Metal powder core type welding wire, preparation method and method for preparing copper-based hydrogen permeation resisting cladding layer

Abstract

The invention discloses a metal powder core type welding wire which comprises a powder core and a welding skin, the powder core comprises 10.0%-25.0% of Cr, 10.0%-30.0% of Ni, 1.0%-5.0% of Mn, 1.0%-3.0% of Si, 10%-25% of Sn, 4.0%-5.0% of Al and the balance Cu, and the total content of the Cr, the Ni, the Mn, the Si, the Sn, the Al and the Cu is 100%. The invention further discloses a preparation method of the metal powder core type welding wire, the powder core powder is evenly mixed and placed in a furnace, and argon is introduced for drying; and wrapping the powder core in a T2 copper strip, closing the copper strip through a mold, and reducing the diameter. The welding wire is suitable for a cladding layer in a hydrogen storage tank, the cladding layer can form a compact barrier on the inner wall of a hydrogen storage container, hydrogen atoms are prevented from entering metal to cause damage such as hydrogen embrittlement and bubbling, hydrogen permeation is greatly hindered, the leakage rate of hydrogen is effectively reduced, and the hydrogen storage efficiency and safety of the hydrogen storage container are improved.

Description

Technical Field

[0001] The present invention belongs to the field of welding material preparation, specifically relates to metal cored wires, also relates to a preparation method of metal cored wires, and further relates to a method for preparing a copper-based hydrogen permeation resistant cladding layer. Background Art

[0002] As a key component in the hydrogen energy utilization system, the safety and reliability of hydrogen storage tanks are directly related to the wide application and sustainability of hydrogen energy. As one of the key technologies for the internal surface strengthening and protection of hydrogen storage tanks, the cladding layer plays a crucial role in improving the hydrogen permeation resistance, corrosion resistance, and overall performance of the tank. The cladding layer material needs to have excellent hydrogen permeation resistance to cope with the complex tests under high pressure, low temperature, and long-term hydrogen environment exposure. Especially during long-term hydrogen storage, the cladding layer material needs to effectively resist the penetration and diffusion of hydrogen atoms. This is mainly because the metal materials in these transportation devices will face an important and fatal safety problem during service, namely "hydrogen embrittlement".

[0003] As an efficient and flexible surface modification method, TIG cladding technology forms a cladding layer with specific properties by melting and depositing powder materials or wires with specific components on the surface of the substrate. It shows great application potential in the manufacturing and maintenance of hydrogen storage tanks. However, traditional cladding materials have certain limitations in terms of hydrogen permeation resistance and are difficult to meet the high-performance requirements of hydrogen storage tanks in extreme hydrogen environments.

[0004] Currently, although there are various cladding materials for hydrogen storage tanks, which perform well in terms of strength, toughness, etc., there is still room for improvement in hydrogen permeation resistance. Traditional cladding materials are prone to micropore defects during the cladding process, and the diffusion rate of hydrogen atoms in the cladding layer is relatively fast, which increases the risk of hydrogen-induced cracking and threatens the structural integrity and safety of hydrogen storage tanks. Research shows that only 10 - 1000 appm of hydrogen can cause "hydrogen embrittlement" in most metal materials, manifested as phenomena such as reduced strength and toughness, decreased fatigue life, and sudden intergranular fracture. Therefore, there is an urgent need to provide a solution to improve the above problems. Summary of the Invention

[0005] The first object of the present invention is to provide a metal cored wire, which has good bonding strength between the cladding layer and the substrate material when used for the internal cladding layer of a hydrogen storage tank, playing a role in hydrogen resistance.

[0006] The second object of the present invention is to provide a preparation method of the metal cored wire.

[0007] The third object of the present invention is to provide a method for preparing a copper-based hydrogen permeation resistant cladding layer using the metal cored wire.

[0008] The technical solution adopted by the present invention is a metal cored wire, which includes a cored powder and a welding skin. The cored powder is composed of the following components by mass percentage: Cr: 10.0% - 25.0%, Ni: 10.0% - 30.0%, Mn: 1.0% - 5.0%, Si: 1.0% - 3.0%, Sn: 10% - 25%, Al: 4.0% - 5.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%.

