A nickel-based alloy forged bar and its preparation method

Abstract

This invention relates to the field of alloy processing technology, specifically disclosing a nickel-based alloy forged bar and its preparation method. The nickel-based alloy forged bar comprises: C: 0.05%–0.1%, Mn: 0.2%–0.5%, Al: 3%–4%, Si: 0.2%–0.4%, Ti: 0.3%–0.5%, Nb: 1%–2%, Cr: 25%–31%, Cu: 0.1%–0.31%, S: 0.0003%–0.001%, Fe: 4.0%–5.3%, with the balance being Ni and unavoidable impurities. By adjusting the chemical composition and limiting the forging process, a nickel-based alloy forged bar with both high strength and high plasticity is obtained, avoiding the cracking problem that easily occurs during the preparation of N06693 nickel-based alloy.

Description

Technical Field

[0001] This invention relates to the field of alloy processing technology, and specifically discloses a nickel-based alloy forged bar and its preparation method. Background Technology

[0002] N06693 alloy is a novel nickel-based corrosion-resistant high-temperature alloy, obtained by adding Al and Ti elements to N06690 alloy. Under annealing conditions, N06693 alloy exhibits a single solid solution disordered face-centered cubic (fcc) austenite (γ) phase, which improves the alloy strength, and the addition of Al enhances its high-temperature corrosion resistance.

[0003] However, the N06693 alloy also has significant performance shortcomings. During forging at 950℃, very fine γ′ phase particles precipitate in the γ phase, leading to brittle failure, specifically cracking of the forged bar. Furthermore, the alloy is highly sensitive to cooling rates after solution treatment. Cooling at rates below 4500℃ / min results in the formation of more γ′ phase particles below 950℃. These γ′ phase particles introduce severe strain into the matrix and reduce plasticity during deformation, ultimately causing transgranular brittle cracking during deformation. Due to the need for rapid cooling after hot deformation to prevent cracking, this stringent production requirement limits its domestic production. Summary of the Invention

[0004] In view of this, the present invention provides a nickel-based alloy forged bar and its preparation method. The nickel-based alloy forged bar provided by the present invention, by adjusting the chemical composition and limiting the forging process, yields a nickel-based alloy forged bar with both high strength and high plasticity, avoiding the cracking problem that easily occurs during the preparation of N06693 nickel-based alloy.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0006] This invention provides a nickel-based alloy forged bar, comprising the following chemical composition by mass percentage: C: 0.05%–0.1%, Mn: 0.2%–0.5%, Al: 3%–4%, Si: 0.2%–0.4%, Ti: 0.3%–0.5%, Nb: 1%–2%, Cr: 25%–31%, Cu: 0.1%–0.31%, S: 0.0003%–0.001%, Fe: 4.0%–5.3%, with the balance being Ni and unavoidable impurities.

[0007] Compared to existing technologies, the nickel-based alloy forged bars provided by this invention utilize a specific amount of aluminum to form a dense alumina film on the bar surface, slowing down the oxidation rate and inhibiting the intrusion of elements such as sulfur, thereby improving the bar's corrosion resistance. Furthermore, the addition of aluminum can form stable reinforcing phases at high temperatures, effectively hindering dislocation movement between grains and improving the bar's high-temperature strength. Specific amounts of carbon and niobium form stable carbides that pin to grain boundaries, inhibiting grain growth and thus improving strength and creep resistance. Niobium also refines the grain structure of the bar, increasing the number of grains and inhibiting the formation of harmful phases, thereby improving the bar's strength and toughness. Manganese and iron optimize the matrix toughness and reduce slip resistance. Moreover, the inventors discovered during their research that a specific amount of manganese dissolved in the alloy matrix does not cause significant lattice distortion in the bar matrix, thus balancing the bar's strength and plasticity. Titanium, nickel, and aluminum combine to form a nanoscale γ′ phase, which significantly improves the strength of the rod by hindering dislocation movement in the grain structure. Furthermore, the low lattice mismatch between the nanoscale γ′ phase and the rod alloy matrix prevents the rod from becoming excessively embrittled and cracking. A specific amount of copper is dissolved in the rod matrix, which causes slight lattice distortion in the matrix to improve the strength of the rod. Due to its small amount, it also ensures that the rod has good toughness.

