A process method for inhibiting copper-nickel alloy dendritic segregation and refining the structure based on powder core wire electric arc additive manufacturing

Abstract

The application discloses a process method for inhibiting copper-nickel alloy dendritic segregation and refining organization based on powder core wire electric arc additive manufacturing, adopts rolled CuNi30 alloy belt as an outer skin, fills CuNi30 alloy powder into the inner part, obtains CuNi30 alloy powder core wire through closing and drawing, and deposits CuNi30 alloy welding bead or components. The powder core wire forms a composite melting behavior of melting of the metal outer skin first and melting of the core powder later in the electric arc melting process. The powder absorbs heat in the melting process, promotes local liquid metal flow, produces stirring effect on the molten pool, makes the overall temperature of the molten pool more uniform, and reduces the temperature gradient; the powder acts as a heterogeneous nucleation site to promote solidification nucleation. The joint action weakens the interdendritic element segregation, changes the interdendritic microscopic continuous segregation band under the traditional solid welding wire condition into fine and dispersed distribution, and obtains finer and more uniform solidification organization, and weakens the tendency of continuous expansion of the corrosion medium along the interdendritic.

Description

Technical Field

[0001] This invention relates to the field of electric arc additive manufacturing and copper-nickel alloy microstructure control technology, specifically a process method based on powder-core wire electric arc additive manufacturing to suppress dendritic segregation and refine the microstructure of copper-nickel alloys. Background Technology

[0002] CuNi30 alloy possesses excellent resistance to seawater corrosion, mechanical properties, and machinability, making it widely used in marine engineering, shipbuilding, heat exchangers, chemical equipment, and corrosion-resistant structural components. Arc additive manufacturing technology achieves near-net-shape construction of components through layer-by-layer metal deposition, offering advantages such as high deposition efficiency, high material utilization, and suitability for manufacturing large components. The cold metal transition arc additive manufacturing process features relatively low heat input and stable droplet transition, making it suitable for additive manufacturing of copper-nickel alloy components.

[0003] When using traditional S231 solid welding wire for arc additive manufacturing of CuNi30 alloy, the molten pool undergoes rapid heating and solidification, resulting in significant non-equilibrium solute redistribution at the solidification interface. Due to the large temperature gradient within the molten pool under the influence of the arc heat source, grains tend to grow epitaxially towards the liquid phase along the direction of the maximum temperature gradient. Grains with favorable orientations compete for growth, forming columnar dendrite structures with a distinct directionality. When the local heat input of the molten pool is high, the number of nucleation sites is insufficient, or the molten pool disturbance is weak, the columnar dendrites can obtain sufficient growth space, leading to an increase in dendrite spacing. This increases the distance between the final solidified region between the dendrites and the dendrite trunk, making it difficult for the solute elements enriched in the residual liquid phase to fully back-diffuse and homogenize into the dendrites within a limited solidification time. This makes Cu, Ni, and trace elements more likely to remain in the final solidified interdendritic region, forming a wider and continuous element segregation band. These segregation bands enhance local compositional differences and electrochemical inhomogeneities within the weld bead, making it easier for corrosive media to preferentially propagate along the interdendritic regions, thereby reducing the microstructure uniformity and corrosion resistance stability of the CuNi30 alloy weld bead. This segregation morphology indicates insufficient microstructure and compositional uniformity in local areas, which affects the microstructure stability of the deposited layer and the service reliability of corrosion-resistant components. Current methods for improving the microstructure in arc additive manufacturing mainly include optimizing heat input, adjusting interpass temperature, applying external field assistance, or changing the alloy composition. While these methods can improve the microstructure to some extent, they may have drawbacks such as a narrow process window, complex equipment, or increased costs. Therefore, it is necessary to propose a method that utilizes the wire's own structure to control melting and solidification behavior, improving the microstructure of CuNi30 alloy arc additive manufacturing without significantly increasing equipment complexity. Summary of the Invention

[0004] The purpose of this invention is to provide a process method for suppressing dendritic segregation and refining the microstructure of copper-nickel alloys based on powder-cored wire arc additive manufacturing, comprising the following steps:

[0005] Step 1: Using CuNi30 alloy strip as the outer sheath material, CuNi30 alloy powder is filled into the outer sheath material to prepare CuNi30 alloy powder core wire.

