A nuclear-grade zirconium alloy strip and its production method

Abstract

The present invention relates to the technical field of nuclear-grade nonferrous metal processing, and specifically provides a nuclear-grade zirconium alloy strip and a production method thereof, comprising: subjecting a slab after a single hot rolling to water grinding and / or sandblasting treatment to obtain a zirconium alloy slab precursor; subjecting the zirconium alloy slab precursor to pickling treatment to obtain a zirconium alloy slab with a smooth and uniform surface; subjecting the zirconium alloy slab to a secondary hot rolling and atmospheric annealing treatment to obtain a primary zirconium alloy plate; subjecting the primary zirconium alloy plate to sandblasting treatment to obtain an intermediate zirconium alloy plate with no oxide scale on the surface and uniform size; subjecting the intermediate zirconium alloy plate to pickling and / or partial grinding treatment to obtain a finished zirconium alloy plate with a smooth and uniform surface; subjecting the finished zirconium alloy plate to repeated cold rolling and annealing one or more times to obtain a zirconium alloy strip precursor; and subjecting the cold-rolled and annealed zirconium alloy strip precursor to polishing and / or pickling treatment to obtain a zirconium alloy strip with a smooth, uniform surface and no "orange peel".

Description

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on January 3, 2023, with application number 202310007072.8 and application name “A nuclear-grade zirconium alloy strip and its production method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of nuclear-grade nonferrous metal processing, and in particular to a nuclear-grade zirconium alloy strip and a production method thereof. Background Art

[0003] Zirconium alloys are widely used in the manufacture of nuclear reactor core materials and nuclear fuel assembly materials due to their low thermal neutron absorption cross-section, good comprehensive mechanical properties, good pressure processing and forming properties, welding properties, and resistance to high-temperature and high-pressure water vapor corrosion. Among them, zirconium alloy strips are mainly used in the manufacture of positioning grids. The strips are formed into grids after being stamped by dies. The surface quality of the finished strips is one of the main factors affecting the stamping and corrosion resistance. Summary of the Invention

[0004] In order to solve the above problems, the embodiments of the present application provide a nuclear-grade zirconium alloy strip and a production method thereof, which are used to produce nuclear-grade zirconium alloy strips with excellent surface quality and reduce stamping cracking caused by surface textures and defects of the strips.

[0005] To this end, the following technical solutions are adopted in the embodiments of the present application:

[0006] In a first aspect, the present application provides a method for producing a nuclear-grade zirconium alloy strip, comprising:

[0007] The slab after the primary hot rolling is subjected to water grinding and / or sandblasting to obtain a zirconium alloy slab precursor having no oxide scale on the surface;

[0008] The zirconium alloy slab precursor is pickled to obtain a zirconium alloy slab with a smooth and uniform surface;

[0009] The zirconium alloy slab is subjected to secondary hot rolling and atmospheric annealing to obtain a primary zirconium alloy plate;

[0010] sandblasting the primary zirconium alloy plate to obtain an intermediate zirconium alloy plate with no oxide scale on the surface and uniform size;

[0011] Pickling and / or partially grinding the intermediate zirconium alloy plate to obtain a finished zirconium alloy plate with a smooth and uniform surface;

[0012] performing one or more repeated cold rolling annealing on the finished zirconium alloy plate to obtain a zirconium alloy strip precursor;

[0013] The zirconium alloy strip precursor after cold rolling and annealing is polished and / or pickled to obtain a zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0014] As a feasible implementation method, the total amount of slab removed by water grinding after the single hot rolling is greater than 0.2 mm, and the amount removed by pickling after water grinding does not exceed 0.25 mm.

[0015] As a feasible implementation, the total removal amount of the intermediate zirconium alloy plate after pickling and / or local grinding does not exceed 0.4 mm.

[0016] As a feasible embodiment, the total removal amount of the zirconium alloy strip precursor during polishing and / or pickling treatment does not exceed 0.02 mm.

