Nuclear-grade zirconium and zirconium alloy plate welding method, coiled material and strip

Abstract

The invention provides a nuclear-grade zirconium and zirconium alloy plate welding method, a coiled material and a strip, and the nuclear-grade zirconium and zirconium alloy plate welding method comprises the steps that after the first end face of a first plate and the second end face of a second plate are assembled and fixed, argon tungsten-arc welding is conducted; the first plate and the second plate are nuclear-grade zirconium and zirconium alloy plates, and the thickness difference value of the first plate and the second plate is within + / -10%; the welding current of argon tungsten-arc welding, the average thickness of the first plate and the second plate and the welding speed meet the formula # imgabs0 #, wherein I is the welding current; h is the average thickness of the first plate and the second plate; v is the welding speed; p is a constant. According to the nuclear-grade zirconium and zirconium alloy plate welding method, the tungsten electrode argon arc self-fluxing welding technology is adopted, and nuclear and zirconium alloy coiled materials with excellent weld joint quality can be produced by limiting the relation among the welding current, the plate thickness and the welding speed.

Description

Technical Field

[0001] The present application relates to the technical field of nuclear-grade nonferrous metal processing, and in particular to a nuclear-grade zirconium and zirconium alloy plate welding method and application. Background Art

[0002] 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 forming properties, welding properties and high temperature and high pressure water vapor corrosion resistance. Among them, zirconium alloy strips are mainly used in the manufacture of nuclear power plant fuel assembly positioning grids. The current strips need to be produced by cold rolling after the plates are welded into coils. Therefore, the plate welding quality directly affects the strip rolling quality.

[0003] The inventors have found that the following problems may occur during the welding process of zirconium alloy plates:

[0004] 1. Porosity, lack of fusion, cracks, etc. These defects will become stress concentration points, reduce the strength and toughness of the weld, and affect the subsequent strip rolling.

[0005] 2. During the welding process, local high temperature will cause microstructural changes in the heat affected zone (HAZ). Especially for nuclear grade zirconium alloys, it is easy to produce problems such as grain coarsening after welding, resulting in a decrease in the mechanical properties of the material.

[0006] These defects will lead to a decrease in the mechanical strength of the material after welding, and cause problems such as uneven deformation, cracking, and strip breakage in subsequent strip rolling. Summary of the invention

[0007] In view of this, an object of the present application is to provide a nuclear-grade zirconium and zirconium alloy plate welding method, which adopts tungsten inert gas arc self-melting welding process technology and limits the relationship between welding current, plate thickness and welding speed to produce nuclear and zirconium alloy coils with excellent weld quality, thereby reducing or avoiding strip breakage caused by poor weld quality during the rolling process of the welding coil.

[0008] Another object of the present application is to provide a coiled material.

[0009] Yet another object of the present application is to provide a strip.

[0010] To achieve the above-mentioned purpose, the first aspect of the present application proposes a nuclear-grade zirconium and zirconium alloy plate welding method, comprising:

[0011] After assembling and fixing the first end face of the first plate and the second end face of the second plate, tungsten inert gas arc welding is performed;

[0012] The first plate and the second plate are both nuclear grade zirconium and zirconium alloy plates, and the difference between the first plate and the second plate is within ±10%;

[0013] The welding current of the tungsten inert gas arc welding, the average thickness of the first plate and the second plate, and the welding speed satisfy:

[0014]

[0015] Wherein, I is the welding current, in A; H is the average thickness of the first plate and the second plate, in mm; V is the welding speed, in mm / min; P is a constant, -10≤P≤10.

[0016] In some embodiments, the thickness of the first plate and the second plate are both 1.0-3.0 mm.

[0017] In some embodiments, the welding speed of the argon tungsten arc welding is 200-400 mm / min.

[0018] In some embodiments, the welding voltage of the argon tungsten arc welding is 8-12V, preferably 9-10V.

[0019] In some embodiments, the diameter of the tungsten electrode used in the tungsten inert gas arc welding is a mm, the thickness of the first plate and the second plate are both b mm, and a and b satisfy:

[0020] When 1.0≤b﹤1.8, a is 1.6; and / or,

[0021] When 1.8≤b≤3.0, a is 2.0.

[0022] In some embodiments, during the tungsten inert gas welding process, a welding torch shielding gas is provided in the welding area for protecting the welding torch nozzle, the tungsten electrode and the molten pool.

[0023] In some embodiments, during the tungsten inert gas welding process, a back area of ​​the weld formed by the welding is provided with a back shielding gas for protecting the back of the weld from contamination.

[0024] In some embodiments, during the tungsten inert gas welding process, a hood shielding gas is provided on the weld to protect the weld.

[0025] In some embodiments, the drag hood protective gas is filled in the drag hood, and the drag hood is arranged on the weld and can move along the welding direction with the welding gun.

[0026] In some embodiments, the welding torch shielding gas, the back shielding gas and the drag hood shielding gas are all argon gas with a purity of more than 99.99% by volume.

[0027] In some embodiments, the flow rates of the welding gun shielding gas, the back shielding gas and the drag hood shielding gas are all 8-15 L / min.

[0028] In some embodiments, the nuclear-grade zirconium and zirconium alloy plate comprises the following components in mass percentage: Sn 1.20-1.70%, Fe 0.18-0.24%, Cr 0.07-0.13%, O 0.09-0.16%, and the balance is Zr; the total mass content of Fe and Cr in the nuclear-grade zirconium and zirconium alloy plate is 0.28-0.37%.