[0009] The characteristics of the present invention also lie in that

[0010] The welding skin is an annealed T2 copper strip.

[0011] The filling amount of the cored powder is 20wt% - 30wt%.

[0012] The second technical solution adopted by the present invention is a method for preparing a metal cored wire, which is specifically implemented according to the following steps:

[0013] Step 1: Weigh the following cored powder respectively by mass percentage: Cr: 10.0% - 25.0%, Ni: 10.0% - 30.0%, Mn: 1.0% - 5.0%, Si: 1.0% - 3.0%, Sn: 10% - 25%, Al: 4.0% - 5.0%, and the balance is Cu. The sum of the contents of the above components is 100%;

[0014] Step 2: Uniformly mix the cored powder weighed in Step 1, place it in a tube furnace and continuously introduce argon for drying, and then place the cored powder in a powder mixer for sufficient mixing;

[0015] Step 3: Roll the annealed T2 copper strip on a wire drawing machine, wrap the cored powder prepared in Step 2 inside the T2 copper strip, close the copper strip through a die, reduce the wire diameter to 1.6 mm using the die, and remove the impurities on the surface of the wire to obtain a metal cored wire.

[0016] The third technical solution adopted by the present invention is a method for preparing a copper-based hydrogen permeation resistant cladding layer using a metal cored wire, specifically: Clad the metal cored wire on the inner surface of the hydrogen storage tank body, and use TIG welding for cladding. The welding method is multi-layer and multi-pass welding cladding.

[0017] The cladding layer is divided into two layers up and down. The thickness of each cladding layer is 1 - 3 mm. Each cladding layer includes multiple parallel and overlapping weld beads. The width of each weld bead is 10 mm, and the fusion lap coverage rate of adjacent weld beads is 45% - 60%.

[0018] The welding voltage is 15 - 19V, the welding current is 110 - 150A, pure Ar is used as the shielding gas, the shielding gas flow rate is 15L / min, the weaving welding process is adopted, the welding speed at the weaving welding part is 0.20m / min, the weaving amplitude is 10.5mm, the weaving frequency is 1.2Hz, and the left and right dwell time of the weaving is 0.16s.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) For the design of the copper-based hydrogen-resistant permeation cladding layer, the present invention adopts the cladding method of an automatic TIG welding robot to carry out surfacing on the surface of low-alloy steel of the hydrogen storage tank. During the welding process, inert gas is used for protection, effectively avoiding the generation of defects such as oxidation, impurities, and pores, ensuring the advantages of fast welding speed, high efficiency, less spatter, and no pores. By cladding an anti-hydrogen alloy layer on the surface of the substrate material of the hydrogen storage tank, the overall performance and service life of the hydrogen storage tank are significantly improved, and its stability in extreme environments such as high pressure and low temperature is enhanced.

[0021] (2) The metal cored wire used in the present invention is easy to operate and has good welding effect during preparation, and can reduce the loss of hydrogen storage materials; this wire is particularly suitable for the internal cladding layer of the hydrogen storage tank. The copper-based hydrogen-resistant permeation cladding layer can form a dense barrier on the inner wall of the hydrogen storage container, preventing hydrogen atoms from entering the metal interior and causing damage such as hydrogen embrittlement and blistering, greatly hindering the permeation of hydrogen, effectively reducing the hydrogen leakage rate, improving the hydrogen storage efficiency and safety of the hydrogen storage container, and extending the service life of the hydrogen storage equipment. The copper-based hydrogen-resistant permeation cladding layer has good bonding strength with the substrate material. While playing a role in hydrogen resistance, it can also strengthen and protect the substrate material to a certain extent, improve the surface hardness, wear resistance, and corrosion resistance of the substrate material, enabling the substrate material to maintain good performance in various harsh environments, and broadening the application range of the substrate material.

