A method for producing a high-quality zirconium or zirconium alloy cold-rolled thick plate

Abstract

The present application belongs to the technical field of metal material processing, and relates to a preparation method of high-quality zirconium or zirconium alloy cold-rolled thick plate. The method uses the advantage of a hot rolling mill having a large rolling capacity, innovatively adopts cold rolling of the hot rolling mill, selects specific rolls, and simultaneously matches appropriate rolling parameters to roll the slab to a thickness range acceptable to the cold rolling mill for rolling by the cold rolling mill; by controlling the rolling process, the size, state and surface treatment during the process, the combination of "hot rolling mill cold rolling + cold rolling mill cold rolling" is adopted, the plate rolling precision is improved, the problems of poor size precision and mechanical properties of the hot rolling mill are solved, the limitation of the cold rolling mill only being able to roll thin plate is changed, the preparation thickness of the cold-rolled plate is expanded, the high-precision and high-performance zirconium or zirconium alloy cold-rolled thick plate can be obtained, and the method has been applied to batch production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metal material processing, and relates to a preparation method of high-quality zirconium or zirconium alloy cold-rolled thick plate. BACKGROUND

[0002] Zirconium and zirconium alloy have been widely used in the fields of nuclear industry, chemical industry and the like due to good corrosion resistance and mechanical properties. The processing of zirconium materials is a strategic pillar industry for the development of nuclear power and nuclear power in a country, and plays an important role in national defense construction. Among them, the stability of the performance and size of the zirconium or zirconium alloy plate as a key material for future special use is crucial. In order to meet the long-term, large-scale and high-quality plate requirements, solve the key preparation technology of the plate, and prepare high-quality plates, it has become a difficult problem to be solved.

[0003] It is well known that the performance and precision of the plate after cold processing are higher than those of the plate in the hot processing state. At present, the plate with a relatively thick thickness (> 10 mm) and low mechanical property requirement is generally prepared by hot processing (hot rolling), and the plate with a relatively thin thickness (< 5 mm) and high mechanical and dimensional precision requirement is generally prepared by cold processing (cold rolling). However, for the plate with a relatively thick thickness (between the above two) and high mechanical and dimensional precision requirement, it is limited by the equipment in the non-ferrous metal industry, especially the rolling mill processing capacity (the cold rolling mill generally requires the incoming material thickness to be less than 10 mm, and a few requires the incoming material thickness to be less than 12 mm). Therefore, there is no mature processing technology at present, and the plate is generally prepared by hot processing. However, there is a great risk that the performance and precision cannot meet the requirements. Therefore, under the existing equipment capacity conditions, it is of great significance to research the preparation process of the cold-rolled thick plate, fill the gap, and prepare the high-quality cold-rolled thick plate. SUMMARY

[0004] The purpose of the application is to overcome the shortcomings of the prior art, provide a preparation method of high-quality zirconium or zirconium alloy cold-rolled thick plate, and use a hot rolling mill matching roller and rolling parameters to perform cold rolling operation, so as to expand the thickness range of the cold-rolled plate and solve the precision and mechanical property problems of the thick plate.

[0005] In order to achieve the above purpose, the application provides the following technical scheme:

[0006] The preparation method of the high-quality zirconium or zirconium alloy thick plate specifically includes the following steps,

[0007] Step 1, pretreatment (cutting, grinding and chamfering) is performed on the incoming plate blank:

[0008] Step 1.1, the tongues at both ends of the incoming plate blank are cut off, and the remaining plate blank is cut into a specific size;

[0009] Step 1.2, the slit plate blank is again polished by a grinding machine to remove surface cracks, scale and inclusions and other defects; wherein the polishing direction is the same as the next rolling direction, the thickness deviation after polishing is not more than ±0.5mm, and the same plate difference is not more than 0.8mm;

[0010] Step 1.3, finally, a chamfer θ1 is processed along the width direction of the plate blank, the angle of the chamfer θ1 is 30°-60°, to facilitate the bite during subsequent rolling.

