Nickel-based alloy welding wire for nuclear power and preparation method of nickel-based alloy welding wire

Abstract

The invention belongs to the field of metal material processing, and particularly relates to a nuclear power nickel base alloy welding wire and a preparation method thereof.The nuclear power nickel base alloy welding wire comprises, by weight, 0.01%-0.05% of C, 0.10%-0.30% of Si, 28.5%-30.5% of Cr, 7.0%-11.0% of Fe, smaller than or equal to 0.10% of Co, 0.50%-1.00% of W, 3.0%-4.0% of Mo, 0.005%-0.010% of B, 0.1%-0.3% of Al, 0.1%-0.2% of Ti, 0.005%-0.020% of Zr, 2.0%-2.5% of Nb, 0.1%-0.5% of Ta, 0.20%-0.30% of RE, smaller than 0.005% of S, smaller than 0.005% of P, 2.0%-4.0% of nano ceramic materials and the balance Ni, the nickel-based alloy welding material is prepared through the steps of smelting, high-low temperature refining, annealing, forging, rolling, multi-pass drawing, annealing, solid solution-aging treatment, acid pickling, coating and plating, and the problems that in the prior art, when used for welding, a nickel-based alloy welding material is prone to cracks, and the strength is low due to hot corrosion can be effectively solved.

Description

Technical Field

[0001] The invention belongs to the field of metal materials, and in particular relates to a nickel-based alloy welding wire for nuclear power and a preparation method thereof. Background Art

[0002] There are many key components in nuclear reactors such as pressurized water reactors. Due to the complex service environment, these components are exposed to primary coolant liquid or steam containing corrosive components such as boric acid for a long time, and are subjected to high temperature (up to 320°C), high pressure (15.5MPa) and nuclear radiation. At the same time, they are subjected to repeated sliding or impact due to vibrations caused by their mechanical movement or high coolant flow. This puts extremely high demands on the materials that can be used in pressurized water reactors.

[0003] As the main element used in high-temperature alloy materials, Ni is one of the few alloy elements that can improve the strength of alloy materials without significantly weakening the plasticity of the materials. It also has excellent high temperature resistance, oxidation resistance, and corrosion resistance. This also directly led to the selection of a large number of nickel-based corrosion-resistant alloys for key parts of the main equipment of the nuclear island of the third-generation advanced pressurized water reactor, among which 690 alloy is the largest. Correspondingly, NiCrFe series nickel-based corrosion-resistant alloy welding materials are also widely used in butt welding, surface cladding, and dissimilar metal welding of related components. In recent years, the welding wire used in engineering is mainly ERNiCrFe-7A. However, due to the high viscosity, poor fluidity, poor weldability, and greater tendency to hot cracks of nickel-based alloys, the requirements for welding materials are very high and the manufacturing difficulty is very high.

[0004] In addition, when nickel-based alloy welding materials are used in nuclear power, their performance degradation caused by nuclear radiation must also be considered, which undoubtedly further increases the requirements for materials. Summary of the invention

[0005] The purpose of the present invention is to provide a new type of nickel-based alloy welding wire for nuclear power and its preparation method in view of the problem that the nickel-based alloy welding wire for nuclear power is prone to cracking and low strength due to thermal corrosion during welding in the prior art; the new material has the advantage of radiation resistance while solving the above problems. To achieve the above purpose, the technical solution adopted by the present invention to solve its technical problems is: The present invention provides a nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.01-0.05%, Si: 0.10-0.30%, Cr: 28.5-30.5%, Fe: 7.0-11.0%, Co: ≤0.10%, W: 0.50-1.00%, Mo: 3.0-4.0%, B: 0.005-0.010%, Al: 0.1-0.3%, Ti: 0.1-0.2%, Zr: 0.005-0.020%, Nb: 2.0-2.5%, Ta: 0.1-0.5%, RE: 0.20-0.30%, S: <0.005%, P: <0.005%, nano-ceramic materials: 2.0-4.0%, Ni balance.

[0006] Furthermore, the total amount of Cr and Mo is not less than 32.5%.

[0007] Furthermore, the weight ratio of Fe to Nb is (3.5-4.5):1.

[0008] Furthermore, the weight ratio of Al to Ti is (0.8-1.5):1.

[0009] Furthermore, the RE is one or more of Y, Ce, Sm, Gd, Nd, and Pr.

[0010] Furthermore, the nano-ceramic material is carbide.

[0011] Furthermore, the carbide is boron carbide.