[0017] As a feasible implementation method, the water grinding treatment specifically includes: at room temperature, using a grinding stone with a particle size of 60# to 600#, first performing rough grinding to evenly remove the oxide scale and rolling defects on the upper and lower surfaces of the slab, and then performing fine grinding to smooth the surface grinding lines so that the surface roughness Ra is better than 3.2μm.

[0018] As a feasible implementation method, the sandblasting specifically includes: at room temperature, online sandblasting is performed using at least one sand particle selected from silicon carbide, brown corundum, and garnet, the spray gun pressure is ≥0.3MPa, and the distance between the spray gun and the material surface is ≤300mm, so as to evenly remove the oxide scale on the upper and lower surfaces.

[0019] As a feasible implementation method, the pickling specifically includes: the acid solution is a mixture of hydrofluoric acid, nitric acid and water, with a specific ratio of 20% to 65% HNO3 + 2% to 15% HF + H2O. During pickling, the acid solution temperature of the plate shall not be higher than 60°C, and the pickling temperature of the strip shall not be higher than 35°C. After rinsing the surface of the plate with deionized water, pickling, rinsing, re-rinsing and hot water drying are carried out in sequence to obtain nuclear-grade zirconium alloy plates and strips with smooth surfaces.

[0020] As a feasible implementation, the finished zirconium alloy plate is subjected to one or more repeated cold rolling annealing to obtain a zirconium alloy strip precursor, including: the zirconium alloy strip precursor is cold rolled using a roller with a surface roughness better than 0.3 μm.

[0021] As a feasible embodiment, the polishing of the zirconium alloy strip precursor specifically includes: at room temperature, after welding the leader strip at the head and tail of the zirconium alloy strip precursor using argon arc welding flat plate welding, polishing is performed using a 3M polishing wheel with a particle size ≥600#, the polishing wheel rotation speed is 800-4000 rpm, the strip transmission speed is 0.5-6m / min, the strip is polished and air-dried and coiled, and the strip roughness Ra after polishing is better than 0.8μm, obtaining a nuclear-grade zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0022] As an achievable embodiment, the thickness of the slab after the first hot rolling is 10 to 60 mm; and / or

[0023] The thickness of the primary zirconium alloy plate is 1 to 10 mm; and / or

[0024] The thickness of the zirconium alloy strip precursor is 0.425-0.8 mm.

[0025] In a second aspect, the present application provides a nuclear-grade zirconium alloy strip prepared using the above-mentioned production method.

[0026] In the above embodiment, the slab after one hot rolling is a hot-rolled thick plate, and the surface of the hot-pressed thick plate is treated with water grinding / sandblasting and pickling to fully remove the oxide scale (zirconium dioxide) and rolling defects generated on the surface of the plate due to heating and rolling, thereby obtaining a metallic zirconium alloy slab.

[0027] The primary zirconium alloy plate obtained after secondary hot rolling and atmospheric annealing is a hot-rolled thin plate. The surface of the hot-rolled thin plate is treated by sandblasting, pickling and local grinding to evenly remove the oxide scale (zirconium dioxide) and rolling defects on the upper and lower surfaces, thereby obtaining a uniform, smooth and metallic zirconium alloy plate.

[0028] The precursor of the zirconium alloy strip obtained by cold rolling annealing is a cold-rolled plate. The cold-rolled plate adopts polishing and pickling processes to remove rolling defects on the upper and lower surfaces to prevent defects from being brought into the strip rolling process.

[0029] The finished zirconium alloy strip is cold-rolled using rollers with a surface roughness better than 0.3μm. At the same time, the finished strip is pickled and polished to homogenize the surface and ultimately obtain excellent surface quality.

[0030] In summary, the above technical solution of the present invention has the following beneficial technical effects:

[0031] (1) Surface treatment is performed on the intermediate plate products in the production process of nuclear-grade zirconium alloy strips to remove surface defects of the intermediate plate products and prevent defects from being brought into the subsequent production process of the strips. At the same time, the surface of the finished strips is surface treated to finally obtain nuclear-grade zirconium alloy strips with excellent surface quality.

