An oxidation-resistant low-expansion high-temperature alloy thin strip and a preparation method thereof

Abstract

The application relates to the technical field of high-temperature alloys, and particularly discloses an oxidation-resistant low-expansion high-temperature alloy thin strip and a preparation method thereof. The preparation method of the oxidation-resistant low-expansion high-temperature alloy thin strip comprises the following procedures: plate shearing, plate welding, weld heat treatment, initial strip blank grinding, intermediate strip blank cold rolling, intermediate strip blank annealing, intermediate strip blank grinding, finished product strip cold rolling and finished product strip annealing. In the plate shearing, the plate is cut along the transverse direction to obtain a plate, and the included angle between the cutting angle and the longitudinal direction of the plate is 45-60 degrees. In the plate welding, two or more plates obtained through the plate shearing are butt-welded by adopting an argon arc welding process, so that a strip blank is obtained. The oxidation-resistant low-expansion high-temperature alloy thin strip has the advantages of a thickness of less than or equal to 0.3 mm, uniform and small grains, good matching of strength and plasticity, good process performance, high size precision, small surface roughness and remarkable economic benefits, and can meet the use requirements of domestic military and civilian markets.

Description

Technical Field

[0001] This application relates to the field of high-temperature alloy technology, specifically to an antioxidant low-expansion high-temperature alloy thin strip and its preparation method. Background Technology

[0002] GH6783 alloy is a Co-Ni-Fe based precipitation-hardening ferromagnetic, oxidation-resistant, low-expansion deformation high-temperature alloy. Its internal structure consists of a three-phase coexistence structure formed by a γ matrix phase, a γ' dispersed strengthening phase, and a β-NiAl phase. GH6783 alloy possesses excellent room-temperature and high-temperature mechanical properties, a low coefficient of thermal expansion, oxidation resistance, and low density. It achieves complete oxidation resistance below 750℃ and exhibits excellent hot-working and cold-forming properties after microalloying. Therefore, alloy bars, rings, and cold-rolled sheets made from GH6783 alloy are widely used in clearance control components such as sealing rings, load-bearing rings, and casings in advanced aero-engines.

[0003] With the development of aerospace and other fields, the demand for anti-oxidation, low-expansion, high-temperature alloy thin strips is gradually increasing, and the requirements for the thickness and performance of the strips are becoming increasingly stringent. Currently, the thickness of GH6783 alloy thin strips prepared using general processes is only as low as 0.5 mm, and the overall performance of the obtained strips, including grain structure, properties, dimensional accuracy, and surface quality, is insufficient to meet the requirements for component forming and design. Furthermore, there is very little research on the preparation process of alloy thin strips in China. Therefore, there is an urgent need to develop a method for producing low-thickness, high-quality GH6783 alloy thin strips. Summary of the Invention

[0004] In order to obtain a high-temperature alloy strip with oxidation resistance and low expansion and excellent comprehensive performance with a thickness of ≤0.3mm, this application provides a high-temperature alloy strip with oxidation resistance and low expansion and its preparation method.

[0005] In a first aspect, this application provides a method for preparing an oxidation-resistant, low-expansion high-temperature alloy thin strip, employing the following technical solution:

[0006] A method for preparing an oxidation-resistant, low-expansion high-temperature alloy thin strip includes: sheet shearing, sheet welding, weld heat treatment, initial strip grinding, intermediate strip cold rolling, intermediate strip annealing, intermediate strip grinding, finished strip cold rolling, and finished strip annealing.

[0007] Sheet cutting: Cutting sheet material horizontally to obtain sheet material. The cutting angle is 45-60° with the longitudinal direction of the sheet material. The longitudinal direction is the rolling direction of the sheet material.

[0008] Plate welding: Take two or more plates from the cut plate material, and then use argon arc welding process to butt weld the plates to obtain a strip blank;

[0009] The thickness of the antioxidant low-expansion high-temperature alloy strip is ≤0.3mm.

[0010] This application utilizes the above-mentioned process to prepare an oxidation-resistant, low-expansion high-temperature alloy thin strip with a thickness of ≤0.3mm. The aforementioned oxidation-resistant, low-expansion high-temperature alloy thin strip has a uniform and fine grain structure, good strength and plasticity, high dimensional accuracy, low surface roughness, and significant economic benefits, which can meet the needs of the domestic military and civilian markets.

[0011] In this application, a special sheet metal shearing process is adopted to prepare oxidation-resistant, low-expansion high-temperature alloy thin strip with a thickness ≤0.3mm. In this shearing process, the cutting angle needs to form a certain angle with the longitudinal direction of the sheet, so that the plane of the sheet in the longitudinal and thickness directions presents a parallelogram-like shape. Then, multiple sheets are butt-welded together by argon arc welding. Since the welding surface area between two adjacent sheets is large, the connection between the sheets is stronger, which makes it easier to ensure the smooth progress of the cold rolling process, and the obtained oxidation-resistant, low-expansion high-temperature alloy thin strip has more stable performance.