[0008] This invention achieves a balance between strength and plasticity in nickel-based alloy forging bars by rationally optimizing the chemical composition and component ratio, and making the bars less prone to cracking during the forging process.

[0009] This invention provides a method for preparing the above-mentioned nickel-based alloy forged bar, comprising the following steps:

[0010] S1. The ingot is kept at 1120℃~1150℃. After the heat preservation is completed, the ingot is upsetting forging and drawing forging to obtain the first treated ingot.

[0011] S2. The first processed ingot is kept at 1110℃~1130℃, and the ingot after the heat preservation is completed is drawn and forged to obtain the second processed ingot.

[0012] S3. The second-treated ingot is kept at 1090℃~1120℃, and the ingot after the heat preservation is completed is wrapped with ceramic fiber, drawn and forged, air-cooled, and heat-treated to obtain nickel-based alloy forged bars.

[0013] Compared with the prior art, the method for preparing nickel-based alloy forged bars provided by the present invention includes the following steps: S1, the ingot is kept at a specific temperature, which can homogenize the metal composition and reduce internal stress, providing a good plastic basis for subsequent upsetting and drawing forging; upsetting forging can compact defects such as porosity and shrinkage cavities inside the ingot, making the metal denser; drawing forging can break the coarse cast grain structure through plastic deformation, transforming the structure in the ingot from a cast grain structure to a forged grain structure, initially improving the plasticity and strength of the ingot, while also avoiding early cracking caused by embrittlement of the cast structure.

[0014] In S2, holding the ingot at a specific temperature ensures the plasticity of the second-processed ingot. Then, through elongation forging, the grain structure is fully refined, and the broken grain structure is evenly distributed along the deformation direction, strengthening the grain boundary bonding force. This not only improves the strength but also the plasticity, avoiding the problem of cracks in the bar caused by insufficient plasticity during forging. In addition, the fully refined grain structure prepares for obtaining uniform equiaxed grains in the subsequent process.

[0015] In S3, during the drawing and forging process after holding at a specific temperature, the grain structure in the second-treatment ingot transforms into a fibrous grain structure. This grain structure possesses a high internal energy state due to the presence of numerous dislocations and grain boundary distortions. As heat is generated during forging, the grain structure reduces defects through dislocation movement and merging, laying the foundation for recrystallization. When forging reaches a certain stage, no new dislocation nuclei are found within the fibrous grains or at the grain boundaries. Through recrystallization, an equiaxed grain structure is formed, eliminating deformation defects. Subsequently, the grain structure grows to a specific size, achieving the transformation from a fibrous grain structure to an equiaxed grain structure, ensuring the performance of the bar. Wrapping the ingot with ceramic fibers after holding at the temperature allows for slow cooling, reducing thermal and structural stresses during cooling, eliminating residual stress, and ensuring that the bar does not crack during the drawing and forging process.

[0016] For example, in S1, the ingot is obtained by vacuum induction and electroslag remelting of the raw material.

[0017] Preferably, in S1, the diameter of the ingot is 480mm to 500mm.

[0018] Preferably, in S1, the ingot includes the following pretreatment steps: heating to 1000℃~1150℃ and holding for 3h~5h, and after the holding is completed, pressing the handle is performed to obtain an ingot with a handle at the tail.

[0019] The clamp can detect the deformation resistance and plasticity of the ingot at the heating temperature, preparing it for forging by clamping in the forging machine during the subsequent drawing process.

[0020] Preferably, in S1, the heat preservation time is 1 hour to 2 hours.

[0021] Preferably, in S1, the upsetting ratio of the upsetting forging is 1.45 to 1.55.

[0022] Preferably, in S1, the drawing ratio of the drawing forging is 1.89 to 2.1.

[0023] By limiting the specific parameters of upsetting and drawing forging, it is beneficial to improve the plasticity of the ingot and the plasticity of subsequent forging.

[0024] For example, in S1, the cross-sectional area of ​​the first processed ingot is square.

[0025] Preferably, in S2, the heat preservation time is 1 hour to 2 hours.

[0026] Preferably, in S2, the drawing ratio of the drawing forging is 1.66 to 1.9.