[0032] (2) The process flow is simple, the process parameters are highly controllable, and it is easy to apply to industrial production;

[0033] (3) It has the characteristics of high surface finish and strong corrosion resistance;

[0034] (4) The nuclear-grade zirconium alloy strip processed according to the above surface treatment method has excellent stamping performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0036] Figure 1 This is a schematic flow chart of a method for producing a nuclear-grade zirconium alloy strip according to an embodiment of the present application;

[0037] Figure 2 The surface quality of the water-milled plate obtained by water-milling the slab after a single hot rolling is shown;

[0038] Figure 3 These are low-magnification morphological images and actual images of nuclear-grade zirconium alloy strips prepared according to the production method provided in the examples of this application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0040] It should be understood that the scope of protection of the present application is not limited to the specific embodiments described below; it should also be understood that the terms used in the examples of the present application are for the purpose of describing specific embodiments rather than for the purpose of limiting the scope of protection of the present application; in the specification and claims of the present application, unless otherwise expressly stated herein, the singular forms "a", "an" and "the" include plural forms.

[0041] When the embodiments provide numerical ranges, it should be understood that, unless otherwise specified herein, both endpoints of each numerical range and any numerical value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those generally understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, according to the grasp of the prior art by those skilled in the art and the record of this application, any method, equipment, and material of the prior art similar or equivalent to the methods, equipment, and materials described in the embodiments of the present application can also be used to realize this application.

[0042] It is particularly noted that, unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this application relates. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments, and equipment used in the following examples are all commercially available or can be obtained through existing methods; the amounts of experimental reagents used, unless otherwise specified, are the amounts used in conventional experimental procedures; and the experimental methods described, unless otherwise specified, are all conventional methods.

[0043] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0044] Unless otherwise stated, the following terms used in the specification and claims have the following meanings.

[0045] The "room temperature" mentioned in this application has a meaning well known in the art, generally referring to 24-28°C.

[0046] Figure 1 This is a schematic flow chart of a method for producing a nuclear-grade zirconium alloy strip provided in an embodiment of the present application.

[0047] According to a method for producing a nuclear-grade zirconium alloy strip provided in an embodiment of the present application, Figure 1 As shown, specifically including:

[0048] S101, performing water grinding and / or sandblasting on the slab after the primary hot rolling to obtain a zirconium alloy slab precursor having no oxide scale on the surface;

[0049] S102, pickling the zirconium alloy slab precursor to obtain a zirconium alloy slab with a smooth and uniform surface;

[0050] S103, performing secondary hot rolling on the zirconium alloy slab and performing atmospheric annealing to obtain a primary zirconium alloy plate;

[0051] S104, sandblasting the primary zirconium alloy plate to obtain an intermediate zirconium alloy plate with no oxide scale on the surface and uniform size;

[0052] S105, pickling and / or partially grinding the intermediate zirconium alloy plate to obtain a finished zirconium alloy plate with a smooth and uniform surface;

[0053] S106, performing one or more repeated cold rolling annealing on the finished zirconium alloy plate to obtain a zirconium alloy strip precursor;

[0054] S107. Polishing and / or pickling the cold-rolled and annealed zirconium alloy strip precursor to obtain a zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0055] This method produces nuclear-grade zirconium alloy strips with a simple process and highly controllable process parameters, making them easily applicable to industrial production. While maintaining the same alloy composition, it significantly improves the surface finish of the strips, providing excellent corrosion resistance and stamping properties. A strip without an "orange peel" finish exhibits excellent surface quality, indicating a lack of surface lines and defects.

[0056] Specifically, the thickness of the slab after one hot rolling is 10 to 60 mm. More preferably, the thickness of the slab after one hot rolling is 19 to 60 mm.

[0057] Optionally, the total removal amount of the slab by water grinding after one hot rolling is greater than 0.2 mm, and the removal amount by pickling after water grinding does not exceed 0.25 mm.