[0012] In one specific implementation, the angle between the cutting angle and the longitudinal direction of the sheet material can be 45° or 60°.

[0013] Preferably, in the argon arc welding process, the purity of the argon gas is ≥99.99%, the arc voltage is 6-12V, the current is 90-140A, the argon gas flow rate is 8-12L / min, and the welding speed is 300-450mm / min.

[0014] Preferably, the weld heat treatment process is as follows: the heat treatment furnace temperature is set to 1080-1130℃, and then the strip obtained by welding the plate is placed in the heat treatment furnace. When the temperature rises back to the heat treatment furnace temperature, it is held for 5-30 minutes, and finally air-cooled.

[0015] In this application, setting the parameters in the argon arc welding process within the above-mentioned range can ensure good weld quality and uniform weld structure. By controlling the temperature and holding time of the heat treatment furnace within the above-mentioned range, welding stress at the weld can be eliminated, weld structure can be improved, resulting in good strength and uniform structure at the weld of the strip.

[0016] In this application, the welding wire used for sheet metal welding is a strip of sheet metal cut from an alloy sheet.

[0017] In some embodiments, the temperature of the heat treatment furnace can be 1080-1090°C, 1080-1120°C, or 1090-1120°C.

[0018] In one specific implementation, the temperature of the heat treatment furnace can also be 1080°C, 1090°C, or 1120°C.

[0019] Preferably, in the intermediate strip cold rolling process, the first cold rolling deformation per pass is ≤10%, and the cold rolling deformation per pass is 35%-60%.

[0020] In one specific implementation, the deformation amount of the first cold rolling pass per heat treatment is 10%.

[0021] In one specific implementation, the deformation per cold rolling pass can be 35%, 40%, 40%, 44.4%, 50%, 53%, or 60%.

[0022] Preferably, in the intermediate strip annealing process, a pure hydrogen atmosphere is used for protection, the annealing temperature is 1080-1130℃, and the holding time is 2-10 min.

[0023] Preferably, the surface roughness of the initial strip after grinding is ≤1.8μm, and the surface roughness of the intermediate strip after grinding is ≤1.5μm.

[0024] In this application, by controlling the amount of cold rolling deformation per pass and the amount of cold rolling deformation in the first pass of the intermediate strip cold rolling process within the aforementioned range, precise control of the strip dimensional accuracy can be achieved. Furthermore, by performing intermediate annealing on strips of different thicknesses and grinding the initial strip in the intermediate annealing process, intermediate strips with high surface quality can be obtained, thereby yielding strips with high surface quality.

[0025] Preferably, in the cold rolling process of the finished strip, the deformation amount of the first cold rolling pass is ≤10%, and the deformation amount of the finished product is 40%-50%.

[0026] In this application, controlling the deformation amount of the first cold rolling pass and the deformation amount of the finished cold rolling pass within the above-mentioned range enables the anti-oxidation low-expansion high-temperature alloy thin strip to have a uniform and fine grain structure, high elongation, and good dimensional accuracy.

[0027] Preferably, in the annealing process of the finished strip, a pure hydrogen atmosphere is used for protection, the annealing temperature is 1100-1120℃, and the holding time is 1-3 minutes.

[0028] In one specific implementation, the annealing temperature can be 1100°C.

[0029] In one specific implementation, the heat preservation time can be 1.5 min or 2 min.

[0030] Secondly, this application provides a method for preparing antioxidant low-expansion high-temperature alloy thin strips.

[0031] Preferably, the thickness of the antioxidant low-expansion high-temperature alloy strip is 0.1-0.3 mm.

[0032] The anti-oxidation, low-expansion high-temperature alloy thin strip provided in this application not only has good microstructure uniformity, excellent grain size, superior mechanical properties, and low surface roughness, but also has a thickness of only 0.1-0.3 mm, thus having broad application prospects.

[0033] In summary, this application has the following beneficial effects:

[0034] 1. This application provides a method for preparing an oxidation-resistant, low-expansion high-temperature alloy thin strip. By adjusting the cross-cutting angle of the sheet, adding a weld heat treatment process, optimizing the welding process parameters, optimizing the cold rolling and annealing process parameters of the intermediate billet and the finished product, and adding a grinding process for the initial and intermediate billets, an oxidation-resistant, low-expansion high-temperature alloy thin strip with a thickness ≤0.3mm is obtained, which has a uniform fine-grained structure, good tensile strength and plasticity, good processability, high dimensional accuracy, and low surface roughness.

