Rare-earth-containing hard alloy sintered welding rod for surface laying welding of petroleum workover tool and manufacturing method of rare-earth-containing hard alloy sintered welding rod

Abstract

The invention provides a rare earth-containing hard alloy sintered welding rod for surface laying welding of a petroleum workover tool and a manufacturing method thereof.The manufacturing method includes the steps that the sintered welding rod is obtained by sintering hard alloy particles and soft metal, the component content of the hard alloy particles in the sintered welding rod is 60-75%, the component content of the soft metal in the sintered welding rod is 25-40%, and the component content of the hard alloy particles in the sintered welding rod is 20-30%. The hard alloy material adopts a WC, TiC, NbC, Cr2C3, rare earth Ce and Co composite sintering material, the hardness, toughness and grinding performance of sintered hard alloy particles are improved by optimizing the components and content of the hard alloy material, and then the grinding and milling effect of the hard alloy material on the high-strength tubular column is improved. Cu-Ni-Zn-Mn series material powder is adopted as a soft metal material, so that the strength and the wear resistance of matrix metal are improved, the problem that WC particles are prone to falling off in the milling operation process is effectively solved, and the milling efficiency of a hard alloy paving and welding material is improved during field workover operation.

Description

Technical Field

[0001] The invention belongs to the field of well repair tool manufacturing in the petroleum and natural gas industry, and in particular relates to a rare earth-containing hard alloy sintered welding rod for surface welding of well repair tools and a manufacturing method thereof. Background Art

[0002] As a large number of oil and gas wells in my country enter the middle and late stages of production, downhole tubulars are frequently damaged, and milling tools are needed to repair the tubulars. Milling tools are usually made of alloy steel to form the base shape, and then large-sized hard alloy particles are welded at the position where the tool mills the tubular. The milling function of the milling tool on the damaged tubular is mainly achieved by the hard alloy particles welded on its surface. At present, the hard alloy particles welded on the surface of the milling tool are mainly WC particles. YD series welding rods are mostly used for welding in China. However, due to the high hardness and brittleness of WC particles, the hardness is relatively low, about HV1350-HV1450, the impact resistance is weak, and the properties are quite different from those of the steel matrix. WC particles are prone to fall off during the milling operation. A method for manufacturing a composite tungsten-based tubular welding rod hard surface material (CN201510384142.7) proposes to prepare hard surface materials by composite methods of cast carbides and cemented carbide balls and other materials, but the particle size of this material is small, and it is mechanically mixed and loaded into tubular welding rods for use. It is mainly used in roller drill bits and perforating reamer, and is mainly used for rock layer grinding, but the milling effect on pipe column steel is very limited. In addition, with the large-scale application of high-strength pipe columns, the pipe columns have higher strength and higher hardness, which puts higher requirements on the milling performance of milling tools. At present, the milling efficiency of WC particles welded on the surface of milling tools is low, which can no longer meet the needs of on-site well repair operations. It is urgent to develop hard alloy welding materials with higher milling efficiency for high-strength pipe columns. The present invention optimizes the composition and process of hard alloy particles, combines the special role of rare earth elements, improves the bonding performance of hard alloy sintered particles, and reduces the falling of alloy particles during milling. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools and a manufacturing method thereof, which solves the problem of WC particles easily falling off during the grinding and milling operation and improves the grinding and milling efficiency of hard alloy welding materials during on-site well repair operations.

[0004] The present invention is achieved through the following technical solutions:

[0005] A rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools, comprising: a sintered welding rod obtained by sintering hard alloy particles and soft metal, wherein the hard alloy particles in the sintered welding rod account for 60-75% of the component content, the soft metal component content accounts for 25wt%-40wt%,

[0006] The composition of the hard alloy particles includes WC: 60wt%-70wt%, TiC: 12wt%-16wt%, NbC: 5wt%-7wt%, Cr2C3: 1wt%-2wt%, rare earth Ce: 0.6wt%-1.2wt%, and the rest is Co;

[0007] The soft metal is Cu-Ni-Zn-Mn system material powder.

