Method for welding zirconium alloy through combination of thermal hydrogen treatment and vacuum thermal compression

Abstract

The invention discloses a method for welding zirconium alloy through combination of thermal hydrogen treatment and vacuum thermal compression, and belongs to the technical field of materials and welding. The problem that the zirconium alloy is prone to plastic attenuation in the fusion welding and high-temperature diffusion bonding processes is solved. According to the method, the to-be-welded zirconium alloy element is firstly subjected to thermal hydrogen treatment, hydrogen can reduce the phase transition temperature of the zirconium alloy, then the zirconium alloy is subjected to vacuum hot pressing in the diffusion bonding process, large-scale recrystallization and recrystallization occur in the zirconium alloy under the combined action of temperature and pressure, and crystal grains are refined to a certain extent. And meanwhile, the zirconium alloy subjected to thermal hydrogen treatment can release a large amount of hydrogen, and hydrogen embrittlement of the zirconium alloy is avoided. The vacuum hot pressing process also enables the zirconium alloy to generate work hardening so as to further improve the strength of the zirconium alloy. The welding rate of a zirconium alloy element connector obtained through welding reaches 100%, the shear strength of the connector can reach 450 MPa or above, and the shear elongation reaches 29%.

Description

Technical Field

[0001] The invention belongs to the technical field of materials and welding, and particularly relates to a method for welding zirconium alloys by combining hot hydrogen treatment with vacuum hot pressing. Background Art

[0002] In nuclear engineering, fuel elements are the core components of nuclear reactors. They primarily consist of a fuel core and a cladding. The fuel core must be sealed within the cladding to prevent fission products from contaminating the reactor coolant and to effectively dissipate heat. During operation, the cladding is subjected to high temperatures, high pressures, and intense neutron radiation. In particular, the inner cladding wall is subject to the pressure of fission gases and the expansion of the core, while the outer cladding wall is threatened by coolant pressure and vibration. Therefore, the quality of the welds between the cladding and the cladding directly impacts the performance of new fuel elements and determines the safe, stable, and reliable operation of the nuclear reactor. Zirconium alloy, with its low thermal neutron absorption cross-section, good corrosion resistance, and moderate mechanical properties, is currently the only cladding material used in water-cooled nuclear reactors.

[0003] Currently, the majority of zirconium alloy heat treatments are rolled annealed, resulting in mechanical properties characterized by consistent strength and relatively good ductility. However, conventional processing methods for components such as zirconium alloy fuel cladding typically involve fusion welding, such as vacuum electron beam welding, gas tungsten arc welding, pulsed laser welding, and pressure resistance welding. The significant heat input from these processes significantly degrades both the local and overall properties of the zirconium alloy, particularly its ductility. Even with the more suitable vacuum diffusion bonding technique, the existing bonding temperatures and pressures are extremely high, and zirconium alloys can become significantly brittle under these conditions.

[0004] In the field of zirconium alloy applications, good plasticity is an essential characteristic that makes it stand out. At the same time, how to heat-process it to produce application components without affecting its good plasticity is also a key difficulty. Summary of the Invention

[0005] In order to solve the problem that zirconium alloys are prone to plastic attenuation during high-temperature diffusion bonding, the present invention proposes a method for welding zirconium alloys by combining thermal hydrogen treatment with vacuum hot pressing.

[0006] The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy of the present invention is carried out according to the following steps:

[0007] Step 1: Grind and clean the zirconium alloy components to be welded;

[0008] Step 2: Place the zirconium alloy components to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace, evacuate the furnace at room temperature, and wait until the vacuum degree in the furnace is lower than 5×10 -3Pa, start heating; first heat to 680~720℃ at a rate of 5~10℃ / min, then fill the furnace with hydrogen, and wait until the hydrogen pressure in the furnace is higher than 1×10 5 After reaching Pa, the holding time is started, and the holding time is 45 to 90 minutes. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0009] Step 3: Grind and clean the surface to be welded of the zirconium hydride alloy component to be welded;

[0010] Step 4: stack and assemble the surfaces of the zirconium hydride alloy components to be welded after the treatment in step 3 to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating to 400~450℃ at a rate of 5~10℃ / min, and apply a pressure of 25~30MPa to the workpiece to be welded; then heat to 680~700℃ at a rate of 5~10℃ / min and keep warm for 30~45min; finally turn off the heating furnace and take out the weldment after it cools to room temperature.