[0035] 2. In the preparation method of this application, the plate welding process does not require beveling, the weld is narrow, and the heat-affected zone is small. Several single plates of anti-oxidation low-expansion high-temperature alloy are welded into a coil by butt welding, and the thin strip after coil rolling has excellent grain structure morphology and grain size. This overcomes the problems of easy breakage at the weld and difficulty in controlling the weld structure during cold rolling of strip billets in related technologies.

[0036] 3. This application provides an antioxidant low-expansion high-temperature alloy thin strip with a thickness of 0.10-0.30 mm. The grain size of this antioxidant low-expansion high-temperature alloy thin strip is ASTM 7.0-10.0 grade. The delivery state room temperature elongation is ≥30%, the Ericsson cupping value is ≥7.5 mm, the delivery state + aged state room temperature tensile strength is ≥1100 MPa, the yield strength is ≥850 MPa, the elongation is ≥5%, the dimensional accuracy is less than ±5% of the thickness, and the surface roughness Ra value is 0.10-0.15 μm. This indicates that the antioxidant low-expansion high-temperature alloy thin strip provided by this application has good uniformity of microstructure and properties, excellent mechanical properties, high processability, and high surface quality, making it suitable for widespread application. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of plate welding in the preparation method of the anti-oxidation low expansion high temperature alloy thin strip of this application (1 is the weld, 2 is the angle between the cutting angle and the longitudinal direction of the plate).

[0038] Figure 2 This is a photograph of the anti-oxidation, low-expansion, high-temperature alloy thin strip provided in Embodiment 5 of this application.

[0039] Figure 3 This is a photograph of the grain structure of the antioxidant low-expansion high-temperature alloy thin strip provided in Example 5 of this application. Detailed Implementation

[0040] This application provides a method for preparing antioxidant, low-expansion high-temperature alloy thin strips, specifically including the following steps:

[0041] (1) Longitudinal cutting of sheet metal: GH6783 alloy sheet metal with a thickness of 1.0-3.5mm, a width of ≥500mm and a length of ≥2000mm is cut longitudinally into several sheets with a width of ≥248mm and retaining the original thickness and length;

[0042] (2) Sheet material cross-cutting: The above sheet material is cut in the transverse direction to obtain a sheet material. The angle between the cutting angle and the longitudinal direction of the sheet material is 45-60°, and the longitudinal direction is the rolling direction of the sheet material.

[0043] (3) Plate welding: Take four or more plates obtained in step (2), and then use argon arc welding to butt weld each plate and roll them to obtain a strip blank. The argon arc welding process uses argon gas with a purity of 99.99%, an arc voltage of 6-12V, a current of 90-140A, an argon gas flow rate of 8-12L / min, and a welding speed of 300-450mm / min. The butt welding method is as follows: Figure 3 As shown.

[0044] (4) Heat treatment of weld: Set the temperature of the heat treatment furnace to 1080-1130℃, and then place the strip obtained in step (3) into the heat treatment furnace. When the temperature rises back to the temperature of the heat treatment furnace, keep it for 5-30 minutes, and finally air cool to obtain the initial strip.

[0045] (5) Initial strip grinding: The initial strip obtained in step (4) is ground on a continuous grinding line. After grinding, the surface roughness Ra value of the strip is ≤1.8μm.

[0046] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill. The first cold rolling deformation is 10% and the cold rolling deformation is 35%-60% per cold rolling pass.

[0047] (7) Intermediate strip annealing: The strips of different thicknesses in step (6) are annealed in a continuous annealing furnace. The intermediate strip annealing is carried out under pure hydrogen atmosphere protection, the annealing temperature is 1080-1130℃, and the holding time is 2-10min.

[0048] (8) Intermediate strip grinding: The strip obtained in step (7) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is ≤1.5μm.

[0049] (9) Cold rolling of finished strip: The ground strip blank is placed on a cold rolling mill for cold rolling. The deformation of the first cold rolling is ≤10%, the deformation of the cold rolling is 40%-50%, and the thickness of the finished strip is 0.1-0.3mm.

[0050] (10) Annealing of finished strip: The finished strip is placed in a continuous annealing furnace for annealing under pure hydrogen atmosphere protection. The annealing temperature is 1100-1120℃ and the holding time is 1-3min, thereby obtaining an anti-oxidation low expansion high temperature alloy thin strip.

[0051] The GH6783 alloy sheet used in this application is a self-produced sheet of Beijing Steel Research Gaona Technology Co., Ltd.

[0052] The present application will be further described in detail below with reference to embodiments, accompanying drawings, and performance testing. Example

[0053] Example 1

[0054] Example 1 provides an antioxidant, low-expansion, high-temperature alloy thin strip.

[0055] The preparation method of the above-mentioned antioxidant, low-expansion high-temperature alloy thin strip specifically includes the following steps:

[0056] (1) Longitudinal cutting of sheet material: The GH6783 alloy sheet material with a thickness of 2.0mm, a width of 1000mm and a length of 2000mm is cut longitudinally into sheet materials with a width of 248mm and a length of 2000mm.