[0058] Optionally, the water grinding treatment specifically includes: at room temperature, using a grinding stone with a particle size of 60# to 600#, first performing rough grinding to evenly remove the oxide scale and rolling defects on the upper and lower surfaces of the slab, and then performing fine grinding to smooth the surface grinding lines so that the surface roughness Ra is better than 3.2μm.

[0059] For example, grinding stones with particle sizes of 60#, 180#, 240#, 320#, and 600# are used in sequence for grinding from coarse to fine, so as to completely remove defects such as oxide scale, indentations, folds, and microcracks on the surface of the slab caused by hot rolling and prevent them from being inherited to subsequent processes. Figure 2 The surface quality of the water-milled plate obtained by water-milling the slab after one hot rolling is shown in FIG. Figure 2During water grinding, the grinding method is transverse grinding, that is, grinding along the width direction of the slab, which can significantly reduce the increase in grinding thickness difference caused by the unevenness of the slab, thereby improving the thickness consistency of the slab before rolling.

[0060] Optionally, the thickness of the primary zirconium alloy plate is 1 to 10 mm, preferably, the thickness of the primary zirconium alloy plate is 3.5 to 10 mm, silicon carbide sand is used for online uniform sandblasting, and the roller running speed is 200 to 300 mm / min.

[0061] Optionally, the total removal amount of the intermediate zirconium alloy plate after pickling and / or local grinding does not exceed 0.4 mm.

[0062] Optionally, the sandblasting specifically includes: at room temperature, online sandblasting is performed using at least one of silicon carbide, brown corundum, and garnet sand particles, the spray gun pressure is ≥0.3MPa, and the distance between the spray gun and the material surface is ≤300mm, so as to evenly remove the oxide scale on the upper and lower surfaces.

[0063] Optionally, the zirconium alloy slab precursor after the primary hot rolling and water grinding, and the intermediate zirconium alloy plate and strip precursor after the secondary hot rolling and sandblasting, are pickled. For example, the pickling process includes: an acid solution comprising a mixture of hydrofluoric acid, nitric acid, and water, with a specific ratio of 20% to 65% HNO₃ + 2% to 15% HF + H₂O. The plate acid solution temperature during pickling must not exceed 60°C, effectively smoothing the plate surface quality, optimizing roughness while preventing over-pickling, pickling, and bluing. The strip pickling temperature must not exceed 35°C. After rinsing the plate surface with deionized water, the plate is pickled, rinsed, re-rinsed, and dried with hot water in a sequential process to obtain a smooth nuclear-grade zirconium alloy plate and strip. Optionally, the finished zirconium alloy plate is subjected to one or more repeated cold rolling annealing processes to obtain a zirconium alloy strip precursor, including: the zirconium alloy strip precursor is cold rolled using rollers with a surface roughness of better than 0.3 μm.

[0064] For example, the polishing of the zirconium alloy strip precursor specifically includes: at room temperature, after welding the leader strip at the head and tail of the zirconium alloy strip precursor using argon arc welding flat plate welding, polishing is performed using a polishing wheel produced by 3M with a particle size ≥600#, the polishing wheel speed is 800-4000 rpm, the strip transmission speed is 0.5-6m / min, the strip is polished and air-dried and coiled, and paper is placed between layers. After polishing, the strip roughness Ra is better than 0.8μm, and a nuclear-grade zirconium alloy strip with a smooth, uniform surface and no "orange peel" is obtained.

[0065] Optionally, the thickness of the zirconium alloy strip precursor is 0.425 to 0.8 mm. The total amount of polishing and / or pickling of the zirconium alloy strip precursor does not exceed 0.02 mm, so as to remove the hardened contamination layer that may be generated on the strip surface during the finished product annealing and optimize the subsequent strip polishing consistency.