[0022] (3) When preparing the cladding layer, the present invention adopts the arc cladding technology to form a protective layer to enhance its surface performance. The arc cladding technology has strong applicability and high cladding efficiency, can form a uniform and dense cladding layer, and improve the adhesion and hardness. The metal cored wire is used as the cladding material, which is easy to prepare and can accurately provide the required components, effectively preventing the generation of defects such as oxidation and pores. Description of the Drawings

[0023] Figure 1 is the macroscopic surface morphology diagram of the multi-pass cladding experiment of the metal cored wire prepared in Example 3 of the present invention;

[0024] Figure 2 is the microscopic structure diagram of the cladding layer prepared in Example 3 of the present invention. Detailed Embodiments

[0025] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The metal cored wire of the present invention includes a cored powder and a welding skin. The cored powder is composed of the following components by mass percentage: Cr: 10.0% - 25.0%, Ni: 10.0% - 30.0%, Mn: 1.0% - 5.0%, Si: 1.0% - 3.0%, Sn: 10% - 25%, Al: 4.0% - 5.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%;

[0027] The welding skin is an annealed T2 copper strip; the filling amount of the cored powder in the metal cored wire is 20wt% - 30wt%.

[0028] The functions of each element in the wire are as follows:

[0029] Mn: The appropriate addition of manganese element has a positive effect on improving the weld bead morphology, can effectively reduce the deformation degree during welding, and reduce the formation of cracks. In the formula of the anti-hydrogen wire, due to its unique chemical properties, manganese element interacts with other components in the weld to form stable compounds, which are crucial for optimizing the microstructure of the weld. The optimized microstructure not only improves the strength and toughness of the weld, but also makes the welded joint more solid and reliable, which is particularly important for welded structures working in a high-hydrogen environment.

[0030] Si: As an indispensable deoxidizer in the wire, the main function of silicon element is to prevent the chemical reaction between iron and oxygen, and reduce FeO in the molten pool, thereby significantly reducing the oxide inclusions in the weld. This function plays a key role in improving the purity and overall quality of the weld. In view of the strict requirements of the anti-hydrogen wire for the hydrogen content in the weld, the deoxidation effect of silicon element helps to inhibit the formation of hydrides that may occur during welding, thereby reducing the hydrogen content in the weld to a certain extent. Although silicon element itself does not directly reduce the hydrogen content in the weld, through the synergistic effect with other elements such as manganese, silicon element can indirectly affect the hydrogen content in the weld, and by forming compounds such as silicate, it hinders the diffusion and penetration of hydrogen in the weld, thus enhancing the anti-hydrogen performance of the weld.

[0031] Ni: The addition of nickel can significantly enhance the hydrogen corrosion resistance of the welded joint. Nickel has a relatively high hydrogenolysis activation energy, which means that a large amount of energy is required to "separate" hydrogen from its structure, effectively preventing the diffusion of hydrogen. In addition, the permeability coefficient of nickel to hydrogen is much lower than that of iron and copper, further enhancing its ability to prevent hydrogen penetration. Therefore, nickel can form an effective barrier in the copper-based hydrogen permeation-resistant cladding layer to prevent hydrogen from entering the material, thus preventing the occurrence of hydrogen embrittlement. In addition, nickel can also optimize the microstructure of the weld metal, making its grains more uniform and finer. When the weld metal with this structure is subjected to external forces, it can better resist the penetration and diffusion of hydrogen atoms, thereby reducing the risk of hydrogen embrittlement. At the same time, nickel can also improve the strength and toughness of the weld metal, enabling the welded joint to have higher load-bearing capacity and stability in a hydrogen-containing environment.

[0032] Cr: Chromium can react with oxygen in the welded structure to form a dense chromium oxide layer covering the surface of the weld. This oxide layer has a significant effect on blocking the further erosion of corrosion media such as oxygen and water, including the penetration and diffusion process of hydrogen atoms. Therefore, adding chromium to the welding wire can significantly improve the hydrogen corrosion resistance of the weld, enabling it to maintain excellent stability in a harsh hydrogen-containing environment.

