A method for manufacturing a marine gradient copper alloy heat exchange tube

Abstract

The application discloses a preparation method of a marine gradient copper alloy heat exchange pipe, which comprises the following steps: preparing material 1; preparing material 2; carrying out entity modeling on the marine gradient copper alloy heat exchange pipe, and layering the model characteristics; preparing the inner pipe and the outer pipe by using an additive manufacturing system; and finally, processing the marine gradient copper alloy heat exchange pipe by using a wire cutting equipment and a numerical control milling machine. The application provides a gradient copper alloy pipe which is strong outside and tough inside, and the wear resistance of the pipe is improved under the premise that the antibacterial property of the pipe is not greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mechanical manufacturing, and particularly relates to a preparation method of a marine gradient copper alloy heat exchange tube. BACKGROUND

[0002] Fresh water resource has always been a problem that mankind needs to solve, and the fresh water obtained by distillation from high-salinity seawater in the ocean is currently a highly efficient water production method. The core component of this process is the heat exchange tube (also known as the condensing tube), which is usually made of copper alloy. This is because copper alloy has good thermal conductivity and antibacterial properties, which are much better than the effect of chemical sterilization. At the same time, the good thermal conductivity reduces the energy loss during the distillation process.

[0003] However, due to the poor mechanical properties of copper alloy, the marine heat exchange tube often suffers from pitting corrosion or wear failure under the action of seawater and abrasive particles, greatly reducing its service life. Researchers have prepared various high-strength copper alloy materials (such as tin bronze and silicon bronze), but the antibacterial properties and thermal conductivity of copper alloy will be greatly reduced in this process. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art.

[0005] The technical solution of the present application is: a preparation method of a marine gradient copper alloy heat exchange tube, comprising the following steps:

[0006] Step 1: Preparation of Material 1: metal powders are weighed according to the mass percentage: manganese powder 10%~15%, aluminum powder 10~15%, spherical tungsten carbide powder 20~25%, silicon powder 5~8%, tin powder: 10~15%, and copper powder as the balance; and a full-automatic flux-cored wire drawing machine is used to prepare a flux-cored wire with a diameter of 1.2mm, which is named 1# wire material;

[0007] Step 2: Preparation of Material 2: metal powders are weighed according to the mass percentage: manganese powder 10%~12%, aluminum powder 10~15%, spherical tungsten carbide powder 55~60%, silicon powder 3~5%, tin powder: 8~10%, and copper powder as the balance; and a full-automatic flux-cored wire drawing machine is used to prepare a flux-cored wire with a diameter of 1.2mm, which is named 2# wire material;

[0008] Step 3: First, the marine gradient copper alloy heat exchange tube is modeled, and the preparation path and preparation sequence are determined, and then the model features are processed layer by layer, and the CAM software is used to convert it into a program that can be recognized by a six-axis robot;

[0009] Step 4: the 1# wire prepared in step 1 is loaded into an additive manufacturing system composed of a six-axis arc welding robot, and then the preparation of the inner tube of the marine gradient copper alloy heat exchange tube is carried out;

[0010] Step 5: when the part accumulated layer by layer in step 4 is cooled to 250~300℃, the 2# wire prepared in step 2 is loaded into the additive manufacturing system composed of the six-axis arc welding robot, and then the preparation of the outer tube of the marine gradient copper alloy heat exchange tube is carried out;

[0011] Step 6: the marine gradient copper alloy heat exchange tube is processed by using a wire cutting equipment and a numerical control milling machine, and the heat dissipation holes and the counterbores are precisely processed by using a five-axis laser cutting equipment.

[0012] In step 3, the inner tube is first manufactured, and then the outer tube is manufactured; the thickness of the layered slice is 2~2.5mm, the arc starting point is located at the edge of the inner tube, and a circular scanning path is adopted, and the arc starting point of the previous layer is consistent with the arc extinguishing point of the next layer.