[0011] The principles and beneficial effects of the present invention are:

[0012] 1. The present invention first subjects the zirconium alloy components to be welded to a thermal hydrogen treatment, which lowers the zirconium alloy's phase transition temperature. Subsequently, during the diffusion bonding process, the zirconium alloy is vacuum hot-pressed. Under the combined effects of temperature and pressure, large-scale recrystallization and recrystallization occur within the zirconium alloy, resulting in a certain degree of grain refinement. Simultaneously, the hydrogen-treated zirconium alloy releases a significant amount of hydrogen, preventing hydrogen embrittlement. The vacuum hot-pressing process also causes the zirconium alloy to undergo work hardening, further enhancing its strength.

[0013] 2. The method of combining thermal hydrogen treatment with vacuum hot pressing welding of high-strength zirconium alloys of the present invention utilizes hydrogen to lower the phase transition temperature. Under the combined action of temperature and pressure, large-scale recrystallization and recrystallization occur inside the zirconium alloy. During the recrystallization process, a large amount of dislocations slip inside the alloy, and the principle of accelerated inter-atomic diffusion is used to achieve complete welding under this process. The welding rate of the welded zirconium alloy component joints reaches 100%. The welding rate of the same commonly used rolled annealed zirconium alloy joints under the same process is less than 5%, and the joint welding rate is greatly improved.

[0014] 3. The shear strength of the zirconium alloy component joint obtained by combining the thermal hydrogen treatment with vacuum hot pressing welding of high-strength zirconium alloys in the present invention can reach above 450 MPa, and the shear elongation can reach 29%.

[0015] 4. The method of the present invention of thermal hydrogen treatment combined with vacuum hot pressing welding of high-strength zirconium alloy is used in hot processing scenarios such as forging and welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an image of the grain distribution state of the Zr-4 alloy diffusion bonded joint obtained in Example 1;

[0017] Figure 2 This is the interface welding rate image of the Zr-4 alloy diffusion bonded joint obtained in Example 1;

[0018] Figure 3 is the shear curve of the Zr-4 alloy diffusion welded joint; Figure 4 This is an image of the welding rate of the existing Zr-4 alloy diffusion welding joint. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0020] Specific embodiment 1: The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy in this embodiment is carried out according to the following steps:

[0021] Step 1: Grind and clean the zirconium alloy components to be welded;

[0022] Step 2: Place the zirconium alloy components to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace, evacuate the furnace at room temperature, and wait until the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating; first heat to 680~720℃ at a rate of 5~10℃ / min, then fill the furnace with hydrogen, and wait until the hydrogen pressure in the furnace is higher than 1×10 5 After reaching Pa, the holding time is started, and the holding time is 45 to 90 minutes. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0023] Step 3: Grind and clean the surface to be welded of the zirconium hydride alloy component to be welded;

[0024] Step 4: stack and assemble the surfaces of the zirconium hydride alloy components to be welded after the treatment in step 3 to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3Pa, start heating to 400~450℃ at a rate of 5~10℃ / min, and apply a pressure of 25~30MPa to the workpiece to be welded; then heat to 680~700℃ at a rate of 5~10℃ / min and keep warm for 30~45min; finally turn off the heating furnace and take out the weldment after it cools to room temperature.

[0025] This embodiment has the following beneficial effects:

[0026] 1. This embodiment first performs a thermal hydrogen treatment on the zirconium alloy components to be welded. Hydrogen can lower the phase transition temperature of the zirconium alloy. Then, during the diffusion bonding process, the zirconium alloy is vacuum hot pressed. Under the combined effects of temperature and pressure, large-scale recrystallization and recrystallization occur within the zirconium alloy, resulting in a certain degree of grain refinement. Simultaneously, the hydrogen-treated zirconium alloy releases a large amount of hydrogen, preventing hydrogen embrittlement. The vacuum hot pressing process also causes work hardening of the zirconium alloy, further enhancing its strength.