[0008] Preferably, the soft metal composition includes Cu: 76wt%-80wt%, Ni: 4wt%-8wt%, Mn: 5wt%-8wt%, and the remainder is Zn.

[0009] Preferably, the hard alloy particles are of a polygonal structure.

[0010] A method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools, comprising:

[0011] S1, wet-grinding and mixing the components of the hard alloy particles in an oxygen-free environment, adding a binder after drying and mixing evenly, pressing and molding the alloy material through a polygonal mold to obtain a polygonal alloy material, and sintering the pressed alloy material under high temperature conditions to obtain hard alloy particles;

[0012] S2. Spread the hard alloy particles in the mold in proportion, place the mold in a hydrogen environment and heat it to 500±50℃, then spread the soft metal powder around the hard alloy particles in the mold in proportion, place the mold in a hydrogen environment again and heat it to 1200±50℃, keep it warm for 10-15 minutes, and then place it in a 200±50℃ environment to cool it down to obtain a rare earth-containing hard alloy sintered welding rod.

[0013] Preferably, the temperature during the wet grinding and mixing process does not exceed 26° C., and the wet grinding time is 25 h to 30 h.

[0014] Preferably, anhydrous alcohol is added during the wet grinding and mixing process to maintain humidity and temperature.

[0015] Preferably, the hardness of the hard alloy particles is HV1600-HV1800.

[0016] Preferably, the polygonal mold is a triangular prism, a seven-pointed star or an eight-pointed star.

[0017] Preferably, the specific process of sintering the pressed alloy material under high temperature conditions is: first put the pressed alloy material into the sintering equipment to form a vacuum environment, then heat it from room temperature to 400±50℃, keep it warm for 1h±0.2h, then heat it to 1000±50℃, keep it warm for 1h±0.2h, and finally heat it to the sintering temperature of 1400±50℃, and keep it warm for 8h±1h.

[0018] Preferably, a layer of borax mold release agent is spread on the bottom of the mold before spreading the hard alloy particles.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] The present invention provides a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools, comprising a sintered welding rod obtained by sintering hard alloy particles and soft metals, wherein the hard alloy particles in the sintered welding rod account for 60-75% of the component content, and the soft metal component content accounts for 25wt%-40wt%. By optimizing the composition of hard alloy particles and soft metal matrix materials, introducing ceramic reinforcement phases and rare earth elements, the strength and toughness of hard alloy particles are improved, the occurrence of hard particle fracture and falling accidents is reduced, and the grinding and milling ability and service life of sintered hard alloy welding materials are improved. The hard alloy material in the present invention adopts WC, TiC, NbC, Cr 2 C 3 , rare earth Ce and Co composite sintered materials, by optimizing the composition and content of hard alloy materials, improving the hardness, toughness and grinding performance of sintered hard alloy particles, thereby improving its grinding and milling effect on high-strength pipes; soft metal materials use Cu-Ni-Zn-Mn material powder to improve the strength and wear resistance of the matrix metal itself, effectively solving the problem of WC particles falling off during the grinding and milling operation, and improving the grinding and milling efficiency of hard alloy welding materials during on-site well repair operations.

[0021] Furthermore, in the process of preparing the hard alloy particles, anhydrous alcohol is added in a timely manner during the wet grinding and mixing process to ensure a certain humidity of the powder, and at the same time, the ambient temperature is lowered to ensure that the wet grinding ambient temperature is within 26° C., so as to maintain the hardness performance of the hard alloy particles to achieve the best effect;

[0022] Furthermore, the polygonal mold for pressing the hard alloy particles of the present invention should be a mold with sharp edges and corners such as a triangular prism, a seven-pointed star or an eight-pointed star. The size of the polygonal alloy material particles obtained by pressing is controlled in the range of 3mm-10mm, and the hardness of the hard alloy particles reaches HV1600-HV1800, which effectively improves the hardness, toughness and grinding performance of the hard alloy particles, thereby improving its grinding effect on high-strength pipes. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0024] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] The invention provides a hard alloy sintered welding rod for surface welding of a milling tool for milling a high-strength pipe column and a manufacturing process thereof.