[0033] Cu: The addition of copper can change the physical properties of the welding wire, and the most significant one is to lower its melting point. This property reduces the heat required during the welding process, thus simplifying the welding operation and improving the welding efficiency. At the same time, the lower melting point also helps the rapid formation of the weld and reduces the generation of welding defects. The addition of copper can also enhance the toughness of the weld metal and reduce its sensitivity to hydrogen-induced cracks.

[0034] In the metal cored wire of the present invention, iron is the main element, and its content is made up to 100% after the other components are determined to ensure the basic performance of the cladding layer. Metal elements such as Cr, Ni, Si, Sn, and Mn in the cored wire can form alloy compounds, and the alloy compounds further prevent hydrogen penetration, thereby improving the hydrogen permeation resistance of the base material and the coating. The filling amount of the cored powder is precisely calculated and controlled within a reasonable range of 20wt.% - 30wt.% to ensure the uniformity and performance optimization of the cladding layer.

[0035] The welding wire of the present invention is designed specifically for the internal cladding layer of hydrogen storage tanks, and can form a high-performance copper-based alloy cladding layer, significantly improving the hardness, wear resistance, corrosion resistance, and long-term stability of the hydrogen storage tank structure under a high-pressure hydrogen environment.

[0036] The preparation method of the metal cored wire of the present invention is specifically implemented according to the following steps:

[0037] Step 1: Weigh the following cored powder by mass percentage respectively: Cr: 10.0% - 25.0%, Ni: 10.0% - 30.0%, Mn: 1.0% - 5.0%, Si: 1.0% - 3.0%, Sn: 10% - 25%, Al: 4.0% - 5.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%;

[0038] Step 2: Uniformly mix the cored powder weighed in Step 1, place it in a tube furnace and continuously introduce argon for drying. Set the furnace temperature to 120°C - 150°C and the drying time to 1h - 2h; after drying, place the cored powder in a powder mixer for sufficient mixing, and the mixing time is 2h - 3h;

[0039] Step 3: Roll the annealed T2 copper strip on a wire drawing machine, wrap the cored powder prepared in Step 2 inside the T2 copper strip, close the copper strip through a die, reduce the wire diameter to 1.6mm by using the die, and remove the impurities on the surface of the wire; obtain a metal cored wire, and the filling amount of the cored powder in the metal cored wire is 20wt% - 30wt%.

[0040] The method for preparing a copper-based hydrogen permeation resistant cladding layer by using a metal cored wire in the present invention is as follows: specifically, use the metal cored wire to prepare a cladding layer on the inner surface of the hydrogen storage tank body, and adopt TIG welding cladding, and the welding method is multi-layer and multi-pass welding cladding;

[0041] Among them, the cladding layer is divided into two layers, the thickness of each layer of the cladding layer is 1 - 3mm, each layer of the cladding layer includes multiple parallel and overlapping weld beads, the width of each weld bead is 10mm, and the fusion lap coverage rate of adjacent weld beads is 45% - 60%;

[0042] The specific parameters of TIG welding are: welding voltage is 15 - 19V, welding current is 110 - 150A, the shielding gas is pure Ar with a volume fraction of 99.99%, the shielding gas flow rate is 15L / min, adopt the weaving welding process, the welding speed at the weaving welding part is 0.20m / min, the weaving amplitude is 10.5mm, the weaving frequency is 1.2Hz, and the left and right residence time of the weaving is 0.16s;

[0043] Import the set parameters into the MIG welding robot in a program manner to carry out the welding preparation of the cladding layer;

[0044] Example 1

[0045] Prepare a metal cored wire for the inner surface modification of the hydrogen storage tank body, specifically:

[0046] Step 1: Weigh the following cored wires by mass percentage respectively: Cr: 10.0%, Ni: 30.0%, Mn: 3.0%, Si: 2.0%, Sn: 25%, Al: 4.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%;

[0047] Step 2: Uniformly mix the cored wire powder weighed in Step 1, place it in a tubular furnace, and continuously introduce argon. Set the furnace temperature to 150 °C and the drying time to 1 h; the dried cored wire is placed in a powder mixer for sufficient mixing, and the mixing time is 2 h;

[0048] Step 3: Roll the annealed T2 copper strip on a wire drawing machine, wrap the cored wire prepared in Step 2 inside the annealed T2 copper strip, close the copper strip through a die, then reduce the diameter of the thick wire to 1.6 mm, and remove the impurities on the surface of the wire; the filling amount of the cored wire powder in the metal cored wire is 25 wt.%.

