under high temperature conditions. In addition, the present invention optimizes the formula of the alloy so that the synergistic effect between the elements can be fully utilized, not only focusing on the appropriate content of each element, but also considering the mutual influence between the elements, thereby achieving a more comprehensive improvement in material performance. The technical solution in the present invention effectively solves the problem of insufficient tensile strength of the GH696 alloy under the traditional manufacturing method in the prior art, especially meeting the strict requirements of certain special industries for tensile strength greater than 1600MPa. By optimizing the linkage between cold drawing and heat treatment processes and combining the innovative design of alloy formula, the comprehensive performance of the alloy is further improved, so that it can still maintain stable mechanical properties in harsh environments such as high temperature and high pressure. Therefore, the present invention not only provides effective technical support for the promotion of GH696 alloy in high-strength application fields, but also opens up new directions for research and application in related fields.

[0107] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0108] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for manufacturing a GH696 alloy cold-drawn bar, characterized in that: The following steps are involved: S1: preparing cold-drawn blank: polishing the surface of the hot-rolled GH696 alloy bar, and processing the cold-drawn head and transition section to obtain the cold-drawn blank; S2: preparing lubricant: mixing lime, engine oil, graphite powder and water in proportion to prepare lubricant; S3: Dipping into coating: dipping the cold-drawn blank obtained in step S1 into the lubricant obtained in step S2, so that a uniform coating is formed on the surface of the cold-drawn blank; S4: cold drawing production: drawing the cold drawn blank with coating after the treatment in step S3 into a cold drawn material on a drawing machine, and the deformation amount of the cold drawn material diameter is 9%-10%; S5: Aging heat treatment: The cold drawn material obtained in step S4 is kept at 700-800°C for 15-17 hours, then reduced to 600-650°C for 13-15 hours, and then cooled; S6: Post-processing: The cold-drawn material after the heat treatment in step S5 is subjected to mechanical post-processing to obtain GH696 alloy cold-drawn bars.

2. The manufacturing method according to claim 1, characterized in that: In step S2, the method for manufacturing the lubricant includes: stirring lime and engine oil evenly, adding part of water and graphite powder and stirring until evenly mixed, adding water again while stirring continuously and adding the remaining raw materials.

3. The manufacturing method according to claim 1, characterized in that: In step S2, the components of the lubricant are lime, engine oil, graphite powder and water, and the mass ratio thereof is (35-45):(4-6):(25-35):(160-180).

4. The manufacturing method according to claim 1, in the step S3, after the coating is formed, the step further comprises curing the coating, wherein the curing method is sun exposure or drying.

5. The manufacturing method according to claim 1, characterized in that: In step S5, the aging heat treatment conditions are: the cold drawn material is kept at 750° C. for 16 hours, then reduced to 620° C. for 14 hours, and air-cooled after being taken out of the furnace.

6. The manufacturing method according to claim 1, characterized in that: In the step S6, the mechanical post-processing includes straightening and polishing; The straightening treatment comprises: cutting off the cold-drawn head and the transition section of the cold-drawn material after the aging heat treatment, and then straightening it on a straightening machine; The polishing treatment includes: polishing the cold-drawn material after the straightening treatment with a sanding machine to remove the surface oxide scale.

7. The manufacturing method according to claim 1, characterized in that: In the step S6, the mechanical post-processing also includes the step of sampling and preparing the cold-drawn material and then testing its tensile strength, including: cutting a section of the bar at one end of the cold-drawn material, making a room temperature tensile specimen, and breaking it on a universal testing machine to measure the tensile strength.

8. A GH696 alloy cold drawn bar, characterized in that: The GH696 alloy cold-drawn bar is prepared by any one of the manufacturing methods of claims 1-7, and the chemical composition range of the bar includes: C: 0.040-0.050%, Mn: 0.025-0.035%, Si: 0.004-0.006%, S: 0.0008-0.0012%, P: 0.0020-0.0030%, Cr: 11.20-11.35%, Ni: 22.90-23.00%, Mo: 1.25-1.35%, Al: 0.55-0.60%, Ti: 2.85-2.95%, B: 0.005-0.007%, Fe: 60.70-60.85%, and the remainder is unavoidable impurities, and the tensile strength of the GH696 alloy cold-drawn bar is greater than 1600MPa.

9. The GH696 alloy cold-drawn bar according to claim 8, characterized in that: The chemical composition range of the rod includes: C: 0.045%, Mn: 0.029%, Si: 0.005%, S: 0.001%, P: 0.0025%, Cr: 11.27%, Ni: 22.95%, Mo: 1.30%, Al: 0.57%, Ti: 2.89%, B: 0.006%, Fe: 60.78%.

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