[0011] Step 2, the plate blank is degreased and pickled with corresponding degreasing agent and acid solution to remove oil stains, residual oxides and impurities on the surface of the plate blank.

[0012] Step 3, after the treatment of step 2, the thickness of the plate blank is measured at the middle and both ends of the plate blank, and the length and width dimensions of the plate blank are measured, and the corresponding hot rolling mill and hot rolling roller are selected according to the dimensions of the plate blank, and the plate blank is cold rolled once at room temperature (i.e. the temperature of the environment where the rolling is carried out) to obtain plate A, and the rolling speed, processing rate and other parameters need to be controlled during the whole rolling process.

[0013] Step 4, the surface and dimensions of the plate A after the first cold rolling of step 3 are checked, the surface of the plate A should be free of regional cracks or pitting and other defects, and the plate shape should be flat; the thickness of the plate A is measured at the middle and both ends of the plate A, and the length and width dimensions of the plate A are measured, and the thickness dimension should meet the process requirements; if necessary, the length of the plate A can be cut, the cracked edges can be cut off, and then the plate A after the first cold rolling is polished by a grinding machine to remove surface cracks, pitting, inclusions and other defects of the plate A; finally, a chamfer θ2 is processed along the width direction of the plate A, the angle of the chamfer θ2 is 30°-60°, to facilitate the bite during subsequent rolling.

[0014] Step 5, the surface of the plate A after the treatment of step 4 is degreased and pickled, and when the surface of the plate A presents a bright metallic color, the pickling is stopped and washed clean to completely remove the residual oil stains and impurities on the surface of the plate A.

[0015] Step 6, the dimensions of the plate A after the treatment of step 5 are measured, and the corresponding cold rolling mill and cold rolling roller are selected according to the dimensions of the plate A, and the plate A is cold rolled twice to obtain plate B, and the rolling speed, processing rate and other parameters need to be controlled during the whole rolling process.

[0016] Step 7, after rolling, the surface and dimensions of the plate B are checked, the surface of the plate B should be free of regional cracks or pitting and other defects, and the plate shape should be flat; the thickness of the plate B is measured at the middle and both ends of the plate B, and the length and width dimensions of the plate are measured, and the thickness dimension should meet the process requirements.

[0017] Step 8, the surface of the plate B meeting the requirements in step 7 is subjected to degreasing and pickling treatment, and when the surface of the plate B presents a bright metallic color, the pickling is stopped and washed clean, and the residual oil stains and impurities on the surface of the plate B are completely removed.

[0018] Step 9, the plate B after the degreasing and pickling treatment in step 8 is subjected to heat treatment, and the final cold-rolled thick plate is obtained.

[0019] Further, the incoming plate blank in step 1 is a hot-rolled plate blank subjected to a certain heat treatment, and the main purpose of the heat treatment is to soften the structure to facilitate the subsequent deformation of rolling; in addition, the thickness of the plate blank should not be too thick, and if it is too thick, the subsequent cold rolling deformation will be too large and cause deformation cracking, and the thickness should not be too thin, and if it is too thin, the deformation will not be enough, thereby resulting in low performance, and at the same time, to improve the plate precision, the incoming plate blank should be controlled within a certain range after grinding.

[0020] Further, the primary cold rolling in step 3 only represents one rolling process, and the specific rolling times can be determined according to the actual deformation amount. Since the plate blank in the present application is thicker and far exceeds the rolling capacity range of the existing cold rolling mill, the hot rolling mill is innovatively used for cold rolling, but the roll type and the concave-convex degree are different from those selected during hot rolling, and appropriate rolls can be selected according to the rolling characteristics; at the same time, during rolling, appropriate rolling speed should be matched to control the size of the plate A, and the plate A after rolling should reach a certain deformation amount.

[0021] Further, the secondary cold rolling in step 6 also represents a rolling process, and the specific rolling times can be determined according to the actual deformation amount. The selected equipment for this rolling process is a cold rolling mill, and in order to ensure sufficient deformation of the plate, the incoming thickness is generally at the upper limit of the equipment, and sufficient deformation is left for the secondary cold rolling to better control the size and shape of the plate after rolling; in addition, appropriate roll types can be selected according to the thickness and width of the plate A, and the corresponding rolling speed is matched, thereby obtaining a high-precision plate B.

