Manufacturing method of a highly wear-resistant dredging pipe

Abstract

A manufacturing method of a highly wear-resistant dredging pipe, which relates to the technical field of metal material welding. It includes alloy strip skin and flux-cored powder; the flux-cored powder includes the following components (wt.%): iron powder 15.48% - 22.12%, nickel powder 16.27% - 23.25%, chromium powder 14.42% - 20.60%, cobalt powder 16.34% - 23.34%, aluminum powder 7.49% - 10.69%, M(Al2O3) 5% - 30%; the sum of the mass percentages of the above components is 100%; the FeCoNiCrAl-Mx high-entropy alloy matching flux-cored wire in the present invention is used for arc additive manufacturing technology, the pipe forming quality is excellent, there are no obvious defects such as cracks and pores, the arc light and soot during the welding process are relatively small, and it makes great contributions to the green development strategy.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material welding, and particularly to a preparation method of a highly wear-resistant dredging pipe. Background Art

[0002] Since stainless steel emerged, it has a history of 80 or 90 years. As a great achievement in the history of materials in the world, it is a leader among metal materials. It has many excellent properties, such as heat resistance, corrosion resistance, good appearance and processing performance. It is an outstanding functional material and has been widely used in various industrial and civil fields, and has contributed greatly to the industrial development of our country. With the advancement of the socialist modernization process, the demand for metal materials is increasing day by day. One reason is the continuous expansion of the industrial scale, and on the other hand, traditional single materials are limited greatly and it is difficult to break through the material limit, and controlling costs has always been the core essence during the development process. In order to implement the comprehensive green development, seeking breakthroughs in the performance of stainless steel materials is a long-term and urgent task.

[0003] At present, the processing technologies of high-entropy alloys are mainly vacuum melting or laser cladding technology. However, when using laser cladding to prepare high-entropy alloys, there are problems such as low efficiency, defects such as pores and cracks, and a large amount of powder burn-out during laser cladding, resulting in high costs; melting technology is a relatively traditional preparation process. Vacuum melting has extremely high requirements for equipment and cannot completely isolate air. Defects such as dross and pores are easily generated during the melting process. At the same time, the segregation degree of alloys prepared by casting is relatively large and the nominal alloy composition cannot be achieved. The arc additive manufacturing technology can be widely and flexibly applied to different working conditions, with the advantages of large heat input, flat and beautiful bead forming, and a wide adjustable range of cladding rates. Moreover, the arc additive manufacturing has good controllability, stable arc, and high welding machine accuracy. Compared with solid wires, the composition of flux-cored wires can be flexibly adjusted to meet the requirements of materials. The smelting and preparation process of solid wires is complex, and the drawing performance is poor. The production cycle of flux-cored wires is short and the weld quality is easy to guarantee, with higher comprehensive benefits. Therefore, it is of great significance to carry out research on the microstructure and property evolution of flux-cored wire electrodes and matching alloys for arc additive manufacturing technology for Fe-Co-Ni-based high-entropy alloys.

[0004] Prior art, such as the invention patent for "A Wear-Resistant and Corrosion-Resistant Flux-Cored Wire for Hardfacing and Its Preparation Method," published on December 12, 2022, discloses a wear-resistant, corrosion-resistant flux-cored wire comprising a core powder and a steel strip coated on the core surface. The raw materials, by weight, consist of the following components: 1.2% ferrotitanium, 3.5% low-silicon ferrosilicon, 1.0% medium-carbon ferromanganese, 4% nickel powder, 3.5% metallic chromium, 55% high-carbon ferrochrome, 12% rutile, 4% fluorite, and 1.0% potassium sodium titanate. This wear-resistant, corrosion-resistant flux-cored wire for hardfacing can rationally adjust the ratio of acid and base in the coating, improving the process performance of the weldment. It meets the requirements for excellent oxidation and cavitation resistance, high hardness, and good wear resistance of the cladding metal. Furthermore, the complete alloying of the core reduces the cost of raw materials. However, 3.5% metallic chromium will lead to a decrease in the eutectoid ferrite in the weld, and the acicular ferrite will be replaced by bainite. Although this significantly improves the strength and hardness of the structure, it also leads to a decrease in the plasticity of the material. In addition, this type of welding wire can only have good performance when used below 500°C. Pipelines need to face various extreme environmental tests during use, and many problems will arise in actual applications. Summary of the Invention

[0005] In view of the above problems, the present invention provides a flux-cored welding wire for a highly wear-resistant dredging pipe and a method for preparing the dredging pipe, which has high welding efficiency, convenient operation, excellent pipeline forming quality, and no obvious defects such as cracks and pores.