[0006] Step 2: Using CuNi30 alloy powder core wire as the feed wire, CuNi30 alloy weld beads or components are deposited on the substrate under a protective atmosphere.

[0007] Furthermore, when forming CuNi30 alloy weld beads or components, a cold metal transition arc additive manufacturing process is adopted.

[0008] Furthermore, the CuNi30 alloy powder has a particle size of 200 mesh to 325 mesh.

[0009] Furthermore, the core filling rate of the CuNi30 alloy core wire is 15% to 30%.

[0010] Furthermore, the diameter of the CuNi30 alloy powder core wire is 1.2 mm and 1.6 mm.

[0011] Furthermore, the cold metal transition arc additive manufacturing process parameters are: welding current 112 A to 225 A, voltage 11 V to 20.5 V, travel speed 0.2 m / min to 0.5 m / min, wire feed speed 5 m / min to 9.6 m / min, interpass temperature 150 ℃ to 300 ℃, shielding gas is pure argon, and shielding gas flow rate is 15 L / min to 25 L / min.

[0012] Furthermore, the CuNi30 alloy powder core wire exhibits a composite melting behavior during the arc melting process, where the outer metal skin melts first and the core powder melts later, thereby enhancing the stirring of the molten pool and promoting solidification and nucleation.

[0013] Furthermore, after grinding, polishing, and etching, the weld bead obtained by the CuNi30 alloy powder core wire deposition has a mixed structure including cellular dendrites, equiaxed cellular crystals, and locally columnar cellular crystals, with reduced microsegregation scale and continuity.

[0014] Furthermore, the substrate is a metal substrate suitable for arc additive manufacturing of copper-nickel alloys.

[0015] Furthermore, the deposited CuNi30 alloy weld beads or components are used in corrosion-resistant components in marine engineering, shipbuilding, or chemical equipment.

[0016] In this invention, the powder-cored wire exhibits a composite melting behavior under the action of an electric arc, where the outer metal skin melts first, followed by the core powder. This behavior enhances the heat, momentum, and compositional disturbances within the molten droplets and molten pool, resulting in a more uniform heat distribution in the molten pool, reducing the temperature gradient, strengthening the stirring effect of the molten pool, and providing more nucleation disturbances during solidification, promoting heterogeneous nucleation and refining the solidified structure. Compared to solid welding wire, the weld bead microstructure prepared by arc additive manufacturing of powder-cored wire transforms from coarse columnar dendrites to a mixed structure dominated by fine cellular dendrites, equiaxed cellular crystals, and locally columnar cellular crystals. The dendrite spacing decreases, the solidified structure becomes denser and more uniform, and the microsegregation scale and continuity are weakened.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention achieves microstructure control by altering the structure of additive manufacturing filaments rather than adding complex equipment, resulting in strong process adaptability. The post-melting powder in the powder-core filament can absorb some of the arc heat, reducing local overheating in the molten pool, decreasing the temperature gradient within the molten pool, and inhibiting the directional growth of coarse columnar dendrites. Simultaneously, the continuous input of powder particles increases disturbance and heterogeneous nucleation sites within the molten pool, promoting the transformation of the solidification microstructure from coarse columnar crystals to fine cellular, equiaxed cellular, and fine dendrite structures. This shortens the solute diffusion distance, transforming the solute element enrichment region between dendrites from a continuous, coarse distribution to a fine, dispersed distribution, thereby reducing the microsegregation of elements such as Cu and Ni during solidification. Metallographic observation of the weld beads prepared from the obtained powder-core wire showed a reduction in continuous dendrite segregation morphology and improved microstructure uniformity. This method eliminates the need for additional pre-placed powder or external powder feeding devices, enabling simultaneous feeding of alloy powder and metal outer layer into the molten pool for uniform melting. It offers advantages such as high process stability, low cost, significant microstructure refinement, marked improvement in compositional uniformity, and reduction in corrosion-sensitive areas between dendrites. This method is suitable for arc additive manufacturing of corrosion-resistant CuNi30 alloy components and has significant engineering application value. Attached Figure Description

[0019] Figure 1 The diagram shows a cross-sectional view of the powder-core wire and a schematic diagram of the arc additive manufacturing process of the powder-core wire in this invention.