[0012] Another object of the present invention is to provide a method for preparing the above-mentioned nickel-based alloy welding wire for nuclear power, comprising the following steps: S1: The raw materials are weighed according to the mass percentage of the formula and processed to obtain a uniform and refined mixed powder; S2: Put the mixed powder and nano-ceramic material in S1 into a smelting furnace for smelting, and after high-temperature refining and low-temperature refining, remelt and refine, and cast into alloy ingots; S3: After annealing the alloy ingot, forging and rolling are performed to prepare alloy wire rods; S4: Pre-treating the alloy wire rod and then performing multiple drawing-annealing steps; S5: Processing the alloy wire into the required size and performing solution-aging treatment; S6: pickling the alloy wire; coating; and S7: Plating is performed on the surface to obtain the target product.

[0013] Furthermore, the solution-aging treatment in S5 is a multi-step graded treatment.

[0014] The present invention has the following beneficial effects: (1) The present invention provides a nickel-based alloy welding wire for nuclear power, with Ni as the matrix. Cr can improve the high-temperature oxidation resistance and corrosion resistance of the alloy; Mo can refine the grains and improve the thermal stability of the alloy; and W can improve the strength of the alloy. The addition of Cr, Mo, and W achieves a solid solution strengthening effect, improving its high-temperature oxidation resistance and thermal strength; at the same time, Cr, Mo, and W can generate carbides with C, and hard phases such as chromium carbide are dispersed in the solid solution strengthened matrix, improving high-temperature strength and plasticity; moreover, the improvement of high-temperature oxidation resistance and high-temperature strength can effectively inhibit welding pores caused by oxidation, and can effectively improve welding strength.

[0015] (2) The present invention provides a nickel-based alloy welding wire for nuclear power, in which a certain proportion of Mo, Fe and B are added. During the high-temperature remelting process, a reaction can occur to form Mo2FeB2 and Mo2NiB2 ternary boride hard phases, which have excellent mechanical properties such as corrosion resistance, hardness and wear resistance; in addition, B also has the function of improving the plasticity of nickel alloys.

[0016] (3) The present invention provides a nickel-based alloy welding wire for nuclear power, wherein a certain amount of Fe, Nb and rare earth element RE are added to the alloy. First, Fe can improve the resistance to high-temperature carburizing environment and control thermal expansion; and when combined with Nb, it can improve the plasticity and high-temperature strength of the alloy and reduce stress cracking; second, Nb is a high-temperature strengthening phase forming element, which can effectively improve the high-temperature strength and high-temperature stability of the alloy. The precipitation of its carbides at the grain boundaries can make the grain boundary morphology more complex and curved, increase the grain boundary sliding resistance, and thus reduce the tendency of strain cracking; in addition, Nb has a good affinity with O and can generate stable oxide Nb2O5, which has the effect of delaying corrosion; third, the rare earth element RE, on the one hand, can synergize with Nb to improve the adhesion of the oxide film and refine the oxide grains at high temperatures; on the other hand, it can form coordination with O and S at high temperatures to preferentially form smaller-sized rare earth oxide nanoparticles, which can serve as heterogeneous cores in the welding process, refine the grains, and improve the mechanical strength of the weld; in addition, the rare earth element RE also has a certain neutron absorption effect, which improves radiation resistance.

[0017] (4) The present invention provides a nickel-based alloy welding wire for nuclear power, in which a certain amount of Al and Ti elements are added. On the one hand, Al and Ti can improve the weldability of the alloy. They have a strong affinity with oxygen and can be used as deoxidizing elements to protect the weld from oxidation, thereby effectively inhibiting the formation of CO and N2 pores, facilitating the formation of the weld, and having a certain strengthening effect on the alloy; on the other hand, Al will generate Al2O3 during the high-temperature oxidation process of the alloy, and this oxide structure is conducive to improving the high-temperature oxidation resistance of the alloy.

[0018] (5) The present invention provides a nickel-based alloy welding wire for nuclear power, in which a certain amount of nano-ceramic material is added to the alloy, which is a carbide structure. First, it can improve the high-temperature oxidation resistance and wear resistance of the welding material; second, it can terminate the microcracks generated by stress and improve the mechanical properties; third, the carbide structure, especially the boron carbide structure, is an excellent neutron shielding material, which can effectively improve the radiation resistance of the nickel alloy weld and improve the mechanical retention rate.

[0019] (6) The present invention provides a method for preparing nickel-based alloy welding wire for nuclear power, which adopts a multi-step graded solid solution-aging treatment. On the one hand, the interfacial bonding force between carbides and nickel alloy matrix is ​​improved, thereby improving performance; on the other hand, the grain size can be refined, thereby further improving mechanical properties. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present invention, and are not intended to limit the scope of the present invention.