[0006] The technical solution of the present invention is:

[0007] A flux-cored welding wire for a highly wear-resistant dredging pipe comprises an alloy sheath and flux-cored powder; the flux-cored powder comprises the following components (wt.%):

[0008] Iron powder 15.48%~22.12%,

[0009] Nickel powder 16.27%~23.25%,

[0010] Chromium powder 14.42%~20.60%,

[0011] Cobalt powder 16.34%~23.34%,

[0012] Aluminum powder 7.49%~10.69%,

[0013] M(Al2O3) 5%~30%;

[0014] The sum of the mass percentages of the above components is 100%.

[0015] Specifically, the alloy strip is a Fe-Co-Ni alloy strip.

[0016] Specifically, the filling amount of the flux-cored powder is 30wt.% - 42wt.%.

[0017] The flux-cored wire of this case has the following beneficial effects:

[0018] First, compared with using solid wires, the flux-cored wire for arc additive manufacturing technology in the present invention has a simple production process, convenient operation, high controllability of composition, flexible adjustment, low cost, higher heat transfer efficiency during the cladding process of the wire, and higher welding efficiency;

[0019] Second, in the flux-cored wire of the present invention, elements Ni and Cr can play a good solid solution strengthening role, directly determining the corrosion resistance and wear resistance of the alloy, and the presence of Cr and Ni elements will reduce the precipitation of brittle phases; element Co can improve the hardness of the alloy to a certain extent, thereby improving the wear resistance of the alloy; a dense oxide film will form on the surface of element Al, so it can effectively improve the wear resistance and corrosion resistance of the alloy; element Fe can inhibit the segregation phenomenon between the substrate and the cladding layer during the welding process; at the same time, the addition of Al2O3 can be evenly and dispersedly distributed in the pipeline and play a role of dispersion strengthening, improving the overall performance of the pipeline.

[0020] Third, the FeCoNiCrAl-M x High-entropy alloy matching flux-cored wire for arc additive manufacturing technology has excellent pipe forming quality, no obvious defects such as cracks and pores, less arc light and soot during the welding process, and makes great contributions to the green development strategy.

[0021] A manufacturing method of a highly wear-resistant dredging pipe includes the following steps:

[0022] S100, use Pro E modeling software to draw and model the designed dredging pipe, weigh 15.48% - 22.12% of iron powder, 16.27% - 23.25% of nickel powder, 14.42% - 20.60% of chromium powder, 16.34% - 23.34% of cobalt powder, 7.49% - 10.69% of aluminum powder, and 5% - 30% of M(Al2O3). The sum of the mass percentages of the above components is 100%; then mix the weighed flux-cored powder evenly and dry it;

[0023] S200, the Fe-Co-Ni-based alloy strip is pressed into a U shape by a drawing machine through a cold pressing method, and then the dried flux-cored powder obtained in step S100 is filled into the U-shaped Fe-Co-Ni-based alloy strip and rolled into an O shape, and the powder feeding speed is adjusted according to the actual situation; then use anhydrous ethanol to wipe and clean the surface of the welding strip, gradually reduce the diameter of the thick wire to obtain a wire of 1.47 mm; finally, use anhydrous ethanol to remove impurities and oil stains on the surface of the wire and perform coiling treatment;

[0024] S300. Cut the welding wire obtained in step S200 to obtain an appropriate length, perform arc additive manufacturing and cooling. After cladding, the required FeCoNiCrAl-Mx series high-entropy alloy pipeline is obtained, and the cladding substrate is 304 stainless steel.