[0029] In some embodiments, the nuclear-grade zirconium and zirconium alloy plate welding method further includes the step of shearing the first end face and the second end face smooth before the assembling.

[0030] In some embodiments, the first end surface is disposed perpendicularly to a placement plane of the first plate.

[0031] In some embodiments, the second end surface is disposed perpendicularly to a placement plane of the second plate.

[0032] In some embodiments, the first plate and the second plate are placed on the same plane.

[0033] In some embodiments, the first end surface and the second end surface are in close contact.

[0034] In some embodiments, the nuclear grade zirconium and zirconium alloy plate welding method further includes the step of cleaning the first plate and the second plate before the assembling.

[0035] A second aspect of the present application provides a coiled material, which is prepared by the nuclear-grade zirconium and zirconium alloy plate welding method described in the present application.

[0036] A third aspect of the present application provides a strip material, which is cold-rolled from the coil material as described in the present application.

[0037] The nuclear-grade zirconium and zirconium alloy plate welding method described in this application can at least bring the following beneficial effects:

[0038] 1. By adopting tungsten inert gas arc self-melting welding technology, by limiting the relationship between welding current, plate thickness and welding speed, nuclear and zirconium alloy coils with excellent weld quality can be produced. The weld quality can meet the subsequent cold rolling production of 85% (85% refers to the dimensional change of the thickness of the plate after being subjected to the rolling force during the cold rolling process. Its representative meaning is the degree of plastic deformation of the plate during the cold rolling process.) of the total cold rolling deformation, reducing or avoiding the breakage caused by poor weld quality during the rolling process of the welding coil (that is, the nuclear-grade zirconium and zirconium alloy plate welding method of this application is not prone to breakage after cold rolling).

[0039] 2. The process parameters are highly controllable and easy to apply to industrial production.

[0040] 3. The plate thickness range is wide and it can be used to weld all nuclear-grade zirconium alloy plates into coils.

[0041] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings.

[0043] in:

[0044] Figure 1 This is a photo of the weld surface quality obtained after welding using the nuclear-grade zirconium and zirconium alloy plate welding method of Example 1 of the present application.

[0045] Figure 2 This is a metallographic structure diagram of the weld at a scale of 500 microns obtained after welding using the nuclear-grade zirconium and zirconium alloy plate welding method of Example 1 of the present application.

[0046] Figure 3 This is a metallographic structure diagram of the weld at a scale of 100 microns obtained after welding using the nuclear-grade zirconium and zirconium alloy plate welding method of Example 1 of the present application.

[0047] Figure 4 This is a surface quality diagram of the weld front side formed in comparative example 1.

[0048] Figure 5 This is a surface quality diagram of the back side of the weld formed in comparative example 1.

[0049] Figure 6 This is the weld quality diagram formed in comparative example 2. DETAILED DESCRIPTION

[0050] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0051] In this application, the disclosure of numerical ranges includes all values ​​within the entire range and the disclosure of further subdivided ranges, including the endpoints and sub-ranges given in these ranges.

[0052] In this application, the raw materials, equipment, etc. involved, unless otherwise specified, are all raw materials and equipment that can be made through commercial channels or known methods; the methods involved, unless otherwise specified, are all conventional methods.

[0053] <Welding Methods for Nuclear Grade Zirconium and Zirconium Alloy Plates>

[0054] The nuclear-grade zirconium and zirconium alloy plate welding method of the embodiment of the present application includes: assembling and fixing a first end face of a first plate and a second end face of a second plate, and then performing tungsten inert gas arc welding.

[0055] It can be understood that the “pairing” in the embodiment of the present application refers to arranging the first end face of the first plate and the second end face of the second plate opposite to each other to form a weld by welding, thereby connecting the first plate and the second plate together.

[0056] In some embodiments, both the first plate and the second plate are nuclear grade zirconium and zirconium alloy plates.

[0057] In the embodiment of the present application, the material composition and specifications (length, width, thickness) of the first plate material and the second plate material may be the same or different.

[0058] In some embodiments, the nuclear-grade zirconium and zirconium alloy plate material comprises the following components in mass percentage: Sn (tin) 1.20-1.70%, Fe (iron) 0.18-0.24%, Cr (chromium) 0.07-0.13%, O (oxygen) 0.09-0.16%, and the balance is Zr (zirconium).

[0059] For example, in the nuclear-grade zirconium and zirconium alloy plate material, the mass content of Sn includes but is not limited to 1.3%, 1.4%, 1.5% or 1.6%.

[0060] For example, in the nuclear-grade zirconium and zirconium alloy plate, the mass content of Fe includes but is not limited to 0.19%, 0.2%, 0.21%, 0.22% or 0.23%, etc.

[0061] For example, in the nuclear-grade zirconium and zirconium alloy plate material, the mass content of Cr includes but is not limited to 0.08%, 0.09%, 0.1%, 0.11% or 0.12%.

[0062] For example, in the nuclear-grade zirconium and zirconium alloy plate material, the mass content of O includes but is not limited to 0.1%, 0.11%, 0.12%, 0.13%, 0.14% or 0.15%, etc.

[0063] In some embodiments, the total mass content of Fe and Cr in the nuclear-grade zirconium and zirconium alloy plate is 0.28-0.37%.

