A method for preparing high-precision GH4169 alloy strip for metal sealing ring

Abstract

The present invention discloses a method for preparing a high-precision GH4169 alloy strip for metal sealing rings, the method comprising: 1. rolling the GH4169 alloy strip blank in one rolling process; 2. heating and heat preservation annealing; 3. surface treatment and intermediate treatment; 4. rolling in two rolling processes; 5. heating and heat preservation annealing; 6. surface treatment and intermediate treatment; 7. rolling in three rolling processes; 8. solution treatment. The present invention repeatedly rolls the strip two or three times and controls the rolling tension and rolling pressure, comprehensively regulates the roller convexity, and eliminates internal stress by combining intermediate annealing, so that the internal structure of each strip semi-finished product becomes more uniform, removes undesirable plate shapes such as edge waves, middle waves, and rib waves, reduces plate shape defects, and reduces thickness tolerance, thereby obtaining a GH4169 alloy strip with high precision and good surface quality, which is suitable for metal sealing rings, and has a simple and flexible preparation process, meeting the production needs of small batches, multiple varieties, and multiple specifications.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal processing, and particularly relates to a method for preparing a high-precision GH4169 alloy strip for a metal sealing ring. Background Art

[0002] GH4169 high-temperature alloy is a precipitation-strengthened nickel-based high-temperature alloy with body-centered cubic γ' and face-centered cubic γ" as strengthening phases. It has high yield strength, tensile strength, endurance strength and plasticity between -253℃ and 650℃, and has good fatigue resistance, oxidation resistance, corrosion resistance, and radiation resistance, as well as good processing properties, weldability and long-term structural stability. It is widely used in aviation, aerospace, shipbuilding, nuclear industry, petroleum and chemical industries. This alloy can be used to produce various parts with different uses and shapes, such as rods, cakes, rings, plates, strips, wires, tubes, etc. Its consumption accounts for more than 45% of the world's total output of wrought high-temperature alloys.

[0003] GH4169 alloy strip is used in core engine components for aviation, aerospace, shipbuilding, and nuclear industries. It can operate for extended periods in environments with high temperatures, high stresses, high speeds, high airflow, and highly corrosive media. It can withstand harsh service environments, heavy workloads, and high failure rates. In the aviation sector, GH4169 alloy strip is primarily used for metal sealing rings in engines.

[0004] Because the forming and manufacturing of metal sealing rings involves a nonlinear and complex deformation process, and their service environment is even more complex, very high requirements are placed on the processing accuracy, flatness, and surface quality of GH4169 strip. Currently, there is a certain gap between my country and imported products in the preparation of high-precision GH4169 alloy strip, resulting in its inability to fully replace imports in the high-end field. Summary of the Invention

[0005] The present invention addresses the shortcomings of the prior art by providing a method for preparing high-precision GH4169 alloy strip for metal sealing rings. This method utilizes two or three repetitive rolling cycles with controlled rolling tension and pressure, comprehensively regulating the roll crown, and combining intermediate annealing to eliminate internal stress. This method achieves a more uniform internal structure for each semi-finished strip, resulting in a GH4169 alloy strip with high precision and excellent surface quality, suitable for metal sealing rings. This method addresses the precision challenges associated with GH4169 alloy strip.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a high-precision GH4169 alloy strip for a metal sealing ring, characterized in that the method comprises the following steps:

[0007] Step 1: Feeding a GH4169 alloy strip with a thickness of 1.8 mm to 2.2 mm and a width of 300 mm to 400 mm into a rolling mill for one rolling process, controlling the rolling pressure of the rolling mill to be 500 t to 600 t and the rolling tension to be 70 kN to 100 kN, to obtain a primary strip semi-finished product with a thickness of 0.7 mm to 1.2 mm;

[0008] Step 2: Place the semi-finished strip obtained in step 1 into a heating furnace, keep it at 990°C to 1020°C for 15 to 60 minutes, and then cool it down after being taken out of the furnace; the cooling method is air cooling, wind cooling, or water cooling;

[0009] Step 3: sandblasting and pickling the semi-finished strip after cooling in step 2 to remove surface oxide scale, and then polishing, trimming and striping;