[0022] Further, the plate B finally obtained after the primary cold rolling and the secondary cold rolling should not be too large or too small in total processing rate, and should be controlled within an appropriate range, in order to obtain a high-quality cold-rolled thick plate.

[0023] Further, the incoming plate blank in step 1.1 is a hot-rolled plate blank subjected to heat treatment above the stress relief annealing temperature, the thickness of the plate blank is 12-30 mm, the width of the plate blank is designed according to the product specifications and the width of the roll, and the width of the plate blank should be within the range of 30%-90% of the width of the roll, and the cutting length should be not less than the shortest length required by the rolling mill. Among them, the stress relief annealing temperature is determined according to the alloy grade of the plate blank, the previous processing deformation and the thickness, so as to eliminate all or part of the internal stress and reduce the deformation and cracking tendency.

[0024] Further, the hot rolling roller profile in step 3 is flat roller or convex roller with convexity ≤0.15mm, and the working parameters of the first cold rolling are as follows: rolling speed is 8m / min-55m / min, and processing rate is 10%-55%; the thickness deviation of the plate A obtained by the first cold rolling is not more than ±0.25mm, and the same plate difference is not more than 0.45mm.

[0025] Further, the grinding direction of the plate A in step 4 is the same as the next rolling direction, and the thickness deviation and the same plate difference of the plate A after grinding are within the corresponding requirements of the thickness deviation and the same plate difference of the plate A after the first cold rolling, and the grinding is to further reduce the thickness deviation and the same plate difference.

[0026] Further, the degreasing agent is used in the degreasing treatment in steps 2, 5 and 8, and the pickling solution used in the pickling treatment is the mixed acid solution of nitric acid, hydrofluoric acid and water, and the volume ratio of each component in the mixed acid solution is as follows: hydrofluoric acid 1-5 parts, nitric acid 20-40 parts, and the rest is water.

[0027] Further, the cold rolling roller profile in step 6 is flat roller or convex roller with convexity ≤0.2mm, and the working parameters of the second cold rolling are as follows: rolling speed is 5m / min-60m / min, and processing rate is 15%-60%.

[0028] Further, the total processing rate of the first cold rolling in step 3 and the second cold rolling in step 6 is between 40%-70%.

[0029] Further, in step 7, the plate B is free of regional cracks or point pit defects on the surface, and the plate shape is flat, the thickness of the plate B is 5mm-10mm, the thickness deviation is not more than ±0.2mm, and the same plate difference is not more than 0.3mm.

[0030] Further, the heat treatment in step 9 adopts vacuum annealing, and the vacuum degree is ≤1.0×10 -1 The annealing temperature of Pa is the recrystallization temperature.

[0031] Compared with the prior art, the technical scheme provided by the application has the following beneficial effects: the preparation method uses the advantage of a hot rolling mill having a large rolling capacity, innovatively uses the hot rolling mill for cold rolling, selects appropriate roll type and roll convexity according to the final plate size and performance requirements, designs a rolling process matched with the roll type and roll convexity, rolls the slab to a thickness range acceptable to a cold rolling mill, and then uses the cold rolling mill for rolling, so that the rolling precision of the plate is improved, the problems of poor size precision and mechanical property of the plate rolled by the hot rolling mill are solved, the limitation that the cold rolling mill can only roll thin plates is changed, the preparation thickness of the cold rolled plate is expanded, and high-precision and high-performance zirconium and zirconium alloy cold rolled thick plates can be obtained.