[0049] Clad the wire obtained in Step 3 on the inner surface of the hydrogen storage tank body. Use an automatic TIG robot welding as the cladding method. The thickness of each cladding layer is: 2 mm; the number of cladding layers: 2 layers; the cladding process is multi-layer multi-pass welding. The width of each cladding weld bead is 10 mm. The swing arc welding process is adopted. The welding speed at the swing arc welding part is 0.20 m / min, the swing arc amplitude is 10.5 mm, the swing arc frequency is 1.2 Hz, the left and right residence time of the swing arc is 0.16 s, and the lap coverage rate of each cladding is 45%-60%. Set the cladding process parameters as: the cladding welding voltage is 18 V, the cladding current is 150 A, the shielding gas uses pure Ar with a volume fraction of 99.99%, the gas flow rate is 15 L / min, import the welding process program into the automatic TIG welding robot, and use the prepared wire to prepare the cladding layer on the surface of the base material. The lap between the previous and the next cladding is 39%.

[0050] The obtained cladding layer is uniform and continuous, without pores and slag inclusions on the surface. The test results of the cladding layer show that after mechanical property testing and microstructural observation, the average microhardness can reach 239.6 HV 0.5 , the corrosion current density of the cladding layer is 1.08×10 -4 A·cm -2 , the hydrogen diffusion coefficient is 2.13×10 -6 cm 2 / s, which is lower than that of the hydrogen storage tank body base material, and the hydrogen diffusion coefficient is smaller (the corrosion current density of the base material is 1.6×10 -4 A·cm -2 , and the hydrogen diffusion coefficient is 2.98×10 -6 cm 2 / s), indicating that the corrosion resistance and hydrogen resistance of the 5.5% Ni cladding layer are improved.

[0051] Example 2

[0052] Prepare a metal-cored wire for the internal surface modification of a hydrogen storage tank body, specifically as follows:

[0053] Step 1: Weigh the following cored powder by mass percentage respectively: Cr: 25.0%, Ni: 25.0%, Mn: 5.0%, Si: 2.0%, Sn: 20%, Al: 4.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%;

[0054] Step 2: Uniformly mix the cored powder weighed in Step 1, place it in a tubular furnace, and continuously introduce argon. Set the furnace temperature to 150°C and the drying time to 1 h; place the dried cored powder in a powder mixer for sufficient mixing, and the mixing time is 2 h;

[0055] Step 3: Roll the annealed T2 copper strip on a wire drawing machine, wrap the cored powder prepared in Step 2 inside the annealed T2 copper strip, close the alloy strip through a die, then reduce the diameter of the thick wire to 1.6 mm, and remove the impurities on the wire surface; the filling amount of the cored powder in the metal-cored wire is 25 wt.%.

[0056] Clad the wire obtained in Step 3 on the internal surface of the hydrogen storage tank body. Use an automatic TIG robot welding as the cladding method. The thickness of each cladding layer is: 2 mm; the number of cladding layers: 2 layers; the cladding process is multi-layer and multi-pass welding. The width of each cladding weld bead is 10 mm. Adopt a weaving welding process. The welding speed at the weaving welding part is 0.20 m / min, the weaving amplitude is 10.5 mm, the weaving frequency is 1.2 Hz, the left and right dwell time at the weaving is 0.16 s, and the lap coverage rate of each cladding is 45%-60%. Set the cladding process parameters as: the cladding welding voltage is 18 V, the cladding current is 150 A, the shielding gas uses pure Ar with a volume fraction of 99.99%, the gas flow rate is 15 L / min, import the welding process program into the automatic TIG welding robot, and use the prepared wire to prepare the cladding layer on the substrate surface. The lap between the previous and the next cladding is 39%.