[0010] In step 4, the semi-finished primary strip after the strip processing in step 3 is fed into the rolling mill for second rolling, and the rolling pressure of the rolling mill is controlled to be 40t-90t, and the rolling tension is controlled to be 12kN-50kN, to obtain a semi-finished secondary strip with a thickness of 0.3mm-0.5mm;

[0011] Step 5: Place the semi-finished secondary strip obtained in step 4 into a gas-shielded continuous annealing furnace, keep the temperature at 990°C to 1050°C for 3 to 20 minutes, and then cool it to room temperature by high-speed air cooling before taking it out of the furnace;

[0012] Step 6: pickling and polishing the semi-finished secondary strip after cooling and taking out of the furnace in step 5, and then trimming the edges;

[0013] In step 7, the secondary strip semi-finished product after the edge trimming treatment in step 6 is fed into the rolling mill for three-pass rolling, and the rolling pressure of the rolling mill is controlled to be 40t-90t, and the rolling tension is controlled to be 9kN-35kN, to obtain a tertiary strip semi-finished product with a thickness of 0.2mm-0.3mm;

[0014] Step 8: The secondary strip semi-finished product obtained in step 4 or the tertiary strip semi-finished product obtained in step 7 is cleaned and sent into a gas-shielded continuous annealing furnace for solution treatment. After trimming and cutting to size, a GH4169 alloy strip with a thickness of 0.2 mm to 0.3 mm and a width of 100 mm to 280 mm is obtained.

[0015] The present invention uses GH4169 alloy strip as raw material, and sequentially rolls through a first rolling process to obtain a primary strip semi-finished product, annealing and air cooling, surface treatment, and striping and trimming; a second rolling process to obtain a secondary strip semi-finished product, annealing and air cooling, surface treatment, and trimming; and a third rolling process to obtain a tertiary strip semi-finished product. The secondary or tertiary strip semi-finished product is then solutionized, trimmed, and cut to size to obtain a GH4169 alloy strip. During the preparation process of the present invention, the internal structure of each strip semi-finished product is made more uniform by repeated rolling two or three times while controlling the rolling tension and rolling pressure, comprehensively regulating the roll crown, and combining intermediate annealing to eliminate internal stress, thereby obtaining a GH4169 alloy strip with high precision and good surface quality, suitable for use in metal sealing rings.

[0016] The above-mentioned method for preparing high-precision GH4169 alloy strip for metal sealing rings is characterized by preparing the GH4169 alloy strip described in step 1 by using a triple smelting process of vacuum induction melting, electroslag remelting, and vacuum consumable remelting to obtain a GH4169 alloy ingot, followed by high-temperature homogenization treatment, forging, and hot rolling to obtain the GH4169 alloy strip. The present invention utilizes a triple smelting process of "vacuum induction melting + electroslag remelting + vacuum consumable remelting" to smelt the GH4169 alloy ingot, effectively reducing the content of harmful impurity elements in the GH4169 alloy ingot and ensuring the uniformity and purity of the GH4169 alloy strip composition.

[0017] The aforementioned method for preparing high-precision GH4169 alloy strip for metal sealing rings is characterized by a thickness tolerance of within ±0.15 mm, an average grain size of 5 to 7, and an elongation exceeding 50%. By controlling the thickness tolerance, average grain size, and elongation of the GH4169 alloy strip, the present invention achieves high dimensional accuracy and uniform microstructure and performance, providing the foundation for producing high-precision GH4169 alloy strip.

[0018] The aforementioned method for producing high-precision GH4169 alloy strip for metal sealing rings is characterized by the following: the rolling mills described in steps 1, 4, and 7 are all reversible cold rolling mills, and the upper and lower work rolls of the rolling mill are crowned rolls. The outer contours of the crowned rolls are curved along the axis, with the crown being greatest in the middle of the roll body and symmetrically distributed at both ends. By utilizing a reversible cold rolling mill with crowned rolls and optimizing the crown of the crowned rolls, the present invention achieves a stable and reliable roll profile, effectively eliminating undesirable strip shapes such as edge waves, center waves, and rib waves, thereby improving the precision of the GH4169 alloy strip.

