A copper-nickel alloy and a method for producing the same

Abstract

The application relates to a copper-nickel alloy and a preparation method thereof, and relates to the technical field of alloy materials, and mainly adopts the technical scheme that the copper-nickel alloy comprises the following chemical components in percentage by weight: Ni: 10-30 wt%; Fe: 0-1.8 wt%; Mn: 0-1.0 wt%; micro-alloying elements: 0.05-0.2 wt%; impurity elements: <0.5 wt%; and the balance is Cu; wherein the micro-alloying elements comprise noble metal elements. The application mainly utilizes the synergistic effect of the micro-alloying elements in accelerating the anodic and cathodic reactions of the copper-nickel alloy in a corrosive salt solution and promoting non-uniform deposition nucleation, so that the protective property of a corrosion product film on the surface of the copper-nickel alloy is greatly improved, and the copper-nickel alloy has excellent corrosion resistance, and the erosion corrosion rate is reduced by more than 60% compared with that of the existing copper-nickel alloy.

Description

Technical Field

[0001] This invention relates to the field of alloy materials technology, and in particular to a copper-nickel alloy and its preparation method. Background Technology

[0002] Copper-nickel alloys possess excellent resistance to seawater corrosion, fouling, and cold and hot working properties, making them widely used in piping systems of ships and marine engineering equipment. They are key materials in naval and marine engineering projects and are irreplaceable. However, copper-nickel alloys often operate in flowing media and are highly susceptible to erosion corrosion damage. Therefore, effectively addressing the erosion corrosion problem of copper-nickel alloys and extending their service life is of great significance for national defense security and the national marine development strategy.

[0003] Currently, the traditional approach to improving the corrosion resistance of copper-nickel alloys is to increase the content of the corrosion-resistant element Ni. Although Ni participates in film formation, making the surface film of copper-nickel alloys denser and thus improving their protective properties, this beneficial effect only occurs in the middle and later stages of film formation; Ni does not participate in the initial surface film growth. In this case, Ni obviously cannot increase the surface film formation rate, which may be an important reason why localized corrosion perforation events still occur frequently in B30 copper-nickel alloys (with Ni content increased to 30%).

[0004] In summary, traditional design approaches for corrosion-resistant copper-nickel alloys cannot fully meet the demand for significantly improved corrosion resistance, necessitating further exploration of new design methods. Therefore, providing a highly corrosion-resistant copper-nickel alloy and its preparation method has become a pressing issue for those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a copper-nickel alloy and a method for preparing the same, the main purpose of which is to improve the surface film formation rate of the copper-nickel alloy in corrosive salt solutions, thereby improving the corrosion resistance of the copper-nickel alloy.

[0006] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0007] On one hand, embodiments of the present invention provide a copper-nickel alloy, wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition:

[0008] Ni: 10–30 wt%; Fe: 0–1.8 wt%; Mn: 0–1.0 wt%; Microalloying elements: 0.05–0.2 wt%; Impurity elements: <0.5 wt%; Balance Cu;

[0009] The microalloying elements include noble metal elements.

[0010] Preferably, in the copper-nickel alloy, the content of the noble metal element is 0.05 to 0.2 wt%.

[0011] Preferably, the precious metal element includes one or both of Pd and Pt.

[0012] Preferably, the microalloying elements further include rare earth elements; preferably, the content of rare earth elements in the copper-nickel alloy is 0 to 0.05 wt%; preferably, the sum of the contents of the noble metal elements and rare earth elements in the copper-nickel alloy is 0.05 to 0.2 wt%; preferably, the rare earth elements include one or more of Y, Sc, and La.

[0013] Preferably, the impurity element includes one or more of Zn, C, Si, P, S, and Pb.

[0014] Preferably, the average grain size in the copper-nickel alloy is 16–18 μm.

[0015] Preferably, the copper-nickel alloy, after being immersed in a 3.5±0.1wt% NaCl solution for 14±1 days, exhibits a polarization resistance of 2.6~5.9×10⁻⁶. 4 Ω / cm 2 The surface film thickness is 2–5 μm.

[0016] Furthermore, embodiments of the present invention also provide a method for preparing the above-mentioned copper-nickel alloy, wherein the preparation method includes the following steps:

[0017] Step 1): Prepare raw materials according to the component ratio, and smelt the raw materials to prepare alloy ingots;

[0018] Step 2), the alloy ingot is melted and cast into a casting;

[0019] Step 3) The ingot is subjected to homogenization annealing treatment, and after cooling, a homogenized annealed ingot is obtained.

[0020] Step 4) The ingot after homogenization annealing is subjected to plastic processing to obtain the plastically deformed alloy;

[0021] Step 5) The plastically deformed alloy is subjected to recrystallization annealing treatment, and after cooling, a copper-nickel alloy is obtained.

[0022] Preferably, in step 1), the raw material is selected from one or more of pure metal, B10 commercial alloy, and B30 commercial alloy; preferably, the purity of the pure metal is >99%.

[0023] Preferably, in step 2): all raw materials except the microalloying element are placed in the crucible of the melting furnace; the furnace cavity is evacuated to a set pressure; after evacuation is stopped, inert gas is introduced to achieve a set vacuum level; after the raw materials except the microalloying element have melted, the microalloying element is added to the molten pool; then melting and cooling are performed to obtain an alloy ingot; preferably, the melting current is 350–400 A; preferably, the melting time is 3–5 minutes; preferably, the set pressure is 3–4 × 10⁻⁶. -3 Pa; preferably, the vacuum degree is -0.07 to -0.09 MPa; preferably, the melting and cooling process needs to be repeated 3 to 6 times.