[0025] S400. Use a numerical control machine tool and wire electrical discharge machining to perform surface finishing and polishing on the prepared pipeline blank to ensure its surface finish.

[0026] Specifically, in step S100, the drying temperature is 100°C to 200°C, and the drying time is 0.5 h to 1.5 h. During the drying process, 99.9% pure Ar gas is introduced throughout, and the Ar gas flow rate is 5 L / min to 10 L / min.

[0027] Specifically, the welding process parameters in step S300 are as follows: the welding current is 170 A to 195 A, the welding voltage is automatically matched with the welding current of the welding machine, the welding speed is 0.40 m / min to 0.55 m / min, and the interlayer cooling temperature is 120°C to 180°C.

[0028] Specifically, the welding process in step S300 adopts arc additive manufacturing technology, the shielding gas is 99.9% pure Ar gas, and the Ar gas flow rate is 10 L / min to 15 L / min.

[0029] Specifically, the welding method in step S300 adopts multi-layer and multi-pass.

[0030] The manufacturing method of a highly wear-resistant dredging pipe in this case has the following beneficial effects:

[0031] First, there are serious waste and burn of raw materials in the laser cladding or vacuum melting process. The density of the formed workpiece is relatively low, the degree of segregation is relatively serious, there are many defects, and the efficiency is low. The material utilization rate of the arc additive manufacturing technology process is relatively high, and the accuracy of the welding process is relatively high. The dredging pipe prepared by this method has excellent forming, obvious metallic luster, showing obvious fish-scale patterns, and good bonding performance between the substrate and the beads.

[0032] Second, the arc additive manufacturing technology is suitable for various harsh and complex working conditions, with relatively low input costs and flexible manual operation. It can strongly promote the response and call in the field of dredging pipe preparation, and lay a solid foundation for industrial innovation and development.

[0033] Third, the use of FeCoNiCrAl-M xThe arc additive manufacturing technology is used for cladding with a high-entropy alloy matching flux-cored wire. The surface of the pipeline has a gloss, showing regular fish-scale patterns, and there are no defects such as collapse cracks. With the arc additive manufacturing technology, the shielding gas is 99.9% pure Ar gas, which can avoid contact with air or impurities during the welding process, inhibit the possibility of the molten pool being oxidized, and reduce the droplet spatter during the welding process.

[0034] The addition of nickel in the flux-cored wire for highly wear-resistant dredging pipes in the present invention has the effect of solid solution strengthening. The acicular ferrite structure has a greater effect on improving the toughness of the joint than the coarsening of the martensite structure, which has an enhancing effect on the plasticity and impact toughness of the joint. Moreover, the flux-cored wire of the present invention can cope with harsh high-temperature environments, has a relatively low input cost, flexible manual operation, and features low energy consumption, high efficiency, high precision, and greenness, and can be widely applied in industrial production. Brief Description of the Drawings

[0035] Figure 1 It is the microstructure diagram of the FeCoNiCrAl-M x high-entropy alloy channel prepared in Example 1 of the present invention;

[0036] Figure 2 It is the microstructure diagram of the FeCoNiCrAl-M x high-entropy alloy channel prepared in Example 2 of the present invention;

[0037] Figure 3 It is the microstructure diagram of the FeCoNiCrAl-M x high-entropy alloy channel prepared in Example 3 of the present invention;

[0038] Figure 4 It is the microstructure diagram of the FeCoNiCrAl-M x high-entropy alloy channel prepared in Example 4 of the present invention;

[0039] Figure 5 It is the microstructure diagram of the FeCoNiCrAl-M x high-entropy alloy channel prepared in Example 5 of the present invention;

[0040] Figure 6 It is the macroscopic morphology diagram of the dredging pipe blank prepared in the implementation of the present invention. Detailed Description of the Embodiment

[0041] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0042] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In the description of the present invention, unless otherwise specified, the meaning of "plural" is two or more.