[0027] 2. In this embodiment, a method of combining thermal hydrogen treatment with vacuum hot-pressing welding of high-strength zirconium alloys utilizes hydrogen to lower the phase transition temperature. Under the combined action of temperature and pressure, large-scale recrystallization and recrystallization occur inside the zirconium alloy. During the recrystallization process, a large amount of dislocations slip inside the alloy, and the principle of accelerated inter-atomic diffusion is used to achieve complete welding under this process. The welding rate of the welded zirconium alloy component joints reaches 100%. The welding rate of the same commonly used rolled annealed zirconium alloy joints under the same process is less than 5%, and the joint welding rate is greatly improved.

[0028] 3. The shear strength of the zirconium alloy element joint obtained by combining the thermal hydrogen treatment with the vacuum hot pressing welding method for high-strength zirconium alloy in this embodiment can reach above 450 MPa, and the shear elongation can reach 29%.

[0029] 4. The method of combining thermal hydrogen treatment with vacuum hot pressing welding of high-strength zirconium alloy in this embodiment is used in hot processing scenarios such as forging and welding.

[0030] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that: the polishing in step 1 uses 400#~600# sandpaper to remove the surface oxide scale.

[0031] Specific embodiment three: This embodiment differs from specific embodiment one or two in that: the cleaning in step one adopts ultrasonic cleaning with anhydrous ethanol for 5 to 20 minutes.

[0032] Specific embodiment 4: This embodiment differs from any one of specific embodiments 1 to 3 in that: the zirconium alloy in step 1 is Zr-0, Zr-2, Zr-4 or Zr-2.5Nb.

[0033] Specific embodiment 5: This embodiment differs from any one of specific embodiments 1 to 4 in that the hydrogen in step 2 is high-purity hydrogen with a purity of 99.999%.

[0034] Specific embodiment six: This embodiment differs from any one of specific embodiments one to five in that: the polishing in step three uses 800#, 1500# or 3000# sandpaper to remove the oxide scale and finely control the flatness and roughness of the surface of the zirconium hydride alloy to be welded.

[0035] Specific embodiment seven: This embodiment differs from any one of specific embodiments one to six in that: the cleaning in step three is performed by ultrasonic cleaning with anhydrous ethanol for 5 to 20 minutes.

[0036] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that: in step two, the zirconium alloy component to be welded after the treatment in step one is placed in a hot hydrogen treatment furnace, and vacuumed at room temperature until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 700℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After reaching Pa, the holding time starts, and the holding time is 60 min. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0037] Specific embodiment 9: This embodiment differs from any one of specific embodiments 1 to 8 in that: in step 2, the zirconium alloy component to be welded after the treatment in step 1 is placed in a hot hydrogen treatment furnace, and vacuumed at room temperature until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 680℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After Pa, the holding time is started, and the holding time is 50 minutes; finally, the heating furnace is turned off, and after the zirconium alloy component to be welded is cooled to room temperature with the furnace, excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0038] Specific embodiment 10: The difference between this embodiment and the first to ninth embodiments is that: in step 2, the zirconium alloy component to be welded after the treatment in step 1 is placed in a hot hydrogen treatment furnace, and vacuum is drawn at room temperature until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 720℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5After Pa, the holding time starts, and the holding time is 90 minutes; finally, the heating furnace is turned off, and after the zirconium alloy component to be welded is cooled to room temperature with the furnace, excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0039] Example 1

[0040] The method of combining thermal hydrogen treatment with vacuum hot pressing welding of zirconium alloy in this embodiment is carried out in the following steps:

[0041] Step 1: Grind and clean the zirconium alloy component to be welded; use 400# sandpaper for grinding to remove surface oxide scale; and use anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0042] The zirconium alloy is Zr-4;

[0043] Step 2: Place the zirconium alloy components to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace, evacuate the furnace at room temperature, and wait until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 700℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After reaching Pa, the holding time is started, and the holding time is 60 min. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0044] The hydrogen is high-purity hydrogen with a purity of 99.999%;

[0045] Step 3: Grind and clean the surface to be welded of the zirconium hydride alloy component to be welded;

[0046] The polishing is performed using 3000# sandpaper to remove the oxide scale and finely control the flatness and roughness of the surface of the zirconium hydride alloy to be welded; the cleaning is performed using anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0047] Step 4: stack and assemble the surfaces of the zirconium hydride alloy components to be welded after the treatment in step 3 to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating to 450℃ at a rate of 10℃ / min, and apply a pressure of 28MPa to the workpiece to be welded; then heat to 690℃ at a rate of 10℃ / min and keep warm for 30 min; finally turn off the heating furnace and take out the weldment after it cools to room temperature.