[0026] Technical solution:

[0027] (1) The sintered welding rod of the present invention is obtained by sintering polygonal sintered hard alloy particles and soft metal, wherein the hard alloy particles account for 60wt%-75wt% and the soft metal accounts for 25wt%-40wt%. The composition of the polygonal sintered hard alloy particles is WC: 60wt%-70wt%, TiC: 12wt%-16wt%, NbC: 5wt%-7wt%, Cr 2 C 3 :1wt%-2wt%, rare earth Ce: 0.6wt%-1.2wt%, and the rest is Co. The soft metal is a Cu-Ni-Zn-Mn system material powder, with the composition of Cu: 76wt%-80wt%, Ni: 4wt%-8wt%, Mn: 5wt%-8wt%, and the rest is Zn.

[0028] (2) First, WC: 60wt%-70wt%, TiC: 12wt%-16wt%, NbC: 5wt%-7wt%, Cr 2 C 3 :1wt%-2wt%, rare earth Ce:0.6wt%-1.2wt%, the rest is Co, the powders are mixed, wet-milled in an oxygen-free environment for 25h-30h to make the powders of different components fully mixed and uniform, and the temperature does not exceed 26°C during the wet-milling mixing process. The uniformly mixed alloy powder is dried, a binder is added to the powder mixture, and the mixture is evenly modulated, and the powder mixture is pressed into a multi-prism-shaped alloy material using a multi-prism-shaped mold to obtain a multi-prism-shaped alloy material, and the pressed alloy material is sintered under high temperature conditions to obtain hard alloy particles.

[0029] (3) It should be further explained that anhydrous alcohol should be added in time during the wet grinding process to ensure a certain humidity of the powder and reduce the ambient temperature to ensure that the wet grinding ambient temperature is within 26°C;

[0030] (4) It needs to be further explained that the polygonal mold for pressing the hard alloy particles should be a mold with sharp edges and corners such as a triangular prism, a seven-pointed star or an eight-pointed star, and the size of the polygonal alloy particles obtained by pressing is controlled in the range of 3mm-10mm;

[0031] (5) The sintering of alloy particles needs to be carried out in a vacuum environment using a gradient heating method. First, the alloy particles are placed in the sintering equipment to form a vacuum environment, and then the temperature is gradually raised from room temperature to 400±50℃, and kept at this temperature for 1h±0.2h, then raised to 1000±50℃, and kept at this temperature for 1h±0.2h, and finally raised to the sintering temperature of 1400±50℃, and the holding time is 8h±1h;

[0032] (6) After sintering, the hard alloy particles are slowly cooled in the furnace to obtain polyhedral hard alloy particles, and the hardness of the alloy particles is HV1600-HV1800.

[0033] (7) Spreading the sintered hard alloy particles evenly in a long groove mold at a ratio of 60-75 wt%, and spreading a layer of borax release agent at the bottom of the mold;

[0034] (8) Place the mold in a hydrogen environment heating furnace and heat it to 500±50℃;

[0035] (9) Spread the soft metal powder evenly around the hard alloy particles in the mold at a ratio of 25-40wt%, and put the mold back into the hydrogen environment heating furnace and heat it to 1200±50℃ for 10-15 minutes;

[0036] (10) It should be further explained that the soft metal components are Cu: 76-80wt%, Ni: 4-8wt%, Mn: 5-8wt%, and the rest is Zn.

[0037] (11) The sintered hard alloy rod is placed in an environment of 200±50℃ for slow cooling to obtain a finished hard alloy sintered welding rod.

[0038] Example 1

[0039] (1) The sintered welding rod of the present invention is obtained by sintering polygonal sintered hard alloy particles and soft metal, wherein the hard alloy particles account for 60wt% and the soft metal accounts for 40wt%. The composition of the polygonal sintered hard alloy particles is WC: 60wt%, TiC: 12wt%, NbC: 5wt%, Cr 2 C 3 :1wt%, rare earth Ce:0.6wt%, and the rest is Co. The soft metal is a Cu-Ni-Zn-Mn system material powder, with a composition of Cu:76wt%, Ni:4wt%, Mn:5wt%, and the rest is Zn.