[0021] The purpose of the present invention is to develop a nickel-based alloy welding wire for nuclear power to solve the problems existing in the existing nickel-based alloy welding wire for nuclear power. The idea of ​​implementation is: mainly Ni, adding high temperature resistant elements such as Cr, Mo, W through formula design to achieve solid solution strengthening, improve oxidation resistance and thermal corrosion resistance; adding elements such as B and Fe to improve hardness and plasticity, and compounding Fe-Nb ratio to improve weld strength and thermoplasticity; at the same time, adding precipitation strengthening elements such as Al, Ti, Ta, RE, etc. to improve high temperature strength and purify grain boundaries; finally, compounding boron carbide nano-ceramic materials to further improve radiation resistance while improving mechanical properties. The above components are subjected to a grain refinement process to improve the interphase compatibility and thus further improve performance. The embodiments of the present invention are as follows: An embodiment of the present invention provides a nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.01-0.05%, Si: 0.10-0.30%, Cr: 28.5-30.5%, Fe: 7.0-11.0%, Co: ≤0.10%, W: 0.50-1.00%, Mo: 3.0-4.0%, B: 0.005-0.010%, Al: 0.1-0.3%, Ti: 0.1-0.2%, Zr: 0.005-0.020%, Nb: 2.0-2.5%, Ta: 0.1-0.5%, RE: 0.20-0.30%, S: <0.005%, P: <0.005%, nano-ceramic materials: 2.0-4.0%, Ni balance.

[0022] The total amount of the above Cr and Mo is not less than 32.5%.

[0023] Cr is the main element to ensure the high temperature oxidation resistance of the alloy of the present invention, and is the most important element to stabilize the alloy surface. It forms a dense Cr2O3 protective layer on the surface of the base material that is resistant to oxidation and corrosion, and can prevent oxidation and thermal corrosion of materials caused by high temperature and nuclear radiation. Generally, when the Cr content exceeds 12%, it will have better high temperature oxidation resistance. When it exceeds 33%, the increase in Cr content has little effect on improving the high temperature oxidation resistance, and will precipitate α Cr phase that is not conducive to mechanical properties. Therefore, the present invention controls the Cr content to 28.5-30.5%.

[0024] The Mo element can improve the high temperature strength and corrosion resistance of the alloy, especially in the case of compounding with chromium, the pitting corrosion resistance is more excellent; at the same time, Mo can enhance the creep resistance of the alloy through solid solution strengthening and reduce the grain boundary weakening caused by radiation. The addition of Mo can significantly improve the corrosion resistance and high temperature strength of the welding wire. Therefore, the present invention controls the Mo content to 3.0-4.0%.

[0025] At the same time, considering the compounding effect of Cr and Mo, the total amount shall not be less than 32.5%.

[0026] The weight ratio of Fe to Nb is (3.5-4.5):1.

[0027] Fe is a matrix element of Ni Cr Fe alloy, which can improve the strength of the weld by solid solution strengthening. Therefore, the Fe content is controlled within 7.0-11.0% in the present invention.

[0028] Nb is a strengthening element in high temperature environment, which can increase the solid solution lattice distortion and lattice atomic bond attraction, strengthen the matrix, and has a significant solid solution strengthening effect; at the same time, it is also a strong carbide forming element, which can form MC, M6C or M2C type carbides, which plays a significant second phase strengthening role on the weld metal, improves the high temperature strength and plasticity combination, and improves the high temperature durability of the nickel alloy of the present invention; in addition, it can also reduce the segregation of alloy elements and improve the plasticity of the weld metal. Therefore, the present invention controls the Nb content to 2.0-2.5%.

[0029] At the same time, the combination of Fe and Nb can further improve the strength and thermoplasticity of the weld.

[0030] The weight ratio of Al to Ti is (0.8-1.5):1.

[0031] Al and Ti can improve the weldability of the alloy, can be used as deoxidizing elements, are conducive to the formation of welds, and have a certain toughening effect on the alloy. At the same time, Al will generate Al2O3 during the high-temperature oxidation process of the alloy. This oxide structure is beneficial to improving the high-temperature oxidation resistance of the alloy. However, excessive Al and Ti content will affect hot workability and weldability, and the formed oxides are prone to cause weld slag inclusions, reducing the resistance to thermal cracking. If the Al+Ti content is too high, secondary phases such as γ and γ' will be precipitated, reducing the high-temperature durability enhancement effect, and inducing the precipitation of harmful phase σ phase. Considering all factors, it is controlled at Al: 0.1-0.3%, Ti: 0.1-0.2%; and the weight ratio of Al to Ti is (0.8-1.5): 1.

[0032] The above-mentioned RE is one or more of Y, Ce, Sm, Gd, Nd, and Pr.

[0033] Rare earth element RE is a key functional element to improve high-temperature oxidation resistance. After adding Cr element to nickel alloy, the heat resistance and corrosion resistance are excellent, but at high temperatures above 600°C, the Cr2O3 formed on the surface is easy to volatilize, resulting in reduced oxidation resistance. After adding RE element, a new phase can be formed, which is conducive to the formation of the alloy selective oxidation film Cr2O3, improves the adhesion between the oxide film and the matrix, inhibits the volatilization of Cr2O3, reduces the oxidation rate, and improves the high-temperature oxidation resistance of the alloy. At the same time, rare earth element RE element is a strong deoxidizer in the secondary metallurgical process of welding, which can improve crack resistance and improve the welding processability of welding wire. In addition, some commonly used RE elements, such as Gd, also have a certain neutron absorption effect and improve radiation resistance. Therefore, the RE content is controlled at 0.20-0.30%.