[0064] Exemplarily, the total mass content of Fe and Cr in the nuclear-grade zirconium and zirconium alloy plate includes but is not limited to 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35% or 0.36%, etc.

[0065] As a preferred example, the first plate material and the second plate material have the same material composition.

[0066] In some embodiments, the thickness of the first plate and the second plate are both 1.0-3.0 mm, including but not limited to 1.0 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm, etc. The thickness of the first plate and the second plate is within the above range, which can ensure that the heat input in the welding area is moderate, thereby effectively controlling the morphology and quality of the weld, reducing the generation of welding defects such as pores and cracks, and ensuring the toughness and ductility of the material under the premise of meeting the strength requirements; if it is less than 1.0 mm, the strength of the plate may be insufficient, and it is easy to cause penetration, deformation or substandard weld strength during the welding process, resulting in a decrease in mechanical properties after welding; if it is greater than 3 mm, the heat input during the welding process will increase significantly, which is easy to cause overheating in the weld area, resulting in increased welding stress and even large deformation. Thicker plates require longer welding time and larger welding current input, that is, when the thickness is greater than 3 mm, the single-sided welding using this formula cannot achieve penetration.

[0067] As a preferred example, the difference in thickness between the first plate and the second plate is within ±10%, including but not limited to -10%, -5%, 0, 5% or 10%, etc. When the difference in thickness between the first plate and the second plate is 0, the thicknesses of the first plate and the second plate are the same.

[0068] In some embodiments, the welding current of the tungsten inert gas arc welding, the average thickness of the first plate and the second plate, and the welding speed satisfy:

[0069]

[0070] Wherein, I is the welding current, in A; H is the average thickness of the first plate and the second plate, in mm; V is the welding speed, in mm / min; P is a constant, -10≤P≤10.

[0071] For example, the value of P includes but is not limited to -10, -7, -5, -3, 0, 3, 5, 8 or 10, etc.

[0072] When P is 0, it means that the welding current is Equal, at this time can be Calculate the welding current, that is:

[0073]

[0074] The welding current at this time can be regarded as the standard welding current. When the welding current is the standard welding current, the quality of the weld formed by the tungsten inert gas arc welding in the embodiment of the present application is the best.

[0075] Based on this, it can be considered that when P takes a value other than 0, the welding current of this application can fluctuate within 10A relative to the standard welding current calculated when P is 0, which can meet the requirements of this application and achieve the technical effect of this application. The only difference is that the quality of the weld formed is slightly reduced compared to when the welding current is the standard welding current.

[0076] In the embodiment of the present application, when the thickness of the first plate and the second plate are the same, the welding current, the thickness of the first plate or the second plate, and the welding speed satisfy the relationship defined by the above formula, and the nuclear and zirconium alloy coils with excellent weld quality can be produced, reducing or avoiding the broken strip caused by poor weld quality during the rolling process of the welded coil. If the welding current, the thickness of the first plate or the second plate, and the welding speed do not satisfy the relationship defined by the above formula, the weld quality obtained by welding is poor, and the broken strip may be caused during the rolling process of the welded coil. Specifically, if the formula is not satisfied, the following weld quality problems will be caused: welding produces large thermal stress and thermal deformation, affecting the accuracy and size after welding; the heat input and thermal stress in welding are difficult to control evenly, which is easy to cause penetration in the weld (the heat input during welding is difficult to control, which is easy to cause penetration, causing excessive penetration of the weld, resulting in deformation of the joint or too thin weld area, reducing the welding strength), pores (due to the large heat input, the molten pool may cool unevenly, and pores are easy to form, especially when the welding speed is fast, the gas in the molten pool will be wrapped in the weld before it can escape, etc.), thereby affecting the overall mechanical properties.

[0077] In some embodiments, the welding speed of the tungsten inert gas arc welding is 200-400mm / min, including but not limited to 200mm / min, 250mm / min, 300mm / min, 350mm / min or 400mm / min. In the embodiment of the present application, the welding speed is within the above range, the heat input is moderate, the penetration depth and the size of the formed weld are appropriate, the shape is neat, and the weld quality is good. When the welding speed is lower than 200mm / min, the weld will be too high or too wide, the shape is not neat, and the speed is too slow, which will cause the heat input to be too high, resulting in the material burning through the weld joint. When the welding speed is higher than 400mm / min, the weld penetration depth is reduced, which is easy to cause the phenomenon of incomplete penetration or incomplete fusion, reduce the reliability of the weld, and cause the weld quality to decline.

[0078] In some embodiments, the welding voltage of the tungsten inert gas welding is 8-12V, including but not limited to 8V, 8.5V, 9V, 9.2V, 9.5V, 9.7V, 10V, 10.5V, 11V, 11.5V or 12V, etc.

[0079] As a preferred example, the welding voltage of the tungsten inert gas arc welding is 9-10V.

[0080] In the embodiments of the present application, the functions of the tungsten electrode in tungsten inert gas arc welding are as follows: 1) Conducting current, responsible for conducting the welding current from the power source to the welding area, generating an arc and the basis for welding. 2) Ignition of the arc, at the beginning of welding, the high voltage difference between the tungsten electrode and the workpiece ignites the arc, and the high temperature of the arc melts and connects the welding materials together. 3) Maintaining the normal burning of the arc, during the welding process, the high temperature and high strength characteristics of the tungsten electrode enable the arc to burn stably.