[0057] (2) Sheet material cross-cutting: The above sheet material is cut in the transverse direction to obtain a sheet material. The angle between the cutting angle and the longitudinal direction of the sheet material is 60°, and the longitudinal direction is the rolling direction of the sheet material.

[0058] (3) Plate welding: Take 5 plates obtained in step (2), and then use argon arc welding to butt weld each plate and roll them to obtain a strip blank. The argon arc welding process uses 99.99% pure argon gas, an arc voltage of 8V, a current of 120A, an argon gas flow rate of 10L / min, and a welding speed of 350mm / min. The butt welding method is as follows: Figure 1 As shown.

[0059] (4) Heat treatment of weld: Set the temperature of the heat treatment furnace to 1090℃, and then place the strip obtained in step (3) into the heat treatment furnace. When the temperature rises back to the temperature of the heat treatment furnace, keep it for 10 minutes, and finally air cool to obtain the initial strip.

[0060] (5) Initial strip grinding: The initial strip obtained in step (4) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is 1.8 μm.

[0061] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill with a rolling stroke of 2.00mm→1.20mm→0.72mm→0.40mm. The deformation amount of each rolling stroke is 40%, 40%, and 44.4%, respectively. The deformation amount of the first cold rolling in each stroke is 10%.

[0062] (7) Intermediate strip annealing: The strips of different thicknesses from step (6) are subjected to intermediate annealing in a continuous annealing furnace; the intermediate strip annealing is carried out under a pure hydrogen atmosphere; the intermediate annealing is specifically as follows:

[0063] The intermediate strip blank with a thickness of 1.2 mm was annealed at a temperature of 1130℃ for a holding time of 6 min.

[0064] The intermediate strip billet with a thickness of 0.72 mm was annealed at 1120℃ for 5 minutes.

[0065] The intermediate blank with a thickness of 0.4 mm was annealed at 1120℃ for 4 minutes.

[0066] (8) Intermediate strip grinding: The strip obtained in step (7) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is 1.5 μm.

[0067] (9) Cold rolling of finished strip: The ground strip is placed on a cold rolling mill for cold rolling until it is 0.2 mm thick. The deformation of the first cold rolling is 10%, and the deformation of the finished strip is 50%.

[0068] (10) Annealing of finished strip: The finished strip is placed in a continuous annealing furnace for annealing under pure hydrogen atmosphere protection. The annealing temperature is 1110℃ and the holding time is 2min, thereby obtaining an anti-oxidation low expansion high temperature alloy thin strip.

[0069] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Example 1 has a thickness of 0.2 mm and a width of 235 mm. The various properties of the above-mentioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the following methods:

[0070] The grain size test method refers to GB / T 6394; the room temperature elongation test method refers to GB / T 228.1; the Ericsson cupping value test method refers to GB / T 4156; the room temperature tensile strength test method refers to GB / T 228.1; the room temperature yield strength test method refers to GB / T 228.1; the thickness accuracy is tested using a micrometer; the surface roughness Ra is tested using GB / T 1031 and GB / T12767.

[0071] The anti-oxidation, low-expansion high-temperature alloy strip provided in Example 1 was tested and found to have a grain size of ASTM 8.0 grade, a room temperature elongation of 40% in the delivery state, an Ericsson cupping value of 8.0 mm, a room temperature tensile strength of 1143 MPa in the delivery state + aged state, a yield strength of 895 MPa in the delivery state + aged state, an elongation of 12% in the delivery state + aged state, a dimensional accuracy of ±8 μm, and a surface roughness Ra value of 0.132 μm.

[0072] Example 2

[0073] Example 2 provides an antioxidant, low-expansion, high-temperature alloy thin strip.

[0074] The difference between the above embodiments and Embodiment 1 lies in the plate welding process and the weld heat treatment process; the specific details of the plate welding process (3) and the weld heat treatment process (4) in Embodiment 2 are as follows:

[0075] (3) Plate welding: Take 5 plates obtained in step (2), and then use argon arc welding to butt weld each plate and roll them to obtain a strip blank. The argon arc welding process uses 99.99% pure argon gas, an arc voltage of 10V, a current of 140A, an argon gas flow rate of 12L / min, and a welding speed of 450mm / min. The butt welding method is as follows: Figure 1 As shown.

[0076] (4) Heat treatment of weld: Set the temperature of the heat treatment furnace to 1120℃, and then place the strip obtained in step (3) into the heat treatment furnace. When the temperature rises back to the temperature of the heat treatment furnace, keep it for 20 minutes, and finally air cool to obtain the initial strip.

[0077] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Example 2 has a thickness of 0.2 mm and a width of 235 mm. The properties of the aforementioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the same methods as in Example 1.