[0013] In step 4, the additive manufacturing process parameters are as follows: additive current: 200~210A, arc swing width is 8mm, wire extension length is 12mm; interlayer temperature is 200~250℃; the protective gas is 99.99% pure argon, the gas flow is 10~15L / min, and the wire filling speed is 400mm / min; the additive height is 10~12mm.

[0014] In step 5, the additive manufacturing process parameters are as follows: additive current: 220~230A, arc swing width is 8mm, wire extension length is 12mm, interlayer temperature is 250~300℃; the protective gas is 99.99% pure argon, the gas flow is 10~15L / min, and the wire filling speed is 500mm / min; the additive height is 25~30mm.

[0015] In step 6, the four light holes are processed by using a YAG pulse laser, the laser output pulse width is 8ns, and the laser output power is 80W.

[0016] The heat dissipation holes are annular and uniformly arranged on the outer tube, and the counterbores are annular and uniformly arranged on the inner tube.

[0017] The beneficial effects of the present application are:

[0018] (1) The preparation method of the marine gradient copper alloy heat exchange tube provides a method for accurately, intelligently and automatically preparing the marine gradient copper alloy heat exchange tube.

[0019] (2) The preparation method of the marine gradient copper alloy heat exchange pipe of the present application is prepared by electric arc additive manufacturing, and the marine gradient copper alloy heat exchange pipe has a compact structure and no defects, and is more low-pollution compared with the casting preparation method.

[0020] (3) In the preparation method of the marine gradient copper alloy heat exchange pipe of the present application, a YAG pulse laser is used for hole processing, and the heat affected zone is small and the fatigue performance is high.

[0021] (4) The adding effect of the elements in the wire is as follows:

[0022] The addition of Mn element serves as a deoxidizing element on one hand, and forms a Cu-Mn solid solution on the other hand, thereby forming solid solution strengthening and improving the strength and wear resistance of the copper alloy;

[0023] The addition of Al element can effectively increase the fluidity of the molten pool at high temperature, thereby reducing the H pores easily generated in the rapid solidification process of the copper alloy, and the addition of Al element promotes the generation of kappa phase in the copper alloy, thereby further improving the strength;

[0024] WC is a hard particle phase with high melting point and good thermal stability, which serves as a heterogeneous nucleation point to refine the grains on one hand, and WC is decomposed into hard phase W under the influence of high temperature of the molten pool, thereby forming dispersion strengthening and particle strengthening and improving the wear resistance; in addition, spherical WC has better fluidity under the action of electric arc, so that WC is more uniformly distributed;

[0025] The addition of Si element forms a deoxidizing effect, and Si element has good wettability with WC, which can promote the uniform distribution of WC;

[0026] The addition of Sn element serves to form solid solution strengthening and form a Cu-Sn solid solution, and the addition of Sn element significantly improves the wear resistance; in addition, Sn element can improve the corrosion resistance in view of the long-term existence of petroleum medium corrosion in the petroleum brake disc. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is a modeling diagram of the marine gradient copper alloy heat exchange pipe prepared in Example 1 of the present application;

[0028] Figure 2 is a macroscopic microstructure of the marine gradient copper alloy heat exchange pipe prepared in Example 1 of the present application;

[0029] Figure 3 is a high-magnification microstructure of part a of the marine gradient copper alloy heat exchange pipe prepared in Example 1 of the present application;

[0030] Figure 4This is the high-magnification microstructure of part b of the marine gradient copper alloy heat exchange tube prepared in Example 1 of the present invention. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] Implementation Example 1

[0033] The technical solution adopted in this invention is a method for preparing a marine gradient copper alloy heat exchange tube.

[0034] Step 1: Preparation of material 1 for marine gradient copper alloy heat exchange tubes: Weigh the following metal powders by mass percentage: 10% manganese powder, 10% aluminum powder, 20% spherical tungsten carbide powder, 5% silicon powder, 10% tin powder, and 45% copper powder; and use a fully automatic flux-cored wire drawing machine to prepare flux-cored wire with a diameter of 1.2 mm. The outer sheath of the wire is made of annealed T2 pure copper and named it No. 1 wire.