[0027] Optimized drawing and forging parameters are beneficial for further improving the plasticity and strength of the bar stock and preventing cracking.

[0028] For example, in S2, the cross-section of the second processed ingot is square.

[0029] Preferably, in S3, the heat preservation time is 1 hour to 1.5 hours.

[0030] Preferably, in S3, the drawing ratio of the drawing forging is 1.94 to 2.

[0031] The present invention further defines the parameters of the elongation forging in S3, which can ensure that the bar forms an equiaxed grain structure of a specific size, so that the prepared bar has both high strength and plasticity, and ensures that the bar does not crack during heat treatment.

[0032] Preferably, in S3, the coating thickness of the ceramic fiber is 5mm to 10mm.

[0033] Preferably, in S3, the heat treatment conditions are: holding at 1050℃~1150℃ followed by water cooling, and then holding at 800℃~810℃ followed by air cooling.

[0034] Through extensive research, the inventors discovered that, for ingots subjected to the aforementioned forging conditions, the heat treatment conditions are beneficial for further optimizing the performance of nickel-based alloy forged bars.

[0035] Preferably, the heat preservation time at 1050℃~1150℃ is 60min~90min.

[0036] Preferably, the heat preservation time at 800℃~810℃ is 360min~380min.

[0037] This invention, by limiting the composition and preparation process of nickel-based alloy forging bars, enables the prepared nickel-based alloy forging bars to possess both high strength and excellent plasticity, and prevents cracking during production. This solves the problem of high production requirements and easy cracking of existing N06693 alloys. Attached Figure Description

[0038] Figure 1 This is a metallographic diagram of the ingot in Embodiment 1 of the present invention;

[0039] Figure 2 This is a metallographic diagram of the nickel-based alloy forged bar in Embodiment 1 of the present invention. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The method for preparing the ingot provided by this invention includes the following steps:

[0042] Step 1: Weigh out C, Mn, Si, Ti, Nb, Cr, Cu, and Fe and add them to an induction crucible. Melt the mixture at 1490℃~1500℃. Analyze the composition of the molten steel and fine-tune each component to: C: 0.05%~0.1%, Si: 0.2%~0.4%, Ti: 0.3%~0.5%, Nb: 1%~2%, Cr: 25%~31%, and Cu: 0.1%~0.31%, to obtain the first molten steel.

[0043] Step 2: At 1500℃~1520℃ and vacuum degree ≤2Pa, Al is added to the first molten steel, and the steel is refined for more than 1.5 hours. The composition of the molten steel is analyzed and adjusted to: C: 0.05%~0.1%, Al: 3%~4%, Si: 0.2%~0.4%, Ti: 0.3%~0.5%, Nb: 1%~2%, Cr: 25%~31%, Cu: 0.1%~0.31%, S: 0.0003%~0.001%, Fe: 4.0%~5.3%, to obtain the second molten steel.

[0044] Step 3: Inject argon gas into the second molten steel, control the argon gas pressure to be ≥6000Pa, then add Mn and stir for 5min to 10min. After controlling the temperature of the molten steel to be 1430℃ to 1450℃, pour the molten steel into two Φ250mm electrodes.

[0045] Step 4: Control the cooling time of the electrode mold to >40 min, cool the mold to 700℃~800℃, and after the mold is cooled, cover the electrode to cool it to <150℃, and the cooling time is >24 h.

[0046] Step 5: Polish the surfaces of the two electrodes obtained in Step 4 using a non-atmosphere protected electroslag furnace, and then perform electroslag remelting. After power is cut off, the furnace cooling time is ≥60min. After demolding, air cooling is performed to obtain the ingot.

[0047] The slag material comprises the following components by mass percentage: CaF2: 60%, Al2O3: 20%, CaO: 10%, MgO: 10%;

[0048] The parameters for electroslag remelting are: voltage 56V~65V, current 6500A~8000A, slag formation time 40min~50min, and feeding time 35min~50min.

[0049] The ingot preparation method provided by this invention can be obtained by referring to the above method, but is not limited to the above preparation method.