[0078] The above-mentioned antioxidant low-expansion high-temperature alloy strip was tested and found to have a grain size of ASTM 8.0 grade, a room temperature elongation of 37% in the delivery state, an Ericsson cupping value of 7.8 mm, a room temperature tensile strength of 1135 MPa in the delivery state + aged state, a yield strength of 882 MPa in the delivery state + aged state, an elongation of 10.8% in the delivery state + aged state, a dimensional accuracy of ±7 μm, and a surface roughness Ra value of 0.125 μm.

[0079] Example 3

[0080] Example 3 provides an antioxidant, low-expansion, high-temperature alloy thin strip.

[0081] The difference between the above embodiments and Embodiment 1 lies in the intermediate strip cold rolling and subsequent processes. The specific intermediate strip cold rolling and subsequent processes in Embodiment 3 are as follows:

[0082] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill with a rolling stroke of 2.00mm→1.30mm→0.85mm→0.35mm. The deformation amount of each rolling stroke is 35%, 35%, and 59%, respectively. The deformation amount of the first cold rolling in each stroke is 10%.

[0083] (7) Intermediate strip annealing: The strips of different thicknesses from step (6) are subjected to intermediate annealing in a continuous annealing furnace; the intermediate strip annealing is carried out under a pure hydrogen atmosphere; the intermediate annealing is specifically as follows:

[0084] The intermediate strip blank with a thickness of 1.3 mm was annealed at 1110℃ for 6 minutes.

[0085] The intermediate strip blank with a thickness of 0.85 mm was annealed at 1100℃ for 5 minutes.

[0086] The intermediate blank with a thickness of 0.35 mm was annealed at a temperature of 1090℃ for 4 minutes.

[0087] (8) Intermediate strip grinding: The strip obtained in step (7) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is 1.5 μm.

[0088] (9) Cold rolling of finished strip: The ground strip is placed on a cold rolling mill for cold rolling until it is 0.2 mm thick. The deformation of the first cold rolling pass is 10%, and the deformation of the finished cold rolling pass is 43%.

[0089] (10) Annealing of finished strip: The finished strip is placed in a continuous annealing furnace for annealing under pure hydrogen atmosphere protection. The annealing temperature is 1110℃ and the holding time is 2min, thereby obtaining an anti-oxidation low expansion high temperature alloy thin strip.

[0090] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Example 3 has a thickness of 0.2 mm and a width of 235 mm. The various properties of the above-mentioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the same methods as in Example 1.

[0091] The above-mentioned anti-oxidation low-expansion high-temperature alloy thin strip was tested and found to have a grain size of ASTM 9.0 grade, a room temperature elongation of 38% in the delivery state, an Eriksen cupping value of 8.1 mm, a room temperature tensile strength of 1135 MPa in the delivery state + aged state, a yield strength of 897 MPa in the delivery state + aged state, an elongation of 11.5% in the delivery state + aged state, a dimensional accuracy of ±8 μm, and a surface roughness Ra value of 0.128 μm.

[0092] Example 4

[0093] Example 4 provides an antioxidant, low-expansion, high-temperature alloy thin strip.

[0094] The difference between the above embodiments and Embodiment 1 is that the intermediate strip cold rolling process and the intermediate strip annealing process are used; the intermediate strip cold rolling process (6) and intermediate strip annealing process (7) in Embodiment 3 are as follows:

[0095] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill with a rolling stroke of 2.00mm→1.0mm→0.4mm. The deformation amount of each rolling stroke is 50% and 60% respectively, and the deformation amount of the first cold rolling in each stroke is 10%.

[0096] (7) Intermediate strip annealing: The strips of different thicknesses from step (6) are subjected to intermediate annealing in a continuous annealing furnace; the intermediate strip annealing is carried out under a pure hydrogen atmosphere; the intermediate annealing is specifically as follows:

[0097] The intermediate strip blank with a thickness of 1.0 mm was annealed at a temperature of 1130℃ for 10 minutes.

[0098] The intermediate blank with a thickness of 0.4 mm was annealed at a temperature of 1120℃ for 5 minutes.

[0099] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Example 4 has a thickness of 0.2 mm and a width of 235 mm. The various properties of the above-mentioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the same methods as in Example 1.

[0100] The above-mentioned antioxidant low-expansion high-temperature alloy thin strip was tested and found to have a grain size of ASTM 7.0 grade, a room temperature elongation of 36% in the delivery state, an Ericsson cupping value of 8.0 mm, a room temperature tensile strength of 1137 MPa in the delivery state + aged state, a yield strength of 920 MPa in the delivery state + aged state, an elongation of 11% in the delivery state + aged state, a dimensional accuracy of ±7 μm, and a surface roughness Ra value of 0.130 μm.

[0101] Example 5

[0102] Example 5 provides an antioxidant, low-expansion, high-temperature alloy thin strip.