[0035] Step 2: Preparation of Material 2 for Marine Gradient Copper Alloy Heat Exchanger Tubes: Weigh the following metal powders by mass percentage: 10% manganese powder, 10% aluminum powder, 55% spherical tungsten carbide powder, 5% silicon powder, 10% tin powder, and 10% copper powder; and use a fully automatic flux-cored wire drawing machine to prepare flux-cored wire with a diameter of 1.2 mm. The outer sheath of the wire is made of annealed T2 pure copper, and it is named No. 2 wire.

[0036] Step 3: Perform solid modeling of the marine gradient copper alloy heat exchange tube, as follows: Figure 1 As shown, the fabrication path and sequence are determined. Next, the model is layered for characteristic processing, with a slice thickness of 2mm. The arc initiation point is located at the edge of the inner tube, using a circular scanning path. The inner tube is manufactured first, followed by the outer tube. The arc initiation point of the upper layer coincides with the arc extinguishing point of the lower layer. Wires #1 and #2 extend 12mm beyond the conductive nozzle, and the angle between the wire and the base plate is 90°. The process is then converted into a program recognizable by a six-axis robot using CAM software.

[0037] The thickness of the slices ensures the density of each layer, resulting in a lower defect rate in a single layer. Layered slicing allows for interaction with an arc welding robot.

[0038] The length of wires #1 and #2 extending out of the conductive tip is 12~13mm. Among them, 12~13mm is the optimal processing length, which results in less spatter, lower porosity, and the ability to achieve short-circuit transition.

[0039] The angle between the wire and the base plate is 90°. The base plate is made of T2 pure copper, and the 90° angle achieves the best gas protection effect.

[0040] Step 4: The 1# wire prepared in step 1 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, and the additive process parameters are as follows: additive current: 200 A, arc swing width: 8 mm, wire extension length: 12 mm; interlayer temperature: 200℃; shielding gas: 99.99% pure argon, gas flow rate: 10 L / min, wire filling speed: 400 mm / min; additive height: 10-12 mm, and then the preparation of the inner tube of the marine gradient copper alloy heat exchange tube is carried out, that is, Figure 1 Part a of the parameter; the heat input provided by the parameter can make the WC decompose at high temperature without being burned out in large quantities.

[0041] Step 5: When the part accumulated layer by layer in step 4 cools to 250℃, the 2# wire prepared in step 2 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, and the additive process parameters are as follows: additive current: 220 A, arc swing width: 8 mm, wire extension length: 12 mm, interlayer temperature: 250℃; shielding gas: 99.99% pure argon, gas flow rate: 10 L / min, wire filling speed: 500 mm / min; additive height: 25-30 mm, and then the preparation of the outer tube of the marine gradient copper alloy heat exchange tube is carried out, that is, Figure 1 Part b of the parameter. The heat input provided by the parameter can make the WC decompose at high temperature without being burned out in large quantities.

[0042] The inner tube material has a low hard phase content and has little effect on the antibacterial property of copper itself, and the outer tube has a high hard phase content, mainly to improve its mechanical properties, and the two materials are well combined.

[0043] Step 6: The marine gradient copper alloy heat exchange tube is processed by wire cutting equipment and numerical control milling machine to ensure its surface roughness, five-axis laser cutting equipment is used for precise machining of the heat dissipation hole and the counterbore, and a YAG pulse laser is used for machining of the four light holes, the laser output pulse width is 8 ns, and the laser output power is 80 W.

[0044] In example 1, a marine gradient copper alloy heat exchange tube is prepared by the method, the formed marine gradient copper alloy heat exchange tube is well formed, has good machinability, and has a small amount of subtractive machining, the average friction coefficient is 0.452 and the wear amount is 0.5 mg in the pin-on-disk friction test under 5N for 30 min, the shear strength is 392 MPa, the average microhardness of part a is 237.4 HV 0.1 , the average microhardness of part b is 289.1 HV 0.1 , the microstructure is uniformly distributed, the hard second phase improves the wear resistance, and the measured mechanical properties meet the actual working condition requirements.