[0043] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] Fe-Co-Ni series high-entropy alloys have excellent comprehensive properties, flexible composition adjustment, and the elements cooperate to regulate the properties. Excellent corrosion resistance and wear resistance are the most typical characteristics of Fe-Co-Ni series high-entropy alloys. Therefore, Fe-Co-Ni series high-entropy alloys can be used as an excellent strengthening material and are widely used in the fields of oil pipelines, dredging pipe repair or strengthening, so as to meet the dual needs of cost reduction and performance improvement, and make outstanding contributions to the sustainable development, greening and ecologicalization of our country. Studying a new type of arc additive manufacturing technology for flux-cored wires used in the manufacture and modification of dredging pipes has important guiding significance for large industrial fields in our country.

[0045] A flux-cored wire for dredging pipes in the present invention, the flux-cored wire includes an alloy sheath and flux-cored powder. The flux core includes the following components (wt.%): iron powder 15.48% - 22.12%, nickel powder 16.27% - 23.25%, chromium powder 14.42% - 20.60%, cobalt powder 16.34% - 23.34%, aluminum powder 7.49% - 10.69%, M(Al2O3) 5% - 30%. The sum of the mass percentages of the above components is 100%. The alloy sheath material is an Fe-Co-Ni series alloy sheath; the alloy powder filling rate is 30wt.% - 42wt.%.

[0046] The functions and roles of each component in the flux-cored wire are as follows:

[0047] Elements Ni and Cr can play a good solid solution strengthening role, directly determining the corrosion resistance and wear resistance of the alloy, and the presence of Cr and Ni elements will reduce the precipitation of brittle phases;

[0048] The Co element can improve the hardness of the alloy to a certain extent, thereby enhancing the wear resistance of the alloy;

[0049] A dense oxide film will form on the surface of the Al element, so it can effectively improve the wear resistance and corrosion resistance of the alloy;

[0050] The Fe element can inhibit the segregation phenomenon between the matrix and the cladding layer during the welding process;

[0051] The addition of Al2O3 can be evenly dispersed in the pipeline and play a role in dispersion strengthening, improving the overall performance of the pipeline.

[0052] A preparation method of a highly wear-resistant dredging pipe uses an arc additive manufacturing technology to prepare a dredging pipe with a FeCoNiCrAl-M x high-entropy alloy matching flux-cored wire. The specific steps are as follows:

[0053] Step 1: Use Pro E modeling software to draw and model the designed dredging pipe. Weigh 15.48% - 22.12% of iron powder, 16.27% - 23.25% of nickel powder, 14.42% - 20.60% of chromium powder, 16.34% - 23.34% of cobalt powder, 7.49% - 10.69% of aluminum powder, and M(Al2O3) 5% - 30%. The sum of the mass percentages of the above components is 100%. Then mix the weighed alloy powders evenly and dry them. The drying is carried out in a vacuum tube furnace, continuously introducing 99.9% Ar gas, with an Ar gas flow rate of 5 L / min - 10 L / min, a drying temperature of 100°C - 200°C, and a drying time of 0.5 h - 1.5 h.

[0054] Step 2: First, use a wire drawing machine to press the Fe-Co-Ni-based alloy strip into a U shape by cold pressing method. Then fill the dried mixed powder obtained in Step 1 into the U-shaped welding strip and roll it into an O shape. The powder feeding speed is adjusted according to the actual situation. Then use anhydrous ethanol to wipe and clean the surface of the welding strip, gradually reduce the diameter of the thick wire to obtain a wire of 1.47 mm. Finally, use anhydrous ethanol to remove impurities and oil stains on the surface of the wire and perform wire coiling treatment.

[0055] Step 3: Cut the wire obtained in Step 2 to get a suitable length, perform arc additive manufacturing technology and cool it. The welding current is 170 A - 195 A, the welding voltage is automatically matched with the welding current of the welding machine, the welding speed is 0.40 m / min - 0.55 m / min, and the interlayer cooling temperature is 120°C - 180°C. The welding process uses arc additive manufacturing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 10 L / min - 15 L / min. The welding method uses multi-pass multi-layer cladding. After surfacing, the required FeCoNiCrAl-M xHigh-entropy alloy dredging pipe, with a cladding matrix of 304 stainless steel.