[0050] Example 1

[0051] This embodiment provides a nickel-based alloy forged bar, which, by mass percentage, is composed of the following chemical composition: C: 0.1%, Mn: 0.2%, Al: 4%, Si: 0.2%, Ti: 0.5%, Nb: 2%, Cr: 25%, Cu: 0.31%, S: 0.001%, Fe: 4.0%, with the balance being Ni and unavoidable impurities.

[0052] This embodiment provides a method for preparing the above-mentioned nickel-based alloy forged bar, including the following steps:

[0053] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.45 and a drawing ratio of 2.1, to obtain a first-treatment ingot with a square cross-section.

[0054] S2. The first-processed ingot is kept at 1130℃ for 2 hours. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.66 to obtain a second-processed ingot with a square cross-section.

[0055] S3. The second-processed ingot is held at 1090℃ for 1 hour. After the holding period, 5mm of ceramic fiber is wrapped around the ingot, and it is drawn and forged with a drawing ratio of 1.94. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0056] Example 2

[0057] This embodiment provides a nickel-based alloy forged bar, which, by mass percentage, is composed of the following chemical composition: C: 0.05%, Mn: 0.5%, Al: 3%, Si: 0.4%, Ti: 0.3%, Nb: 1%, Cr: 31%, Cu: 0.1%, S: 0.0006%, Fe: 5.3%, with the balance being Ni and unavoidable impurities.

[0058] This embodiment provides a method for preparing the above-mentioned nickel-based alloy forged bar, including the following steps:

[0059] S1. Pre-treatment of Φ500mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 5 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1150℃ for 1 hour; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.55 and a drawing ratio of 1.89, to obtain a first-treatment ingot with a square cross-section.

[0060] S2. The first-processed ingot is kept at 1110℃ for 1 hour. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.9 to obtain a second-processed ingot with a square cross-section.

[0061] S3. The second-processed ingot is held at 1120℃ for 1.5h. After the holding period, the ingot is wrapped with 10mm ceramic fiber and then drawn and forged with a drawing ratio of 2. It is then air-cooled, held at 1150℃ for 90min, water-cooled, held at 810℃ for 360min, and air-cooled to obtain a nickel-based alloy forged bar.

[0062] Example 3

[0063] This embodiment provides a nickel-based alloy forged bar, which, by mass percentage, is composed of the following chemical composition: C: 0.07%, Mn: 0.4%, Al: 3.5%, Si: 0.3%, Ti: 0.3%, Nb: 1.5%, Cr: 27%, Cu: 0.2%, S: 0.0007%, Fe: 5%, with the balance being Ni and unavoidable impurities.

[0064] This embodiment provides a method for preparing the above-mentioned nickel-based alloy forged bar, including the following steps:

[0065] S1. Pre-treatment of Φ500mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 4 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1140℃ for 1 hour; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.5 and a drawing ratio of 2, to obtain a first-treatment ingot with a square cross-section.

[0066] S2. The first-processed ingot is kept at 1120℃ for 1.5h. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.8 to obtain a second-processed ingot with a square cross-section.

[0067] S3. The second-processed ingot is held at 1100℃ for 1 hour. After the holding period, 7mm ceramic fiber is wrapped around the ingot and then drawn and forged with a drawing ratio of 2. It is then air-cooled, held at 1100℃ for 80 minutes, water-cooled, held at 800℃ for 370 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0068] Example 4

[0069] The difference between this embodiment and Embodiment 1 is that in S3, the elongation ratio is 2.2; specifically as follows:

[0070] The nickel-based alloy forged bars are composed of the following chemical composition by weight percentage: C: 0.1%, Mn: 0.2%, Al: 4%, Si: 0.2%, Ti: 0.5%, Nb: 2%, Cr: 25%, Cu: 0.31%, S: 0.001%, Fe: 4.0%, with the balance being Ni and unavoidable impurities.

[0071] This embodiment provides a method for preparing the above-mentioned nickel-based alloy forged bar, including the following steps:

[0072] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.45 and a drawing ratio of 2.1, to obtain a first-treatment ingot with a square cross-section.

[0073] S2. The first-processed ingot is kept at 1130℃ for 2 hours. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.66 to obtain a second-processed ingot with a square cross-section.