[0066] Optionally, the finished strip is finally polished. After the strip head and tail are welded with the leader by argon arc welding flat plate welding, a polishing wheel with a particle size better than 600# is selected, the polishing wheel speed is 800-4000rpm, the strip transmission speed is 0.5-6m / min, the strip is polished and air-dried and coiled. After polishing, the strip roughness Ra is better than 0.8μm, and a nuclear-grade zirconium alloy strip with a smooth, uniform surface and no "orange peel" is obtained.

[0067] Example

[0068] Example 1

[0069] A method for producing a 0.6 mm thick nuclear-grade zirconium alloy strip comprises:

[0070] S201. The slab after the first hot rolling is subjected to water grinding to obtain a zirconium alloy slab precursor without oxide scale on the surface.

[0071] Specifically, a zirconium alloy ingot is kept at a temperature of 1050°C in the β phase region for 180 minutes, and is forged to obtain a slab with a thickness of 114 mm; a 104 mm slab without oxide scale after machining is kept at a temperature of 620°C in the α phase region for 180 minutes, and is hot rolled once to obtain a slab with a thickness of 20 mm; the slab after the single hot rolling is water-milled, and at room temperature, grinding is carried out from coarse to fine using grinding stones with particle sizes of 60#, 180#, 240#, 320#, and 600#, and the grinding method during water milling is horizontal grinding; the water milling removal amount is 0.22 mm, and a zirconium alloy slab precursor with a thickness of 19.78 mm and no oxide scale on the surface is obtained.

[0072] S202, pickling the zirconium alloy slab precursor to obtain a zirconium alloy slab with a smooth and uniform surface.

[0073] The pickling process specifically includes: the acid solution is a mixture of 50wt% hydrofluoric acid, 40wt% nitric acid and water, with a specific ratio of 20% HNO3+15% HF+65% H2O. The temperature of the acid solution during pickling is 35°C. After rinsing the surface of the slab with deionized water, pickling, rinsing, re-rinsing and hot water drying are carried out in sequence to obtain a zirconium alloy slab with a smooth surface.

[0074] The pickling removal amount was 0.12 mm, and a zirconium alloy slab with a thickness of 19.66 mm was obtained.

[0075] S203 , performing secondary hot rolling on the zirconium alloy slab and performing atmospheric annealing to obtain a primary zirconium alloy plate.

[0076] Specifically, the zirconium alloy slab was kept at a temperature of 620° C. for 1 hour and then hot rolled to obtain a primary zirconium alloy plate with a thickness of 3.5 mm.

[0077] S204 , performing sandblasting on the primary zirconium alloy plate to obtain an intermediate zirconium alloy plate with no oxide scale on the surface and uniform size.

[0078] Sand blasting specifically includes: at room temperature, using silicon carbide sand particles for online sand blasting, with a spray gun pressure ≥0.3MPa, a distance between the spray gun and the material surface ≤300mm, and a roller running speed of 260mm / min, so as to evenly remove the oxide scale on the upper and lower surfaces.

[0079] S205 , performing pickling treatment on the intermediate zirconium alloy plate to obtain a finished zirconium alloy plate with a smooth and uniform surface.

[0080] The pickling process specifically includes: the acid solution is a mixture of 50wt% hydrofluoric acid, 40wt% nitric acid and water, with a specific ratio of 20% HNO3+15% HF+65% H2O. The acid solution temperature during pickling is 50°C. After rinsing the plate surface with deionized water, pickling, rinsing, re-rinsing and hot water drying are carried out in sequence to obtain a finished zirconium alloy plate with a smooth surface.

[0081] The pickling removal amount of the intermediate zirconium alloy plate is 0.3 mm, and the finished zirconium alloy plate with a thickness of 3.2 mm is obtained.

[0082] S206 , performing one or more repeated cold rolling annealing on the finished zirconium alloy plate to obtain a zirconium alloy strip precursor.