[0081] In some embodiments, the diameter of the tungsten electrode used in the tungsten inert gas arc welding is a mm, the thickness of the first plate and the second plate are both b mm, and a and b satisfy:

[0082] When 1.0≤b﹤1.8, a is 1.6; and / or,

[0083] When 1.8≤b≤3.0, a is 2.0.

[0084] For example, when a is 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6 or 1.7, etc., b is 1.6.

[0085] For example, when a is 1.8, 1.9, 2.1, 2.3, 2.5, 2.7, 2.9 or 3.0, etc., b is 2.0.

[0086] In the embodiment of the present application, the main reasons for selecting tungsten electrodes of different diameters for the first plate and the second plate of different plate thicknesses are as follows: 1) Arc stability: For thicker plates, a larger welding current and a more stable arc are required to maintain sufficient melting depth and width. A tungsten electrode with a thicker diameter can provide good arc stability and carry a larger current; for thinner plates, using a tungsten electrode with a smaller diameter can reduce heat input and avoid burning through the plate. 2) Welding quality: Too large or too small a diameter may cause defects in the weld, such as lack of fusion, slag inclusions, pores, etc.

[0087] In some embodiments, during the tungsten inert gas welding process, a welding torch shielding gas is provided in the welding area for protecting the welding torch nozzle, the tungsten electrode and the molten pool.

[0088] In some embodiments, during the tungsten inert gas welding process, a back area of ​​the weld formed by the welding is provided with a back shielding gas for protecting the back of the weld from contamination.

[0089] In some embodiments, during the tungsten inert gas welding process, a hood shielding gas is provided on the weld to protect the weld.

[0090] In some embodiments, the drag hood protective gas is filled in the drag hood, and the drag hood is arranged on the weld and can move along the welding direction with the welding gun.

[0091] In the embodiments of the present application, the structure of the drag hood is not limited and can be any drag hood used for welding, but the drag hood disclosed in the paper "Improvement and Application of Inert Gas Protection Device for Zirconium Alloy Plate Welding" (authors are Hu Xukun, Ma Anguo, Zhang Pengfei and Xu Bin) published by the applicant in the journal "Metal World" No. 4, 2019, pages 64-71 is preferred.

[0092] In some embodiments, the welding torch shielding gas, the back shielding gas and the drag hood shielding gas are all argon gas with a purity of more than 99.99% by volume.

[0093] Exemplarily, the purity of the above argon gas is above 99.992% by volume, above 99.995% by volume, above 99.998% by volume, above 99.999% by volume, or above 99.9995% by volume.

[0094] In the embodiments of the present application, the flow rate of shielding gas (torch shielding gas, back shielding gas and hood shielding gas) is theoretically an adjustable parameter within a certain range. In the actual welding process, the welder should comprehensively consider and select the most appropriate gas flow rate according to the welding environment, etc. According to the actual operation of the applicant, 8L / min is selected. The actual value greater than this value can ensure that the welding quality requirements are met.

[0095] As a preferred example, the flow rates of the welding gun shielding gas, the back shielding gas and the drag hood shielding gas are all 8-15 L / min, including but not limited to 8 L / min, 10 L / min, 12 L / min, 14 L / min or 15 L / min, etc.

[0096] In the embodiments of the present application, the welding gun shielding gas, the back shielding gas and the drag hood shielding gas together constitute an important barrier to ensure welding quality during the welding process.

[0097] In some embodiments, the nuclear-grade zirconium and zirconium alloy plate welding method further includes the step of shearing the first end face and the second end face smooth before the assembling.

[0098] In some embodiments, the first end surface is disposed perpendicularly to a placement plane of the first plate.

[0099] In some embodiments, the second end surface is disposed perpendicularly to a placement plane of the second plate.

[0100] In some embodiments, the first plate and the second plate are placed on the same plane.

[0101] In some embodiments, the first end surface and the second end surface are in close contact.

[0102] In the embodiment of the present application, during the tungsten inert gas arc welding process, a V-shaped groove is not provided but a 90-degree close end face connection is adopted, mainly to simplify the welding steps, ensure the welding quality, and reduce the generation of deformation and residual stress. Specifically:

[0103] 1. The butt joint method with two 90-degree end faces close together can ensure the strength and sealing of the weld. This butt joint method is easy to control the arc and molten pool during welding due to the flat end faces, thus obtaining a weld with stable quality.

[0104] 2. Setting a V-shaped groove will produce a larger weld area, which usually causes a larger heat input, resulting in weld deformation or increased welding residual stress. Choosing a 90-degree end-face close-fitting butt joint has relatively small heat input, which can effectively reduce the deformation and stress generated during welding, thereby improving the quality and structural stability of the weldment.

[0105] 3. When the 90-degree end faces are butted, the gap in the weld area is small, and there is no need to use a large amount of filler welding materials like in V-shaped grooves. This not only simplifies the welding operation, but also reduces the cost of welding materials.

[0106] In some embodiments, the nuclear grade zirconium and zirconium alloy plate welding method further includes the step of cleaning the first plate and the second plate before the assembling.

[0107] The purpose of cleaning is to remove impurities such as scale, oil stains, etc. on the surface of the plate. At the same time, when there is a step of shearing the first end face and the second end face to make them smooth, the cleaning step is before the shearing step. It should be noted that in the welding method of the present application, the first plate and the second plate can be directly made of cleaned plates.