[0056] Step 4: Use a numerical control machine tool and wire electrical discharge machining to perform surface finishing and polishing on the prepared pipe blank to ensure its surface finish.

[0057] Example 1

[0058] Step 1: Use Pro E modeling software to draw and model the designed dredging pipe. Weigh 22.12% iron powder, 23.25% nickel powder, 15.60% chromium powder, 23.34% cobalt powder, 10.69% Al powder, and M(Al2O3) 5%. The sum of the mass percentages of the above components is 100%.

[0059] Step 2: Mix the alloy powders weighed in Step 1 evenly and dry them. The drying is carried out in a vacuum tube furnace, continuously introducing 99.9% Ar gas. The drying temperature is 100°C to 200°C, the drying time is 0.5 h to 1.5 h, and the Ar gas flow rate is 5 L / min to 10 L / min.

[0060] Step 3: First, use a wire drawing machine to press the Fe-Co-Ni-based alloy strip into a U-shaped shape by cold pressing method, and then fill the dried mixed powder obtained in Step 2 into the U-shaped welding strip and roll it into an O-shaped shape. The powder feeding speed is adjusted according to the actual situation; then use anhydrous ethanol to wipe and clean the surface of the welding strip, gradually reduce the diameter of the thick welding wire to obtain a 1.47 mm welding wire; finally, use anhydrous ethanol to remove impurities and oil stains on the surface of the welding wire and perform coiling treatment.

[0061] Step 4: Cut the welding wire obtained in Step 3 to obtain a suitable length, perform arc additive manufacturing technology and cool it. The welding current is 170 A to 195 A, the welding voltage is automatically matched with the welding current of the welding machine, the welding speed is 0.40 m / min to 0.55 m / min, and the interlayer cooling temperature is 120°C to 180°C. The welding process uses arc additive manufacturing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 10 L / min to 15 L / min. The welding method uses multi-pass multi-layer cladding. After surfacing, the required FeCoNiCrAl-M is obtained. x High-entropy alloy dredging pipe, with a cladding matrix of 304 stainless steel.

[0062] Step 5: Use a numerical control machine tool and wire electrical discharge machining to perform surface finishing and polishing on the prepared dredging pipe blank to ensure its surface finish.

[0063] After the welding test, perform a mechanical property test on the pipe. The test results show that the average hardness is 650.6 HV. 0.2, the wear amount is 19 mg, the average friction coefficient is 0.66, and the mechanical properties meet the expectations. Its microstructure is as Figure 1 shown. The microstructure consists of cellular crystals and columnar crystals, with uniform structure and good friction performance. From the microstructure and mechanical properties, it can be seen that the Fe-Co-Ni high-entropy alloy pipeline of the present invention has excellent comprehensive performance and is suitable for the preparation and modification of dredging pipes.

[0064] Example 2

[0065] Step 1: Use Pro E modeling software to draw and model the designed dredging pipe. Weigh 19.92% iron powder, 20.92% nickel powder, 18.54% chromium powder, 21.00% cobalt powder, 9.62% Al powder, and the sum of the mass percentages of the above components is 100%.

[0066] Step 2: Mix the alloy powders weighed in Step 1 evenly and dry them. The drying is carried out in a vacuum tube furnace, continuously introducing 99.9% Ar gas. The drying temperature is 100°C to 200°C, the drying time is 0.5 h to 1.5 h, and the Ar gas flow rate is 5 L / min to 10 L / min.

[0067] Step 3: First, use a wire drawing machine to press the Fe-Co-Ni alloy strip into a U shape by cold pressing method, and then fill the dried mixed powder obtained in Step 2 into the U-shaped welding strip and roll it into an O shape. The powder feeding speed is adjusted according to the actual situation. Then, wipe and clean the surface of the welding strip with anhydrous ethanol, and gradually reduce the diameter of the thick welding wire to obtain a 1.47 mm welding wire. Finally, remove the impurities and oil on the surface of the welding wire with anhydrous ethanol and perform coiling treatment.