[0024] Preferably, in step 3): the alloy ingot is placed in the crucible of the electric arc furnace, the furnace cavity is evacuated to a set pressure, and after evacuation is stopped, inert gas is introduced to bring the furnace cavity to the set pressure. The alloy ingot is then melted and cast into a mold for cooling to obtain an alloy ingot. Preferably, the set pressure is 3–4 × 10⁻⁶. -3 Pa; preferably, the set pressure is 400-600 mbar.

[0025] Preferably, in step 3), the homogenization annealing temperature is 950–1050°C, and the holding time is 2–4 h; preferably, the homogenization annealing is carried out in an inert atmosphere; preferably, the cooling method after the homogenization annealing is furnace cooling.

[0026] Preferably, in step 4), the plastic processing includes any one of hot rolling, cold rolling, and drawing.

[0027] Preferably, in step 5), the recrystallization annealing treatment is carried out at a temperature of 700–900°C for 10–30 minutes; preferably, the recrystallization annealing treatment is carried out in an inert atmosphere; preferably, the cooling method after the recrystallization annealing treatment is furnace cooling.

[0028] Compared with the prior art, the copper-nickel alloy and its preparation method of the present invention have at least the following advantages:

[0029] Beneficial effects:

[0030] On one hand, the present invention provides a copper-nickel alloy, wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni: 10-30 wt%; Fe: 0-1.8 wt%; Mn: 0-1.0 wt%; microalloying element: 0.05-0.2 wt%; impurity element: <0.5 wt%; balance Cu; wherein the microalloying element includes noble metal elements. Here, the copper-nickel alloy designed in this invention, by introducing microalloying elements containing noble metal elements, can significantly improve the surface reactivity of the copper-nickel alloy in corrosive salt solutions, accelerate the cathodic reaction on the surface of the copper-nickel alloy, increase the pH value of the surface, and generate more film-forming anions (OH-). - It can also refine the grains, accelerate the anodic dissolution reaction of copper, and generate more film-forming cations (CuCl2). - This promotes the formation of the Cu2O precipitate film, which plays a major role in corrosion resistance, thereby achieving rapid formation of a protective surface film and improving the corrosion resistance of copper-nickel alloys.

[0031] Furthermore, the microalloying elements in the copper-nickel alloy provided by the present invention also include rare earth elements such as Y, Sc, and La, with a content of 0 to 0.05 wt%. Here, the selective addition of rare earth elements in the present invention can promote the dissolution of Cu and the formation of hydroxide precipitates. These precipitates can act as heterogeneous nucleating agents, further accelerating the formation of Cu2O precipitate films and amplifying the beneficial effects of precious metal microalloying elements such as Pd.

[0032] In summary, the copper-nickel alloy provided by this invention, through targeted microalloying, reduces the grain size of the alloy, thereby accelerating the anodic reaction of the copper-nickel alloy in corrosive salt solutions to generate more film-forming cations (accelerated anodic reaction strategy). On the other hand, it enhances the surface reactivity of the copper-nickel alloy in corrosive salt solutions, thereby accelerating the cathodic reaction to generate more film-forming anions (accelerated cathodic reaction strategy). Furthermore, it forms heterogeneous nucleation sites to accelerate the film formation rate (non-uniform precipitation nucleation strategy). By utilizing the above synergistic effects, the formation rate of the surface film of the copper-nickel alloy is improved, thereby enhancing the copper-nickel alloy's resistance to erosion corrosion and other localized corrosion.

[0033] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0034] Figure 1 The microstructures of the Cu-10Ni-0.1Pd alloy of Example 1, the Cu-10Ni-0.1Pd / Y alloy of Example 2, and the Cu-10Ni alloy of Comparative Example 1 are as follows: Figure 1Figure (a) shows the metallographic morphology of the Cu-10Ni alloy, Figure (b) shows the metallographic morphology of the Cu-10Ni-0.1Pd alloy, Figure (c) shows the metallographic morphology of the Cu-10Ni-0.1Pd / Y alloy, and Figure (d) shows the XRD patterns of the three alloys.

[0035] Figure 2 The polarization resistance comparison graphs are shown for Cu-10Ni-0.1Pd alloy of Example 1, Cu-10Ni-0.1Pd / Y of Example 2, Cu-10Ni-0.1Pd / Sc of Example 3, Cu-10Ni-0.1Pt alloy of Example 4, Cu-10Ni-0.1Pt / La alloy of Example 5, Cu-10Ni alloy of Comparative Example 1 and Cu-10Ni-0.1Y of Comparative Example 2, after immersion in a 3.5wt% NaCl solution for 14 days.

[0036] Figure 3 The images show the corrosion morphology of the Cu-10Ni-0.1Pd alloy of Example 1, the Cu-10Ni-0.1Pd / Y alloy of Example 2, and the Cu-10Ni alloy of Comparative Example 1 after immersion in a 3.5wt% NaCl solution for 14 days. Figure 3 Figure (a) shows the surface corrosion morphology of Cu-10Ni-0.1Pd alloy, (b) shows the surface corrosion morphology of Cu-10Ni-0.1Pd / Y alloy, (c) shows the surface corrosion morphology of Cu-10Ni alloy, (d) shows the cross-sectional corrosion morphology of Cu-10Ni-0.1Pd alloy, (e) shows the cross-sectional corrosion morphology of Cu-10Ni-0.1Pd / Y alloy, and (f) shows the cross-sectional morphology of Cu-10Ni alloy.