[0048] The existing diffusion bonding process for annealed Zr-4 alloy is:

[0049] Step 1: Grind and clean the Zr-4 alloy to be welded; the grinding uses 400#, 800#, 1500# and 3000# sandpaper to remove the oxide scale on the surface to be welded; the cleaning uses anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0050] Step 2: stack and assemble the surfaces of the Zr-4 alloy to be welded after the treatment step to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating to 450℃ at a rate of 10℃ / min, and apply a pressure of 10~30 MPa to the workpiece to be welded; then heat to 820℃ at a rate of 10℃ / min and keep warm for 30 min; finally turn off the heating and cool with the furnace, and take out the weldment after it cools to room temperature.

[0051] Figure 1 This is an image of the grain distribution state of the Zr-4 alloy diffusion bonded joint obtained in Example 1; Figure 1 It can be seen that the average grain size of the joint interface and the parent materials on both sides is only ~1.1μm, the interface is completely filled with fine recrystallized grains, and the interface is completely welded; Figure 2 This is the interface welding rate image of the Zr-4 alloy diffusion bonded joint obtained in Example 1; Figure 2 It can be seen that there is no interface trace in the diffusion bonded joint, and complete welding is achieved; Figure 3 is the shear curve of the Zr-4 alloy diffusion welded joint; Figure 4 This is an image of the welding rate of the existing Zr-4 alloy diffusion welded joint (rolled annealed Zr-4 alloy diffusion welded joint), and the dotted line represents the unwelded area. The Zr-4 alloy component obtained in this example has a welding rate of 100%, that is, it is completely welded, the shear strength can reach 460 MPa, and the shear elongation reaches 29%. The welding rate of the existing rolled annealed Zr-4 alloy diffusion welded joint is less than 60%, the shear strength is 310 MPa, and the shear elongation is less than 15%.

[0052] Example 2

[0053] The method of combining thermal hydrogen treatment with vacuum hot pressing welding of high-strength zirconium alloy in this embodiment is carried out in the following steps:

[0054] Step 1: Grind and clean the zirconium alloy component to be welded; use 400# sandpaper for grinding to remove surface oxide scale; and use anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0055] The zirconium alloy is Zr-4;

[0056] Step 2: Place the zirconium alloy components to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace, evacuate the furnace at room temperature, and wait until the vacuum degree in the furnace is lower than 5×10 -3Pa, heating was started; first heated to 680℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After reaching Pa, the holding time is started, and the holding time is 50 minutes. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0057] The hydrogen is high-purity hydrogen with a purity of 99.999%;

[0058] Step 3: Grind and clean the surface to be welded of the zirconium hydride alloy component to be welded;

[0059] The polishing is performed using 3000# sandpaper to remove the oxide scale and finely control the flatness and roughness of the surface of the zirconium hydride alloy to be welded; the cleaning is performed using anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0060] Step 4: stack and assemble the surfaces of the zirconium hydride alloy components to be welded after the treatment in step 3 to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating to 450℃ at a rate of 10℃ / min, and apply a pressure of 25MPa to the weldment; then heat to 680℃ at a rate of 10℃ / min and keep warm for 30 min; finally turn off the heating and cool with the furnace, and take out the weldment after it cools to room temperature.

[0061] The Zr-4 alloy components obtained in this example have a shear strength of up to 450 MPa and a shear elongation of 29%.

[0062] Example 3:

[0063] The method of combining thermal hydrogen treatment with vacuum hot pressing welding of high-strength zirconium alloy in this embodiment is carried out in the following steps:

[0064] Step 1: Grind and clean the zirconium alloy component to be welded; use 400# sandpaper for grinding to remove surface oxide scale; and use anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0065] The zirconium alloy is Zr-4;

[0066] Step 2: Place the zirconium alloy components to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace, evacuate the furnace at room temperature, and wait until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 720℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5After reaching Pa, the holding time is started, and the holding time is 90 minutes. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

[0067] The hydrogen is high-purity hydrogen with a purity of 99.999%;