[0108] The nuclear-grade zirconium and zirconium alloy plate welding method of the embodiment of the present application can at least bring the following beneficial effects:

[0109] 1. By adopting the tungsten inert gas arc self-melting welding process technology, by limiting the relationship between welding current, plate thickness and welding speed, nuclear and zirconium alloy coils with excellent weld quality can be produced, reducing or avoiding the breakage caused by poor weld quality during the rolling process of the welding coil (that is, the nuclear-grade zirconium and zirconium alloy plate welding method of this application is not prone to breakage after cold rolling).

[0110] 2. The process parameters are highly controllable and easy to apply to industrial production.

[0111] 3. The plate thickness range is wide and it can be used to weld all nuclear-grade zirconium alloy plates into coils.

[0112] <Roll>

[0113] The coiled material of the embodiment of the present application is prepared by the nuclear-grade zirconium and zirconium alloy plate welding method described in the present application.

[0114] <Strip>

[0115] The strip material of the embodiment of the present application is formed by cold rolling the coil material of the embodiment of the present application.

[0116] In some embodiments, the method for preparing the strip comprises: subjecting the strip to a first cold rolling, followed by continuous annealing, and then a second cold rolling.

[0117] In the embodiments of the present application, the thickness of the zirconium alloy is reduced and the strength, hardness and surface finish are improved by a cold rolling process; the zirconium alloy usually adopts a higher rolling ratio, generally a total deformation of 50%-90%, and is rolled multiple times in steps, with each deformation controlled at about 20%-30%.

[0118] Continuous annealing eliminates the work hardening of zirconium alloy materials produced during the cold rolling process, restores the plasticity and toughness of the material, and at the same time refines the grains and improves the uniformity and corrosion resistance of the material.

[0119] Annealing temperature: The annealing temperature of zirconium alloy is generally between 550℃-650℃, and the specific temperature depends on the specific composition and requirements of the material. The annealing time depends on the annealing temperature and the thickness of the material, and is usually kept between 0.5-2h to ensure sufficient recrystallization and stress relief of the material. Continuous annealing also needs to consider the strip running rate. For materials of different thicknesses, the running rate must also be adapted. Thicker strips require slower running speeds to ensure that the core temperature of the material can fully meet the annealing requirements; while thinner strips can increase the running rate. The specific rate is adjusted according to material thickness, annealing temperature, product requirements and equipment characteristics.

[0120] The coils and strips of the embodiments of the present application have at least the beneficial effects of the nuclear-grade zirconium and zirconium alloy plate welding method of the embodiments of the present application.

[0121] Certain features of the present technology are further illustrated in the following non-limiting examples.

[0122] The nuclear-grade zirconium and zirconium alloy plates involved in the following embodiments and comparative examples are all plates that have been cleaned to remove impurities such as oxide scales, and their compositions are the same, as shown in Table 1.

[0123] Table 1 Composition of nuclear grade zirconium and zirconium alloy plates

[0124]

[0125] In the following embodiments and comparative examples, for the same embodiment or comparative example, the specifications (length, width and thickness) of the two nuclear-grade zirconium and zirconium alloy plates are the same.

[0126] In the following embodiments, the welding current of tungsten inert gas arc welding, the average thickness of the first plate and the second plate (that is, the average thickness of the two nuclear-grade zirconium and zirconium alloy plates) and the welding speed all meet the following requirements:

[0127]

[0128] Wherein, I is the welding current, unit A; H is the average thickness of the first plate and the second plate (that is, the average thickness of the two nuclear-grade zirconium and zirconium alloy plates), unit mm; V is the welding speed, unit mm / min; P is a constant, wherein the value of P in Examples 1-7 is 0, the value of P in Example 8 is -10, and the value of P in Example 9 is 10.

[0129] Example 1

[0130] The nuclear grade zirconium and zirconium alloy plate welding method of this embodiment comprises the following steps:

[0131] (1) Two nuclear-grade zirconium and zirconium alloy plates with a thickness of 2.0 mm are cut and smoothed at the end, and then assembled. The two nuclear-grade zirconium and zirconium alloy plates are placed horizontally; the two end surfaces after shearing are set perpendicular to the horizontal plane, and the two are tightly attached after assembly.

[0132] (2) A fixing device (e.g., a clamp) is used to fix the ends of two nuclear-grade zirconium and zirconium alloy plates, and tungsten inert gas arc welding is performed to form a weld to obtain a 2.0 mm nuclear-grade zirconium alloy strip coil.

[0133] During the tungsten inert gas welding process: the tungsten electrode is selected with a diameter of 2.0mm, the voltage is 10V, the welding speed is 400mm / min, and the current is 150A; the welding area is provided with a welding torch shielding gas, the back area of ​​the weld is provided with a back shielding gas, and the weld is provided with a drag shielding gas, which is filled in the drag shield, and the drag shield is provided on the weld and can move along the welding direction with the welding torch. The welding torch shielding gas, back shielding gas and drag shielding gas all use argon gas with a purity of 99.999% (volume fraction), and the flow rates of the welding torch shielding gas, back shielding gas and drag shielding gas are all 8L / min.

[0134] The surface quality of the weld formed in this embodiment is as follows Figure 1 As shown, from Figure 1 It can be seen that there are no pores and cracks on the weld surface, and there are no unfused parts, indicating that the weld quality is excellent.