[0068] Step 4: Cut the welding wire obtained in Step 3 to get a suitable length, and perform arc additive manufacturing technology and cooling. The welding current is 170 A to 195 A, the welding voltage is automatically matched with the welding current of the welding machine, the welding speed is 0.40 m / min to 0.55 m / min, and the interlayer cooling temperature is 120°C to 180°C. The welding process adopts arc additive manufacturing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 10 L / min to 15 L / min. The welding method adopts multi-pass multi-layer cladding. After surfacing, the required FeCoNiCrAl-M x high-entropy alloy dredging pipe is obtained, and the cladding substrate is 304 stainless steel.

[0069] Step 5: Use a numerical control machine tool and wire electrical discharge machining to perform surface finishing and polishing on the prepared pipe blank to ensure its surface finish.

[0070] After the welding test, perform a mechanical property test on the pipe. The test results show that the average hardness is 680.6 HV0.2 , the wear amount is 14 mg, the average friction coefficient is 0.58, and the mechanical properties meet the expectations. Its microstructure is as Figure 2 shown. The microstructure consists of cellular crystals and columnar crystals, with uniform organization and good friction performance. From both the microstructure and mechanical properties, it can be shown that the Fe-Co-Ni-based high-entropy alloy pipeline of the present invention has excellent comprehensive performance and is suitable for the preparation and modification of dredging pipes.

[0071] Example 3

[0072] Step 1: Use Pro E modeling software to draw and model the designed dredging pipe. Weigh 18.80% iron powder, 19.76% nickel powder, 17.51% chromium powder, 19.84% cobalt powder, 9.09% Al powder, and M(Al2O3) 15%. The sum of the mass percentages of the above components is 100%.

[0073] Step 2: Mix the alloy powders weighed in Step 1 evenly and dry them. The drying is carried out in a vacuum tube furnace, continuously introducing 99.9% Ar gas. The drying temperature is 100°C to 200°C, the drying time is 0.5 h to 1.5 h, and the Ar gas flow rate is 5 L / min to 10 L / min.

[0074] Step 3: First, use a wire drawing machine to press the Fe-Co-Ni-based alloy strip into a U shape by cold pressing, and then fill the dried mixed powder obtained in Step 2 into the U-shaped welding strip and roll it into an O shape. The powder feeding speed is adjusted according to the actual situation. Then, use anhydrous ethanol to wipe and clean the surface of the welding strip, and gradually reduce the diameter of the thick welding wire to obtain a 1.47 mm welding wire. Finally, use anhydrous ethanol to remove impurities and oil stains on the surface of the welding wire and perform coiling treatment.

[0075] Step 4: Cut the welding wire obtained in Step 3 to obtain a suitable length, perform arc additive manufacturing technology and cool it. The welding current is 170 A to 195 A, the welding voltage is automatically matched with the welding current of the welding machine, the welding speed is 0.40 m / min to 0.55 m / min, and the interlayer cooling temperature is 120°C to 180°C. The welding process adopts arc additive manufacturing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 10 L / min to 15 L / min. The welding method adopts multi-pass multi-layer cladding. After surfacing, the required FeCoNiCrAl-M x high-entropy alloy dredging pipe is obtained, and the cladding substrate is 304 stainless steel.

[0076] Step 5: Use a numerical control machine tool and wire electrical discharge machining to perform surface finishing and polishing on the prepared pipe blank to ensure its surface finish

[0077] After the welding test, a mechanical property test was carried out on the pipeline. The test results were as follows: the average hardness was 630.1 HV 0.2 , the wear amount was 9 mg, the average friction coefficient was 0.47, and the mechanical properties met the expectations. Its microstructure was as shown in Figure 3 . The microstructure was composed of cellular crystals and columnar crystals, with uniform organization and good friction performance. From the microstructure and mechanical properties, it can be seen that the Fe-Co-Ni high-entropy alloy pipeline of the present invention has excellent comprehensive performance and is suitable for the preparation and modification of large dredging pipes.