[0068] Step 3: Grind and clean the surface to be welded of the zirconium hydride alloy component to be welded;

[0069] The polishing is performed using 3000# sandpaper to remove the oxide scale and finely control the flatness and roughness of the surface of the zirconium hydride alloy to be welded; the cleaning is performed using anhydrous ethanol ultrasonic cleaning for 20 minutes;

[0070] Step 4: stack and assemble the surfaces of the zirconium hydride alloy components to be welded after the treatment in step 3 to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating to 450℃ at a rate of 10℃ / min, and apply a pressure of 30MPa to the workpiece to be welded; then heat to 700℃ at a rate of 10℃ / min and keep warm for 40 min; finally turn off the heating and cool with the furnace, and take out the weldment after it cools to room temperature.

[0071] The Zr-4 alloy components obtained in this example are completely welded, with a shear strength of 472 MPa and a shear elongation of 29%.

Claims

1. A method for thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy, characterized in that: The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy is carried out in the following steps: Step 1: Grind and clean the zirconium alloy components to be welded; Step 2: Place the zirconium alloy components to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace, evacuate the furnace at room temperature, and wait until the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating; first heat to 680~720℃ at a rate of 5~10℃ / min, then fill the furnace with hydrogen, and wait until the hydrogen pressure in the furnace is higher than 1×10 5 After reaching Pa, the holding time is started, and the holding time is 45 to 90 minutes. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded. Step 3: Grind and clean the surface to be welded of the zirconium hydride alloy component to be welded; Step 4: stack and assemble the surfaces of the zirconium hydride alloy components to be welded after the treatment in step 3 to obtain the welded parts, and then weld them; the welding process is: the vacuum degree in the furnace is lower than 5×10 -3 Pa, start heating to 400~450℃ at a rate of 5~10℃ / min, and apply a pressure of 25~30MPa to the workpiece to be welded; then heat to 680~700℃ at a rate of 5~10℃ / min and keep warm for 30~45min; finally turn off the heating furnace and take out the weldment after it cools to room temperature.

2. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: The polishing described in step 1 uses 400#~600# sandpaper to remove the surface oxide scale.

3. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: The cleaning in step 1 is performed by ultrasonic cleaning with anhydrous ethanol for 5 to 20 minutes.

4. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: The zirconium alloy in step 1 is Zr-0, Zr-2, Zr-4 or Zr-2.5Nb.

5. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: The hydrogen in step 2 is high-purity hydrogen with a purity of 99.999%.

6. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: The polishing in step 3 uses 800#, 1500# or 3000# sandpaper to remove the oxide scale and finely control the flatness and roughness of the surface of the zirconium hydride alloy to be welded.

7. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: The cleaning in step 3 is performed by ultrasonic cleaning with anhydrous ethanol for 5 to 20 minutes.

8. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: Step 2: Place the zirconium alloy component to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace and evacuate the furnace at room temperature until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 700℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After reaching Pa, the holding time starts, and the holding time is 60 min. Finally, the heating furnace is turned off, and after the zirconium alloy component to be welded cools down to room temperature with the furnace, the excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

9. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: Step 2: Place the zirconium alloy component to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace and evacuate the furnace at room temperature until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 680℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After Pa, the holding time is started, and the holding time is 50 minutes; finally, the heating furnace is turned off, and after the zirconium alloy component to be welded is cooled to room temperature with the furnace, excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

10. The method of thermal hydrogen treatment combined with vacuum hot pressing welding of zirconium alloy according to claim 1, characterized in that: Step 2: Place the zirconium alloy component to be welded after the treatment in step 1 in a thermal hydrogen treatment furnace and evacuate the furnace at room temperature until the vacuum degree in the furnace is lower than 5×10 -3 Pa, heating was started; first heated to 720℃ at a rate of 10℃ / min, and then hydrogen was filled into the furnace. When the hydrogen pressure in the furnace was higher than 1×10 5 After Pa, the holding time starts, and the holding time is 90 minutes; finally, the heating furnace is turned off, and after the zirconium alloy component to be welded is cooled to room temperature with the furnace, excess hydrogen is released, and the thermal hydrogen treatment of the zirconium alloy component to be welded is completed to obtain the hydrogenated zirconium alloy component to be welded.

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