[0019] The aforementioned method for producing high-precision GH4169 alloy strip for metal sealing rings is characterized by the fact that the upper and lower work rolls of the rolling mill have identical shapes and dimensions, and the center outer diameter of each roll is 0.1 mm to 0.2 mm larger than the outer diameters at both ends. By controlling the shape and dimensions of the upper and lower work rolls, as well as the center outer diameter and the outer diameters at both ends, the present invention ensures minimal shape defects and optimal thickness tolerance in the GH4169 alloy strip.

[0020] The aforementioned method for producing high-precision GH4169 alloy strip for metal sealing rings is characterized in that the rolling mill described in step 1 is a six-roll reversible cold rolling mill, and the intermediate rolls of the rolling mill are equipped with a hydraulic bending roll profile control system. By controlling the bending force, the axes and outer contours of the upper and lower intermediate rolls are curved. The present invention achieves online control of the strip shape and thickness tolerance by controlling the bending force to form the axes and outer contours of the upper and lower intermediate rolls.

[0021] The above-mentioned method for preparing a high-precision GH4169 alloy strip for metal sealing rings is characterized in that the first rolling pass in step 1, the second rolling pass in step 4, and the third rolling pass in step 7 are all multi-pass reversible rolling, with the total reduction ratio of the multiple reversible rolling passes being 40% to 65%, and the reduction ratio of each pass being 5% to 20%. By controlling the total reduction ratio and reduction ratio of each rolling pass, the present invention effectively controls dislocation jamming and twinning effects, coordinates cold deformation, and controls the number and morphology of precipitates during cold deformation, thereby facilitating control of the microstructure and properties of the GH4169 alloy strip.

[0022] The above-mentioned method for preparing a high-precision GH4169 alloy strip for a metal sealing ring is characterized in that a lubricant is sprayed during the first rolling process in step one, the second rolling process in step four, and the third rolling process in step seven, and the lubricant is mineral oil or palm oil.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The present invention adopts the triple smelting process of "vacuum induction melting + electroslag remelting + vacuum consumable remelting" to smelt GH4169 alloy ingots, which are subjected to high-temperature homogenization treatment, forging and hot rolling to obtain GH4169 alloy strips as raw materials, thereby reducing the content of harmful impurity elements in the raw materials, ensuring the uniformity and purity of the composition of the GH4169 alloy strips, and at the same time limiting the thickness tolerance, average grain size and elongation of the GH4169 alloy strips, providing basic conditions for obtaining high-precision GH4169 alloy strips.

[0025] 2. The present invention performs reversible rolling on the GH4169 alloy strip two or three times at room temperature. By promptly performing surface treatment and annealing after each reversible rolling, the internal processing stress of the semi-finished strip is effectively eliminated, making the internal structure of the metal more uniform. This is conducive to obtaining a GH4169 alloy strip with good surface quality while ensuring the thickness accuracy of the GH4169 alloy strip.

[0026] 3. The rolling process of the present invention adopts a reversible cold rolling mill, and limits the type, shape and size of the working rolls of the reversible cold rolling mill, effectively eliminating undesirable plate shapes such as edge waves, middle waves and rib waves, reducing plate shape defects and reducing thickness tolerance, thereby improving the thickness accuracy of GH4169 alloy strip.

[0027] 4. The thickness tolerance of the GH4169 alloy strip prepared by the present invention is stably controlled within ±5% of the target thickness, and the dimensional accuracy is better than the high precision requirement (±7%) of the national standard GJB 3318A-2016 (Specification for Cold Strip of High-temperature Alloys for Aviation). In addition, the surface is smooth and free of defects such as cracks, peeling, folds, inclusions, and obvious oxidation. It is suitable for use in metal sealing rings and can replace imported products.

[0028] 5. The preparation method of the present invention has a simple and flexible process and can meet the production needs of small batches, multiple varieties and multiple specifications.

[0029] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the roll structure of the upper and lower working rolls of the reversible cold rolling mill of the present invention.

[0031] Figure 2 It is a schematic diagram of the roll structure of the upper intermediate roll and the lower intermediate roll of the six-roll reversible cold rolling mill of the present invention after hydraulic roll bending. DETAILED DESCRIPTION

[0032] Example 1

[0033] This embodiment includes the following steps:

[0034] Step 1: Set the thickness to 1.80 +0.15 A GH4169 alloy strip with a thickness of 300 mm and a width of 500 mm is fed into a rolling mill for one rolling process. The rolling pressure of the rolling mill is controlled to be 500t-600t and the rolling tension is controlled to be 70kN-90kN to obtain a primary strip semi-finished product with a thickness of 1.0 mm.