[0034] The nano ceramic material is carbide, which may be boron carbide, titanium carbide, zirconium carbide or tantalum carbide.

[0035] The above carbide is boron carbide.

[0036] Another object of the present invention is to provide a method for preparing the above-mentioned nickel-based alloy welding wire for nuclear power, comprising the following steps: S1: The raw materials are weighed according to the mass percentage of the formula and processed to obtain a uniform and refined mixed powder.

[0037] The above treatment process and the treatment process described in the following embodiments of the present invention are: adding raw material powders except nano-ceramic materials to ethanol, stirring at 1000r / min magnetic force for 3h, placing it in 50KHz ultrasonic treatment for 2h to obtain an ethanol suspension; filtering, taking insoluble matter, placing it in an 80°C drying oven for drying for 2h, placing the insoluble matter in a ball mill, adding long-chain fatty acids, and placing the ball mill on a high-energy ball mill for ball milling to obtain a uniform and refined mixed powder; wherein the grinding ball material is corundum ball, the ball-to-material mass ratio is 6:1, the ball milling process is 7h, and the ball mill speed is 150 200r / min; The ratio of the above long-chain fatty acid to the total mass of the raw material powder is 2g:100g; The above-mentioned long-chain fatty acid is myristic acid.

[0038] S2: The mixed powder and nano-ceramic material in S1 are placed in a smelting furnace for smelting, and after high-temperature refining and low-temperature refining, they are remelted and cast into alloy ingots.

[0039] The above high temperature refining is smelting at 1750-1850°C for 30-45 minutes; The above-mentioned low temperature refining is smelting at 1650-1700°C for 15-25 minutes; The above remelting is electroslag remelting, and the furnace temperature is 1750-1850°C.

[0040] S3: After annealing the alloy ingot, forging and rolling are performed to prepare alloy wire rods.

[0041] The above annealing process is heating to 1000-1050°C and keeping the temperature for 20-35h; The forging process is as follows: at 950°C, the billet is forged into alloy billet I with a forging ratio of 3-4; after tempering at 950-1000°C for 1-2 hours, the billet is forged into alloy billet II at 1050°C with a forging ratio of 5-6; and then the billet is forged into alloy billet III at the same temperature with a forging ratio of 3-4; The above rolling process is to keep the temperature at 1000-1050°C for 0.5-1.5h and hot-roll the alloy wire rod at 950-1100°C into Φ4.05.0mm.

[0042] S4: After pre-treatment, the alloy wire rod is subjected to multiple drawing-annealing steps.

[0043] The above-mentioned pretreatment is to heat the alloy wire rod to 950°C and keep it at that temperature for 1.5 hours, oil cool it for softening treatment, alkali boil it, then high-pressure water wash it, then pickle it after water washing, and then ultrasonic wash it; In the above-mentioned drawing, a lubricant is added before drawing, and the alloy wire is obtained by multiple drawing processes; The above annealing is vacuum annealing after 6-10 drawing passes, and the annealing temperature is 640-800°C.

[0044] S5: Processing the alloy wire into the required size and performing solution-aging treatment.

[0045] The solid solution-aging treatment in S5 is a multi-step graded treatment; specifically, in a nitrogen environment, heating to 950-1050°C, keeping warm for 2-3h, continuing to heat to 1050-1100°C, keeping warm for 2-3h, continuing to heat to 1100-1150°C, keeping warm for 1-2h, continuing to heat to 1150-1170°C, keeping warm for 1-2h, and rapidly quenching in water to obtain a solid solution alloy; the above-mentioned aging is heating to 800-850°C, keeping warm for 3-8h, air cooling, and then heating to 750-770°C, keeping warm for 10-15h, and air cooling.

[0046] S6: pickling the alloy wire; coating; and The pickling described above and in the following embodiments of the present invention are all to pickle the alloy wire after the solution heat treatment, first pickle it with a mixed pickling solution containing 100 g / L nitric acid and 20 g / L hydrofluoric acid, control the temperature to be ≤50°C, and the pickling time to be 10 min; finally, clean the residual acid on the surface; The above coating and the coating described in the following embodiments of the present invention are all obtained by coating a layer of water-soluble coating agent on the surface of the alloy wire after pickling, and the coated alloy wire is naturally air-dried.

[0047] S7: Plating is performed on the surface to obtain the target product.