[0020] Figure 2 The figures show schematic diagrams of interdendritic elemental segregation in CuNi30 alloy weld beads prepared by solid wire arc additive manufacturing, and schematic diagrams of elemental segregation suppression and microstructure refinement by powder-core wire arc additive manufacturing.

[0021] Figure 3 The images show the microstructures of CuNi30 alloy weld beads prepared using solid wire and powder-core wire respectively during the actual process.

[0022] In the figure, 1 is the core wire, 2 is the outer sheath material, 3 is the CuNi alloy powder, 4 is the molten droplet, 5 is the weld solidification structure, 6 is the mixed particle size powder, 7 is the molten pool, 8 is the coarse columnar dendrites, 9 is the microsegregation region, 10 is the dendrite boundary particles, and 11 is the cellular dendrites. Detailed Implementation

[0023] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0024] Example 1:

[0025] A process for suppressing dendritic segregation and refining the microstructure of copper-nickel alloys based on arc additive manufacturing of powder-cored wire includes a powder-cored wire preparation step and an arc additive manufacturing step.

[0026] The preparation steps of the powder core wire are as follows: a rolled CuNi30 alloy strip is used as the outer skin material 2, CuNi30 alloy powder 3 is filled into the outer skin material, and CuNi30 alloy powder core wire 1 is obtained by closing and drawing.

[0027] The arc additive manufacturing step is as follows: using a cold metal transition arc additive manufacturing process, with the CuNi30 alloy powder core wire as the feed wire, CuNi30 alloy weld beads or components are deposited on the substrate under a protective atmosphere.

[0028] Example 2:

[0029] A process for suppressing dendritic segregation and refining the microstructure of copper-nickel alloy based on arc additive manufacturing of powder-core wire is described. The technical content is the same as in Example 1. Furthermore, the particle size of the CuNi30 alloy powder is 200 mesh to 325 mesh, and in this example it is set to 300 mesh.

[0030] Example 3:

[0031] A process method for suppressing dendritic segregation and refining the microstructure of copper-nickel alloy based on arc additive manufacturing of powder-cored wire is provided. The technical content is the same as any one of Examples 1-2. Further, the powder core filling rate of the CuNi30 alloy powder-cored wire is 15% to 30%, and is set to 25% in this example.

[0032] Example 4:

[0033] A process for suppressing dendritic segregation and refining the microstructure of copper-nickel alloy based on arc additive manufacturing of powder-core wire is provided. The technical content is the same as any one of Examples 1-3. Further, the diameter of the CuNi30 alloy powder-core wire is 1.2 mm and 1.6 mm. In this example, it is set to 1.2 mm.

[0034] Example 5:

[0035] A process method for suppressing dendritic segregation and refining the microstructure of copper-nickel alloys based on powder-cored wire arc additive manufacturing is provided. The technical content is the same as any one of Examples 1-4. Further, the cold metal transition arc additive manufacturing process parameters are: welding current 112 A to 225 A, voltage 11 V to 20.5 V, travel speed 0.2 m / min to 0.5 m / min, wire feed speed 5 m / min to 9.6 m / min, interpass temperature 150 ℃ to 300 ℃, and the shielding gas is pure argon with a flow rate of 15 L / min to 25 L / min.

[0036] Example 6:

[0037] A process method for suppressing dendritic segregation and refining microstructure in copper-nickel alloys based on powder-cored wire arc additive manufacturing is provided. The technical content is the same as any one of Examples 1-5. Further, the process parameters for the cold metal transition arc additive manufacturing are set as follows in this example: welding current 136 A, voltage 12.6 V, travel speed 0.3 m / min, wire feed speed 6 m / min, interpass temperature 150℃, and argon flow rate 20 L / min.

[0038] Example 7:

[0039] A process for suppressing dendritic segregation and refining the microstructure of copper-nickel alloy based on arc additive manufacturing of powder-core wire is described. The technical content is the same as any one of Examples 1-6. Furthermore, the CuNi30 alloy powder-core wire forms a composite melting behavior in the arc melting process, in which the outer metal skin melts first and the core powder melts later, so as to enhance the stirring of the molten pool and promote solidification nucleation.