[0083] The surface-treated finished zirconium alloy plate is rolled on a cold rolling mill with a roller having a surface roughness better than 0.3 μm. The zirconium alloy strip precursor is cold rolled from 3.2 mm to 1.2 mm, with a deformation per pass of 3% to 8% and a total deformation of about 62%. The cold-rolled plate is degreased to completely remove oil stains on the surface of the plate, and then vacuum annealed at 600° C. for 2.5 hours, with a vacuum degree of no more than 0.7×10-2 Pa in the vacuum annealing furnace. The vacuum-annealed zirconium alloy plate is cold rolled on a cold rolling mill from 1.2 mm to 0.62 mm, with a deformation per pass of 1% to 5% and a total deformation of about 48%.

[0084] The cold-rolled strip is subjected to continuous degreasing annealing on a continuous degreasing annealing device at a temperature of 625° C. and kept at this temperature for 3 minutes to obtain a zirconium alloy strip with uniform structure.

[0085] S207. Polishing the cold-rolled and annealed zirconium alloy strip precursor to obtain a zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0086] The zirconium alloy strip precursor polishing specifically includes: at room temperature, after welding the leader strip at the head and tail of the zirconium alloy strip precursor using argon arc welding flat plate welding, polishing is performed using a 3M polishing wheel with a particle size of ≥600#, the polishing wheel rotation speed is 800-4000 rpm, the strip transmission speed is 0.5-6 m / min, the strip is polished and air-dried and coiled, and paper is placed between layers. After polishing, the strip roughness Ra is better than 0.8 μm, thereby obtaining a nuclear-grade zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0087] The total removal amount of the zirconium alloy strip precursor during polishing is 0.02 mm, and a nuclear-grade zirconium alloy strip with a thickness of 0.6 mm is obtained.

[0088] Example 2

[0089] A method for producing a 0.45 mm thick nuclear-grade zirconium alloy strip comprises:

[0090] S201. The slab after the first hot rolling is subjected to water grinding to obtain a zirconium alloy slab precursor without oxide scale on the surface.

[0091] Specifically, a zirconium alloy ingot is kept at a temperature of 1050°C in the β phase region for 180 minutes, and is forged to obtain a slab with a thickness of 114 mm; a 104 mm slab without oxide scale after machining is kept at a temperature of 620°C in the α phase region for 180 minutes, and is hot rolled once to obtain a slab with a thickness of 20 mm; the slab after the single hot rolling is water-milled, and at room temperature, grinding is carried out from coarse to fine using grinding stones with particle sizes of 60#, 180#, 240#, 320#, and 600#, and the grinding method during water milling is horizontal grinding; the water milling removal amount is 0.22 mm, and a zirconium alloy slab precursor with a thickness of 19.78 mm and no oxide scale on the surface is obtained.

[0092] S202, pickling the zirconium alloy slab precursor to obtain a zirconium alloy slab with a smooth and uniform surface.

[0093] The pickling process specifically includes: the acid solution is a mixture of 50wt% hydrofluoric acid, 40wt% nitric acid and water, with a specific ratio of 20% HNO3+15% HF+65% H2O. The temperature of the acid solution during pickling is 35°C. After rinsing the surface of the slab with deionized water, pickling, rinsing, re-rinsing and hot water drying are carried out in sequence to obtain a zirconium alloy slab with a smooth surface.

[0094] The pickling removal amount was 0.12 mm, and a zirconium alloy slab with a thickness of 19.66 mm was obtained.

[0095] S203 , performing secondary hot rolling on the zirconium alloy slab and performing atmospheric annealing to obtain a primary zirconium alloy plate.

[0096] Specifically, the zirconium alloy slab was kept at a temperature of 620° C. for 1 hour and then hot rolled to obtain a primary zirconium alloy plate with a thickness of 3.5 mm.

[0097] S204 , performing sandblasting on the primary zirconium alloy plate to obtain an intermediate zirconium alloy plate with no oxide scale on the surface and uniform size.

[0098] Sand blasting specifically includes: at room temperature, using silicon carbide sand particles for online sand blasting, with a spray gun pressure ≥0.3MPa, a distance between the spray gun and the material surface ≤300mm, and a roller running speed of 260mm / min, so as to evenly remove the oxide scale on the upper and lower surfaces.