[0048] The above surface coating process and the surface coating process described in the following embodiments of the present invention are all as follows: Pretreatment: The surface of the high-temperature nickel-based alloy welding wire was cleaned, sanded with sandpaper, and then polished, and then cleaned in a mixed solution of sodium hydroxide (20 g / L), trisodium phosphate (30 g / L), and sodium silicate (30 g / L) at 50°C for 10 min. Finally, electrolytic polishing was performed in a mixed acid of 80% acetic acid and 20% perchloric acid, with an electrolytic voltage of 27 V and a power supply of 7 s to obtain welding wire I; Nickel plating: prepare a Watt-type electrolyte, the plating solution includes nickel sulfate hexahydrate, nickel chloride hexahydrate, and boric acid, electroplate a nickel layer on the surface of welding wire I to obtain welding wire II, and the electroplating process parameters are a current density of 3A / dm 2 , electroplating time 10min, electroplating temperature 45℃, stirring speed 300r / min; TiC plating: prepare TiC electroplating solution, which includes TiC 30g / L, NiSO4 400g / L, NiCl2 45g / L, H3BO 350g / L by mass volume ratio, and the balance is water; the particle size of TiC is 3-10μm, and a TiC coating is electroplated on the nickel layer of welding wire II to obtain welding wire III. The electroplating process parameters are current density 3A / dm 2 , electroplating time 0.5h, electroplating temperature 45℃, stirring speed 300r / min; Nickel plating: prepare a Watt-type electrolyte, which includes 400g / L NiSO4, 45g / L NiCl2, 50g / L H3BO3, and the balance is water. Electroplating a nickel layer on the TiC coating of welding wire III to obtain a nuclear power high-temperature nickel-based alloy composite welding wire. The electroplating process parameters are a current density of 3A / dm 2 , electroplating time 10min, electroplating temperature 45℃, stirring speed 300r / min.

[0049] In order to further understand the present invention, the nickel-based alloy welding wire for nuclear power provided by the present invention is described in detail below in conjunction with specific embodiments, and the protection scope of the present invention is not limited by the following embodiments.

[0050] Example 1 This embodiment provides a nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.19%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0051] The above RE is a mixture of Y, Ce and Gd in a mass ratio of 2:1:1.

[0052] The above-mentioned nano ceramic material is boron carbide.

[0053] This embodiment also provides a method for preparing the above-mentioned nickel-based alloy welding wire for nuclear power, comprising the following steps: S1: The raw materials are weighed according to the mass percentage of the formula and processed to obtain a uniform and refined mixed powder.

[0054] S2: The mixed powder and nano-ceramic material in S1 are placed in a smelting furnace for smelting, and after high-temperature refining and low-temperature refining, they are remelted and cast into alloy ingots.

[0055] The above high temperature refining is smelting at 1800°C for 35 minutes; The above low temperature refining is smelting at 1680°C for 20 minutes; The above remelting is electroslag remelting, and the furnace temperature is 1800°C.

[0056] S3: After annealing the alloy ingot, forging and rolling are performed to prepare alloy wire rods.

[0057] The above annealing process is heating to 1030°C and keeping the temperature for 25h; The forging process is as follows: forging the blank into alloy blank I at 950°C with a forging ratio of 3.5; after tempering at 980°C for 1.4h, forging into alloy blank II at 1050°C with a forging ratio of 5.5; and then forging into alloy blank III at the same temperature with a forging ratio of 3.5; The above rolling process is to keep the temperature at 1020°C for 1 hour and hot-roll the alloy wire rod at 1000°C into Φ4.5mm.

[0058] S4: After pre-treatment, the alloy wire rod is subjected to multiple drawing-annealing steps.

[0059] The above-mentioned pretreatment is to heat the alloy wire rod to 950°C and keep it at that temperature for 1.5 hours, oil cool it for softening treatment, alkali boil it, then high-pressure water wash it, then pickle it after water washing, and then ultrasonic wash it; In the above-mentioned drawing, a lubricant is added before drawing, and the alloy wire is obtained by multiple drawing processes; The above annealing is vacuum annealing after 8 drawing passes, and the annealing temperature is 700°C.

[0060] S5: Processing the alloy wire into the required size and performing solution-aging treatment.

[0061] The solution-aging treatment in S5 is a multi-step graded treatment; specifically, in a nitrogen environment, heating to 1000°C, keeping warm for 2.3 hours, continuing to heat to 1080°C, keeping warm for 2.5 hours, continuing to heat to 1120°C, keeping warm for 1.5 hours, continuing to heat to 1155°C, keeping warm for 1.5 hours, and rapid water quenching to obtain a solid solution alloy; the above-mentioned aging is heating to 820°C, keeping warm for 5 hours, air cooling, and then heating to 760°C, keeping warm for 12 hours, and air cooling.

[0062] S6: pickling the alloy wire; coating; and S7: Plating is performed on the surface to obtain the target product.