[0035] The GH4169 alloy strip is prepared by adopting a triple smelting process of vacuum induction melting, electroslag remelting and vacuum consumable remelting to obtain a GH4169 alloy ingot, and then subjecting the GH4169 alloy ingot to high-temperature homogenization treatment, forging and hot rolling to obtain a GH4169 alloy strip. The thickness tolerance of the GH4169 alloy strip is within ±0.15 mm, the average grain size is grade 6, and the elongation is 60%.

[0036] like Figure 1 As shown, the rolling mill is a six-roll reversible cold rolling mill. The upper and lower working rolls of the rolling mill are both crowned rolls. The outer contour lines of the crowned rolls are arc-shaped along the axis, and the crown is the largest in the middle of the roll body, and the two ends are symmetrically distributed. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.16mm larger than the outer diameter at the two ends. The intermediate rolls of the rolling mill are equipped with a hydraulic bending roll profile control system, as shown in FIG. Figure 2 As shown, Figure 2 The direction of the middle arrow is the direction of the bending roll force. During each rolling process, the bending roll forces of the upper and lower intermediate rolls are equal in value and opposite in direction. The bending roll force of the upper intermediate roll is upward, so that the axis and outer contour of the upper intermediate roll form a downward convex arc line. The bending roll force of the lower intermediate roll is downward, so that the axis and outer contour of the lower intermediate roll form an upward convex arc line. The bending roll force is controlled to be 8.5t~11.5t;

[0037] The rolling process is a 6-pass reversible rolling process, the total reduction rate of the 6-pass reversible rolling process is 44.4%, and the reduction rates of each pass are 8.3%, 12.1%, 13.8%, 8.0%, 7.0%, and 6.5%, respectively, and lubricant mineral oil is sprayed during the rolling process of the rolling process;

[0038] Step 2: Place the semi-finished strip obtained in step 1 into a heating furnace, keep it at 1020°C for 15 minutes, and then air-cool it.

[0039] Step 3: sandblast and pickle the semi-finished strip after the insulation in step 2 to remove the surface oxide scale, then polish and trim the edges, and cut into strips with a width of 105 mm;

[0040] In step 4, the semi-finished primary strip after strip processing in step 3 is fed into a 350mm cold rolling mill for second rolling, and the rolling pressure of the rolling mill is controlled to be 40t-90t, and the rolling tension is 12kN-18kN, to obtain a semi-finished secondary strip with a thickness of 0.5mm;

[0041] The upper and lower working rolls of the 350mm cold rolling mill are both crowned rolls. The outer contour of the crowned roll is an arc along the axis, and the crown is the largest in the middle of the roll body and is symmetrically distributed at both ends. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.16mm larger than the outer diameter at the ends.

[0042] The second rolling process is 7 reversible rolling passes, the total reduction rate of the 7 reversible rolling passes is 50%, and the reduction rate of each pass is 8.0%, 13.0%, 15.0%, 10.3%, 6.6%, 7.0%, and 5.7%, respectively. Lubricant mineral oil is sprayed during the second rolling process;

[0043] Step 5: Place the semi-finished secondary strip obtained in step 4 into a gas-shielded continuous annealing furnace, keep the temperature at 1050°C for 3 minutes, and then cool it to room temperature by high-speed air cooling before taking it out of the furnace;

[0044] Step 6: pickling and polishing the semi-finished secondary strip after cooling and taking out of the furnace in step 5, and then trimming the edges;

[0045] In step 7, the secondary strip semi-finished product after the edge trimming treatment in step 6 is fed into a 350mm cold rolling mill for three-pass rolling, and the rolling pressure of the rolling mill is controlled to be 40t-70t, and the rolling tension is controlled to be 9kN-13kN, to obtain a tertiary strip semi-finished product with a thickness of 0.2mm and a thickness tolerance of ±0.01mm;

[0046] The upper and lower working rolls of the 350mm cold rolling mill are both crowned rolls. The outer contour of the crowned roll is an arc along the axis, and the crown is the largest in the middle of the roll body and is symmetrically distributed at both ends. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.2mm larger than the outer diameter at the ends.