[0037] Figure 4 The graph shows a comparison of the erosion corrosion rates of the B10-0.2Pd alloy of Example 8, the B10-0.2Pd / Y alloy of Example 9, the B30-0.2Pd alloy of Example 10, the B30-0.2Pd / Y alloy of Example 11, the B10 alloy of Comparative Example 3, the B10-0.2Y alloy of Comparative Example 4, the B30 alloy of Comparative Example 5, and the B30-0.2Y alloy of Comparative Example 6 in a 3.5wt% NaCl solution containing 0.1wt% quartz sand at a flow rate of 2.4 m / s. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0039] This invention provides a copper-nickel alloy and its preparation method. Through targeted microalloying, on the one hand, the grain size is reduced, thereby accelerating the anodic reaction to generate more film-forming cations (accelerated anodic reaction strategy); on the other hand, the surface reactivity is increased, thereby accelerating the cathodic reaction to generate more film-forming anions (accelerated cathodic reaction strategy); and furthermore, heterogeneous nucleation sites are formed, accelerating the film formation nucleation rate (non-uniform precipitation nucleation strategy). Utilizing these synergistic effects, the formation rate of the surface film on the copper-nickel alloy is improved, thereby enhancing the copper-nickel alloy's resistance to erosion corrosion and other localized corrosion. The specific details of this invention are as follows:

[0040] On one hand, the present invention provides a copper-nickel alloy, wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition:

[0041] Ni: 10–30 wt%; Fe: 0–1.8 wt%; Mn: 0–1.0 wt%; Microalloying elements: 0.05–0.2 wt%; Impurity elements: <0.5 wt%; Balance Cu;

[0042] The microalloying elements include noble metal elements. Preferably, the content of the noble metal element in the copper-nickel alloy is 0.05–0.2 wt%. Preferably, the noble metal element includes one or more of other noble metal elements such as Pd and Pt.

[0043] Regarding the above scheme, it should be noted that: noble metal elements, as the main microalloying elements, can significantly improve the surface reactivity of copper-nickel alloys in corrosive salt solutions (such as seawater and other corrosive media), accelerate the cathodic reaction on the surface of copper-nickel alloys, increase the surface pH value, generate more film-forming anions (OH-), and at the same time, refine the grains, accelerate the anodic dissolution reaction of copper, and generate more film-forming cations (CuCl2). - This promotes the formation of the Cu2O precipitate film, which plays a major role in corrosion resistance, thereby achieving rapid formation of a protective surface film and improving corrosion resistance.

[0044] Preferably, the microalloying elements further include rare earth elements; preferably, the content of rare earth elements in the copper-nickel alloy is 0 to 0.05 wt%; preferably, the sum of the contents of the noble metal elements and rare earth elements in the copper-nickel alloy is 0.05 to 0.2 wt%; preferably, the rare earth elements include one or more of Y, Sc, and La.

[0045] It should be noted that rare earth elements can preferentially dissolve with Cu to form hydroxide precipitates. These precipitates can act as heterogeneous nucleation agents, further accelerating the formation of Cu2O precipitate films and amplifying the beneficial effects of precious metal microalloying elements such as Pd.

[0046] Furthermore, compared to the traditional approach of relying on corrosion-resistant elements such as Ni to improve the corrosion resistance of copper-nickel alloys, this invention utilizes a novel approach of achieving rapid film formation through the synergistic effect of microalloying, which can significantly improve the corrosion resistance of copper-nickel alloys.

[0047] The composition design of the copper-nickel alloy of the present invention is explained as follows:

[0048] The Ni content in copper-nickel alloys is 10-30 wt%. If the Ni content is too low, the basic corrosion resistance of the alloy will decrease, while if the content is too high, the cost will increase and it will be detrimental to the application.

[0049] The Fe content in copper-nickel alloys is 0 to 1.8 wt%. If the Fe content is too high, it will lead to the formation of a second phase, which is detrimental to corrosion resistance and processing performance.

[0050] The Mn content in copper-nickel alloys is 0 to 1.0 wt%. If the Mn content is too high, it will lead to the formation of a second phase, which is detrimental to corrosion resistance and processing performance.

[0051] The content of precious metal elements in copper-nickel alloys is 0.05 to 0.2 wt%. If the content of precious metal elements is too low, it will not improve the corrosion resistance. If the content is too high, it will not only lead to the formation of a second phase, which is detrimental to the corrosion resistance and processing performance, but also increase the cost.

[0052] The rare earth element content in copper-nickel alloys is 0 to 0.05 wt%. Excessive rare earth element content will not only fail to improve corrosion resistance, but will also lead to the formation of a second phase, which is detrimental to both corrosion resistance and processing performance.

[0053] In another aspect, embodiments of the present invention provide a method for preparing a copper-nickel alloy, which includes the following steps:

[0054] Step 1): Prepare raw materials according to the component ratio, and smelt the raw materials to prepare alloy ingots.

[0055] For raw materials: the raw materials shall be selected from one or more of pure metals, B10 commercial alloys, and B30 commercial alloys; preferably, the purity of pure metals is >99%.