[0045] Example 2

[0046] The technical scheme adopted by the present application is a preparation method of a marine gradient copper alloy heat exchange pipe,

[0047] Step 1: Preparation of material 1 for the marine gradient copper alloy heat exchange pipe: metal powders are weighed according to mass percentages, namely manganese powder 12%, aluminum powder 12%, spherical tungsten carbide powder 22%, silicon powder 5%, tin powder 15%, and copper powder 34%, and the sum of the mass percentages of the above components is 100%; and a full-automatic flux-cored wire drawing machine is used to prepare a flux-cored wire with a diameter of 1.2 mm, the wire sheath adopts annealed T2 pure copper, and is named as 1# wire;

[0048] Step 2: Preparation of material 2 for the marine gradient copper alloy heat exchange pipe: metal powders are weighed according to mass percentages, namely manganese powder 12%, aluminum powder 13%, spherical tungsten carbide powder 60%, silicon powder 5%, and tin powder 10%, and the sum of the mass percentages of the above components is 100%; and a full-automatic flux-cored wire drawing machine is used to prepare a flux-cored wire with a diameter of 1.2 mm, the wire sheath adopts annealed T2 pure copper, and is named as 2# wire;

[0049] Step 3: The entity modeling of the marine gradient copper alloy heat exchange pipe is performed as shown in Figure 1 , the preparation path and the preparation sequence are determined, then the model characteristics are processed in layers, the slice thickness is 2-2.5 mm, the arc starting point is located at the edge of the inner pipe, and a circular scanning path is adopted. The inner pipe is manufactured first, and then the outer pipe is manufactured, and the scanning track is as shown in Figure 2 . The arc starting point of the upper layer is consistent with the arc extinguishing point of the lower layer, the 1# and 2# wires extend out of the conductive nozzle by 12-13 mm, the wire and the base plate form an angle of 90°, and the CAM software is used to convert the program into a program that can be recognized by a six-axis robot.

[0050] Step 4: The 1# wire prepared in step 1 is loaded into an additive manufacturing system composed of a six-axis arc welding robot, and the additive manufacturing process parameters are as follows: additive current is 210 A, arc swing width is 8 mm, wire extension length is 12 mm, interlayer temperature is 250℃, protective gas is 99.99% pure argon, gas flow is 15 L / min, wire filling speed is 400 mm / min, additive height is 10-12 mm, and then the inner pipe of the marine gradient copper alloy heat exchange pipe is prepared, namely Figure 1 a part in

[0051] Step 5: when the parts in step 4 are stacked layer by layer and cooled to 300 DEG C, the 2# wire prepared in step 2 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, and the additive manufacturing process parameters are as follows: additive current: 230 A, arc swing width is 8 mm, wire extension length is 12 mm, interlayer temperature is 300 DEG C; the protective gas is 99.99% pure argon, the gas flow is 10 L / min, the wire filling speed is 500 mm / min; the additive height is 25-30 mm, and then the preparation of the marine gradient copper alloy heat exchange tube outer tube is carried out, that is, Figure 1 Part b in the middle.

[0052] Step 6: The marine gradient copper alloy heat exchange tube is processed by using a wire cutting equipment and a numerical control milling machine to ensure the surface roughness, a five-axis laser cutting equipment is used for precise machining of the heat dissipation hole and the counterbore, and a YAG pulse laser is used for machining of the four light holes, the laser output pulse width is 8 ns, and the laser output power is 80 W.

[0053] In example 2, a marine gradient copper alloy heat exchange tube is prepared by using a preparation method, the formed marine gradient copper alloy heat exchange tube is well formed, has good machinability, and has a small subtractive machining amount, in the pin-on-disc friction test under 5N for 30 min, the average friction coefficient is 0.472, the wear amount is 0.45 mg, the shear strength is 389.2 MPa, the average microhardness of part a is 242.8 HV 0.1 , the average microhardness of part b is 295.1 HV 0.1 , the microstructure is uniformly distributed, the hard second phase improves the wear resistance, and the measured mechanical properties meet the actual working condition requirements.