[0078] Example 4

[0079] Step 1: Use Pro E modeling software to draw and model the designed dredging pipe. Weigh 17.70% iron powder, 18.60% nickel powder, 16.48% chromium powder, 18.67% cobalt powder, 8.55% Al powder, and the sum of the mass percentages of the above components is 100%.

[0080] Step 2: Mix the alloy powders weighed in Step 1 evenly and dry them. The drying is carried out in a vacuum tube furnace, continuously introducing 99.9% Ar gas. The drying temperature is 100°C to 200°C, the drying time is 0.5 h to 1.5 h, and the Ar gas flow rate is 5 L / min to 10 L / min.

[0081] Step 3: First, use a wire drawing machine to press the Fe-Co-Ni alloy strip into a U shape by cold pressing method, and then fill the dried mixed powder obtained in Step 2 into the U-shaped welding strip and roll it into an O shape. The powder feeding speed is adjusted according to the actual situation; then use anhydrous ethanol to wipe and clean the surface of the welding strip, and gradually reduce the diameter of the thick welding wire to obtain a welding wire of 1.47 mm; finally, use anhydrous ethanol to remove impurities and oil stains on the surface of the welding wire and carry out coiling treatment.

[0082] Step 4: Cut the welding wire obtained in Step 3 to obtain a suitable length, carry out arc additive manufacturing technology and cool it. The welding current is 170 A to 195 A, the welding voltage is automatically matched with the welding current of the welding machine, the welding speed is 0.40 m / min to 0.55 m / min, and the interlayer cooling temperature is 120°C to 180°C. The welding process adopts arc additive manufacturing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 10 L / min to 15 L / min. The welding method adopts multi-pass multi-layer cladding. After surfacing, the required FeCoNiCrAl-M x high-entropy alloy pipeline is obtained, and the cladding substrate is 304 stainless steel.

[0083] Step 5: Use a numerical control machine tool and wire electrical discharge machining to perform surface finishing and polishing on the prepared pipeline blank to ensure its surface finish

[0084] After the welding test, the pipeline was subjected to mechanical property test. The test results showed that the average hardness was 660.8HV 0.2 The wear amount is 12 mg, the average friction coefficient is 0.55, and the mechanical properties are in line with expectations. Figure 4 As shown, the microstructure is composed of cellular crystals and columnar crystals, the structure is uniform, and the friction performance is good. Both the microstructure and mechanical properties show that the Fe-Co-Ni high entropy alloy pipeline of the present invention has excellent comprehensive performance and is suitable for the preparation and modification of dredging pipes.

[0085] Example 5

[0086] Step 1: Use Pro E modeling software to draw and model the designed dredging pipe. Weigh 15.48% iron powder, 16.27% nickel powder, 16.27% chromium powder, 16.34% cobalt powder, and 7.49% aluminum powder. The sum of the mass percentages of components with M (Al2O3) above 30% is 100%.

[0087] Step 2: Mix the alloy powder weighed in step 1 evenly and dry it. The drying is carried out in a vacuum tube furnace. 99.9% Ar gas is continuously introduced. The drying temperature is 100°C~200°C, the drying time is 0.5h~1.5h, and the Ar gas flow rate is 5 L / min~10 L / min.

[0088] Step 3: First, the Fe-Co-Ni alloy strip is cold-pressed into a U-shape by a wire drawing machine, and then the dry mixed powder obtained in step 2 is filled into the U-shaped welding strip and rolled into an O-shape. The powder feeding speed is adjusted according to the actual situation; then the surface of the welding strip is wiped clean with anhydrous ethanol, and the thick welding wire is gradually reduced to obtain a 1.47mm welding wire; finally, the impurities and oil on the surface of the welding wire are removed with anhydrous ethanol and the wire is coiled.

[0089] Step 4: Cut the welding wire obtained in step 3 to obtain the appropriate length, perform arc additive manufacturing and cool it. The welding current is 170A~195A, the welding voltage automatically matches the welding current of the welding machine, the welding speed is 0.40m / min~0.55m / min, and the interlayer cooling temperature is 120℃~180℃. The welding process adopts arc additive manufacturing technology, the shielding gas is 99.9% Ar gas, and the Ar gas flow rate is 10 L / min~15 L / min. The welding method adopts multi-pass multi-layer cladding. After the cladding is completed, the required FeCoNiCrAl-M x High entropy alloy pipe, the cladding substrate is 304 stainless steel.