[0047] The three-pass rolling process is a 7-pass reversible rolling process, wherein the total reduction ratio of the 7-pass reversible rolling process is 60%, and the reduction ratio of each pass is 20.0%, 17.5%, 12.1%, 10.3%, 7.7%, 8.3%, and 9.1%, respectively. Lubricant mineral oil is sprayed during the three-pass rolling process.

[0048] Step 8: The tertiary strip semi-finished product obtained in step 7 is cleaned and sent into a gas-shielded continuous annealing furnace for solution treatment at 1020° C. After trimming and cutting to size, a GH4169 alloy strip with a thickness of 0.2 mm and a width of 100 mm is obtained.

[0049] According to the national standard GJB 3318-2016 "Specification for Cold Strip of High-Temperature Alloys for Aviation Use", the GH4169 alloy strip product prepared in this embodiment has a thickness of 0.2 mm and a thickness tolerance of ±0.01 mm, which is only ±5% of the product thickness. The dimensional accuracy is better than the high precision requirement of ±7% of the national standard. At the same time, the surface of the GH4169 alloy strip product prepared in this embodiment is bright and metallic, which is better than the silver-gray or dark color specified in the national standard GJB 3318A-2016 "Specification for Cold Strip of High-Temperature Alloys for Aviation Use". In addition, the GH4169 alloy strip product prepared in this embodiment has a straight plate shape and is free of defects such as cracks, bubbles, inclusions and scars on the surface. It can meet the requirements of the national military standard and can replace imported products.

[0050] Example 2

[0051] This embodiment includes the following steps:

[0052] Step 1: A GH4169 alloy strip with a width of 400 mm is fed into a rolling mill for one rolling process. The rolling pressure of the rolling mill is controlled to be 540t-600t, and the rolling tension is controlled to be 80kN-100kN, to obtain a primary strip semi-finished product with a thickness of 1.2 mm.

[0053] The GH4169 alloy strip is prepared by adopting a triple smelting process of vacuum induction melting, electroslag remelting and vacuum consumable remelting to obtain a GH4169 alloy ingot, and then subjecting the GH4169 alloy ingot to high-temperature homogenization treatment, forging and hot rolling to obtain a GH4169 alloy strip. The thickness tolerance of the GH4169 alloy strip is within ±0.15 mm, the average grain size is level 5, and the elongation is 54%.

[0054] like Figure 1 As shown, the rolling mill is a six-roll reversible cold rolling mill. The upper and lower working rolls of the rolling mill are both crowned rolls. The outer contour lines of the crowned rolls are arc-shaped along the axis, and the crown is the largest in the middle of the roll body, and the two ends are symmetrically distributed. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.1mm larger than the outer diameter at the two ends. The intermediate rolls of the rolling mill are equipped with a hydraulic bending roll profile control system, as shown in FIG. Figure 2 As shown, Figure 2 The direction of the middle arrow is the direction of the bending roll force. During each rolling process, the bending roll forces of the upper and lower intermediate rolls are equal in value and opposite in direction. The bending roll force of the upper intermediate roll is upward, so that the axis and outer contour of the upper intermediate roll form a downward convex arc line. The bending roll force of the lower intermediate roll is downward, so that the axis and outer contour of the lower intermediate roll form an upward convex arc line. The bending roll force is controlled to be 8.5t~11.5t;

[0055] The rolling process is a 6-pass reversible rolling process, the total reduction rate of the 6 reversible rolling processes is 45.5%, and the reduction rates of each pass are 9.1%, 10.0%, 11.1%, 12.5%, 8.6%, and 6.3%, respectively. Lubricant palm oil is sprayed during the rolling process.

[0056] Step 2: Place the semi-finished strip obtained in step 1 into a heating furnace, keep the temperature at 990°C for 60 minutes, and then air-cool it.