[0099] S205 , performing pickling treatment on the intermediate zirconium alloy plate to obtain a finished zirconium alloy plate with a smooth and uniform surface.

[0100] The pickling process specifically includes: the acid solution is a mixture of 50wt% hydrofluoric acid, 40wt% nitric acid and water, with a specific ratio of 20% HNO3+15% HF+65% H2O. The acid solution temperature during pickling is 50°C. After rinsing the plate surface with deionized water, pickling, rinsing, re-rinsing and hot water drying are carried out in sequence to obtain a finished zirconium alloy plate with a smooth surface.

[0101] The pickling removal amount of the intermediate zirconium alloy plate is 0.3 mm, and the finished zirconium alloy plate with a thickness of 3.2 mm is obtained.

[0102] S206 , performing one or more repeated cold rolling annealing on the finished zirconium alloy plate to obtain a zirconium alloy strip precursor.

[0103] The surface-treated finished zirconium alloy plate is rolled on a cold rolling mill with a roller having a surface roughness better than 0.3 μm. The zirconium alloy strip precursor is cold rolled from 3.2 mm to 1.2 mm, with a deformation per pass of 3% to 8% and a total deformation of about 62%. The cold-rolled plate is degreased to completely remove oil stains on the surface of the plate, and then vacuum annealed at 600° C. for 2.5 hours, with a vacuum degree of no more than 0.7×10-2 Pa in the vacuum annealing furnace. The vacuum-annealed zirconium alloy plate is cold rolled on a cold rolling mill from 1.2 mm to 0.47 mm, with a deformation per pass of 1% to 5% and a total deformation of about 61%.

[0104] The cold-rolled strip is subjected to continuous degreasing annealing on a continuous degreasing annealing device at a temperature of 625° C. and kept at this temperature for 3 minutes to obtain a zirconium alloy strip with uniform structure.

[0105] S207. Polishing the cold-rolled and annealed zirconium alloy strip precursor to obtain a zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0106] The zirconium alloy strip precursor polishing specifically includes: at room temperature, after welding the leader strip at the head and tail of the zirconium alloy strip precursor using argon arc welding flat plate welding, polishing is performed using a 3M polishing wheel with a particle size of ≥600#, the polishing wheel rotation speed is 800-4000 rpm, the strip transmission speed is 0.5-6 m / min, the strip is polished and air-dried and coiled, and paper is placed between layers. After polishing, the strip roughness Ra is better than 0.8 μm, thereby obtaining a nuclear-grade zirconium alloy strip with a smooth, uniform surface and no "orange peel".

[0107] The total removal amount of the zirconium alloy strip precursor during polishing is 0.02 mm, and a nuclear-grade zirconium alloy strip with a thickness of 0.45 mm is obtained.

[0108] The surface morphology, corrosion resistance and stamping performance of the nuclear-grade zirconium alloy strip prepared by this method were tested. Figure 3 These are low-magnification morphology images and actual images of nuclear-grade zirconium alloy strips prepared according to the production method provided in the examples of this application. The strip smoothness test results are shown in Table 1, the strip corrosion performance test results are shown in Table 2, and the strip stamping performance test results are shown in Table 3.

[0109] Table 1 Surface finish test results of nuclear grade zirconium alloy strips prepared by this method

[0110]

[0111] Table 2 Corrosion performance test results of nuclear grade zirconium alloy strips prepared by this method

[0112]

[0113]

[0114] Table 3 Stamping performance test results of nuclear grade zirconium alloy strips prepared by this method

[0115]

[0116] Combine Figure 3 As can be seen from Tables 1-3, the nuclear-grade zirconium alloy strip prepared by the method of the present application has the characteristics of high surface finish, strong corrosion resistance and excellent stamping performance.