[0056] The process of melting raw materials using a high-vacuum non-consumable arc furnace includes the following steps: Raw materials other than the microalloying element are placed in the crucible of the furnace; the furnace cavity is evacuated to a set pressure; after evacuation is stopped, inert gas is introduced to achieve the set vacuum level; after the raw materials other than the microalloying element have melted, the microalloying element is added to the molten pool; then melting and cooling are performed to obtain an alloy ingot. Preferably, the melting current is 350–400 A, and the melting time is 3–5 minutes. Too low a melting current (or too short a time) will result in uneven melting, while too high a melting current (or too long a time) will lead to overheating, affecting the final properties of the alloy.

[0057] Preferably, the vacuum is evacuated to a pressure of 3 to 4 × 10⁻⁶. -3 The vacuum degree after introducing high-purity argon gas is -0.07 to -0.09 MPa. If the pressure is too high (or the vacuum is too low), the metal will be oxidized during the melting process, affecting the final performance of the alloy. If the pressure is too low (or the vacuum is too high), no further beneficial effects will be produced, and the preparation efficiency will be reduced.

[0058] Ideally, the melting and cooling process should be repeated 3 to 6 times. Too few repetitions will result in uneven element distribution in the alloy ingot, affecting the final corrosion resistance, while too many repetitions will not produce any further beneficial effects and will also reduce the preparation efficiency.

[0059] Step 2) The alloy ingot is melted and cast into a casting.

[0060] In this step: the ingot is cast using an electric arc furnace, including the following steps:

[0061] First, the alloy ingot is placed in the crucible of the electric arc furnace. The furnace cavity is evacuated to a certain pressure. After the evacuation is stopped, high-purity argon gas is introduced to make the furnace cavity reach a certain pressure. Then the alloy ingot is melted and finally lowered and cast into a mold for cooling to obtain the alloy ingot.

[0062] Preferably, the vacuum is evacuated to a pressure of 3 to 4 × 10⁻⁶. -3 Pa, the pressure after introducing high-purity argon is 400-600 mbar. If the pressure is too high, the metal will be oxidized during the melting process, affecting the final performance of the alloy. If the pressure is too low, it will not produce any further beneficial effects and will also reduce the preparation efficiency.

[0063] Step 3) The ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained.

[0064] In this step: homogenization annealing is carried out in an argon atmosphere at a temperature of 950–1050℃ for 2–4 hours, and furnace cooling is used. If the temperature is too low, the holding time too short, or the cooling rate too fast (such as water cooling), the homogenization annealing will be insufficient, leading to uneven element distribution. If the temperature is too high, the holding time too long, or the cooling rate too slow, abnormal grain growth can easily occur, which is detrimental to performance.

[0065] It should be noted that conventional techniques for commercial copper-nickel alloys involve directly plastic processing of the ingot; however, in order to achieve a more uniform distribution of microalloying elements, the ingot is first subjected to homogenization annealing before plastic processing.

[0066] Step 4) The ingot after homogenization annealing is subjected to plastic processing to obtain the plastically deformed alloy.

[0067] In this step: plastic processing includes any one of hot rolling, cold rolling, or drawing.

[0068] Step 5) The plastically deformed alloy is subjected to recrystallization annealing treatment, and after cooling, a copper-nickel alloy is obtained.

[0069] In this step: recrystallization annealing is performed under an argon atmosphere at a temperature of 700–900℃ for 10–30 minutes, and cooled by furnace cooling. If the temperature is too low, the holding time too short, or the cooling rate too fast (such as water cooling), the recrystallization annealing will be insufficient, failing to completely eliminate the adverse effects of plastic processing. If the temperature is too high, the holding time too long, or the cooling rate too slow, abnormal grain growth can easily occur, which is detrimental to performance.

[0070] In summary, this invention utilizes the synergistic effect of microalloying elements to accelerate the cathodic and anodic reactions and promote the non-uniform precipitation nucleation, which significantly improves the protective properties of the surface corrosion product film of copper-nickel alloys. The prepared copper-nickel alloy has excellent seawater corrosion resistance, and its scouring corrosion rate is reduced by more than 60% compared with existing copper-nickel alloys.

[0071] The present invention will be further illustrated below through experimental examples:

[0072] Example 1

[0073] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.1Pd), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pd (0.1wt%), and the balance being Cu. The main preparation steps are as follows:

[0074] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, and Pd elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. Once Cu and Ni have melted, Pd is added to the molten pool, and the mixture is then melted to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 400 A, and the melting time is 3 minutes. This melting and cooling process is repeated six times.

[0075] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0076] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0077] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0078] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a Cu-10Ni-0.1Pd alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0079] The Cu-10Ni-0.1Pd alloy plate prepared in this embodiment has the same single-phase microstructure as the un-microalloyed Cu-10Ni alloy plate (see...). Figure 1 (As shown), however, the grain size of the Cu-10Ni-0.1Pd alloy plate is reduced (average grain size is 18μm).

[0080] The Cu-10Ni-0.1Pd alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 5.2 × 10⁻⁶. 4 Ω / cm 2 It is far superior to the unmicroalloyed Cu-10Ni alloy (see...) Figure 2(As shown). It can be seen that the Cu-10Ni-0.1Pd alloy plate prepared in this embodiment exhibits excellent seawater corrosion resistance; here, this excellent corrosion resistance mainly comes from the dense corrosion product film formed on the surface (see...). Figure 3 (As shown in Figures b and e).

