High-strength pure nickel wire and its preparation method

Abstract

This invention relates to a high-strength pure nickel wire and its preparation method. The wire comprises, by mass percentage, 0.05%–0.15% C, 0.05%–0.15% Mn, 0.10%–0.35% Si, 0.10%–0.50% additive element X, with the balance being Ni. The C, Mn, Si, and X are all dissolved in a face-centered cubic nickel-based solid solution. The wire has a tensile strength of 400–500 MPa. The wire of this invention possesses advantages such as high tensile strength, stable mechanical properties, and controllable alloy mechanical properties, making it particularly suitable for preparing high-strength pure nickel filter screens.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials, and specifically relates to a high-strength pure nickel wire and its preparation method. Background Technology

[0002] Pure nickel is susceptible to corrosion in oxidizing environments, but it exhibits excellent corrosion resistance because a protective film easily forms on its surface to prevent further corrosion. It also possesses high-temperature resistance and structural stability at high temperatures, making it commonly used in the manufacture of components for the chemical, nuclear power, and aerospace industries. The most widely used national standard grades of pure nickel are N4 and N6, which have good corrosion resistance and tensile strengths ranging from 300 to 400 MPa.

[0003] Metal filter screens are commonly used in aviation filters, water purifier filters, etc., requiring good corrosion resistance and high tensile strength. The metal filter screen wire needs to have good corrosion resistance and a tensile strength of 400–500 MPa to ensure the filter's service life.

[0004] Yan et al. compared the strength of pure nickel strips at home and abroad. Foreign studies improved the tensile strength of strips by increasing the content of elements such as Mn, Fe, and Si, while the improvement in tensile strength of pure nickel was relatively limited. Their research, by controlling the cold rolling deformation of the strip to 9% and mechanically straightening it, increased the tensile strength to 420-450 MPa. For filter wire, it is necessary to ensure that the material is free from stress to guarantee stability during use; therefore, cold working methods are not suitable for improving tensile strength.

[0005] Yang Zhe et al. analyzed the effects of alloying elements on pure nickel strip and found that increasing the C and Mg content in pure nickel can effectively improve the tensile strength of the strip. C mainly reacts with Ni to form NiC, which easily forms at grain boundaries, leading to grain boundary weakening and brittle fracture. The presence of Mg can increase the nucleation rate of pure nickel and refine the grains, thus improving tensile strength. However, due to the high reactivity of Mg, the yield of Mg after smelting is greatly affected by the cleanliness and purity of the raw materials and the vacuum level of the smelting equipment. Controlling the Mg content in production applications is difficult and not highly feasible.

[0006] Most pure nickel materials currently available can achieve a strength of around 400 MPa through composition optimization, but they are prone to breakage during the fine wire drawing process, resulting in unstable product quality. Summary of the Invention

[0007] The purpose of this invention is to provide a high-strength pure nickel wire and its preparation method. The pure nickel wire of this invention has the advantages of high tensile strength (400-500 MPa) and stable and controllable mechanical properties through the addition of trace elements and annealing process, and is especially suitable for preparing high-strength pure nickel filter screens.

[0008] The technical solution of this invention is:

[0009] High-strength pure nickel wire, the mass percentage of each component is 0.05% to 0.15% C, 0.05% to 0.15% Mn, 0.10% to 0.35% Si, 0.10% to 0.50% added element X, and the balance is Ni;

[0010] The C, Mn, Si and X are all dissolved in a face-centered cubic nickel-based solid solution;

[0011] The tensile strength of the wire is 400-500 MPa.

[0012] A further technical solution is that the mass percentage of each component of the alloy is 0.10% to 0.12% C, 0.10% to 0.12% Mn, 0.10% to 0.15% Si, 0.10% to 0.50% of added element X, and the balance is Ni;

[0013] The added element X is a combination of at least four of the following: Ti, V, Ce, La, Cr, and Mo.

[0014] The added element X comprises, by mass percentage, 0.05%–0.25% Ti, 0.05%–0.25% V, 0.10%–0.30% Ce, 0.10%–0.30% La, 0.05%–0.25% Cr, and 0.05%–0.25% Mo, with a total mass percentage of added element X of 0.10%–0.50%.