[0040] Example 8:

[0041] A process method for suppressing dendritic segregation and refining the microstructure of copper-nickel alloy based on arc additive manufacturing of powder-cored wire is provided. The technical content is the same as any one of Examples 1-7. Further, after the weld bead obtained by the deposition of CuNi30 alloy powder-cored wire is polished and etched, its microstructure changes from obvious coarse and long columnar dendrites to a mixed microstructure dominated by fine cellular dendrites, equiaxed cellular crystals and local columnar cellular crystals, and the microsegregation scale and continuity are weakened.

[0042] Example 9:

[0043] A process method for suppressing dendritic segregation and refining microstructure in copper-nickel alloy based on powder-core wire arc additive manufacturing, with the technical content being the same as any one of Examples 1-8. Further, the substrate is a copper-nickel alloy substrate or a metal substrate suitable for copper-nickel alloy arc additive manufacturing.

[0044] Example 10:

[0045] A process for suppressing dendritic segregation and refining the microstructure of copper-nickel alloy based on arc additive manufacturing of powder-core wire is described. The technical content is the same as any one of Examples 1-9. Furthermore, the prepared product is applied to the preparation of copper-nickel alloy corrosion-resistant components for marine engineering, shipbuilding, or chemical equipment.

[0046] Example 11:

[0047] See Figure 1 This invention provides a process for suppressing dendritic segregation and refining the solidification structure of copper-nickel alloys using arc additive manufacturing based on powder-core wire. First, a rolled CuNi30 alloy strip is used as the outer sheath material. CuNi30 alloy powder is continuously filled into the strip, and then the strip is closed and drawn to obtain CuNi30 alloy powder-core wire.

[0048] In practice, the CuNi30 alloy powder has a particle size of 300 mesh and a core fill rate of 25%. After multiple drawing passes, the core wire diameter is 1.2 mm. CMT arc additive manufacturing equipment is used, with a polished and cleaned copper-nickel alloy substrate as the deposition substrate, and deposition is performed under argon protection. The process parameters are: welding current 136 A, voltage 12.6 V, travel speed 0.3 m / min, wire feed speed 6 m / min, interpass temperature 150 ℃, and argon flow rate 20 L / min.

[0049] For comparison, S231 solid welding wire was used to deposit weld beads under the same process parameters. The microstructure of the deposited weld beads was observed after wire cutting, polishing, and etching. The results showed that the dendrite boundary corrosion pits in the weld beads deposited with the S231 solid welding wire were more obvious, exhibiting continuous interdendritic segregation characteristics; in the weld beads prepared using the powder-core wire of this invention, the dendrite boundaries showed a granular protruding morphology, the continuous pitted segregation morphology was weakened, and the microstructure was denser and more uniform. (See [reference]). Figure 2 and Figure 3 .

[0050] See Figure 1-3 In powder-core wire, the core powder melts later in the molten pool and participates in the solidification process. It can act as a source of nucleation disturbance, promoting dendrite arm melting and free proliferation. At the same time, when the granular phase is distributed near the grain boundaries, it can hinder the continuous migration of grain boundaries, thereby inhibiting grain growth. Under traditional solid wire conditions, the dendrites are coarser and the dendrite boundaries are prone to continuous segregation morphology; under powder-core wire conditions, the dendrite morphology is finer and the granular protrusions at the dendrite boundaries increase, indicating that the wire structure changes the microstructure evolution path during the solidification process of the molten pool.

[0051] Example 12:

[0052] CuNi30 alloy strip was used as the outer sheath material, and CuNi30 alloy powder was used as the core filler material. The CuNi30 alloy powder had a particle size of 300 mesh and was dried before filling to reduce the adsorption of moisture and gas on the powder surface. The core filling rate was 25%, and the diameter of the core wire after multiple drawing passes was 1.2 mm. CMT arc additive manufacturing equipment was used, with a polished and cleaned copper-nickel alloy substrate as the deposition substrate, and deposition was performed under argon protection. The process parameters were: welding current 136 A, voltage 12.6 V, travel speed 0.3 m / min, wire feed speed 6 m / min, interlayer temperature 150 ℃, and argon flow rate 20 L / min.

[0053] During the forming process, the outer CuNi30 strip is first melted by the electric arc and forms droplets 4. The core CuNi30 powder is preheated and partially melted during the droplet formation and transition process, and continues to absorb heat and melt and diffuse after entering the molten pool 7 with the droplets. Compared with solid CuNi30 wire, this powder-core wire can reduce the local overheating of the molten pool, increase the heat and composition disturbance inside the molten pool, and inhibit the continuous growth of coarse columnar dendrites 8 to a certain extent, promote the refinement of the structure, reduce the spacing of dendrite boundary particles 10 in the weld bead solidification structure 5, reduce the micro-segregation region 9 between dendrites, and make the segregation region tend to be smaller and more dispersed, showing the best structure refinement and element segregation suppression effect.