[0074] S3. The second-processed ingot is held at 1090℃ for 1 hour. After the holding period, the ingot is wrapped with 5mm ceramic fiber and then drawn and forged with a drawing ratio of 2.2. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0075] Comparative Example 1

[0076] This comparative example provides a nickel-based alloy forged bar, which differs from Example 1 in that Cu is replaced with an equal amount of Ni, while other components remain unchanged; specifically, it includes the following:

[0077] The nickel-based alloy forged bars are composed of the following chemical composition by weight percentage: C: 0.1%, Mn: 0.2%, Al: 4%, Si: 0.2%, Ti: 0.5%, Nb: 2%, Cr: 25%, S: 0.001%, Fe: 4.0%, with the balance being Ni and unavoidable impurities.

[0078] The specific steps involved in forging nickel-based alloy bars are as follows:

[0079] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.45 and a drawing ratio of 2.1, to obtain a first-treatment ingot with a square cross-section.

[0080] S2. The first-processed ingot is kept at 1130℃ for 2 hours. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.66 to obtain a second-processed ingot with a square cross-section.

[0081] S3. The second-processed ingot is held at 1090℃ for 1 hour. After the holding period, 5mm of ceramic fiber is wrapped around the ingot, and it is drawn and forged with a drawing ratio of 1.94. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0082] Comparative Example 2

[0083] This comparative example provides a nickel-based alloy forged bar, which differs from Example 1 in that Mn is replaced with an equal amount of Ni, while other components remain unchanged; specifically, it includes the following:

[0084] Nickel-based alloy forged bars are composed of the following chemical composition: C: 0.1%, Al: 4%, Si: 0.2%, Ti: 0.5%, Nb: 2%, Cr: 25%, Cu: 0.31%, S: 0.001%, Fe: 4.0%, with the balance being Ni and unavoidable impurities.

[0085] The preparation method of nickel-based alloy forged bars includes the following steps:

[0086] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.45 and a drawing ratio of 2.1, to obtain a first-treatment ingot with a square cross-section.

[0087] S2. The first-processed ingot is kept at 1130℃ for 2 hours. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.66 to obtain a second-processed ingot with a square cross-section.

[0088] S3. The second-processed ingot is held at 1090℃ for 1 hour. After the holding period, 5mm of ceramic fiber is wrapped around the ingot, and it is drawn and forged with a drawing ratio of 1.94. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0089] Comparative Example 3

[0090] This comparative example provides a nickel-based alloy forged bar, which differs from Example 1 in that: only upsetting forging is performed in S1, without drawing forging, while other components and steps remain unchanged; specifically, it includes the following:

[0091] The preparation method of nickel-based alloy forged bars includes the following steps:

[0092] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and upsetting the ingot after holding, with an upsetting ratio of 1.45, to obtain a first-treatment ingot with a square cross-section.

[0093] S2. The first-processed ingot is kept at 1130℃ for 2 hours. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.66 to obtain a second-processed ingot with a square cross-section.

[0094] S3. The second-processed ingot is held at 1090℃ for 1 hour. After the holding period, 5mm of ceramic fiber is wrapped around the ingot, and it is drawn and forged with a drawing ratio of 1.94. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0095] Comparative Example 4

[0096] This comparative example provides a nickel-based alloy forged bar, which differs from Example 1 in that: in S2, the holding temperature is increased, while other components and steps remain unchanged; specifically, it includes the following:

[0097] The preparation method of nickel-based alloy forged bars includes the following steps:

[0098] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.45 and a drawing ratio of 2.1, to obtain a first-treatment ingot with a square cross-section.

[0099] S2. The first-processed ingot is kept at 1180℃ for 2 hours. The ingot after the heat preservation is completed is drawn and forged with a drawing ratio of 1.66 to obtain a second-processed ingot with a square cross-section.