[0015] The above-mentioned wire preparation method includes the following steps:

[0016] 1) Vacuum melting

[0017] Take each component according to the above wire ratio, use vacuum melting (vacuum degree ≤30pa), and cast to obtain ingot;

[0018] 2) Homogenization annealing

[0019] The ingot is forged into a billet and hot rolled to obtain wire rod; the wire rod is homogenized and annealed at 900℃~1050℃ for 1~3 hours, and then rapidly water-cooled after being taken out of the furnace to obtain wire billet;

[0020] 3) Pulling

[0021] The wire blank is homogenized and annealed, and then drawn into wire.

[0022] 4) Recrystallization annealing

[0023] The filament undergoes a first recrystallization annealing; after drawing, a fine filament is obtained, which undergoes a second recrystallization annealing. The temperature for both recrystallization annealings is 850℃~1000℃, and the time is 3~5 minutes. The filament is then rapidly cooled to room temperature at a cooling rate ≥30℃ / second.

[0024] Step 2) The diameter of the wire rod is 8.0 to 12.0 mm.

[0025] The diameter of the wire in step 3) is 3.0 to 5.0 mm.

[0026] Step 4) The diameter of the filament is 0.8 to 1.5 mm.

[0027] Step 4) describes rapid cooling using water cooling.

[0028] The above-mentioned alloys are used in the manufacture of filter screens.

[0029] This invention adds alloying elements to the composition of pure nickel, and improves its tensile strength through solid solution strengthening and grain refinement strengthening, thereby significantly improving the tensile strength of pure nickel wire. This has great practical significance for the production of pure nickel wire for filter screens.

[0030] The main functions of each element in this application in improving tensile strength are as follows:

[0031] The addition of C and Si elements, combined with homogenization annealing and recrystallization annealing processes at 850–1050℃, allows C and Si elements to fully dissolve in the nickel-based solid solution, forming an alloy phase composed of solute atoms dissolved in the crystal lattice of the metal solvent. Pure nickel forms an interstitial solid solution, and the ordered structure undergoes lattice distortion, thereby improving tensile strength.

[0032] The addition of elements such as Mn, Cr, and Mo, whose atomic radii are relatively small compared to nickel, allows them to replace nickel in the pure nickel crystal structure, forming a substitution solid solution, which strengthens the alloy and increases its tensile strength.

[0033] The addition of elements such as Ti, V, Ce, and La can lead to the formation of carbides TiC and VC by Ti and V, and oxides CeO2 and La2O3 by Ce and La. During the nucleation process, oxides can effectively increase the nucleation rate as impurities, resulting in fine-grained strengthening of the alloy.

[0034] The wire preparation method of this invention involves a large number of alloying elements. To ensure sufficient solid solution in the wire, a rapid cooling method is employed to retain interstitial solid solutions within the wire matrix, ensuring that the added elements achieve their purpose of increasing tensile strength. Therefore, the most significant feature of this wire preparation method is the use of homogenization annealing and recrystallization annealing during heat treatment to guarantee the alloy solid solution effect, thus ensuring the wire's processing plasticity. The wire structure is free of precipitated phases, preventing breakage during fine wire drawing, resulting in stable product quality that meets the requirement of over 10,000 meters of wire for filter screens, ensuring the normal operation of the mesh weaving process. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the manufacturing process of the wire described in this invention. Detailed Implementation

[0036] The embodiments of the present invention will be described in detail below.

[0037] Example 1: The components (mass percentage) of the wire were 0.10% C, 0.10% Mn, 0.15% Si, 0.08% Ti, 0.08% V, 0.1% Ce, 0.08% Cr, with the balance being Ni.

[0038] Example 2: The components (mass percentage) of the wire were 0.10% C, 0.10% Mn, 0.15% Si, 0.10% Ti, 0.10% V, 0.1% La, 0.08% Mo, with the balance being Ni.

[0039] Example 3: The composition of the wire was as follows (mass percentage): 0.12% C, 0.12% Mn, 0.10% Si, 0.10% Ce, 0.10% La, 0.1% Cr, 0.08% Mo, with the balance being Ni.

[0040] Example 4: The components (mass percentage) of the wire were 0.10% C, 0.10% Mn, 0.12% Si, 0.08% Ti, 0.08% Ce, 0.10% La, 0.08% Cr, 0.08% Mo, with the balance being Ni.

[0041] Take each component according to the proportions described in any of Examples 1-4 above, and prepare it using the following method (see...). Figure 1 ):

[0042] The alloy is melted in a vacuum induction melting furnace. During the melting process, the vacuum chamber is first evacuated to 10-30 Pa before the power is turned on. After the alloy melts, it is thoroughly stirred to remove gas and finally cast into a water-cooled copper mold to form an ingot. The ingot is forged into a 60mm square billet and then hot-rolled to obtain a wire rod with a diameter of 8.0mm. The wire rod is then subjected to the following treatment.