[0103] The preparation method of the above-mentioned antioxidant, low-expansion high-temperature alloy thin strip is as follows:

[0104] (1) Longitudinal cutting of sheet metal: The GH6783 alloy sheet metal with a thickness of 1.0 mm, a width of 820 mm and a length of 2000 mm is cut longitudinally into sheet metal with a width of 270 mm and a length of 2000 mm.

[0105] (2) Transverse cutting of sheet material: The above sheet material is cut transversely to obtain sheet material. The angle between the cutting angle and the longitudinal direction of the sheet material is 45°. The longitudinal direction is the rolling direction of the sheet material.

[0106] (3) Plate welding: Take 5 plates obtained in step (2), and then use argon arc welding to butt weld each plate and roll them to obtain a strip blank. The argon arc welding process uses 99.99% pure argon gas, an arc voltage of 9V, a current of 135A, an argon gas flow rate of 12L / min, and a welding speed of 400mm / min. The butt welding method is as follows: Figure 1 As shown.

[0107] (4) Heat treatment of weld: Set the temperature of the heat treatment furnace to 1080℃, and then place the strip obtained in step (3) into the heat treatment furnace. When the temperature rises back to the temperature of the heat treatment furnace, keep it at that temperature for 8 minutes, and finally air cool to obtain the initial strip.

[0108] (5) Initial strip grinding: The initial strip obtained in step (4) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is 1.6 μm.

[0109] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill with a rolling stroke of 1.00mm→0.50mm→0.20mm. The deformation amount of each rolling stroke is 50% and 60% respectively, and the deformation amount of the first cold rolling in each stroke is 10%.

[0110] (7) Intermediate strip annealing: The strips of different thicknesses from step (6) are subjected to intermediate annealing in a continuous annealing furnace; the intermediate strip annealing is carried out under a pure hydrogen atmosphere; the intermediate annealing is specifically as follows:

[0111] The intermediate strip blank with a thickness of 0.5 mm was annealed at a temperature of 1120℃ for a holding time of 4 min.

[0112] The intermediate blank with a thickness of 0.2 mm was annealed at a temperature of 1120℃ for 2 minutes.

[0113] (8) Intermediate strip grinding: The strip obtained in step (7) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is 1.4 μm.

[0114] (9) Cold rolling of finished strip: The ground strip blank is placed on a cold rolling mill for cold rolling until it is finished strip with a thickness of 0.1 mm.

[0115] (10) Annealing of finished strip: The finished strip is placed in a continuous annealing furnace for annealing under pure hydrogen atmosphere protection. The annealing temperature is 1100℃ and the holding time is 1.5min, thereby obtaining an anti-oxidation low expansion high temperature alloy thin strip.

[0116] The oxidation-resistant, low-expansion high-temperature alloy thin strip obtained in Example 5 is as follows: Figure 2 As shown in the photograph, the grain structure is as follows: Figure 3 As shown, the thickness of the anti-oxidation, low-expansion high-temperature alloy strip is 0.1 mm, and the width is 255 mm. The various properties of the above-mentioned anti-oxidation, low-expansion high-temperature alloy strip were tested using the same methods as in Example 1.

[0117] The above-mentioned antioxidant low-expansion high-temperature alloy strip was tested and found to have a grain size of ASTM 9.0 grade, a room temperature elongation of 40% in the delivery state, an Eriksen cupping value of 8.2 mm, a room temperature tensile strength of 1126 MPa in the delivery state + aged state, a yield strength of 878 MPa in the delivery state + aged state, an elongation of 7.5% in the delivery state + aged state, a dimensional accuracy of ±5 μm, and a surface roughness Ra value of 0.123 μm.

[0118] Comparative Example 1

[0119] Comparative Example 1 provides an oxidation-resistant, low-expansion, high-temperature alloy thin strip.

[0120] The difference between the above comparative example and Example 1 is that in the cross-cutting process of the board, the angle between the cutting angle and the longitudinal direction of the board is 90°.

[0121] The anti-oxidation, low-expansion high-temperature alloy strip obtained in Comparative Example 1 had a thickness of 0.2 mm and a width of 235 mm. The various properties of the aforementioned anti-oxidation, low-expansion high-temperature alloy strip were tested using the same methods as in Example 1.

[0122] The above-mentioned antioxidant low-expansion high-temperature alloy strip was tested and found to have a grain size of ASTM 7.5 grade, a room temperature elongation of 29% in the delivery state, an Eriksen cupping value of 7.3 mm, a room temperature tensile strength of 1102 MPa in the delivery state + aged state, a yield strength of 850 MPa in the delivery state + aged state, an elongation of 4% in the delivery state + aged state, a dimensional accuracy of ±9 μm, and a surface roughness Ra value of 0.138 μm.

[0123] In the method provided in Comparative Example 1, when the angle between the cutting angle and the longitudinal direction of the sheet is 90°, the initial strip obtained is very prone to breakage during intermediate cold rolling, which in turn affects the production rhythm of the process.