[0081] Example 2

[0082] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.1Pd / Y), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pd (0.08wt%), Y (0.02wt%), with the balance being Cu. The main preparation steps are as follows:

[0083] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, Pd, and Y elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 4 × 10⁻⁶ ppm. -3 After stopping the vacuum pumping, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.09 MPa. Once Cu and Ni have melted, Pd and Y are added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 350 A, and the melting time is 5 minutes. The melting and cooling process is repeated three times.

[0084] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 4×10⁻⁶. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 600 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0085] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0086] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0087] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a Cu-10Ni-0.1Pd / Y alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0088] The Cu-10Ni-0.1Pd / Y alloy plate prepared in this embodiment has the same single-phase microstructure as the un-microalloyed Cu-10Ni alloy plate (see...). Figure 1 (As shown), however, the grain size of the Cu-10Ni-0.1Pd / Y alloy plate is reduced (average grain size is 16μm).

[0089] The Cu-10Ni-0.1Pd / Y alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 5.9 × 10⁻⁶. 4 Ω / cm 2 It is slightly higher than that of Cu-10Ni-0.1Pd microalloyed with single Pd element, and much higher than that of unmicroalloyed Cu-10Ni alloy (see...). Figure 2 (As shown). It can be seen that the Cu-10Ni-0.1Pd / Y alloy plate prepared in this embodiment exhibits excellent seawater corrosion resistance; here, this excellent corrosion resistance mainly comes from the dense corrosion product film formed on the surface (see...). Figure 3 (as shown in diagrams c and f).

[0090] Example 3

[0091] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.1Pd / Sc), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pd (0.08wt%), Sc (0.02wt%), and the balance being Cu. The main preparation steps are as follows:

[0092] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, Pd, and Sc elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 4 × 10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.08 MPa. Once the raw materials Cu and Ni have melted, Pd and Sc are added to the molten pool, and the resulting alloy liquid is then cooled into an alloy ingot. The melting current is 360 A, and the melting time is 5 minutes. The melting and cooling process is repeated five times.

[0093] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 4×10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a pressure of 500 mbar inside the furnace cavity. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0094] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0095] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0096] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a Cu-10Ni-0.1Pd / Sc alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0097] The Cu-10Ni-0.1Pd / Sc alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 5.7 × 10⁻⁶. 4 Ω / cm 2 It is slightly higher than that of Cu-10Ni-0.1Pd microalloyed with single Pd element, and much higher than that of unmicroalloyed Cu-10Ni alloy (see...). Figure 2 (As shown in the figure). It can be seen that the Cu-10Ni-0.1Pd / Sc alloy plate prepared in this embodiment exhibits excellent resistance to seawater corrosion.

[0098] Example 4

[0099] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.1Pt), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pt (0.1wt%), and the balance being Cu. The main preparation steps are as follows:

[0100] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, and Pt elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶ ppm. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. Once the raw materials Cu and Ni have melted, Pt is added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 380 A, and the melting time is 4 minutes. The melting and cooling process is repeated four times.

[0101] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0102] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0103] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0104] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a Cu-10Ni-0.1Pt alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0105] The Cu-10Ni-0.1Pt alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 5.0 × 10⁻⁶. 4 Ω / cm 2 It is similar to Cu-10Ni-0.1Pd microalloyed with a single Pd element, and far superior to the unmicroalloyed Cu-10Ni alloy (see...). Figure 2 (As shown in the figure). It can be seen that the Cu-10Ni-0.1Pt alloy plate prepared in this embodiment exhibits excellent resistance to seawater corrosion.

[0106] Example 5

[0107] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.1Pt / La), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pt (0.08wt%), La (0.02wt%), and the balance being Cu. The main preparation steps are as follows:

[0108] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, Pt, and La elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶. -3 After the vacuum pumping stops, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. After the raw materials Cu and Ni are melted, Pt and La are added to the molten pool for further melting to obtain an alloy liquid, which is then cooled into an alloy ingot. The melting current is 360 A, and the melting time is 5 minutes. The melting and cooling process is repeated four times.

[0109] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0110] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0111] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0112] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a Cu-10Ni-0.1Pt / La alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0113] The Cu-10Ni-0.1Pt / La alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 5.2 × 10⁻⁶. 4 Ω / cm 2 It is slightly higher than that of Cu-10Ni-0.1Pt microalloyed with single Pt element, and much higher than that of unmicroalloyed Cu-10Ni alloy (see...). Figure 2 (As shown). It can be seen that the Cu-10Ni-0.1Pt / La alloy plate prepared in this embodiment exhibits excellent seawater corrosion resistance; here, this excellent corrosion resistance mainly comes from the dense corrosion product film formed on the surface.

[0114] Example 6

[0115] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.05Pd), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pd (0.05wt%), and the balance being Cu. The main preparation steps are as follows:

[0116] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, and Pd elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶. -3After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. Once the raw materials Cu and Ni have melted, Pd is added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 400 A, and the melting time is 3 minutes. The melting and cooling process is repeated four times.

[0117] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0118] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 950℃, the holding time is 4 hours, and the cooling method is furnace cooling.

[0119] Step 4): The ingot after homogenization annealing is drawn.

[0120] Step 5): Under an argon atmosphere, the drawn tube is subjected to recrystallization annealing to obtain a Cu-10Ni-0.05Pd alloy tube. The recrystallization annealing temperature is 700℃, the holding time is 30 minutes, and the cooling method is furnace cooling.