[0057] Conduct multi-pass cladding experiments on the prepared wire. The obtained cladding layer is uniform and continuous, without pores and slag on the surface. The test results of the cladding layer show that after mechanical property testing and microstructure observation, the average microhardness can reach 244.2 HV 0.5 , the corrosion current density of the cladding layer is 1.33×10 -4 A·cm -2 , the hydrogen diffusion coefficient is 2.28×10 -6 cm 2 / s, which is lower than the corrosion current density of the hydrogen storage tank body base material and has a smaller hydrogen diffusion coefficient (the corrosion current density of the base material is 1.6×10- 4 A·cm -2 and the hydrogen diffusion coefficient is 2.98×10 -6 cm 2 / s), indicating that the corrosion resistance and hydrogen resistance of the 5.5% Ni clad layer are improved.

[0058] Example 3

[0059] Prepare a metal cored wire for internal surface modification of a hydrogen storage tank, specifically:

[0060] Step 1: Weigh the following cored powder by mass percentage respectively: Cr: 25.0%, Ni: 25.0%, Mn: 3.0%, Si: 2.0%, Sn: 25%, Al: 5.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%;

[0061] Step 2: Uniformly mix the cored powder weighed in Step 1 and place it in a tube furnace, and continuously introduce argon. Set the furnace temperature to 150°C and the drying time to 1 h; place the dried cored powder in a powder mixer for sufficient mixing, and the mixing time is 2 h;

[0062] Step 3: Roll the annealed T2 copper strip on a wire drawing machine, wrap the cored powder prepared in Step 2 inside the annealed T2 copper strip, close the alloy strip through a die, and then reduce the diameter of the thick wire to 1.6 mm and remove the impurities on the wire surface; the filling amount of the cored powder in the metal cored wire is 25 wt.%.

[0063] Clad the wire obtained in Step 3 on the internal surface of the hydrogen storage tank. Use an automatic TIG robot welding as the cladding method. The thickness of each clad layer is: 1 - 3 mm; the number of clad layers: 2 layers; the cladding process is multi-layer multi-pass welding. The width of each clad weld bead is 10 mm. Use a weaving welding process. The welding speed at the weaving welding part is 0.20 m / min, the weaving amplitude is 10.5 mm, the weaving frequency is 1.2 Hz, the left and right residence time of the weave is 0.16 s, and the overlap coverage rate of each clad layer is 45% - 60%. Set the cladding process parameters as: the cladding welding voltage is 18 V, the cladding current is 150 A, the shielding gas uses pure Ar with a volume fraction of 99.99%, the gas flow rate is 15 L / min, import the welding process program into the automatic TIG welding robot, and use the wire prepared in Step 3 to prepare the clad layer on the substrate surface. The overlap between the previous and the next clad is 39%.

[0064] Example 4

[0065] Multi-pass cladding experiments were carried out on the welding wires prepared in Example 3. The obtained cladding layers were uniform and continuous, without pores or slag inclusions on the surface. The test results of the cladding layers showed that after mechanical property testing and microstructure observation, the average microhardness could reach 257.3 HV 0.5 and the corrosion current density of the cladding layer was 1.23×10 -4 A·cm -2 , and the hydrogen diffusion coefficient was 2.22×10 -6 cm 2 / s. Compared with the base material of the hydrogen storage tank body, the corrosion current density was lower and the hydrogen diffusion coefficient was smaller (the corrosion current density of the base material was 1.6×10 - 4 A·cm -2 and the hydrogen diffusion coefficient was 2.98×10 -6 cm 2 / s), indicating that the corrosion resistance and hydrogen resistance of the cladding layer were improved.

[0066] Example 5

[0067] Figure 1 is the macroscopic surface morphology diagram of the multi-pass cladding experiment of the metal cored wire prepared in Example 3 of the present invention; Figure 2 is the microstructure diagram of the cladding layer prepared in Example 3 of the present invention. It can be seen from the figure that the morphology of the cladding layer is uniform and there are no obvious defects. A planar crystal structure formed by atomic diffusion between the cladding material and the base material was observed, which helps to improve the bonding strength. The bottom of the cladding layer has the characteristics of a typical rapidly directionally solidified dendritic structure, mainly columnar crystals growing in the direction opposite to the heat flow direction. This is because during the cladding process, the molten pool cools rapidly, resulting in the atoms arranging into a dendritic structure with a specific direction. Due to the addition of Ni element in the cladding layer, a Ni zone is formed at the interface. The rapid cooling and solidification process of the cladding layer limits the formation of hot cracks, improves the corrosion resistance at the same time, prevents the further erosion of the corrosive medium, and thus improves the service life of the cladding layer.