[0124] Comparative Example 2

[0125] Comparative Example 2 provides an oxidation-resistant, low-expansion, high-temperature alloy thin strip.

[0126] The difference between the above comparative examples and Example 1 lies in the plate welding process and the weld heat treatment process; the plate welding process (3) and weld heat treatment process (4) in Comparative Example 2 are as follows:

[0127] (3) Plate welding: Take 5 plates obtained in step (2), and then use argon arc welding to butt weld each plate and roll them to obtain a strip blank. The argon arc welding process uses 98.5% argon gas, an arc voltage of 8V, a current of 120A, an argon gas flow rate of 14L / min, and a welding speed of 250mm / min. The butt welding method is as follows: Figure 3 As shown.

[0128] (4) Heat treatment of weld: Set the temperature of the heat treatment furnace to 1000℃, and then place the strip obtained in step (3) into the heat treatment furnace. When the temperature rises back to the temperature of the heat treatment furnace, keep it for 10 minutes, and finally air cool to obtain the initial strip.

[0129] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Comparative Example 2 had a thickness of 0.2 mm and a width of 235 mm. The various properties of the aforementioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the same methods as in Example 1.

[0130] The above-mentioned antioxidant low-expansion high-temperature alloy thin strip was tested and found to have a grain size of ASTM 7.5 grade, a room temperature elongation of 29.5% in the delivery state, an Eriksen cupping value of 7.5 mm, a room temperature tensile strength of 1116 MPa in the delivery state + aged state, a yield strength of 852 MPa in the delivery state + aged state, an elongation of 4.5% in the delivery state + aged state, a dimensional accuracy of ±9 μm, and a surface roughness Ra value of 0.146 μm.

[0131] The welding process conditions and weld heat treatment temperature provided in Comparative Example 2 resulted in an initial strip blank that was not firmly bonded at the weld, which made it prone to strip breakage during intermediate cold rolling. Furthermore, the elongation of the resulting oxidation-resistant, low-expansion high-temperature alloy thin strip was relatively low.

[0132] Comparative Example 3

[0133] Comparative Example 3 provides an antioxidant, low-expansion, high-temperature alloy strip.

[0134] The difference between the above comparative example and Example 1 is that the intermediate strip is cold rolled; the intermediate strip cold rolling process in Comparative Example 3 (6) is as follows:

[0135] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill with a rolling stroke of 2.00mm→1.5mm→1.05mm→0.74mm→0.5mm→0.4mm. The deformation amount of each rolling stroke is 25%, 30%, 30%, 32%, and 20%, respectively. The deformation amount of the first cold rolling in each stroke is 10%.

[0136] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Comparative Example 3 had a thickness of 0.2 mm and a width of 235 mm. The various properties of the aforementioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the same methods as in Example 1.

[0137] The above-mentioned antioxidant low-expansion high-temperature alloy thin strip was tested and found to have a grain size of ASTM 6.0 grade, a room temperature elongation of 30% in the delivery state, an Ericsson cupping value of 6.8 mm, a room temperature tensile strength of 1086 MPa in the delivery state + aged state, a yield strength of 830 MPa in the delivery state + aged state, an elongation of 4% in the delivery state + aged state, a dimensional accuracy of ±10 μm, and a surface roughness Ra value of 0.149 μm.

[0138] Based on the above results, it can be seen that by performing multiple cold rolling processes on the strip and controlling the deformation amount per heat treatment to below 35%, the resulting oxidation-resistant, low-expansion high-temperature alloy thin strip has a coarser grain structure and lower elongation and tensile strength, making it difficult to meet the application requirements.

[0139] Comparative Example 4

[0140] Comparative Example 4 provides an antioxidant, low-expansion, high-temperature alloy strip.

[0141] The difference between the above comparative example and Example 1 lies in the intermediate strip cold rolling and subsequent processes. The specific intermediate strip cold rolling and subsequent processes of Comparative Example 4 are as follows:

[0142] (6) Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill with a rolling stroke of 2.00mm→1.2mm→0.72mm. The deformation amount of each rolling stroke is 40% and 40% respectively, and the deformation amount of the first cold rolling in each stroke is 10%.

[0143] (7) Intermediate strip annealing: The strips of different thicknesses from step (6) are subjected to intermediate annealing in a continuous annealing furnace; the intermediate strip annealing is carried out under a pure hydrogen atmosphere; the intermediate annealing is specifically as follows:

[0144] The intermediate strip blank with a thickness of 1.2 mm was annealed at a temperature of 1130℃ for a holding time of 6 min.

[0145] The intermediate blank with a thickness of 0.72 mm was annealed at 1120℃ for 5 minutes.

[0146] (8) Intermediate strip grinding: The strip obtained in step (7) is ground on a continuous grinding line. The surface roughness Ra value of the strip after grinding is 1.5 μm.