[0135] The metallographic structure diagram of the weld formed in this embodiment is as follows: Figure 2-3 shown. Figure 2 and Figure 3 In the metallographic structure diagram, the coarse small square-shaped flakes are martensite structures, and the very fine small particles on the left are equiaxed grains, indicating that the weld quality is good.

[0136] The 2.0 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 2.0 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0137] The subsequent strip cold rolling is continuous cold rolling. Specifically, the rolling is performed in three steps, and the deformation is controlled at 20% each time. The annealing temperature is 600° C. and the annealing time is 1 hour.

[0138] Example 2

[0139] The nuclear grade zirconium and zirconium alloy plate welding method of this embodiment comprises the following steps:

[0140] (1) Two nuclear-grade zirconium and zirconium alloy plates with a thickness of 3.0 mm are cut and smoothed at the end, and then assembled. The two nuclear-grade zirconium and zirconium alloy plates are placed horizontally; the two end faces after cutting are set perpendicular to the horizontal plane, and the two are tightly attached after assembly.

[0141] (2) A fixing device (e.g., a clamp) is used to fix the ends of two nuclear-grade zirconium and zirconium alloy plates, and tungsten inert gas arc welding is performed to form a weld to obtain a 3.0 mm nuclear-grade zirconium alloy strip coil.

[0142] During the tungsten inert gas welding process: the tungsten electrode is selected with a diameter of 2.0mm, the voltage is 9V, the welding speed is 200mm / min, and the current is 205A; the welding area is provided with a welding torch shielding gas, the back area of ​​the weld is provided with a back shielding gas, and the weld is provided with a drag shielding gas, which is filled in the drag shield, and the drag shield is provided on the weld and can move along the welding direction with the welding torch. The welding torch shielding gas, back shielding gas and drag shielding gas all use argon gas with a purity of 99.999% (volume fraction), and the flow rates of the welding torch shielding gas, back shielding gas and drag shielding gas are all 8L / min.

[0143] The 3.0 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 3.0 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0144] The subsequent strip cold rolling is continuous cold rolling. Specifically, three rolling steps are performed, and the deformation is controlled at 24.4% each time. The annealing temperature is 600° C., and the annealing time is 1 hour.

[0145] Example 3

[0146] The nuclear grade zirconium and zirconium alloy plate welding method of this embodiment comprises the following steps:

[0147] (1) Two nuclear-grade zirconium and zirconium alloy plates with a thickness of 1.0 mm are cut and smoothed at the end, and then assembled. The two nuclear-grade zirconium and zirconium alloy plates are placed horizontally; the two end faces after shearing are set perpendicular to the horizontal plane, and the two are tightly attached after assembly.

[0148] (2) A fixing device (e.g., a clamp) is used to fix the ends of two nuclear-grade zirconium and zirconium alloy plates, and tungsten inert gas arc welding is performed to form a weld to obtain a 1.0 mm nuclear-grade zirconium alloy strip coil.

[0149] During the tungsten inert gas welding process: the tungsten electrode is selected with a diameter of 1.6mm, the voltage is 10V, the welding speed is 400mm / min, and the current is 75A; the welding area is provided with a welding torch shielding gas, the back area of ​​the weld is provided with a back shielding gas, and the weld is provided with a drag shielding gas, which is filled in the drag shield, and the drag shield is provided on the weld and can move along the welding direction with the welding torch. The welding torch shielding gas, back shielding gas and drag shielding gas all use argon gas with a purity of 99.999% (volume fraction), and the flow rates of the welding torch shielding gas, back shielding gas and drag shielding gas are all 8L / min.

[0150] The 1.0 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 1.0 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0151] The subsequent strip cold rolling is performed once, and the deformation is controlled at 20%; the annealing temperature is 600° C., and the annealing time is 1 h.

[0152] Example 4

[0153] The nuclear grade zirconium and zirconium alloy plate welding method of this embodiment comprises the following steps:

[0154] (1) Two nuclear-grade zirconium and zirconium alloy plates with a thickness of 2.0 mm are cut and smoothed at the end, and then assembled. The two nuclear-grade zirconium and zirconium alloy plates are placed horizontally; the two end faces after shearing are set perpendicular to the horizontal plane, and the two are tightly attached after assembly.

[0155] (2) A fixing device (e.g., a clamp) is used to fix the ends of two nuclear-grade zirconium and zirconium alloy plates, and tungsten inert gas arc welding is performed to form a weld to obtain a 2.0 mm nuclear-grade zirconium alloy strip coil.

[0156] During the tungsten inert gas welding process: the tungsten electrode is selected to have a diameter of 2.0mm, the voltage is 9.5V, the welding speed is 300mm / min, and the current is 140A; the welding area is provided with a welding torch shielding gas, the back area of ​​the weld is provided with a back shielding gas, and the weld is provided with a drag shielding gas, which is filled in the drag shield, and the drag shield is provided on the weld and can move along the welding direction with the welding torch. The welding torch shielding gas, the back shielding gas, and the drag shielding gas all use argon gas with a purity of 99.999% (volume fraction), and the flow rates of the welding torch shielding gas, the back shielding gas, and the drag shielding gas are all 8L / min.