[0040] (2) First, WC: 60wt%, TiC: 12wt%, NbC: 5wt%, Cr 2 C 3 :1wt%, rare earth Ce:0.6wt%, the rest is Co, the powders are mixed, wet-milled for 25h in an oxygen-free environment to make the powders of different components fully mixed and uniform, and the temperature does not exceed 26°C during the wet-milling mixing process. The uniformly mixed alloy powder is dried, a binder is added to the powder mixture, and the mixture is evenly modulated, and the powder mixture is pressed into a multi-prism-shaped alloy material using a multi-prism-shaped mold to obtain a multi-prism-shaped alloy material, and the pressed alloy material is sintered under high temperature conditions to obtain hard alloy particles.

[0041] (3) It should be further explained that anhydrous alcohol should be added in time during the wet grinding process to ensure a certain humidity of the powder and reduce the ambient temperature to ensure that the wet grinding ambient temperature is within 26°C;

[0042] (4) It needs to be further explained that the polygonal mold for pressing the hard alloy particles should be a triangular prism-shaped mold, and the size of the triangular prism alloy particles obtained by pressing is controlled in the range of 3mm-5mm;

[0043] (5) The sintering of alloy particles needs to be carried out in a vacuum environment using a gradient heating method. First, the alloy particles are placed in the sintering equipment to form a vacuum environment, and then the temperature is gradually raised from room temperature to 400°C, kept at this temperature for 1 hour, then raised to 800°C, kept at this temperature for 1 hour, and finally raised to the sintering temperature of 1400°C, and kept at this temperature for 8 hours;

[0044] (6) After sintering, the hard alloy particles are slowly cooled in the furnace to obtain polyhedral hard alloy particles, and the hardness of the alloy particles is HV1600-HV1680.

[0045] (7) Spreading the sintered hard alloy particles in a ratio of 60 wt % evenly in the long groove mold, and spreading a layer of borax release agent at the bottom of the mold;

[0046] (8) Place the mold in a hydrogen environment heating furnace and heat it to 500°C;

[0047] (9) Spread the soft metal powder evenly around the hard alloy particles in the mold at a ratio of 40 wt %, put the mold back into the hydrogen environment heating furnace and heat it to 1200° C. for 10-13 minutes;

[0048] (10) It should be further explained that the soft metal components are Cu: 76wt%, Ni: 4wt%, Mn: 5wt%, and the rest is Zn.

[0049] (11) The sintered hard alloy strip is placed in a low temperature environment of 200°C for slow cooling to obtain a finished hard alloy sintered welding rod.

[0050] Example 2

[0051] (1) The sintered welding rod of the present invention is obtained by sintering polygonal sintered hard alloy particles and soft metal, wherein the hard alloy particles account for 75wt% and the soft metal accounts for 25wt%. The composition of the polygonal sintered hard alloy particles is WC: 70wt%, TiC: 16wt%, NbC: 7wt%, Cr 2 C 3 :2wt%, rare earth Ce:1.2wt%, and the rest is Co. The soft metal is a Cu-Ni-Zn-Mn system material powder, with a composition of Cu:80wt%, Ni:8wt%, Mn:8wt%, and the rest is Zn.

[0052] (2) First, WC: 70wt%, TiC: 16wt%, NbC: 7wt%, Cr 2 C 3 :2wt%, rare earth Ce:1.2wt%, the rest is Co, the powders are mixed, wet-milled for 30h in an oxygen-free environment to make the powders of different components fully mixed and uniform, and the temperature does not exceed 26°C during the wet-milling mixing process. The uniformly mixed alloy powder is dried, a binder is added to the powder mixture, and the mixture is evenly modulated, and the powder mixture is pressed into a multi-prism-shaped alloy material using a multi-prism-shaped mold to obtain a multi-prism-shaped alloy material, and the pressed alloy material is sintered under high temperature conditions to obtain hard alloy particles.