[0054] Example 13:

[0055] A process for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing of powder-core wire is described in Example 12. Further, the powder particle size in the CuNi30 alloy powder-core wire is 300 mesh, and the filling rate is 15%.

[0056] The powder can still produce a certain degree of endothermic melting and nucleation disturbance in the droplets and molten pool. Compared with solid wire weld beads, the continuous growth of columnar dendrites is somewhat suppressed, and the continuity of the interdendritic segregation band is reduced. However, since the powder filling rate is at the lower limit of this invention, the amount of powder entering the molten pool is limited, and its control effect on the molten pool temperature field, flow state, and nucleation behavior is weaker than that of the embodiment with a filling rate of 25%.

[0057] Example 14:

[0058] A process for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing of powder-core wire is described in Example 12. Further, the powder particle size in the CuNi30 alloy powder-core wire is 300 mesh, and the filling rate is 30%.

[0059] The endothermic and disturbance effects of the powder on the molten pool are more pronounced, further weakening the directional growth tendency of coarse columnar dendrites, refining the solidification structure, and reducing the continuity of interdendritic segregation bands. However, due to the high powder filling rate, under the relatively low heat input conditions of CMT, the complete melting and uniform diffusion of the powder require more precise matching of process parameters. If the heat input or molten pool residence time is insufficient, localized incomplete powder melting, inclusions, or porosity may occur. Therefore, this embodiment belongs to the upper limit of the scope of implementation of this invention, and its microstructure control effect is significant, but its process stability is weaker than the preferred embodiment with a filling rate of 25%.

[0060] Example 15:

[0061] A process for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing of powder-core wire is described in Example 12. Further, the powder particle sizes in the CuNi30 alloy powder-core wire are 100 mesh and 300 mesh, respectively, with a mass ratio of 1:1, and the powder-core wire filling rate is controlled at 25%.

[0062] The mixed-particle-size powder 6 exhibits a staged melting characteristic during the droplet-molten pool transport process. Among them, the 500-mesh fine powder has a larger specific surface area, which allows it to preheat and melt more quickly after heating, rapidly absorbing heat from the droplets and the local area of ​​the molten pool, thus helping to reduce the degree of local overheating and temperature gradient in the molten pool. The 100-mesh coarse powder has a relatively longer melting time, allowing it to continuously absorb heat in the molten pool and enhance the flow disturbance of the liquid metal. Its semi-melted or molten interface can provide more nucleation disturbance sites. The synergistic effect of coarse and fine powders can improve the powder's packing state in the powder core wire and the heat distribution in the molten pool, resulting in a refined solidification structure. The continuous growth of columnar dendrites is inhibited, and the interdendritic segregation bands change from a coarse and continuous distribution to a fine and dispersed distribution.

[0063] Comparative Example 1:

[0064] Using traditional CuNi30 alloy solid wire S231 welding wire, CuNi30 weld beads were prepared under the same CMT arc additive manufacturing process parameters. The main technical details are described in Example 1. Because the solid wire lacks the staged endothermic melting process of CuNi30 powder, the thermal disturbance and nucleation disturbance in the droplets and molten pool are weaker. The molten pool experiences higher local overheating, making it easier for grains to grow epitaxially along the direction of the maximum temperature gradient, forming a distinct columnar dendritic structure.

[0065] In this comparative example, the dendrite spacing is relatively large, and the final solidification region between the dendrites is relatively continuous. The solute elements enriched in the residual liquid phase are difficult to diffuse in time, easily forming wide and continuous banded segregation between the dendrites. This indicates that conventional solid CuNi30 wire is ineffective in suppressing element segregation and columnar dendrite coarsening during rapid solidification.

[0066] Comparative Example 2:

[0067] CuNi30 alloy strip is used as the outer sheath material, and CuNi30 alloy powder is used as the core filler material. The CuNi30 alloy powder has a particle size of 300 mesh. The main technical details are described in Example 1. The powder filling rate is further 10%.