[0157] The 2.0 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 2.0 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0158] The subsequent strip cold rolling is continuous cold rolling. Specifically, the rolling is performed in three steps, and the deformation is controlled at 20% each time. The annealing temperature is 600° C. and the annealing time is 1 hour.

[0159] Example 5

[0160] The nuclear grade zirconium and zirconium alloy plate welding method of this embodiment comprises the following steps:

[0161] (1) Two nuclear-grade zirconium and zirconium alloy plates with a thickness of 2.2 mm are cut and smoothed at the end, and then assembled. The two nuclear-grade zirconium and zirconium alloy plates are placed horizontally; the two end faces after cutting are set perpendicular to the horizontal plane, and the two are tightly attached after assembly.

[0162] (2) A fixing device (e.g., a clamp) is used to fix the ends of two nuclear-grade zirconium and zirconium alloy plates, and tungsten inert gas arc welding is performed to form a weld to obtain a 2.2 mm nuclear-grade zirconium alloy strip coil.

[0163] During the tungsten inert gas welding process: the tungsten electrode is selected with a diameter of 2.0mm, the voltage is 10V, the welding speed is 200mm / min, and the current is 145A; the welding area is provided with a welding torch shielding gas, the back area of ​​the weld is provided with a back shielding gas, and the weld is provided with a drag shielding gas, which is filled in the drag shield, and the drag shield is provided on the weld and can move along the welding direction with the welding torch. The welding torch shielding gas, back shielding gas and drag shielding gas all use argon gas with a purity of 99.999% (volume fraction), and the flow rates of the welding torch shielding gas, back shielding gas and drag shielding gas are all 8L / min.

[0164] The 2.2 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 2.2 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0165] The subsequent strip cold rolling is continuous cold rolling. Specifically, three rolling steps are performed, and the deformation is controlled at 21.2% each time. The annealing temperature is 600° C., and the annealing time is 1 hour.

[0166] Example 6

[0167] The nuclear grade zirconium and zirconium alloy plate welding method of this embodiment comprises the following steps:

[0168] (1) Two nuclear-grade zirconium and zirconium alloy plates with a thickness of 1.2 mm are cut and smoothed at the end, and then assembled. The two nuclear-grade zirconium and zirconium alloy plates are placed horizontally; the two end faces after cutting are set perpendicular to the horizontal plane, and the two are tightly attached after assembly.

[0169] (2) A fixing device (e.g., a clamp) is used to fix the ends of two nuclear-grade zirconium and zirconium alloy plates, and tungsten inert gas arc welding is performed to form a weld to obtain a 1.2 mm nuclear-grade zirconium alloy strip coil.

[0170] During the tungsten inert gas welding process: the tungsten electrode is selected to have a diameter of 1.6mm, the voltage is 9.6V, the welding speed is 360mm / min, and the current is 86A; the welding area is provided with a welding torch shielding gas, the back area of ​​the weld is provided with a back shielding gas, and the weld is provided with a drag shielding gas, which is filled in the drag shield, and the drag shield is provided on the weld and can move along the welding direction with the welding torch. The welding torch shielding gas, back shielding gas and drag shielding gas all use argon gas with a purity of 99.999% (volume fraction), and the flow rates of the welding torch shielding gas, back shielding gas and drag shielding gas are all 8L / min.

[0171] The 2.2 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 2.2 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0172] The subsequent strip cold rolling is continuous cold rolling. Specifically, three rolling steps are performed, and the deformation is controlled at 21.2% each time. The annealing temperature is 600° C., and the annealing time is 1 hour.

[0173] Example 7 (Argon gas flow rate greater than 8 L / min)

[0174] This embodiment is basically the same as Embodiment 1, except that:

[0175] The flow rates of the welding gun shielding gas, back shielding gas and drag hood shielding gas are all 20L / min.

[0176] The 2 mm nuclear-grade zirconium alloy coil prepared in this embodiment was subsequently cold-rolled from 2 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0177] The subsequent strip cold rolling is continuous cold rolling. Specifically, the rolling is performed in three steps, and the deformation is controlled at 20% each time. The annealing temperature is 600° C. and the annealing time is 1 hour.

[0178] Example 8 (P = -10)

[0179] This embodiment is basically the same as Embodiment 1, except that:

[0180] formula The P value is -10 and the welding current is 140A.

[0181] The 2 mm nuclear grade zirconium alloy coil prepared in this embodiment was subsequently cold rolled from 2 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0182] The subsequent strip cold rolling is continuous cold rolling. Specifically, the rolling is performed in three steps, and the deformation is controlled at 20% each time. The annealing temperature is 600° C. and the annealing time is 1 hour.

[0183] Example 9 (P=10)

[0184] This embodiment is basically the same as Embodiment 1, except that:

[0185] formula The P value is 10 and the welding current is 160A.

[0186] The 2 mm nuclear-grade zirconium alloy coil prepared in this embodiment was subsequently cold-rolled from 2 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. No strip breakage occurred during the rolling process.

[0187] The subsequent strip cold rolling is continuous cold rolling. Specifically, the rolling is performed in three steps, and the deformation is controlled at 20% each time. The annealing temperature is 600° C. and the annealing time is 1 hour.

[0188] Comparative Example 1 (welding current, plate thickness and welding speed do not satisfy the formula of this application, P is lower than the lower limit)

[0189] This comparative example is basically the same as Example 1, except that:

[0190] formula The P value is -15, the welding current is 55A, and the thickness of the two nuclear-grade zirconium and zirconium alloy plates is 1.2mm.