[0053] (3) It should be further explained that anhydrous alcohol should be added in time during the wet grinding process to ensure a certain humidity of the powder and reduce the ambient temperature to ensure that the wet grinding ambient temperature is within 26°C;

[0054] (4) It needs to be further explained that the polygonal die for pressing the hard alloy particles should be a seven-pointed star-shaped die, and the size of the polygonal alloy particles obtained by pressing is controlled in the range of 6mm-8mm;

[0055] (5) The sintering of alloy particles needs to be carried out in a vacuum environment using a gradient heating method. First, the alloy particles are placed in the sintering equipment to form a vacuum environment, and then the temperature is gradually raised from room temperature to 450°C, kept at this temperature for 1.2 h, then raised to 850°C, kept at this temperature for 1.2 h, and finally raised to the sintering temperature of 1450°C, and the holding time is 9 h;

[0056] (6) After sintering, the hard alloy particles are slowly cooled in the furnace to obtain polyhedral hard alloy particles, and the hardness of the alloy particles is HV1750-HV1800.

[0057] (7) Spreading the sintered hard alloy particles evenly in a long groove mold at a ratio of 75 wt%, and spreading a layer of borax release agent at the bottom of the mold;

[0058] (8) Place the mold in a hydrogen environment heating furnace and heat it to 550°C;

[0059] (9) Spread the soft metal powder evenly around the hard alloy particles in the mold at a ratio of 25 wt %, put the mold back into the hydrogen environment heating furnace and heat it to 1250° C. for 13-15 minutes;

[0060] (10) It should be further explained that the soft metal components are Cu: 80wt%, Ni: 8wt%, Mn: 8wt%, and the rest is Zn.

[0061] (11) The sintered hard alloy strip is placed in a low temperature environment of 250°C for slow cooling to obtain a finished hard alloy sintered welding rod.

[0062] Example 3

[0063] (1) The sintered welding rod of the present invention is obtained by sintering polygonal sintered hard alloy particles and soft metal, wherein the hard alloy particles account for 70wt% and the soft metal accounts for 30wt%. The composition of the polygonal sintered hard alloy particles is WC: 65wt%, TiC: 14wt%, NbC: 6wt%, Cr 2 C 3 :1.5wt%, rare earth Ce:1.0wt%, and the rest is Co. The soft metal is Cu-Ni-Zn-Mn system material powder, with the composition of Cu:78wt%, Ni:5wt%, Mn:7wt%, and the rest is Zn.

[0064] (2) First, WC: 65wt%, TiC: 14wt%, NbC: 6wt%, Cr 2 C 3 :1.5wt%, rare earth Ce:1.0wt%, the rest is Co, the powders are mixed, wet-milled for 28h in an oxygen-free environment to make the powders of different components fully mixed and uniform, and the temperature does not exceed 26°C during the wet-milling mixing process. The uniformly mixed alloy powder is dried, a binder is added to the powder mixture, and the mixture is evenly modulated, and the powder mixture is pressed into a multi-prism-shaped alloy material using a multi-prism-shaped mold to obtain a multi-prism-shaped alloy material, and the pressed alloy material is sintered under high temperature conditions to obtain hard alloy particles.

[0065] (3) It should be further explained that anhydrous alcohol should be added in time during the wet grinding process to ensure a certain humidity of the powder and reduce the ambient temperature to ensure that the wet grinding ambient temperature is within 26°C;

[0066] (4) It should be further explained that the polygonal mold for pressing the hard alloy particles should be an octagonal star-shaped mold, and the size of the polygonal alloy particles obtained by pressing is controlled in the range of 7mm-10mm;

[0067] (5) The sintering of alloy particles needs to be carried out in a vacuum environment using a gradient heating method. First, the alloy particles are placed in the sintering equipment to form a vacuum environment, and then the temperature is gradually raised from room temperature to 350°C, kept at this temperature for 0.8 h, then raised to 750°C, kept at this temperature for 0.8 h, and finally raised to the sintering temperature of 1350°C, and the holding time is 7 h;

[0068] (6) After sintering, the hard alloy particles are slowly cooled in the furnace to obtain polyhedral hard alloy particles, and the hardness of the alloy particles is HV1670-HV1750.