[0043] The wire rod was loaded into a bogie furnace for homogenization annealing at 950℃ for 1.5 hours. Immediately after removal from the furnace, it was water-cooled, and then the surface was polished before being drawn to 3.0mm. A first recrystallization annealing was then performed in a continuous heat treatment furnace at 900℃ for 5 minutes, followed by rapid water quenching at a cooling rate ≥30℃ / second. The wire was then drawn to 0.8mm using a wire drawing machine, and a second recrystallization annealing was performed in a continuous heat treatment furnace at 870℃ for 4 minutes, followed by rapid water quenching at a cooling rate ≥30℃ / second. The finished product (pure nickel wire) was then obtained after removing it from the furnace.

[0044] Finished products were sampled and tested for tensile strength. The test method was in accordance with the national standard GB / T 228.1-2010 Metallic materials, tensile testing - Part 1: Test method at room temperature.

[0045] The tensile strength test results are shown in the table below:

[0046] sample Example 1 Example 2 Example 3 Example 4 Tensile strength / MPa 456 463 424 445

[0047] The above description is a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the innovative points of the present invention shall fall within the protection scope of the present invention.

Claims

1. A high-strength pure nickel wire, characterized in that, The wire contains 0.05%–0.15% C, 0.05%–0.15% Mn, 0.10%–0.35% Si, 0.10%–0.50% added element X, and the balance is Ni. The C, Mn, Si and X are all dissolved in a face-centered cubic nickel-based solid solution; The tensile strength of the wire is 400-500 MPa; The added element X is a combination of at least four of Ti, V, Ce, La, Cr, and Mo, wherein the mass percentage of each combination of added element X is 0.05%–0.25% Ti, 0.05%–0.25% V, 0.10%–0.30% Ce, 0.10%–0.30% La, 0.05%–0.25% Cr, and 0.05%–0.25% Mo, and the total mass percentage of added element X is 0.10%–0.50%. The wire is obtained through the following steps: Homogenization annealing The above components are vacuum melted, and the cast ingots are forged into billets and hot rolled to obtain wire rods. The wire rods are homogenized and annealed at 900℃~1050℃ for 1~3 hours, and then rapidly water-cooled after being taken out of the furnace to obtain wire blanks. Pull The wire blank is homogenized and annealed, and then drawn into wire. recrystallization annealing The filament undergoes a first recrystallization annealing; after drawing, a fine filament is obtained, which undergoes a second recrystallization annealing. The temperature for both recrystallization annealings is 850℃~1000℃, and the time is 3~5 minutes. The filament is then rapidly cooled to room temperature at a cooling rate ≥30℃ / second.

2. The wire according to claim 1, characterized in that, The wire comprises, by mass percentage, 0.10%–0.12% C, 0.10%–0.12% Mn, 0.10%–0.15% Si, 0.10%–0.50% added element X, with the balance being Ni.

3. The method for preparing the wire according to any one of claims 1-2, characterized in that, The steps are as follows: 1) Vacuum melting According to the proportions of the wire as described in any one of claims 1-2, each component is taken, vacuum melting is performed, the vacuum degree is ≤30pa, and the ingot is cast. 2) Homogenization annealing The ingot is forged into a billet and hot rolled to obtain wire rod; the wire rod is homogenized and annealed at 900℃~1050℃ for 1~3 hours, and then rapidly water-cooled after being taken out of the furnace to obtain wire billet; 3) Pulling The wire blank is homogenized and annealed, and then drawn into wire. 4) Recrystallization annealing The filament undergoes a first recrystallization annealing; after drawing, a fine filament is obtained, which undergoes a second recrystallization annealing. The temperature for both recrystallization annealings is 850℃~1000℃, and the time is 3~5 minutes. The filament is then rapidly cooled to room temperature at a cooling rate ≥30℃ / second.

4. The method according to claim 3, characterized in that: Step 2) The diameter of the wire rod is 8.0 to 12.0 mm.

5. The method according to claim 3, characterized in that: Step 3) The diameter of the wire is 3.0 to 5.0 mm.

6. The method according to claim 3, characterized in that: Step 4) The diameter of the filament is 0.8 to 1.5 mm.

7. The method according to claim 3, characterized in that: Step 4) The rapid cooling method used is water cooling.

8. Use of the wire according to any one of claims 1-2 in the manufacture of a filter screen.

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