[0057] Step 3: sandblast and pickle the semi-finished strip after the insulation in step 2 to remove the surface oxide scale, then polish and trim the edges, and cut into strips with a width of 2855 mm;

[0058] In step 4, the semi-finished primary strip after strip processing in step 3 is fed into a 350mm cold rolling mill for second rolling, and the rolling pressure of the rolling mill is controlled to be 60t-90t, and the rolling tension is controlled to be 28kN-50kN, to obtain a semi-finished secondary strip with a thickness of 0.5mm;

[0059] The upper and lower working rolls of the 350mm cold rolling mill are both crowned rolls. The outer contour of the crowned roll is an arc along the axis, and the crown is greatest in the middle of the roll body and is symmetrically distributed at both ends. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.1mm larger than the outer diameter at the ends.

[0060] The second rolling process is 9-pass reversible rolling, the total reduction rate of the 9-pass reversible rolling is 58.3%, and the reduction rates of each pass are 8.3%, 13.6%, 10.5%, 11.8%, 9.3%, 8.8%, 8.1%, 7.0%, and 5.7%, respectively. Lubricant palm oil is sprayed during the second rolling process;

[0061] Step 5: Place the semi-finished secondary strip obtained in step 4 into a gas-shielded continuous annealing furnace, keep the temperature at 990°C for 20 minutes, and then cool it to room temperature by high-speed air cooling before taking it out of the furnace;

[0062] Step 6: pickling and polishing the semi-finished secondary strip after cooling and taking out of the furnace in step 5, and then trimming the edges;

[0063] Step 7: The secondary strip semi-finished product after the edge trimming treatment in step 6 is fed into a 350mm cold rolling mill for three-pass rolling. The rolling pressure of the rolling mill is controlled to be 60t-90t, and the rolling tension is controlled to be 20kN-35kN, to obtain a tertiary strip semi-finished product with a thickness of 0.3mm and a thickness tolerance of ±0.01mm.

[0064] The upper and lower working rolls of the 350mm cold rolling mill are both crowned rolls. The outer contour of the crowned roll is an arc along the axis, and the crown is the largest in the middle of the roll body and is symmetrically distributed at both ends. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.14mm larger than the outer diameter at the ends.

[0065] The three-pass rolling process is a 7-pass reversible rolling process, wherein the total reduction rate of the 7-pass reversible rolling process is 40%, and the reduction rates of each pass are 12.0%, 11.4%, 7.7%, 5.6%, 5.9%, and 6.3%, respectively. Palm oil is sprayed as a lubricant during the three-pass rolling process.

[0066] Step 8: The tertiary strip semi-finished product obtained in step 7 is cleaned and sent into a gas-shielded continuous annealing furnace for solution treatment at 1020°C. After trimming and cutting to size, a GH4169 alloy strip with a thickness of 0.3 mm and a width of 280 mm is obtained.

[0067] According to the national standard GJB 3318-2016 "Specification for Cold Strip of High-Temperature Alloys for Aviation Use", the GH4169 alloy strip product prepared in this embodiment has a thickness of 0.3 mm and a thickness tolerance of ±0.015 mm, which is only ±5% of the product thickness. The dimensional accuracy is better than the high precision requirement of ±7% of the national standard. At the same time, the surface of the GH4169 alloy strip product prepared in this embodiment is bright and metallic, which is better than the silver-gray or dark color specified in the national standard GJB 3318A-2016 "Specification for Cold Strip of High-Temperature Alloys for Aviation Use". In addition, the GH4169 alloy strip product prepared in this embodiment has a straight plate shape and is free of defects such as cracks, bubbles, inclusions and scars on the surface. It can meet the requirements of the national military standard and can replace imported products.

[0068] Example 3

[0069] This embodiment includes the following steps:

[0070] Step 1: A GH4169 alloy strip with a width of 350 mm is fed into a rolling mill for one rolling process. The rolling pressure of the rolling mill is controlled to be 520t to 580t, and the rolling tension is controlled to be 75kN to 100kN, to obtain a primary strip semi-finished product with a thickness of 0.7 mm.

[0071] The GH4169 alloy strip is prepared by adopting a triple smelting process of vacuum induction melting, electroslag remelting and vacuum consumable remelting to obtain a GH4169 alloy ingot, and then subjecting the GH4169 alloy ingot to high-temperature homogenization treatment, forging and hot rolling to obtain a GH4169 alloy strip. The thickness tolerance of the GH4169 alloy strip is within ±0.15 mm, the average grain size is grade 7, and the elongation is 58%.