[0068] Example 6

[0069] Since high-pressure hydrogen storage tank bodies are costly and difficult to process, low-carbon steel is used to prepare the hydrogen storage tank body and the inner surface cladding layer is modified. Through the method of the present invention, the hardness, corrosion resistance and hydrogen resistance of the inner surface of the hydrogen storage tank body can be improved. The TIG cladding method is adapted to the prepared welding wire. When TIG welding is used to clad the alloy on the surface of low-carbon steel, a high-quality cladding layer can be formed, which has the advantages of controllable welding process, low heat input, small heat-affected zone and small substrate deformation.

Claims

1. Metal powder cored welding wire, characterized in that: It includes a powder core and a welding skin, wherein the powder core is composed of the following components by mass percentage: Composition: Cr: 10.0%~25.0%, Ni: 10.0%~30.0%, Mn: 1.0%~5.0%, Si: 1.0%~3.0%, Sn: 10%~25%, Al: 4.0%~5.0%, and the balance is Cu. The total content of the above components is 100%.

2. The metal powder cored welding wire according to claim 1, characterized in that: The solder skin is an annealed T2 copper strip.

3. The metal powder cored welding wire according to claim 1, characterized in that: The filling amount of the powder core is 20wt%-30wt%.

4. A method for preparing a metal powder cored welding wire, characterized in that: Follow the steps below to implement it: Step 1: Weigh the following core powders respectively by mass percentage: Cr: 10.0%-25.0%, Ni: 10.0%-30.0%, Mn: 1.0%-5.0%, Si: 1.0%-3.0%, Sn: 10%-25%, Al: 4.0%-5.0%, and the balance is Cu. The sum of the contents of the above raw materials is 100%; Step 2: The powder core powder weighed in step 1 is uniformly mixed, placed in a tube furnace and continuously introduced with argon gas for drying, and then the powder core is placed in a powder mixer for thorough mixing; Step 3: Roll the annealed T2 copper strip on a wire drawing machine, wrap the powder core prepared in step 2 in the T2 copper strip, close the copper strip through a mold, reduce the diameter of the welding wire to 1.6 mm using the mold, remove impurities on the surface of the welding wire, and obtain a metal powder core welding wire.

5. The method for preparing the metal powder cored welding wire according to claim 4, characterized in that: In the step 2, the mixing time is 2 hours to 3 hours; the drying temperature is 120° C. to 150° C., and the drying time is 1 hour to 2 hours.

6. A method for preparing a copper-based hydrogen permeation barrier cladding layer using the metal powder cored welding wire according to any one of claims 1 to 5, characterized in that: Specifically, the metal powder cored welding wire is clad on the inner surface of the hydrogen storage tank body by TIG welding, and the welding method is multi-layer and multi-pass welding.

7. The method for preparing a copper-based hydrogen permeation barrier cladding layer using a metal powder cored welding wire according to claim 6, characterized in that: The cladding layer consists of two layers, the thickness of each cladding layer is 1-3mm, each cladding layer includes multiple parallel overlapping welds, the width of each weld is 10mm, and the cladding overlap coverage of adjacent welds is 45%-60%.

8. The method for preparing a copper-based hydrogen permeation barrier cladding layer using a metal powder cored welding wire according to claim 7, characterized in that: The welding voltage is 15-19V, the welding current is 110-150A, the shielding gas is pure Ar, the shielding gas flow rate is 15L / min, the swing arc welding process is adopted, the welding speed of the swing arc welding part is 0.20m / min, the swing arc amplitude is 10.5mm, the swing arc frequency is 1.2Hz, and the swing arc dwell time is 0.16s.

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