[0063] Example 2 This embodiment provides a nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.01%, Si: 0.30%, Cr: 28.5%, Fe: 7.0%, Co: 0.10%, W: 0.50%, Mo: 4.0%, B: 0.01%, Al: 0.30%, Ti: 0.20%, Zr: 0.005%, Nb: 2.0%, Ta: 0.5%, RE: 0.20%, S: 0.002%, P: 0.002%, nano-ceramic material: 4.0%, Ni balance.

[0064] The above RE is a mixture of Y, Ce and Gd in a mass ratio of 2:1:1.

[0065] The above-mentioned nano ceramic material is boron carbide.

[0066] This embodiment also provides a method for preparing the above-mentioned nickel-based alloy welding wire for nuclear power, comprising the following steps: S1: The raw materials are weighed according to the mass percentage of the formula and processed to obtain a uniform and refined mixed powder.

[0067] S2: The mixed powder and nano-ceramic material in S1 are placed in a smelting furnace for smelting, and after high-temperature refining and low-temperature refining, they are remelted and cast into alloy ingots.

[0068] The above high temperature refining is smelting at 1750°C for 45 minutes; The above low temperature refining is smelting at 1650°C for 25 minutes; The above remelting is electroslag remelting, and the furnace temperature is 1750°C.

[0069] S3: After annealing the alloy ingot, forging and rolling are performed to prepare alloy wire rods.

[0070] The above annealing process is heating to 1000°C and keeping the temperature for 35h; The forging process is as follows: at 950°C, the billet is forged into alloy billet I with a forging ratio of 3; after tempering at 950°C for 2 hours, the billet is forged into alloy billet II at 1050°C with a forging ratio of 6; and then the billet is forged into alloy billet III at the same temperature with a forging ratio of 4; The above rolling process is to keep the temperature at 1000°C for 1.5 hours and hot-roll the alloy wire rod at 950°C into Φ4.0mm.

[0071] S4: After pre-treatment, the alloy wire rod is subjected to multiple drawing-annealing steps.

[0072] The above-mentioned pretreatment is to heat the alloy wire rod to 950°C and keep it at that temperature for 1.5 hours, oil cool it for softening treatment, alkali boil it, then high-pressure water wash it, then pickle it after water washing, and then ultrasonic wash it; In the above-mentioned drawing, a lubricant is added before drawing, and the alloy wire is obtained by multiple drawing processes; The above annealing is vacuum annealing after 10 drawing passes, and the annealing temperature is 640°C.

[0073] S5: Processing the alloy wire into the required size and performing solution-aging treatment.

[0074] The solution-aging treatment in S5 is a multi-step graded treatment; specifically, in a nitrogen environment, heating to 1050°C, keeping warm for 2 hours, continuing to heat to 1100°C, keeping warm for 2 hours, continuing to heat to 1150°C, keeping warm for 1 hour, continuing to heat to 1170°C, keeping warm for 1 hour, and rapid water quenching to obtain a solid solution alloy; the above-mentioned aging is heating to 850°C, keeping warm for 3 hours, air cooling, then heating to 770°C, keeping warm for 10 hours, and air cooling.

[0075] S6: pickling the alloy wire; coating; and S7: Plating is performed on the surface to obtain the target product.

[0076] Example 3 This embodiment provides a nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.05%, Si: 0.10%, Cr: 30.5%, Fe: 11.0%, Co: 0.05%, W: 1.0%, Mo: 3.0%, B: 0.005%, Al: 0.10%, Ti: 0.10%, Zr: 0.02%, Nb: 2.5%, Ta: 0.1%, RE: 0.30%, S: 0.002%, P: 0.002%, nano-ceramic material: 2.0%, Ni balance.

[0077] The above RE is a mixture of Y, Ce and Gd in a mass ratio of 2:1:1.

[0078] The above-mentioned nano ceramic material is boron carbide.

[0079] This embodiment also provides a method for preparing the above-mentioned nickel-based alloy welding wire for nuclear power, comprising the following steps: S1: The raw materials are weighed according to the mass percentage of the formula and processed to obtain a uniform and refined mixed powder.

[0080] S2: The mixed powder and nano-ceramic material in S1 are placed in a smelting furnace for smelting, and after high-temperature refining and low-temperature refining, they are remelted and cast into alloy ingots.

[0081] The above high temperature refining is smelting at 1850°C for 30 minutes; The above low temperature refining is smelting at 1700°C for 15 minutes; The above remelting is electroslag remelting, and the furnace temperature is 1850°C.

[0082] S3: After annealing the alloy ingot, forging and rolling are performed to prepare alloy wire rods.

[0083] The above annealing process is heating to 1050°C and keeping it for 20 hours; The forging process is as follows: forging the blank into alloy blank I at 950°C with a forging ratio of 4; after tempering at 1000°C for 1h, forging into alloy blank II at 1050°C with a forging ratio of 5; and then forging into alloy blank III at the same temperature with a forging ratio of 3; The above rolling process is to keep the temperature at 1050°C for 0.5h and hot-roll the alloy wire rod at 1100°C into Φ5.0mm.