[0072] like Figure 1 As shown, the rolling mill is a six-roll reversible cold rolling mill. The upper and lower working rolls of the rolling mill are both crowned rolls. The outer contour lines of the crowned rolls are arc-shaped along the axis, and the crown is the largest in the middle of the roll body, and the two ends are symmetrically distributed. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.14mm larger than the outer diameter at the two ends. The intermediate rolls of the rolling mill are equipped with a hydraulic bending roll profile control system, as shown in FIG. Figure 2 As shown, Figure 2 The direction of the middle arrow is the direction of the bending roll force. During each rolling process, the bending roll forces of the upper and lower intermediate rolls are equal in value and opposite in direction. The bending roll force of the upper intermediate roll is upward, so that the axis and outer contour of the upper intermediate roll form a downward convex arc line. The bending roll force of the lower intermediate roll is downward, so that the axis and outer contour of the lower intermediate roll form an upward convex arc line. The bending roll force is controlled to be 8.5t~11.5t;

[0073] The rolling process is 10 reversible rolling passes, the total reduction rate of the 10 reversible rolling passes is 65.0%, and the reduction rates of each pass are 9.0%, 11.5%, 13.0%, 12.9%, 13.1%, 11.3%, 9.6%, 7.1%, 6.3%, and 5.4%, respectively, and lubricant mineral oil is sprayed during the rolling process of the rolling process;

[0074] Step 2: Place the semi-finished strip obtained in step 1 into a heating furnace, keep the temperature at 990°C for 60 minutes, and then air-cool it.

[0075] Step 3: sandblast and pickle the semi-finished strip after the insulation in step 2 to remove the surface oxide scale, then polish and trim the edges, and cut into strips with a width of 185 mm;

[0076] In step 4, the semi-finished primary strip after strip processing in step 3 is fed into a 350mm cold rolling mill for second rolling, and the rolling pressure of the rolling mill is controlled to be 50t-80t, and the rolling tension is 15kN-25kN, to obtain a semi-finished secondary strip with a thickness of 0.3mm;

[0077] The upper and lower working rolls of the 350mm cold rolling mill are both crowned rolls. The outer contour of the crowned roll is an arc along the axis, and the crown is the largest in the middle of the roll body and is symmetrically distributed at both ends. The upper and lower working rolls of the rolling mill have the same shape and size, and the outer diameter of the middle part of the upper and lower working rolls is 0.14mm larger than the outer diameter at the ends.

[0078] The second rolling process is 9 reversible rolling passes, the total reduction rate of the 9 reversible rolling passes is 57.1%, and the reduction rates of each pass are 8.6%, 10.9%, 12.3%, 10.0%, 8.9%, 7.3%, 7.9%, 8.6%, and 6.3%, respectively. Lubricant palm oil is sprayed during the second rolling process;

[0079] Step 5: The secondary strip semi-finished product obtained in step 4 is cleaned and sent into a gas-shielded continuous annealing furnace for solution treatment at 1020° C. After trimming and cutting to size, a GH4169 alloy strip with a thickness of 0.3 mm and a width of 180 mm is obtained.

[0080] According to the national standard GJB 3318-2016 "Specification for Cold Strip of High-Temperature Alloys for Aviation Use", the GH4169 alloy strip product prepared in this embodiment has a thickness of 0.3 mm and a thickness tolerance of ±0.015 mm, which is only ±5% of the product thickness. The dimensional accuracy is better than the high precision requirement of ±7% of the national standard. At the same time, the surface of the GH4169 alloy strip product prepared in this embodiment is bright and metallic, which is better than the silver-gray or dark color specified in the national standard GJB 3318A-2016 "Specification for Cold Strip of High-Temperature Alloys for Aviation Use". In addition, the GH4169 alloy strip product prepared in this embodiment has a straight plate shape and is free of defects such as cracks, bubbles, inclusions and scars on the surface. It can meet the requirements of the national military standard and can replace imported products.