[0117] Finally, it should be noted that the above embodiments are merely illustrative of the technical solutions of the present application. Those skilled in the art should understand that, although the present application has been described in detail with reference to the aforementioned embodiments, the technical solutions described in the aforementioned embodiments may be modified or some of the technical features thereof may be replaced with equivalents. However, such modifications or replacements do not deviate from the spirit and scope of the technical solutions in the various embodiments of the present application.

Claims

1. A method for producing a nuclear-grade zirconium alloy strip, characterized in that: include: The slab after the primary hot rolling is subjected to water grinding and sandblasting to obtain a zirconium alloy slab precursor with no oxide scale on the surface; The zirconium alloy slab precursor is pickled to obtain a zirconium alloy slab with a smooth and uniform surface; The zirconium alloy slab is subjected to secondary hot rolling and atmospheric annealing to obtain a primary zirconium alloy plate; sandblasting the primary zirconium alloy plate to obtain an intermediate zirconium alloy plate with no oxide scale on the surface and uniform size; The intermediate zirconium alloy plate is pickled and partially ground to obtain a finished zirconium alloy plate with a smooth and uniform surface; performing one or more repeated cold rolling annealing on the finished zirconium alloy plate to obtain a zirconium alloy strip precursor; Polishing and / or pickling the cold-rolled and annealed zirconium alloy strip precursor to obtain a zirconium alloy strip with a smooth, uniform surface and no "orange peel"; The water grinding treatment specifically includes: using a grinding stone with a grit size of 60# to 600# at room temperature, first performing coarse grinding to uniformly remove the oxide scale and rolling defects on the upper and lower surfaces of the slab, and then performing fine grinding to smooth the surface grinding lines, so that the surface roughness Ra is better than 3.2μm; The sandblasting specifically includes: performing online sandblasting at room temperature using at least one of silicon carbide, brown corundum, and garnet sand particles, with a spray gun pressure of ≥0.3 MPa and a distance of ≤300 mm from the surface of the material, thereby evenly removing oxide scales on both the upper and lower surfaces; The pickling process specifically includes: the acid solution is a mixture of hydrofluoric acid, nitric acid, and water, with a specific ratio of 20% to 65% HNO3 + 2% to 15% HF + H2O. During pickling, the acid solution temperature for the plate shall not be higher than 60°C, and the pickling temperature for the strip shall not be higher than 35°C. After the surface of the plate is rinsed with deionized water, pickling, rinsing, re-rinsing, and hot water drying are sequentially performed to obtain a nuclear-grade zirconium alloy plate with a smooth surface. The zirconium alloy strip precursor polishing specifically includes: at room temperature, after welding the leader strip at the head and tail of the zirconium alloy strip precursor using argon arc welding flat plate welding, polishing using a 3M polishing wheel with a particle size of ≥600#, the polishing wheel rotation speed is 800-4000 rpm, the zirconium alloy strip precursor transmission speed is 0.5-6 m / min, the zirconium alloy strip precursor is polished and air-dried and coiled, and the strip roughness Ra after polishing is better than 0.8 μm, thereby obtaining a nuclear-grade zirconium alloy strip with a smooth, uniform surface and no "orange peel".

2. The method according to claim 1, characterized in that in, The total amount of slab removed by water grinding after the single hot rolling is greater than 0.2 mm, and the amount removed by pickling after water grinding does not exceed 0.25 mm.

3. The method according to claim 1, characterized in that The total removal amount of the intermediate zirconium alloy plate after pickling and / or local grinding treatment does not exceed 0.4 mm.

4. The method according to claim 1, wherein The total amount of the zirconium alloy strip precursor removed during polishing and / or pickling treatment does not exceed 0.02 mm.

5. The method according to claim 1, wherein The thickness of the slab after the first hot rolling is 10 to 60 mm; and / or The thickness of the primary zirconium alloy plate is 1 to 10 mm; and / or The thickness of the zirconium alloy strip precursor is 0.425-0.8 mm.

6. A nuclear-grade zirconium alloy strip, characterized in that: The nuclear-grade zirconium alloy strip is prepared by the production method of any one of claims 1 to 5.

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