[0032] The preparation method is limited by the equipment capacity (especially the rolling mill capacity) of the non-ferrous metal processing industry, and at the same time, the deformation amount of the plate needs to be ensured, so that the existing cold rolled zirconium or zirconium alloy plate is mostly less than 5 mm. However, by using the preparation method provided by the application, the cold rolled thick plate with a thickness of 5 mm to 10 mm can be prepared, the thickness range of the cold rolled plate is obviously expanded, the blank of the cold rolled zirconium or zirconium alloy plate with a thickness of more than 5 mm is made up, and in addition, the size, surface and performance of the plate prepared by using the preparation method provided by the application can meet the high demand of the nuclear industry, the use range of the material is obviously expanded, the quality of the product is improved, and the preparation method has been applied to batch production. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are incorporated into and form part of the specification, together with the specification, serve to explain the principles of the application.

[0034] Figure 1 An example diagram of a certain brand of zirconium alloy cold rolled thick plate provided by the application;

[0035] Figure 2 A flowchart of a preparation method of a high-quality zirconium or zirconium alloy cold rolled thick plate provided by the application. DETAILED DESCRIPTION

[0036] In order for those skilled in the art to better understand the technical scheme of the application, the application will be further described in detail below with reference to the accompanying drawings and examples.

[0037] Related term explanation:

[0038] In the application, the first cold rolling and the second cold rolling respectively represent one rolling process, and the specific rolling times required by the rolling process can be determined according to the actual deformation amount.

[0039] The rolling process mentioned in this invention includes hot rolling of slab, primary cold rolling, and secondary cold rolling. Under the premise of ensuring rolling efficiency, the width of the slab / plate to be rolled is 30% to 90% of the width of the corresponding roll.

[0040] Example 1

[0041] This embodiment provides a method for preparing high-quality cold-rolled thick zirconium or zirconium alloy plates. See [link to relevant documentation]. Figure 2 As shown, the specific steps include:

[0042] Step 1: In this case, a hot-rolled slab that has been heat-treated at 680℃ is selected. The slab thickness δ is 18mm. The slab is divided into thickness × width × length (mm): 18 × 600 × 1000 (mm). Then, the surface of the slab is ground using a grinding machine. The grinding direction is the same as the rolling direction to remove defects such as cracks, oxide scale, and inclusions from the slab surface. After grinding, the thickness deviation is no greater than ±0.3mm and the difference between the same plate is 0.5mm. Finally, a 45° chamfer is made along the width of the slab to facilitate bite-in during subsequent rolling.

[0043] Step 2: First, degrease the zirconium alloy using a degreasing agent. Then, place the slab into a mixed acid solution of nitric acid, hydrofluoric acid, and water for pickling. The volume ratio of each component in the mixed acid solution is: 5 parts hydrofluoric acid, 40 parts nitric acid, and the remainder is water. Stop pickling when there is no residual oil, oxides, or impurities on the surface of the slab and it has a bright metallic color. Rinse it clean with water.

[0044] Step 3: Measure the dimensions of the slab after processing in Step 2, which are thickness × width × length (mm): 17.5 × 600 × 1000 (mm). Based on the dimensions of the slab, select a 1200mm hot rolling mill and hot rolling rolls with a crown of 0.15mm to perform a single cold rolling on the surface-treated slab to obtain plate A. The rolling speed of the entire process is 10m / min to 45m / min, and the processing rate is 37%.

[0045] Step 4: Inspect and measure the surface quality and dimensions of the rolled sheet A. The surface of sheet A is free of visible cracks, pits, and other defects. The sheet is flat. The dimensions of sheet A are thickness × width × length (mm): (11±0.2)×600×1600 (mm), with a difference of 0.25mm between sheets. Since the cracked edge of the sheet is small, it is not necessary to cut off the cracked edge. Instead, the length of sheet A is divided in half. The dimensions after slitting are thickness × width × length (mm): 11×600×800 (mm). In addition, the slitting sheet is ground along the length direction. After grinding, the difference between sheets is <0.23mm. Finally, a 45° chamfer is made along the width of the sheet to facilitate the bite during subsequent rolling.