[0081] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing high-precision GH4169 alloy strip for metal sealing rings, characterized in that: The method comprises the following steps: Step 1: feeding a GH4169 alloy strip with a thickness of 1.8 mm to 2.2 mm and a width of 300 mm to 400 mm into a rolling mill for one rolling process, controlling the rolling pressure of the rolling mill to be 500 t to 600 t and the rolling tension to be 70 kN to 100 kN, to obtain a primary strip semi-finished product with a thickness of 0.7 mm to 1.2 mm; the preparation process of the GH4169 alloy strip is as follows: adopting a triple smelting process of vacuum induction melting, electroslag remelting combined with vacuum consumable remelting to obtain a GH4169 alloy ingot, and then subjecting the GH4169 alloy ingot to high-temperature homogenization treatment, forging and hot rolling to obtain a GH4169 alloy strip; Step 2: Place the semi-finished strip obtained in step 1 into a heating furnace, keep it at 990°C to 1020°C for 15 minutes to 60 minutes, and then cool it down after being taken out of the furnace; the cooling method is air cooling, wind cooling or water cooling; Step 3: sandblasting and pickling the semi-finished strip after cooling in step 2 to remove surface oxide scale, and then polishing, trimming and striping; In step 4, the semi-finished primary strip after the stripping process in step 3 is fed into a rolling mill for second-pass rolling, and the rolling pressure of the rolling mill is controlled to be 40t~90t, and the rolling tension is controlled to be 12kN~50kN, to obtain a semi-finished secondary strip with a thickness of 0.3mm~0.5mm; Step 5: Place the semi-finished secondary strip obtained in step 4 into a gas-shielded continuous annealing furnace, keep the temperature at 990°C to 1050°C for 3 to 20 minutes, and then cool it to room temperature by high-speed air cooling before taking it out of the furnace; Step 6: pickling and polishing the semi-finished secondary strip after cooling and taking out of the furnace in step 5, and then trimming the edges; In step 7, the secondary strip semi-finished product after the edge trimming treatment in step 6 is fed into a rolling mill for three-pass rolling, and the rolling pressure of the rolling mill is controlled to be 40t~90t, and the rolling tension is controlled to be 9kN~35kN, to obtain a tertiary strip semi-finished product with a thickness of 0.2mm~0.3mm; The rolling mills described in steps 1, 4, and 7 are all reversible cold rolling mills, and the upper and lower working rolls of the rolling mill are both crowned rolls. The outer contour lines of the crowned rolls are arc-shaped along the axis, and the crown is largest in the middle of the roll body and symmetrically distributed at both ends. Step 8: The secondary strip semi-finished product obtained in step 4 or the tertiary strip semi-finished product obtained in step 7 is cleaned and sent into a gas-shielded continuous annealing furnace for solution treatment. After trimming and cutting to size, a GH4169 alloy strip with a thickness of 0.2 mm to 0.3 mm and a width of 100 mm to 280 mm is obtained.

2. The method for preparing a high-precision GH4169 alloy strip for a metal sealing ring according to claim 1, characterized in that: The thickness tolerance of the GH4169 alloy strip is within ±0.15 mm, the average grain size is 5 to 7 levels, and the elongation reaches more than 50%.

3. The method for preparing a high-precision GH4169 alloy strip for a metal sealing ring according to claim 1, characterized in that: The upper and lower working rolls of the rolling mill in steps 1, 4 and 7 have the same shape and size, and the outer diameter of the middle portion of the upper and lower working rolls is 0.1 mm to 0.2 mm larger than the outer diameter of the two ends.

4. The method for preparing a high-precision GH4169 alloy strip for a metal sealing ring according to claim 1, characterized in that: The rolling mill described in step 1 is a six-roll reversible cold rolling mill. The intermediate rolls of the rolling mill are equipped with a hydraulic bending roll profile control system, which controls the bending roll force to make the axes and external contours of the upper and lower intermediate rolls form arcs.

5. The method for preparing a high-precision GH4169 alloy strip for a metal sealing ring according to claim 1, characterized in that: The one-pass rolling in step one, the two-pass rolling in step four, and the three-pass rolling in step seven are all multi-pass reversible rolling, and the total reduction rate of the multi-pass reversible rolling is 40% to 65%, and the reduction rate of each pass is 5% to 20%.

6. The method for preparing a high-precision GH4169 alloy strip for a metal sealing ring according to claim 1, characterized in that: Lubricant is sprayed during the first rolling process in step one, the second rolling process in step four, and the third rolling process in step seven. The lubricant is mineral oil or palm oil.

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