[0121] The Cu-10Ni-0.05Pd alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 3.2 × 10⁻⁶. 4 Ω / cm 2 Its performance is far superior to that of un-microalloyed Cu-10Ni alloy pipes, exhibiting excellent resistance to seawater corrosion.

[0122] Example 7

[0123] This embodiment prepares a copper-nickel alloy (Cu-10Ni-0.05Pt), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pt (0.05wt%), and the balance being Cu. The main preparation steps are as follows:

[0124] Step 1): Using high-purity metals as raw materials, weigh the Cu, Ni, and Pt elements according to their mass percentages. Place the Cu and Ni raw materials into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶ ppm. -3After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. Once the raw materials Cu and Ni have melted, Pt is added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 380 A, and the melting time is 3 minutes. The melting and cooling process is repeated four times.

[0125] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0126] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1000℃, the holding time is 3 hours, and the cooling method is furnace cooling.

[0127] Step 4): The homogenized annealed ingot is then hot-rolled. The hot-rolling temperature is 900℃, and the deformation is 50%.

[0128] Step 5): Under an argon atmosphere, the hot-rolled sheet metal is subjected to recrystallization annealing to obtain Cu-10Ni-0.05Pt alloy pipe. The recrystallization annealing temperature is 800℃, the holding time is 20 minutes, and the cooling method is furnace cooling.

[0129] The Cu-10Ni-0.05Pt alloy plate prepared in this embodiment was immersed in a 3.5wt% NaCl solution for 14 days, and its polarization resistance reached as high as 2.6 × 10⁻⁶. 4 Ω / cm 2 Its resistance to seawater corrosion is far superior to that of the un-microalloyed Cu-10Ni alloy.

[0130] Example 8

[0131] This embodiment prepares a copper-nickel alloy (Cu-10Ni-1.5Fe-0.8Mn-0.2Pd, abbreviated as B10-0.2Pd), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pd (0.2wt%), Fe (1.5wt%), Mn (0.8wt%), with the balance being Cu. The main preparation steps are as follows:

[0132] Step 1): Using high-purity metal as raw material, weigh commercial B10 alloy and Pd element raw materials according to mass percentage. Place the raw material B10 alloy into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3×10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. Once the raw material B10 alloy has melted, Pd is added to the molten pool, and the resulting alloy liquid is cooled to form an alloy ingot. The melting current is 360 A, and the melting time is 5 minutes. The melting and cooling process is repeated six times.

[0133] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0134] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0135] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0136] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a B10-0.2Pd alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0137] The B10-0.2Pd alloy plate prepared in this embodiment exhibited a scouring corrosion rate of only 0.15 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is far lower than that of the un-microalloyed B10 alloy (see...). Figure 4 (As shown in the figure). It can be seen that the B10-0.2Pd alloy plate prepared in this embodiment exhibits excellent resistance to erosion corrosion.

[0138] Example 9

[0139] This embodiment prepares a copper-nickel alloy (Cu-10Ni-1.5Fe-0.8Mn-0.2Pd / Y, abbreviated as B10-0.2Pd / Y), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (10wt%), Pd (0.15wt%), Y (0.05wt%), Fe (1.5wt%), Mn (0.8wt%), with the balance being Cu. The main preparation steps are as follows:

[0140] Step 1): Using high-purity metals as raw materials, weigh commercial B10 alloy, Pd, and Y elements according to their mass percentages. Place the raw B10 alloy into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa within the furnace chamber. Once the B10 alloy has melted, Pd and Y are added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 360 A, and the melting time is 5 minutes. The melting and cooling process is repeated six times.

[0141] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0142] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0143] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0144] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a B10-0.2Pd / Y alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0145] The B10-0.2Pd / Y alloy plate prepared in this embodiment exhibited a scouring corrosion rate of only 0.13 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is far lower than that of the un-microalloyed B10 alloy (see...). Figure 4 (As shown in the figure). It can be seen that the B10-0.2Pd / Y alloy plate prepared in this embodiment exhibits excellent resistance to erosion corrosion.

[0146] Example 10

[0147] This embodiment prepares a copper-nickel alloy (Cu-30Ni-1.8Fe-1.0Mn-0.2Pd, abbreviated as B30-0.2Pd), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (30wt%), Pd (0.2wt%), Fe (1.8wt%), Mn (1.0wt%), with the balance being Cu. The main preparation steps are as follows:

[0148] Step 1): Using high-purity metal as raw material, weigh commercial B30 alloy and Pd element raw materials according to mass percentage. Place the raw material B30 alloy into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3×10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa within the furnace chamber. The raw material B30 alloy is melted, and Pd is added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 380 A, and the melting time is 5 minutes. The melting and cooling process is repeated six times.

[0149] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0150] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0151] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0152] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain a B30-0.2Pd alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0153] The B30-0.2Pd alloy plate prepared in this embodiment exhibited a scouring corrosion rate of only 0.06 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is far lower than that of the un-microalloyed B30 alloy (see...). Figure 4(As shown in the figure). It can be seen that the B10-0.2Pd / Y alloy plate prepared in this embodiment exhibits excellent resistance to erosion corrosion.