[0046] Step 5, the plate A is degreased and pickled with the same degreasing agent and acid solution as in step 2, until the surface of the plate A is free of residual oil, oxides and impurities, and appears bright and metallic, the pickling is stopped, and the plate A is washed with clean water;

[0047] Step 6, the thickness, width and length of the plate A after step 5 are measured, the size is thickness x width x length (mm): 10.7 x 600 x 800 mm, the plate A with clean surface is cold-rolled again to obtain plate B by selecting 1200 mm cold rolling mill and roller with 0.2 mm convexity according to the size of the plate A, the rolling speed is 12 m / min to 50 m / min, the processing rate is 39.3%, and the total processing rate in step 3 and this step is about 61%;

[0048] Step 7, the surface quality of the plate B is checked, the plate surface is free of visible cracks and point pits, and the plate shape is flat, the size of the plate B is thickness x width x length (mm): (6.5±0.06) x 600 x 1300 (mm), and the same plate difference is less than 0.1 mm;

[0049] Step 8, the plate B is degreased and pickled with the same degreasing agent and acid solution as in step 2, until the surface of the plate B is free of residual oil, oxides and impurities, and appears bright and metallic, the pickling is stopped, and the plate B is washed with clean water;

[0050] Step 9, the plate B after degreasing and pickling is vacuum annealed to obtain the final cold-rolled thick plate, see Figure 1 ; wherein the vacuum degree is less than 1.0 x 10 -1 Pa, and the annealing temperature is 600°C.

[0051] Example 2

[0052] This example provides another method for preparing high-quality zirconium or zirconium alloy cold-rolled thick plate, which is different from example 1 in that:

[0053] In step 1, the plate blank thickness δ is 22 mm, and the size of the plate blank after cutting is thickness x width x length (mm): 22 x 800 x 1000 (mm), the thickness deviation after grinding is not more than ±0.27 mm, the same plate difference is 0.48 mm, and the 30° chamfer is performed along the width of the plate blank.

[0054] In step 2, the volume ratio of each component in the mixed acid solution is: hydrofluoric acid 3 parts, nitric acid 30 parts, and the rest is water.

[0055] The dimensions of the slab after degreasing and pickling in step 2, measured in step 3, are: thickness × width × length (mm): 21.2 × 800 × 1000 (mm). The rolls are flat rolls, and the rolling speed of one cold rolling process is 8 m / min to 48 m / min, with a processing rate of 45.7%.

[0056] In step 4, the dimensions of board A are thickness × width × length (mm): (11.5±0.22)×800×1800 (mm), with a difference of 0.26mm between boards. Board A is cut in half lengthwise, and the dimensions of board A after cutting are thickness × width × length (mm): 11.5×800×900 (mm). After grinding, the difference between boards is <0.26mm. Finally, a 30° chamfer is made along the width of board A.

[0057] The dimensions of plate A, which were degreased and pickled in step 5, measured in step 6 are: thickness × width × length (mm): 11 × 800 × 900 (mm); flat roll rolling is selected, and the rolling speed during the secondary cold rolling process is 5m / min to 55m / min, with a processing rate of 27.3%; the total processing rate in step 3 and this step is approximately 62%.

[0058] In step 7, the dimensions of board B are thickness × width × length (mm): (8±0.08)×800×1300 (mm), with a difference of <0.12mm between boards.

[0059] In step 9, the annealing temperature of the sheet material is 610℃.

[0060] Example 3

[0061] This embodiment provides another method for preparing high-quality cold-rolled thick zirconium or zirconium alloy plates, which differs from Embodiment 1 in that:

[0062] In step 1, the slab thickness δ is 12mm. After slitting, the slab dimensions are thickness × width × length (mm): 12 × 900 × 800 (mm). After grinding, the thickness deviation is no greater than ±0.32mm, and the difference between the same slab is 0.52mm. A 60° chamfer is made along the width of the slab.

[0063] In step 2, the volume ratio of each component in the mixed acid solution is: 2 parts hydrofluoric acid, 25 parts nitric acid, and the remainder is water.

[0064] The dimensions of the slab after degreasing and pickling in step 2, measured in step 3, are: thickness × width × length (mm): 11.5 × 900 × 800 (mm); the selected roll crown is 0.05 mm, the rolling speed is 8 m / min to 55 m / min, and the processing rate is 21%.