[0100] S3. The second-processed ingot is held at 1090℃ for 1 hour. After the holding period, 5mm of ceramic fiber is wrapped around the ingot, and it is drawn and forged with a drawing ratio of 1.94. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0101] Comparative Example 5

[0102] This comparative example provides a nickel-based alloy forged bar, which differs from Example 1 in that step S3 is omitted, while other components and steps remain unchanged; specifically, it includes the following:

[0103] The preparation method of nickel-based alloy forged bars includes the following steps:

[0104] S1. Pre-treatment of Φ480mm ingots includes: heating the ingot to be treated to 1150℃ and holding it for 3 hours; after holding, pressing the handle to obtain an ingot with a handle at the tail; holding the ingot at 1120℃ for 2 hours; and performing upsetting forging and drawing forging on the ingot after holding, with an upsetting ratio of 1.45 and a drawing ratio of 2.1, to obtain a first-treatment ingot with a square cross-section.

[0105] S2. The first-processed ingot is held at 1130℃ for 2 hours. After the holding period, 5mm ceramic fiber is wrapped around the ingot and then drawn and forged with a drawing ratio of 1.66. It is then air-cooled, held at 1050℃ for 60 minutes, water-cooled, held at 800℃ for 380 minutes, and air-cooled to obtain a nickel-based alloy forged bar.

[0106] Example of effect

[0107] To further demonstrate the technical effects of the present invention, the present invention conducted the following performance tests on the bars obtained in Examples 1-4 and Comparative Examples 1-5.

[0108] Yield strength, tensile strength, elongation, and reduction of area were tested according to ASTM E8 / E8M-24 standard; the results are shown in Table 1.

[0109] Table 1 Performance test results of each bar

[0110]

[0111] The nickel-based alloy forged bar provided in this invention exhibits excellent strength and plasticity, and does not crack during the forging process. Its tensile strength can reach 1117 MPa, elongation can reach 60%, and reduction of area can reach 58%.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A nickel-based alloy forged bar, characterized in that, The chemical composition, by mass percentage, includes the following components: C: 0.05%~0.1%, Mn: 0.2%~0.5%, Al: 3%~4%, Si: 0.2%~0.4%, Ti: 0.3%~0.5%, Nb: 1%~2%, Cr: 25%~31%, Cu: 0.1%~0.31%, S: 0.0003%~0.001%, Fe: 4.0%~5.3%, with the balance being Ni and unavoidable impurities. The preparation method of the nickel-based alloy forged bar includes the following steps: S1. The ingot is kept at 1120℃~1150℃. After the heat preservation is completed, the ingot is upsetting forging and drawing forging to obtain the first-treated ingot. S2. The first processed ingot is kept at 1110℃~1130℃, and the ingot after the heat preservation is completed is drawn and forged to obtain the second processed ingot. S3. The second-treated ingot is kept at 1090℃~1120℃, and the ingot after the heat treatment is completed is wrapped with ceramic fiber, drawn and forged, air-cooled, and heat-treated to obtain nickel-based alloy forged bars.

2. A method for preparing nickel-based alloy forged bars as described in claim 1, characterized in that, Includes the following steps: S1. The ingot is kept at 1120℃~1150℃. After the heat preservation is completed, the ingot is upsetting forging and drawing forging to obtain the first-treated ingot. S2. The first processed ingot is kept at 1110℃~1130℃, and the ingot after the heat preservation is completed is drawn and forged to obtain the second processed ingot. S3. The second-treated ingot is kept at 1090℃~1120℃, and the ingot after the heat treatment is completed is wrapped with ceramic fiber, drawn and forged, air-cooled, and heat-treated to obtain nickel-based alloy forged bars.

3. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S1, the diameter of the ingot is 480mm~500mm.

4. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S1, the heat preservation time is 1h to 2h.

5. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S1, the upsetting ratio of the upsetting forging is 1.45~1.55; and / or In S1, the drawing ratio of the drawing forging is 1.89~2.

1.

6. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S2, the heat preservation time is 1h to 2h.

7. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S2, the drawing ratio of the drawing forging is 1.66 to 1.

9.

8. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S3, the heat preservation time is 1h to 1.5h.

9. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S3, the drawing ratio of the drawing forging is 1.94~2.

10. The method for preparing nickel-based alloy forged bars as described in claim 2, characterized in that, In S3, the coating thickness of the ceramic fiber is 5mm~10mm; and / or In S3, the heat treatment conditions are as follows: after holding at 1050℃~1150℃, water cooling is performed, and then after holding at 800℃~810℃, air cooling is performed.

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