[0068] When the powder filling rate is 10%, less powder enters the molten droplets and molten pool, resulting in insufficient endothermic melting, flow disturbance, and nucleation promotion effects, making it difficult to effectively control the temperature field and solidification process of the molten pool. Therefore, directional columnar dendrites are still easily formed in the weld bead, and continuous segregation bands between dendrites are still relatively obvious. The effects of microstructure refinement and elemental segregation suppression are weaker than those in the embodiments of this invention with a filling rate range of 15% to 30%.

[0069] Comparative Example 3:

[0070] CuNi30 alloy strip is used as the outer sheath material, and CuNi30 alloy powder is used as the core filler material. The CuNi30 alloy powder has a particle size of 300 mesh. The main technical details are described in Example 1. The powder filling rate is further 35%.

[0071] When the powder filling rate is 35%, the powder content is too high. Under the relatively low heat input conditions of CMT, some powder may not be able to fully melt, diffuse, and mix uniformly in the droplets and molten pool, easily forming powder agglomerates, incompletely melted particles, oxide inclusions, or pore defects. Although a higher powder content can enhance heat absorption and disturbance, excessive powder will reduce the metallurgical bonding stability and microstructure uniformity of the molten pool. It may even form new local non-uniform regions at grain boundaries or between dendrites, which is not conducive to obtaining CuNi30 weld beads with weak segregation and dense microstructure.

[0072] The above embodiments are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent adjustments made based on the concept of the present invention within the range of powder particle size, filling rate, wire diameter, substrate material, or cold metal transition process parameters should fall within the scope of protection of the present invention.

Claims

1. A process for suppressing dendritic segregation and refining the microstructure of copper-nickel alloys using arc additive manufacturing based on powder-cored wire, characterized in that, Includes the following steps: Step 1: Using CuNi30 alloy strip as the outer sheath material, CuNi30 alloy powder is filled into the outer sheath material to prepare CuNi30 alloy powder core wire. Step 2: Using CuNi30 alloy powder core wire as the feed wire, CuNi30 alloy weld beads or components are deposited on the substrate under a protective atmosphere.

2. The process for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on powder-cored wire arc additive manufacturing according to claim 1, characterized in that: When forming CuNi30 alloy weld beads or components, a cold metal transition arc additive manufacturing process is used.

3. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing using powder-cored wire as described in claim 1, characterized in that: The CuNi30 alloy powder has a particle size of 200 to 325 mesh.

4. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing using powder-cored wire as described in claim 1, characterized in that: The core filling rate of the CuNi30 alloy core wire is 15% to 30%.

5. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on powder-cored wire arc additive manufacturing according to claim 1, characterized in that: The diameters of the CuNi30 alloy powder core wires are 1.2 mm and 1.6 mm.

6. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing using powder-cored wire as described in claim 1, characterized in that: The cold metal transition arc additive manufacturing process parameters are: welding current 112 A to 225 A, voltage 11 V to 20.5 V, travel speed 0.2 m / min to 0.5 m / min, wire feed speed 5 m / min to 9.6 m / min, interpass temperature 150 ℃ to 300 ℃, shielding gas is pure argon, and shielding gas flow rate is 15 L / min to 25 L / min.

7. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on powder-cored wire arc additive manufacturing according to claim 1, characterized in that: The CuNi30 alloy powder core wire exhibits a composite melting behavior during the arc melting process, where the outer metal skin melts first and the core powder melts later, thereby enhancing the stirring of the molten pool and promoting solidification and nucleation.

8. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on powder-cored wire arc additive manufacturing according to claim 1, characterized in that: After grinding, polishing, and etching, the weld bead obtained by the CuNi30 alloy powder core wire deposition has a mixed structure including cellular dendrites, equiaxed cellular crystals, and local columnar cellular crystals, with reduced microsegregation scale and continuity.

9. The process method for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on powder-cored wire arc additive manufacturing according to claim 1, characterized in that: The substrate is a metal substrate suitable for arc additive manufacturing of copper-nickel alloys.

10. A process for suppressing dendritic segregation and refining solidification structure in copper-nickel alloys based on arc additive manufacturing using powder-cored wire, as described in any one of claims 1 to 9, characterized in that: The deposited CuNi30 alloy weld beads or components are used in corrosion-resistant components in marine engineering, ships or chemical equipment.

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