[0191] The 1.2 mm nuclear-grade zirconium alloy coil prepared in this comparative example was subsequently cold-rolled from 1.2 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. Strip breakage occurred during the rolling process.

[0192] The annealing temperature is 600°C and the annealing time is 1h.

[0193] The surface quality of the front and back surfaces of the weld formed in this comparative example is as follows Figure 4 and Figure 5 As shown. Figure 4 and Figure 5It can be seen that when the thickness of the two nuclear-grade zirconium alloy plates is 1.2 mm, the selected welding current is 75 A, which is too small and does not meet the specified relationship between the welding current of this application, the average thickness of the two nuclear-grade zirconium and zirconium alloy plates and the welding speed, resulting in incomplete penetration of the weld.

[0194] Comparative Example 2 (welding current, plate thickness and welding speed do not satisfy the formula of this application, P is higher than the upper limit)

[0195] This comparative example is basically the same as Example 1, except that:

[0196] formula The P value is 12.5, the welding current is 170A, and the thickness of the two nuclear-grade zirconium and zirconium alloy plates is 2.1mm.

[0197] The 2.1 mm nuclear-grade zirconium alloy coil prepared in this comparative example was subsequently cold-rolled from 2.1 mm to 0.8 mm and then continuously annealed and then rolled to 0.40 mm. Strip breakage occurred during the rolling process.

[0198] The subsequent strip cold rolling is continuous cold rolling. Specifically, three rolling steps are performed, and the deformation is controlled at 20.6% each time. The annealing temperature is 600° C., and the annealing time is 1 hour.

[0199] The quality of the weld formed in this comparative example is as follows Figure 6 As shown. Figure 6 It can be seen that when the thickness of the two nuclear-grade zirconium alloy plates is 2.1 mm, the selected welding current is 170 A. The welding current is too large and does not meet the specified relationship between the welding current, the average thickness of the two nuclear-grade zirconium and zirconium alloy plates and the welding speed in this application, resulting in a weld penetration.

[0200] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean 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 described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0201] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0202] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for welding nuclear grade zirconium and zirconium alloy plates, characterized in that: include: After assembling and fixing the first end face of the first plate and the second end face of the second plate, tungsten inert gas arc welding is performed; The first plate and the second plate are both nuclear grade zirconium and zirconium alloy plates, and the difference in thickness between the first plate and the second plate is within ±10%; The welding current of the tungsten inert gas arc welding, the average thickness of the first plate and the second plate, and the welding speed satisfy the following requirements: Wherein, I is the welding current, in A; H is the average thickness of the first plate and the second plate, in mm; V is the welding speed, in mm / min; P is a constant, -10≤P≤10.

2. The welding method according to claim 1, characterized in that: The thickness of the first plate and the second plate are both 1.0-3.0 mm.

3. The welding method according to claim 1, characterized in that: The welding speed of the tungsten inert gas arc welding is 200-400 mm / min.

4. The welding method according to claim 1, characterized in that: The welding voltage of the tungsten inert gas arc welding is 8-12V, preferably 9-10V.

5. The welding method according to claim 1, characterized in that: The diameter of the tungsten electrode used in the tungsten inert gas arc welding is a mm, the thickness of the first plate and the second plate are both b mm, and a and b satisfy: When 1.0≤b﹤1.8, a is 1.6; and / or, When 1.8≤b≤3.0, a is 2.

0.

6. The welding method according to claim 1, characterized in that: During the tungsten inert gas welding process, the welding area is provided with a welding gun shielding gas for protecting the welding gun nozzle, the tungsten electrode and the molten pool, and / or the back area of ​​the weld formed by the welding is provided with a back shielding gas for protecting the back of the weld from contamination, and / or the weld is provided with a drag hood shielding gas for protecting the weld.

7. The welding method according to claim 6, characterized in that: The welding gun shielding gas, the back shielding gas and the hood shielding gas are all argon gas with a purity of more than 99.99% by volume; and / or, The drag hood is filled with protective gas, and the drag hood is arranged on the weld and can move along the welding direction with the welding gun; and / or, The flow rates of the welding gun shielding gas, the back shielding gas and the drag hood shielding gas are all 8-15 L / min.

8. The welding method according to any one of claims 1 to 7, characterized in that: The nuclear-grade zirconium and zirconium alloy plate comprises the following components in mass percentage: Sn 1.20-1.70%, Fe 0.18-0.24%, Cr 0.07-0.13%, O 0.09-0.16%, and the balance is Zr; the total mass content of Fe and Cr in the nuclear-grade zirconium and zirconium alloy plate is 0.28-0.37%; and / or, The nuclear-grade zirconium and zirconium alloy plate welding method further comprises the step of shearing the first end face and the second end face smooth before the assembling; and / or, The first end surface is arranged perpendicularly to the placement plane of the first plate; and / or, the second end surface is arranged perpendicularly to the placement plane of the second plate; and / or, the first plate and the second plate are placed on the same plane; and / or, the first end surface and the second end surface are in close contact; and / or, The nuclear-grade zirconium and zirconium alloy plate welding method further comprises the step of cleaning the first plate and the second plate before the assembling.

9. A coiled material, characterized in that: The welding method is used to prepare the product.

10. A strip material, characterized in that: The coil is cold rolled as claimed in claim 9.

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