[0090] Step 5: Use CNC machine tools and wire-cut EDM to polish the surface of the prepared pipe blank to ensure its surface smoothness.

[0091] After the welding test, a mechanical property test was carried out on the pipeline. The test results were as follows: the average hardness was 649.5 HV 0.2 , the wear amount was 16 mg, the average friction coefficient was 0.72, and the mechanical properties met the expectations. Its microstructure was as Figure 5 shown. The microstructure was composed of cellular crystals and columnar crystals, with uniform structure and good friction performance; both the microstructure and mechanical properties could demonstrate that the Fe-Co-Ni-based high-entropy alloy pipeline of the present invention had excellent comprehensive performance and was suitable for the preparation and modification of dredging pipes.

[0092] Regarding the content disclosed in this case, the following points need to be explained:

[0093] (1). The attached drawings of the embodiments disclosed in this case only relate to the structures involved in the embodiments disclosed in this case. Other structures can be referred to the general design;

[0094] (2). Without conflict, the embodiments disclosed in this case and the features in the embodiments can be combined with each other to obtain new embodiments;

[0095] The above is only the specific implementation manners disclosed in this case, but the protection scope of this disclosure is not limited thereto. The protection scope disclosed in this case shall be subject to the protection scope of the claims.

Claims

1. A method for manufacturing a highly wear-resistant dredging pipe, characterized in that: The following steps are involved: S100, using Pro E modeling software, draw and model the designed dredging pipe. Weigh 15.48%-22.12% iron powder, 16.27%-23.25% nickel powder, 14.42%-20.60% chromium powder, 16.34%-23.34% cobalt powder, 7.49%-10.69% aluminum powder, and 5%-30% Al2O3. The sum of the mass percentages of the core powder formed by mixing the above components is 100%. Then mix the weighed core powders evenly and dry them. In step S200, the Fe-Co-Ni alloy strip is formed into a U-shape, and the dried flux-cored powder obtained in step S100 is then filled into the U-shaped Fe-Co-Ni alloy strip and rolled into an O-shape. The surface of the welding strip is then cleaned with anhydrous ethanol, and the thick welding wire is gradually reduced to a 1.47 mm welding wire. Finally, anhydrous ethanol is used to remove impurities and oil from the surface of the welding wire and the wire is coiled. S300, cutting the welding wire obtained in step S200 to obtain a suitable length, performing arc additive manufacturing and cooling, and obtaining the desired FeCoNiCrAl-Mx high entropy alloy pipe after cladding, with the cladding substrate being 304 stainless steel; The welding process parameters are: welding current is 170A~195A, welding voltage automatically matches the welding current of the welding machine, welding speed is 0.40m / min~0.55m / min, and interlayer cooling temperature is 120℃~180℃; S400: Surface finishing and polishing of the prepared pipe blank to ensure its surface smoothness.

2. The method for manufacturing a highly wear-resistant dredging pipe according to claim 1, characterized in that: In step S100 , the drying temperature is 100° C. to 200° C., and the drying time is 0.5 h to 1.5 h. During the entire drying process, 99.9% pure Ar gas is introduced, and the Ar gas flow rate is 5 L / min to 10 L / min.

3. The method for manufacturing a highly wear-resistant dredging pipe according to claim 1, characterized in that: The welding process in step S300 adopts arc additive manufacturing technology, the shielding gas is 99.9% pure Ar gas, and the Ar gas flow rate is 10 L / min~15 L / min.

4. The method for manufacturing a highly wear-resistant dredging pipe according to claim 1, characterized in that: The welding method in step S300 adopts multi-layer and multi-pass welding.

5. The method for manufacturing a highly wear-resistant dredging pipe according to claim 1, characterized in that: The filling amount of the drug core powder is 30wt.%-42wt.%.

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