[0065] The size of the plate A in step 4 is thickness x width x length (mm) : (9±0.18) x 900 x 1000 (mm), the same plate difference is 0.22 mm, the same plate difference after grinding is less than 0.22 mm, and finally the 60° chamfer is made along the width of the plate A.

[0066] The size of the plate A treated by degreasing and pickling in step 5 is thickness x width x length (mm) : 8.7 x 900 x 1000 (mm), the roller with the convexity of 0.1 mm is selected, the rolling speed in the secondary cold rolling process is 5 m / min to 60 m / min, and the processing rate is 20% ; the total processing rate in step 3 and in this step is about 40% ;

[0067] The size of the plate B in step 7 is thickness x width x length (mm) : (7±0.15) x 900 x 1250 (mm), and the same plate difference is less than 0.18 mm.

[0068] The annealing temperature of the plate in step 9 is 595℃.

[0069] Example 4

[0070] This example provides another method for preparing high-quality zirconium or zirconium alloy cold-rolled thick plate, which is different from example 1 in that:

[0071] The thickness δ of the plate blank in step 1 is 30 mm, and the size of the plate blank after cutting is thickness x width x length (mm) : 30 x 800 x 800 (mm), and the thickness deviation after grinding is not more than ±0.4 mm, and the same plate difference is 0.7 mm.

[0072] The volume ratio of each component in the mixed acid solution in step 2 is as follows: hydrofluoric acid 3 parts, nitric acid 25 parts, and the rest is water.

[0073] The size of the plate blank treated by degreasing and pickling in step 2 is thickness x width x length (mm) : 29.3 x 800 x 800 (mm), the roller is a flat roller, the rolling speed in the primary cold rolling process is 8 m / min to 50 m / min, and the processing rate is 55%.

[0074] The size of the plate A in step 4 is thickness x width x length (mm) : (13±0.25) x 800 x 1800 (mm), the same plate difference is 0.45 mm, the edge crack of the plate is large, so the edge crack is cut off, the length is divided in the middle, the size after cutting is thickness x width x length (mm) : 13.2 x 780 x 900 (mm), and the same plate difference after grinding is less than 0.4 mm.

[0075] The size of the plate A after the degreasing and pickling treatment in step 5 is thickness x width x length (mm) : 13 x 780 x 900 (mm). The flat roller is selected for rolling, and the rolling speed in the secondary cold rolling process is 5 m / min to 60 m / min, and the processing rate is 32.3%. The total processing rate in step 3 and this step is about 70%.

[0076] The size of the plate B in step 7 is thickness x width x length (mm) : (8.7 ± 0.2) x 780 x 1350 (mm), and the same plate difference is less than 0.3 mm.

[0077] Example 5

[0078] This example provides another method for preparing a high quality zirconium or zirconium alloy cold-rolled thick plate, which is different from the example 1 in that:

[0079] The plate blank thickness δ in step 1 is 15 mm, and the size of the plate blank after the cutting is thickness x width x length (mm) : 15 x 400 x 800 (mm), and the thickness deviation after the grinding is not more than ± 0.3 mm, and the same plate difference is 0.5 mm.

[0080] The volume ratio of each component in the mixed acid solution in step 2 is as follows: hydrofluoric acid 3 parts, nitric acid 30 parts, and the rest is water.

[0081] The size of the plate blank after the degreasing and pickling treatment in step 2 is thickness x width x length (mm) : 14.2 x 400 x 800 (mm), and the roller is a flat roller, and the rolling speed in the primary cold rolling process is 8 m / min to 50 m / min, and the processing rate is about 10%.

[0082] The size of the plate A in step 4 is thickness x width x length (mm) : (12.8 ± 0.2) x 400 x 890 (mm), and the same plate difference is 0.3 mm, and the same plate difference after the grinding is less than 0.3 mm.

[0083] The size of the plate A after the degreasing and pickling treatment in step 5 is thickness x width x length (mm) : 12.5 x 400 x 890 (mm) ; the flat roller is selected for rolling, and the rolling speed in the secondary cold rolling process is 7 m / min to 53 m / min, and the processing rate is 60% ; and the total processing rate in step 3 and this step is about 65%.