[0054] Example 3

[0055] The technical scheme adopted by the present application is a preparation method of a marine gradient copper alloy heat exchange tube,

[0056] Step 1: preparation of marine gradient copper alloy heat exchange tube material 1: metal powders are weighed according to mass percentage: manganese powder 13%, aluminum powder 13%, spherical tungsten carbide powder 23%, silicon powder 5%, tin powder 12%, and copper powder 34%; and a full-automatic flux-cored wire drawing machine is used to prepare a flux-cored wire with a diameter of 1.2 mm, the wire skin adopts annealed T2 pure copper, and is named as 1# wire;

[0057] Step 2: Preparation of the material 2 for marine gradient copper alloy heat exchange tube: the metal powders are weighed according to the mass percentage: manganese powder 11%, aluminum powder 12.5%, spherical tungsten carbide powder 55%, silicon powder 3%, tin powder 10%, and copper powder 8.5%, the sum of the mass percentages of the above components is 100%; and a full-automatic flux-cored wire drawing machine is used to prepare a flux-cored wire with a diameter of 1.2 mm, the wire sheath is annealed T2 pure copper, and the wire is named as 2# wire;

[0058] Step 3: The solid modeling of the marine gradient copper alloy heat exchange tube is performed as shown in Figure 1 , the preparation path and preparation sequence are determined, and then the model features are processed in layers, the slice thickness is 2-2.5 mm, the arc starting point is located at the edge of the inner tube, and a circular scanning path is used. The inner tube is manufactured first, and then the outer tube is manufactured, and the scanning trajectory is as shown in Figure 2 . The arc starting point of the upper layer is consistent with the arc extinguishing point of the lower layer, the extension length of the 1# and 2# wires from the conductive nozzle is 13 mm, and the angle between the wire and the base plate is 90°. The CAM software is used to convert the program into a program that can be recognized by a six-axis robot.

[0059] Step 4: The 1# wire prepared in step 1 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, the additive manufacturing process parameters are as follows: additive current: 206 A, arc swing width: 8 mm, wire extension length: 12 mm, interlayer temperature: 230℃, shielding gas: 99.99% pure argon, gas flow rate: 12 L / min, wire filling speed: 400 mm / min, additive height: 10-12 mm, and then the inner tube of the marine gradient copper alloy heat exchange tube is prepared, which is part a of Figure 1 .

[0060] Step 5: When the part accumulated layer by layer in step 4 cools to 280℃, the 2# wire prepared in step 2 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, the additive manufacturing process parameters are as follows: additive current: 220 A, arc swing width: 8 mm, wire extension length: 12 mm, interlayer temperature: 250℃, shielding gas: 99.99% pure argon, gas flow rate: 12 L / min, wire filling speed: 500 mm / min, additive height: 25-30 mm, and then the outer tube of the marine gradient copper alloy heat exchange tube is prepared, which is part b of Figure 1 .

[0061] Step 6: The marine gradient copper alloy heat exchange tube is processed by wire cutting equipment and numerical control milling machine to ensure the surface roughness, five-axis laser cutting equipment is used for precise machining of the heat dissipation holes and counterbores, YAG pulse laser is used for machining of the four light holes, the laser output pulse width is 8 ns, and the laser output power is 80 W.

[0062] Example 3 describes a method for preparing a marine-grade gradient copper alloy heat exchange tube. The resulting marine-grade gradient copper alloy heat exchange tube exhibits good formability, machinability, and minimal material reduction. In a pin-disc friction test conducted at 5 N for 30 minutes, the average coefficient of friction was 0.452, the wear was 0.5 mg, the shear strength was 392 MPa, and the average microhardness of part a was 254.4 HV. 0.1 The average microhardness of part b is 308.6 HV. 0.1 The microstructure is uniformly distributed, and the hard second phase has improved its wear resistance. The measured mechanical properties all meet the requirements of actual working conditions.