[0147] (9) Cold rolling of finished strip: The ground strip is placed on a cold rolling mill for cold rolling until it is 0.5 mm thick. The cold rolling deformation of the finished strip is 30.5%.

[0148] (10) Annealing of finished strip: The finished strip is placed in a continuous annealing furnace for annealing under pure hydrogen atmosphere protection. The annealing temperature is 1110℃ and the holding time is 2min, thereby obtaining an anti-oxidation low expansion high temperature alloy thin strip.

[0149] The anti-oxidation, low-expansion high-temperature alloy thin strip obtained in Comparative Example 4 had a thickness of 0.5 mm and a width of 235 mm. The various properties of the aforementioned anti-oxidation, low-expansion high-temperature alloy thin strip were tested using the same methods as in Example 1.

[0150] The anti-oxidation, low-expansion high-temperature alloy strip provided in Comparative Example 4 was tested and found to have a grain size of ASTM 6.0 grade, a room temperature elongation of 28% in the delivery state, an Ericsson cupping value of 6.7 mm, a room temperature tensile strength of 1095 MPa in the delivery state + aged state, a yield strength of 821 MPa in the delivery state + aged state, an elongation of 3.5% in the delivery state + aged state, a dimensional accuracy of ±13 μm, and a surface roughness Ra value of 0.144 μm.

[0151] In the production process of the 0.5mm thick anti-oxidation low expansion high temperature alloy thin strip, the strip blank is subjected to two cold rolling and one finished product cold rolling. Due to the small deformation of the finished product cold rolling, the obtained anti-oxidation low expansion high temperature alloy thin strip has a coarser grain structure, poor dimensional accuracy, and low elongation, which makes it difficult to meet the requirements of component use.

[0152] In summary, the oxidation-resistant, low-expansion high-temperature alloy strip provided in this application has a uniform fine-grained structure, excellent room-temperature tensile properties, processability, high dimensional accuracy, and surface quality, thus fully meeting the requirements for component forming and design use.

[0153] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for producing an oxidation resistant, low expansion, high temperature GH6783 alloy thin strip characterized by, The process includes the following steps: sheet metal shearing, sheet metal welding, weld heat treatment, initial strip grinding, intermediate strip cold rolling, intermediate strip annealing, intermediate strip grinding, finished strip cold rolling, and finished strip annealing. Sheet cutting: Cutting sheet material horizontally to obtain sheet material. The cutting angle is 45-60° with the longitudinal direction of the sheet material. The longitudinal direction is the rolling direction of the sheet material. Plate welding: Take two or more plates obtained by cutting the plate material, and then use argon arc welding process to butt weld each plate to obtain a strip blank; the argon gas purity used in the argon arc welding process is 99.99%, arc voltage is 6-12V, current is 90-140A, argon gas flow rate is 8-12L / min, and welding speed is 300-450mm / min. Weld heat treatment: Set the heat treatment furnace temperature to 1080-1130℃, then place the strip obtained by welding the plate into the heat treatment furnace. When the temperature rises back to the heat treatment furnace temperature, hold for 5-30 minutes, and finally air cool to obtain the initial strip. Intermediate strip cold rolling: The ground strip is cold rolled on a cold rolling mill. The deformation of the first pass in each heat is 10%, and the deformation of each pass is 35%-60%. Intermediate strip annealing: The intermediate strips of different thicknesses from the cold rolling process are annealed in a continuous annealing furnace; the intermediate strip annealing is carried out under pure hydrogen atmosphere protection, the annealing temperature is 1080-1130℃, and the holding time is 2-10min. Cold rolling of finished strip: The strip after intermediate strip grinding is placed on a cold rolling mill for cold rolling. The deformation of the first cold rolling pass is ≤10%, and the deformation of the cold rolling pass is 40%-50%. Annealing of finished strip: The finished strip is placed in a continuous annealing furnace for annealing under a pure hydrogen atmosphere. The annealing temperature is 1100-1120℃ and the holding time is 1-3 minutes. The thickness of the anti-oxidation, low-expansion high-temperature alloy thin strip is ≤0.3mm.

2. The production method according to claim 1, characterized by, The surface roughness of the initial strip after grinding is ≤1.8μm, and the surface roughness of the intermediate strip after grinding is ≤1.5μm.

3. The method of claim 1, wherein, In the annealing process of the finished strip, a pure hydrogen atmosphere is used for protection, the annealing temperature is 1100-1120℃, and the holding time is 1-3 minutes.

4. The antioxidant low-expansion high-temperature alloy thin strip prepared by the preparation method of any one of claims 1-3.

5. The thin strip of oxidation resistant low expansion high temperature alloy of claim 4 wherein, The thickness of the antioxidant low-expansion high-temperature alloy strip is 0.1-0.3 mm.

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