[0084] The size of the plate B in step 7 is thickness x width x length (mm) : (5 ± 0.15) x 400 x 2200 (mm), and the same plate difference is less than 0.2 mm.

[0085] The plate annealing temperature in step 9 is 590°C.

[0086] Example 6

[0087] The present embodiment provides another method for preparing high-quality cold-rolled thick zirconium or zirconium alloy plate, which is different from the method of Embodiment 1 in that:

[0088] In Step 1, the slab thickness δ is 17 mm, and the size of the slab after slitting is thickness x width x length (mm): 17 x 800 x 800 (mm). After dressing, the thickness deviation is not more than ±0.28 mm, and the same plate difference is 0.48 mm. The slab is chamfered at 40° along the width of the slab.

[0089] In Step 2, the volume ratio of each component in the mixed acid solution is: hydrofluoric acid 3 parts, nitric acid 30 parts, and the rest is water.

[0090] In Step 3, the size of the slab after degreasing and pickling treatment in Step 2 is measured as thickness x width x length (mm): 16.2 x 800 x 800 (mm). The roller is a flat roller, and the rolling speed in the first cold rolling process is 8 m / min to 48 m / min, and the processing rate is 55%.

[0091] In Step 4, the size of the plate A is thickness x width x length (mm): (7.3 ± 0.22) x 800 x 1750 (mm), and the same plate difference is 0.26 mm. The plate A is divided in the middle of the length, and after slitting, the size of the plate A is thickness x width x length (mm): 7.3 x 800 x 870 (mm). After dressing, the same plate difference is less than 0.26 mm. Finally, the plate A is chamfered at 40° along the width of the plate A.

[0092] In Step 6, the size of the plate A after degreasing and pickling treatment in Step 5 is measured as thickness x width x length (mm): 7 x 800 x 870 (mm). Flat roller is selected for rolling, and the rolling speed in the second cold rolling process is 5 m / min to 55 m / min, and the processing rate is 15%. The total processing rate in Step 3 and this step is about 64.5%.

[0093] In Step 7, the size of the plate B is thickness x width x length (mm): (6 ± 0.15) x 800 x (mm), and the same plate difference is less than 0.2 mm.

[0094] In Step 9, the plate annealing temperature is 605°C.

[0095] In summary, the preparation method provided by the application utilizes the advantage of the large rolling capacity of the hot rolling mill, innovatively uses the hot rolling mill for cold rolling, selects specific rolls, and matches appropriate rolling parameters to roll the slab to a thickness range acceptable to the cold rolling mill for rolling; by controlling the rolling process, the size and state of the incoming material, and the surface treatment during the process, the combination of hot rolling mill cold rolling and cold rolling mill cold rolling is used to improve the rolling precision of the plate, solve the problem of poor size precision and mechanical properties of the hot rolling mill, change the limitation that the cold rolling mill can only roll thin plate, expand the preparation thickness of the cold rolled plate, and through the above method, high-precision and excellent-performance zirconium and zirconium alloy cold-rolled thick plate can be obtained.

[0096] The above description is merely a specific implementation of the application, enabling those skilled in the art to understand or implement the application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application.

[0097] It should be understood that the application is not limited to the above-described and that various modifications and changes can be made without departing from the scope thereof. The scope of the application is limited only by the claims appended hereto.