[0063] The heat dissipation holes are annular and evenly distributed on the outer tube, while the countersunk holes are annular and evenly distributed on the inner tube. The countersunk holes are used for connecting the tubes to meet length requirements; the heat dissipation holes are used for water to pass through and dissipate heat.

[0064] from Figure 3 In part a, W particles are diffusely distributed. Figure 4 In the middle section, the dispersed and agglomerated W particles in part b indicate that the outer tube has extremely high wear resistance.

[0065] This invention provides a gradient copper alloy tube with external strength and internal toughness, which improves wear resistance while ensuring minimal reduction in antibacterial properties. Specifically, the gradient copper alloy has high internal antibacterial properties, high external wear resistance, and a gradient transition in between.

[0066] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for producing a marine gradient copper alloy heat exchange tube, characterized by, Comprise the following steps: Step 1: preparation of material 1: the metal powder is weighed according to the mass percentage: manganese powder 10%~15%, aluminum powder 10~15%, spherical tungsten carbide powder 20~25%, silicon powder 5~8%, tin powder: 10~15%, copper powder as the balance; and prepared into a diameter of 1.2mm flux-cored wire by using full-automatic flux-cored wire drawing machine, and named as 1# wire material; Step 2: preparation of material 2: the metal powder is weighed according to the mass percentage: manganese powder 10%~12%, aluminum powder 10~15%, spherical tungsten carbide powder 55~60%, silicon powder 3~5%, tin powder: 8~10%, copper powder as the balance; and prepared into a diameter of 1.2mm flux-cored wire by using full-automatic flux-cored wire drawing machine, and named as 2# wire material; Step 3: first, the marine gradient copper alloy heat exchange pipe is modeled, the preparation path and preparation sequence are determined, then the model features are layered, and the CAM software is converted into a program that can be recognized by a six-axis robot; Step 4: the 1# wire material prepared in step 1 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, and then the preparation of the inner tube of the marine gradient copper alloy heat exchange pipe is carried out; Step 5: when the part accumulated layer by layer in step 4 cools to 250~300℃, the 2# wire material prepared in step 2 is loaded into the additive manufacturing system composed of a six-axis arc welding robot, and then the preparation of the outer tube of the marine gradient copper alloy heat exchange pipe is carried out; Step 6: the marine gradient copper alloy heat exchange pipe is processed by using wire cutting equipment and numerical control milling machine, and the five-axis laser cutting equipment is used for precise machining of the heat dissipation hole and the counterbore; In step 4, the additive process parameters are: additive current: 200~210A, arc swing width is 8mm, wire extension length is 12mm; interlayer temperature is 200~250℃; protective gas is 99.99% pure argon, gas flow is 10~15L / min, wire filling speed is 400mm / min; additive height is 10~12mm; In step 5, the additive process parameters are: additive current: 220~230A, arc swing width is 8mm, wire extension length is 12mm, interlayer temperature is 250~300℃; protective gas is 99.99% pure argon, gas flow is 10~15L / min, wire filling speed is 500mm / min; additive height is 25~30mm. In step 3, the inner tube is manufactured first, and then the outer tube is manufactured; the thickness of the layered slice is 2~2.5mm, the arc starting point is located at the edge of the inner tube, and a circular scanning path is adopted, and the arc starting point of the previous layer is consistent with the arc extinguishing point of the next layer.

2. The method of producing a marine gradient copper alloy heat exchange tube according to claim 1, characterized by, In step 6, YAG pulse laser is used to process four light holes, the laser output pulse width is 8ns, and the laser output power is 80W.

3. The method of producing a marine gradient copper alloy heat exchange tube according to claim 1, characterized by, The heat dissipation hole is annular and uniformly arranged on the outer tube, and the counterbore is annular and uniformly arranged on the inner tube.

4. The method of producing a gradient copper alloy heat exchange tube for marine use according to claim 1, characterized by, ​

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