[0084] S4: After pre-treatment, the alloy wire rod is subjected to multiple drawing-annealing steps.

[0085] The above-mentioned pretreatment is to heat the alloy wire rod to 950°C and keep it at that temperature for 1.5 hours, oil cool it for softening treatment, alkali boil it, then high-pressure water wash it, then pickle it after water washing, and then ultrasonic wash it; In the above-mentioned drawing, a lubricant is added before drawing, and the alloy wire is obtained by multiple drawing processes; The above annealing is vacuum annealing after 6 drawing passes, and the annealing temperature is 800°C.

[0086] S5: Processing the alloy wire into the required size and performing solution-aging treatment.

[0087] The solution-aging treatment in S5 is a multi-step graded treatment; specifically, in a nitrogen environment, heating to 950°C, keeping warm for 3 hours, continuing to heat to 1050°C, keeping warm for 3 hours, continuing to heat to 1100°C, keeping warm for 2 hours, continuing to heat to 1150°C, keeping warm for 2 hours, and rapid water quenching to obtain a solid solution alloy; the above-mentioned aging is heating to 800°C, keeping warm for 8 hours, air cooling, then heating to 750°C, keeping warm for 15 hours, and air cooling.

[0088] S6: pickling the alloy wire; coating; and S7: Plating is performed on the surface to obtain the target product.

[0089] Example 4 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 8.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.19%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0090] Example 5 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 10.3%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.19%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0091] Example 6 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.13%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0092] Example 7 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.24%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0093] Example 8 The rest is the same as in Example 1, except that: In a formula of nickel-based alloy welding wire for nuclear power, Preferably, RE is a mixture of Y, Ce and Sm in a ratio of 2:1:1 by mass.

[0094] Example 9 The rest is the same as in Example 1, except that: In a formula of nickel-based alloy welding wire for nuclear power, Preferably, RE is a mixture of Y, Nd and Pr in a ratio of 2:1:1 by mass.

[0095] Example 10 The rest is the same as in Example 1, except that: In a formula of nickel-based alloy welding wire for nuclear power, Preferably RE is Y.

[0096] The following comparative examples are compared with Example 1: Comparative Example 1 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 28.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.19%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0097] Comparative Example 2 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.19%, Ti: 0.16%, Zr: 0.010%, Nb: 3.0%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0098] Comparative Example 3 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.19%, Ti: 0.16%, Zr: 0.010%, Nb: 1.8%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0099] Comparative Example 4 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.08%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0100] Comparative Example 5 The rest is the same as in Example 1, except that: A nickel-based alloy welding wire for nuclear power, comprising the following powder raw materials in parts by weight: C: 0.03%, Si: 0.20%, Cr: 29.5%, Fe: 9.0%, Co: 0.08%, W: 0.70%, Mo: 3.5%, B: 0.008%, Al: 0.32%, Ti: 0.16%, Zr: 0.010%, Nb: 2.3%, Ta: 0.3%, RE: 0.26%, S: 0.002%, P: 0.002%, nano-ceramic material: 3.0%, Ni balance.

[0101] Comparative Example 6 The rest is the same as in Example 1, except that: In a formula of nickel-based alloy welding wire for nuclear power, The weight fraction of the RE is 0; that is, no RE is added.

[0102] Comparative Example 7 The rest is the same as in Example 1, except that: In a formula of nickel-based alloy welding wire for nuclear power, The weight fraction of the nano-ceramic material is 0, that is, no nano-ceramic material is added.

[0103] Comparative Example 8 The rest is the same as in Example 1, except that: In a method for preparing a nickel-based alloy welding wire for nuclear power, in S5, The solid solution is heated to 1000°C in a nitrogen environment, kept warm for 2.3 hours, continued to heat to 1155°C, kept warm for 1.5 hours, and quickly water quenched to obtain a solid solution alloy; the aging is heated to 760°C, kept warm for 12 hours, and air cooled.

[0104] The nickel alloy welding materials obtained in the embodiment and the comparative example were used to perform TIG / flat welding on the ASME SB-168 UNS N06690 alloy material, and the post-weld heat treatment parameters were 610° C. and kept at this temperature for 24 hours.

[0105] The physical properties of the nickel-based alloy welding wire for nuclear power prepared in the embodiment of the present invention and the comparative example were measured respectively, and the results are shown in Table 1.

[0106] Table 1 Physical test performance of each embodiment It can be observed from Examples 1-10 that the nickel-based alloy welding wire for nuclear power of the present invention has excellent mechanical properties and corrosion resistance; it also has excellent radiation resistance and the like.