Claims

1. A method for producing a high-quality zirconium or zirconium alloy cold-rolled thick plate, characterized by, Specifically comprising the following steps: Step 1, pretreatment is performed on the incoming slab; the incoming slab is a hot-rolled slab after heat treatment above the stress relief annealing temperature, the thickness of the slab is 12-30 mm, and the width of the slab is 30%-90% of the width of the roller; the pretreatment specifically comprises: Step 1.1, first, the tongues at both ends of the incoming slab are cut off, and the remaining slab is cut into a specific size; Step 1.2, then, a grinding machine is used to grind the cut slab to remove surface cracks, scales and inclusion defects; wherein the grinding direction is the same as the next rolling direction, and the thickness deviation after grinding is not more than ±0.5 mm, and the same plate difference is not more than 0.8 mm; Step 1.3, finally, a chamfer θ1 is machined along the width direction of the slab, and the angle of the chamfer θ1 is 30°-60°, so as to facilitate the bite during subsequent rolling; Step 2, the pretreated slab is subjected to degreasing and pickling treatment, and when the surface of the slab presents a metallic color, the pickling is stopped and washed clean; Step 3, the size of the slab after step 2 is measured, a corresponding hot rolling mill and hot roller are selected according to the size of the slab, and the slab is once cold-rolled at room temperature to obtain a plate A; Step 4, first, the surface quality of the plate A is checked, if there are cracks or pits or inclusion defects on the surface of the plate A, surface grinding treatment is performed thereon, and whether to cut off the crack edge is determined according to the crack edge size of the plate A; then, the size of the plate A is measured, and whether to cut the plate A is determined according to the size of the plate A; finally, a chamfer θ2 is machined along the width direction of the plate A; Step 5, the surface of the plate A after step 4 is subjected to degreasing and pickling treatment, and when the surface of the plate A presents a metallic color, the pickling is stopped and washed clean; Step 6, the size of the plate A after step 5 is measured, a corresponding cold rolling mill and cold roller are selected according to the size of the plate A, and the plate A is twice cold-rolled to obtain a plate B; Step 7, the surface quality of the plate B is checked, and the size of the plate B is measured; Step 8, the surface of the plate B meeting the requirements in step 7 is subjected to degreasing and pickling treatment, and when the surface of the plate B presents a metallic color, the pickling is stopped and washed clean; Step 9, the plate B after the degreasing and pickling treatment in step 8 is subjected to heat treatment to obtain a final cold-rolled thick plate; In step 3, the roller type of the hot roller is a flat roller or a convex roller with a convexity of ≤0.15 mm, and the working parameters of the once cold-rolling are as follows: the rolling speed is 8 m / min-55 m / min, and the processing rate is 10%-55%; the thickness deviation of the plate A obtained after the once cold-rolling is not more than ±0.25 mm, and the same plate difference is not more than 0.45 mm; In step 6, the roller type of the cold roller is a flat roller or a convex roller with a convexity of ≤0.2 mm, and the working parameters of the twice cold-rolling are as follows: the rolling speed is 5 m / min-60 m / min, and the processing rate is 15%-60%; The total processing rate of the once cold-rolling in step 3 and the twice cold-rolling in step 6 is between 40% and 70%.

2. The method of producing a high-quality zirconium or zirconium alloy cold-rolled thick plate according to claim 1, characterized by, The defatting agent is used in the defatting treatment in the steps 2, 5 and 8, and the pickling solution used in the pickling treatment is a mixed acid solution of nitric acid, hydrofluoric acid and water, wherein the volume ratio of the components in the mixed acid solution is as follows: 1-5 parts of hydrofluoric acid, 20-40 parts of nitric acid, and the balance of water.

3. The method of producing a high-quality zirconium or zirconium alloy cold-rolled thick plate according to claim 1, characterized by, In the step 4, the grinding direction of the plate A is the same as the next rolling direction, and the angle of the chamfer θ2 is 30-60°, so as to facilitate the bite in the subsequent rolling.

4. The method of producing a high-quality zirconium or zirconium alloy cold-rolled thick plate according to claim 1, characterized by, In the step 7, the plate B is free of regional cracks or point pit defects on the surface, and the plate shape is flat, the thickness of the plate B is 5-10 mm, the thickness deviation is not greater than ±0.2 mm, and the same plate difference is not greater than 0.3 mm.

5. The method of producing a high-quality zirconium or zirconium alloy cold-rolled thick plate according to claim 1, characterized in that, The heat treatment in step 9 adopts vacuum annealing, vacuum degree ≤ 1.0 × 10 -1 The Pa annealing temperature is the recrystallization temperature.

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