[0154] Example 11

[0155] This embodiment prepares a copper-nickel alloy (Cu-30Ni-1.8Fe-1.0Mn-0.2Pd / Y, abbreviated as B30-0.2Pd / Y), wherein, by weight percentage, the copper-nickel alloy comprises the following chemical composition: Ni (30wt%), Pd (0.15wt%), Y (0.05wt%), Fe (1.8wt%), Mn (1.0wt%), with the balance being Cu. The main preparation steps are as follows:

[0156] Step 1): Using high-purity metals as raw materials, weigh commercial B30 alloy, Pd, and Y elements according to their mass percentages. Place the raw B30 alloy into the crucible of a high-vacuum non-consumable arc melting furnace, and evacuate the furnace cavity to 3 × 10⁻⁶. -3 After stopping the vacuuming process, high-purity argon gas is introduced into the furnace to achieve a vacuum level of -0.07 MPa. Once the raw material B30 alloy has melted, Pd and Y are added to the molten pool for further melting to obtain a liquid alloy, which is then cooled into an alloy ingot. The melting current is 380 A, and the melting time is 5 minutes. The melting and cooling process is repeated six times.

[0157] Step 2): Place the alloy ingot into the crucible of the electric arc furnace, and evacuate the furnace cavity to 3×10⁻⁶ ℃. -3 After the vacuum process is stopped, high-purity argon gas is introduced into the furnace to achieve a pressure of 400 mbar inside the furnace. The alloy ingot is then melted and cast into a mold for cooling to obtain the alloy ingot.

[0158] Step 3): Under an argon atmosphere, the alloy ingot is subjected to homogenization annealing treatment, and after cooling, the homogenized annealed ingot is obtained; wherein, the homogenization annealing temperature is 1050℃, the holding time is 2 hours, and the cooling method is furnace cooling.

[0159] Step 4): The ingot after homogenization annealing is subjected to cold rolling, wherein the deformation is 50%.

[0160] Step 5): Under an argon atmosphere, the cold-rolled sheet is subjected to recrystallization annealing to obtain B30-0.2Pd / Y alloy sheet. The recrystallization annealing temperature is 900℃, the holding time is 10 minutes, and the cooling method is furnace cooling.

[0161] The B30-0.2Pd / Y alloy plate prepared in this embodiment exhibited a scouring corrosion rate of only 0.05 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is far lower than that of the un-microalloyed B30 alloy (see...). Figure 4 (As shown in the figure). It can be seen that the B30-0.2Pd / Y alloy plate prepared in this embodiment exhibits excellent resistance to erosion corrosion.

[0162] Comparative Example 1

[0163] Comparative Example 1 is a Cu-10Ni alloy plate prepared according to the process parameters of Example 1 (the difference from Example 1 is that Comparative Example 1 does not contain precious metal elements).

[0164] The polarization resistance of the Cu-10Ni alloy plate prepared in Comparative Example 1 after immersion in a 3.5 wt% NaCl solution for 14 days was only 5.0 × 10⁻⁶. 3 Ω / cm 2 (see Figure 2 As shown), it is an order of magnitude lower than microalloyed alloys, and no dense corrosion product film forms on the surface (see...). Figure 3 (Figures (a) and (d) show that the seawater corrosion resistance is poor.)

[0165] Comparative Example 2

[0166] Comparative Example 2: Cu-10Ni-0.1Y alloy plate was prepared using the process parameters of Example 1 (the difference from Example 1 is that Comparative Example 2 does not contain noble metal elements, but contains 0.1 wt% rare earth element Y).

[0167] The polarization resistance of the Cu-10Ni-0.1Y alloy plate prepared in Comparative Example 2 was only 9.8 × 10⁻⁶ after immersion in 3.5 wt% NaCl solution for 14 days. 3 Ω / cm 2 (see Figure 2 As shown in the figure, this indicates that adding only rare earth elements cannot significantly improve the seawater corrosion resistance of copper-nickel alloys.

[0168] Comparative Example 3

[0169] Comparative Example 3 prepared a B10 alloy plate according to the process parameters of Example 8 (the difference from Example 8 is that Comparative Example 3 does not contain precious metal elements).

[0170] The B10 alloy plate prepared in Comparative Example 3 exhibited a scouring corrosion rate of up to 0.42 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is significantly higher than that of the microalloyed alloy (see Comparative Example 3). Figure 4(As shown). It can be seen that the B10 alloy plate in Comparative Example 3 has poor resistance to erosion corrosion.

[0171] Comparative Example 4

[0172] Comparative Example 4 prepared a B10-0.2Y alloy plate according to the process parameters of Example 8 (the difference from Example 8 is that Comparative Example 4 does not contain precious metal elements, but contains 0.2wt% Y element).

[0173] The B10-0.2Y alloy plate prepared in Comparative Example 4 exhibited a scouring corrosion rate of up to 0.35 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is significantly higher than that of Pd microalloyed and Pd / Y co-microalloyed alloys (see...). Figure 4 (As shown). It can be seen that the alloy plate in Comparative Example 4 has poor resistance to erosion corrosion, which indicates that adding rare earth elements alone cannot significantly improve the resistance of copper-nickel alloys to seawater erosion corrosion.

[0174] Comparative Example 5:

[0175] Comparative Example 5 prepared a B30 alloy plate according to the process parameters of Example 10 (the difference from Example 10 is that Comparative Example 5 does not contain precious metal elements).

[0176] The B30 alloy plate prepared in Comparative Example 5 exhibited a scouring corrosion rate of up to 0.32 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is significantly higher than that of the microalloyed alloy (see Comparative Example 5). Figure 4 As shown in the figure, the B30 alloy plate has poor resistance to erosion corrosion.