[0107] It can be observed from Example 1 and Comparative Examples 1-7 that the addition of appropriate amounts of Cr and Mo to the nickel-based alloy welding wire for nuclear power of the present invention achieves a solid solution strengthening effect, thereby improving its high temperature corrosion resistance and thermal strength; Nb has the ability to reduce the tendency of strain cracking, and can improve the high temperature strength, creep resistance, corrosion resistance and other properties of the alloy; the compounding of Fe and Nb can improve the strength and thermoplasticity of the weld; Al and Ti have a certain strengthening and toughening effect on the alloy; RE has good high temperature oxidation resistance; and can also improve high temperature strength, etc.; boron carbide nano-ceramic materials have good mechanical strength and radiation resistance, etc.; It can be observed from Example 1 and Comparative Example 8 that the multi-step solution-aging process is conducive to grain refinement and improves the interphase compatibility of materials such as ceramic materials, thereby further improving the performance; that is, the appropriate preparation process has a positive effect on the performance of the nickel-based alloy welding material; In summary, the nickel-based alloy welding wire for nuclear power of the present invention has excellent mechanical properties, corrosion resistance, excellent radiation resistance, etc., and can meet the use requirements of the nuclear industry.

[0108] The test method is as follows: (1) Crack resistance: Observe whether there are visible cracks on the welding strip, and if the specimen is intact after bending or the length of a single crack is ≤1.5mm, it is recorded as "OK". On the contrary, if there are visible cracks and the length of a single crack after bending is greater than 1.5mm, it is recorded as "NG".

[0109] (2) Mechanical properties test: The room temperature mechanical properties and high temperature mechanical properties tests of the welded joints were carried out at room temperature and 350°C respectively in accordance with GB / T2651-2008 “Tensile test method for welded joints”.

[0110] (3) Corrosion rate: The corrosion resistance test was carried out using ASTM G28 A method, and the test time was 120 hours.

[0111] (4) Post-irradiation elongation retention rate: A tensile specimen with a length of 160 mm was irradiated with neutrons in the middle G7 channel of the HFETR. The average fast neutron injection rate (E>0.1 MeV) was 1.961×10 14 cm -2 The total effective full-power operation was 145 days, and the average fast neutron flux (E>0.1MeV) in the irradiation period was measured to be 2.405×10 21 cm -2 . Re-test the mechanical properties after radiation. Retention rate of elongation after irradiation = elongation after irradiation / elongation before irradiation × 100%.

[0112] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A nickel-based alloy welding wire for nuclear power, characterized in that: The powder raw materials include the following parts by weight: C: 0.01-0.05%, Si: 0.10-0.30%, Cr: 28.5-30.5%, Fe: 7.0-11.0%, Co: ≤0.10%, W: 0.50-1.00%, Mo: 3.0-4.0%, B: 0.005-0.010%, Al: 0.1-0.3%, Ti: 0.1-0.2%, Zr: 0.005-0.020%, Nb: 2.0-2.5%, Ta: 0.1-0.5%, RE: 0.20-0.30%, S: <0.005%, P: <0.005%, nano-ceramic materials: 2.0-4.0%, Ni balance.

2. A nickel-based alloy welding wire for nuclear power according to claim 1, characterized in that: The total amount of Cr and Mo is not less than 32.5%.

3. The high-strength nickel-chromium alloy wire according to claim 1, characterized in that: The weight ratio of Fe to Nb is (3.5-4.5):

1.

4. The nickel-based alloy welding wire for nuclear power according to claim 1, characterized in that: The weight ratio of Al to Ti is (0.8-1.5):

1.

5. The nickel-based alloy welding wire for nuclear power according to claim 1, characterized in that: The RE is one or more of Y, Ce, Sm, Gd, Nd, and Pr.

6. The nickel-based alloy welding wire for nuclear power according to claim 1, characterized in that: The nano ceramic material is carbide.

7. The nickel-based alloy welding wire for nuclear power according to claim 1, characterized in that: The carbide is boron carbide.

8. The method for preparing a nickel-based alloy welding wire for nuclear power according to claim 1, characterized in that: The following steps are involved: S1: The raw materials are weighed according to the mass percentage of the formula and processed to obtain a uniform and refined mixed powder; S2: Put the mixed powder and nano-ceramic material in S1 into a smelting furnace for smelting, and after high-temperature refining and low-temperature refining, remelt and refine, and cast into alloy ingots; S3: After annealing the alloy ingot, forging and rolling are performed to prepare alloy wire rods; S4: Pre-treating the alloy wire rod and then performing multiple drawing-annealing steps; S5: Processing the alloy wire into the required size and performing solution-aging treatment; S6: pickling the alloy wire; coating; and S7: Plating is performed on the surface to obtain the target product.

9. A nickel-based alloy welding wire for nuclear power according to claim 8, characterized in that: The solution-aging treatment in S5 is a multi-step graded treatment.

Images