[0177] Comparative Example 6:

[0178] Comparative Example 6 prepared a B30-0.2Y alloy plate according to the process parameters of Example 10 (the difference from Example 10 is that Comparative Example 6 does not contain precious metal elements, but contains 0.2 wt% Y element).

[0179] The B30-0.2Y alloy plate prepared in Comparative Example 6 exhibited a scouring corrosion rate of up to 0.25 mm / a in a 3.5 wt% NaCl solution containing 0.1 wt% quartz sand at a flow rate of 2.4 m / s, which is significantly higher than that of Pd microalloyed and Pd / Y co-microalloyed alloys (see Comparative Example 6). Figure 4 As shown in the figure, the B30-0.2Y alloy plate has poor resistance to erosion corrosion, which further proves that adding rare earth elements alone cannot significantly improve the resistance of copper-nickel alloys to seawater erosion corrosion.

[0180] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A copper-nickel alloy, characterized in that, The chemical composition of the copper-nickel alloy, by weight percentage, is as follows: Ni: 10~30wt%; Fe: 0~1.8wt%; Mn: 0~1.0wt%; Microalloying elements: 0.05~0.2wt%; Impurity elements: <0.5wt%; Balance: Cu; The microalloying elements are noble metal elements and rare earth elements; in the copper-nickel alloy, the content of the noble metal elements is 0.05~0.2wt%; the noble metal elements include one or two of Pd and Pt. The content of the rare earth elements is greater than 0 and less than or equal to 0.05 wt%; The rare earth elements include one or more of Y, Sc, and La; The copper-nickel alloy, after being immersed in a 3.5±0.1wt% NaCl solution for 14±1 days, exhibits a polarization resistance of 5.2~5.9×10⁻⁶. 4 Ω / cm 2 The surface film thickness is 2~5μm.

2. The copper-nickel alloy according to claim 1, characterized in that, The impurity elements include one or more of Zn, C, Si, P, S, and Pb.

3. The copper-nickel alloy according to claim 1, characterized in that, The average grain size in the copper-nickel alloy is 16~18μm.

4. The method for preparing the copper-nickel alloy according to any one of claims 1-3, characterized in that, It includes the following steps: Step 1) Prepare raw materials according to the component ratio, and smelt the raw materials to prepare alloy ingots; Step 2), the alloy ingot is melted and cast into a casting; Step 3) The ingot is subjected to homogenization annealing treatment, and after cooling, a homogenized annealed ingot is obtained. Step 4) The ingot after homogenization annealing is subjected to plastic processing to obtain the plastically deformed alloy; Step 5) The plastically deformed alloy is subjected to recrystallization annealing treatment, and after cooling, a copper-nickel alloy is obtained.

5. The method for preparing the copper-nickel alloy according to claim 4, characterized in that, In step 1): The raw materials are selected from one or more of pure metals, B10 commercial alloys, and B30 commercial alloys; among them, the purity of pure metals is >99%.

6. The method for preparing the copper-nickel alloy according to claim 4, characterized in that, In step 1): All raw materials except for the microalloying element are placed in the crucible of the melting furnace. The furnace cavity is evacuated to the set pressure. After the evacuation is stopped, inert gas is introduced into the furnace cavity to achieve the set vacuum level. After the raw materials except for the microalloying element melt, the microalloying element is added to the molten pool. Then, the melting and cooling processes are carried out to obtain the alloy ingot.

7. The method for preparing the copper-nickel alloy according to claim 6, characterized in that, In step 1): the melting current is 350~400A; and / or The melting time is 3-5 minutes; and / or The set pressure is 3~4×10 -3 Pa; and / or The vacuum level is -0.07 to -0.09 MPa; and / or The smelting and cooling process needs to be repeated 3 to 6 times.

8. The method for preparing the copper-nickel alloy according to claim 4, characterized in that, In step 2): The alloy ingot is placed in the crucible of an electric arc furnace. The furnace cavity is evacuated to a set pressure. After the evacuation is stopped, an inert gas is introduced to bring the furnace cavity to the set pressure. The alloy ingot is then melted and cast into a mold for cooling to obtain an alloy ingot.

9. The method for preparing the copper-nickel alloy according to claim 8, characterized in that, In step 2): The set pressure is 3~4×10 -3 Pa; and / or The set pressure is 400~600mbar.

10. The method for preparing the copper-nickel alloy according to claim 4, characterized in that, In step 3), the homogenization annealing treatment is carried out at a temperature of 950~1050℃ and a holding time of 2~4h. The homogenization annealing treatment is carried out in an inert atmosphere.

11. The method for preparing the copper-nickel alloy according to claim 10, characterized in that, In step 3), the cooling method after homogenization annealing is selected as furnace cooling.

12. The method for preparing the copper-nickel alloy according to claim 4, characterized in that, In step 4), the plastic processing includes any one of hot rolling, cold rolling, and drawing.

13. The method for preparing the copper-nickel alloy according to claim 4, characterized in that, In step 5), the recrystallization annealing treatment is performed at a temperature of 700-900°C for 10-30 minutes.

14. The method for preparing the copper-nickel alloy according to claim 13, characterized in that, The recrystallization annealing process is carried out in an inert atmosphere.

15. The method for preparing the copper-nickel alloy according to claim 13, characterized in that, The cooling method after recrystallization annealing is furnace cooling.

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