[0069] (7) Spreading the sintered hard alloy particles in a ratio of 70 wt % evenly in a long groove mold, and spreading a layer of borax release agent at the bottom of the mold;

[0070] (8) Place the mold in a hydrogen environment heating furnace and heat it to 450°C;

[0071] (9) Spread the soft metal powder evenly around the hard alloy particles in the mold at a ratio of 30 wt %, put the mold back into the hydrogen environment heating furnace and heat it to 1150° C. for 11-14 minutes;

[0072] (10) It should be further explained that the soft metal components are Cu: 78wt%, Ni: 5wt%, Mn: 7wt%, and the rest is Zn.

[0073] (11) The sintered hard alloy strip is placed in a 150°C environment for slow cooling to obtain a finished hard alloy sintered welding rod.

[0074] Example 4

[0075] (1) The sintered welding rod of the present invention is obtained by sintering polygonal sintered hard alloy particles and soft metal, wherein the hard alloy particles account for 65wt% and the soft metal accounts for 35wt%. The composition of the polygonal sintered hard alloy particles is WC: 68wt%, TiC: 15wt%, NbC: 5wt%, Cr 2 C 3 :2wt%, rare earth Ce:1.2wt%, and the rest is Co. The soft metal is a Cu-Ni-Zn-Mn system material powder, with a composition of Cu:78wt%, Ni:7wt%, Mn:5wt%, and the rest is Zn.

[0076] (2) First, WC: 68wt%, TiC: 15wt%, NbC: 5wt%, Cr 2 C 3:2wt%, rare earth Ce:1.2wt%, the rest is Co, the powders are mixed, wet-milled for 30h in an oxygen-free environment to make the powders of different components fully mixed and uniform, and the temperature does not exceed 26°C during the wet-milling mixing process. The uniformly mixed alloy powder is dried, a binder is added to the powder mixture, and the mixture is evenly modulated, and the powder mixture is pressed into a multi-prism-shaped alloy material using a multi-prism-shaped mold to obtain a multi-prism-shaped alloy material, and the pressed alloy material is sintered under high temperature conditions to obtain hard alloy particles.

[0077] (3) It should be further explained that anhydrous alcohol should be added in time during the wet grinding process to ensure a certain humidity of the powder and reduce the ambient temperature to ensure that the wet grinding ambient temperature is within 30°C;

[0078] (4) It should be further explained that the polygonal mold for pressing the hard alloy particles should be a seven-pointed star-shaped mold, and the size of the polygonal alloy particles obtained by pressing is controlled in the range of 5mm-8mm;

[0079] (5) The sintering of alloy particles needs to be carried out in a vacuum environment using a gradient heating method. First, the alloy particles are placed in the sintering equipment to form a vacuum environment, and then the temperature is gradually raised from room temperature to 400°C, kept for 1.1 hours, then raised to 850°C, kept for 1 hour, and finally raised to the sintering temperature of 1400°C, and the holding time is 8 hours;

[0080] (6) After sintering, the hard alloy particles are slowly cooled in the furnace to obtain polyhedral hard alloy particles, and the hardness of the alloy particles is HV1720-HV1770.

[0081] (7) Spreading the sintered hard alloy particles in a ratio of 65 wt % evenly in a long groove mold, and spreading a layer of borax release agent at the bottom of the mold;

[0082] (8) Place the mold in a hydrogen environment heating furnace and heat it to 520°C;

[0083] (9) Spread the soft metal powder evenly around the hard alloy particles in the mold at a ratio of 35 wt %, put the mold back into the hydrogen environment heating furnace and heat it to 1220° C. for 12-15 minutes;

[0084] (10) It should be further explained that the soft metal components are Cu: 78wt%, Ni: 7wt%, Mn: 5wt%, and the rest is Zn.

[0085] (11) The sintered hard alloy strip is placed in a 220°C environment for slow cooling to obtain a finished hard alloy sintered welding rod.

[0086] Table 1 Welding rod material composition and mass percentage

[0087]

[0088] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the specification and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools, characterized in that: The method comprises: obtaining a rare earth-containing hard alloy sintered welding rod by sintering hard alloy particles and soft metal, wherein the hard alloy particles in the rare earth-containing hard alloy sintered welding rod account for 60wt%-75wt%, and the soft metal account for 25wt%-40wt%; The components of the hard alloy particles include WC: 60wt%-70wt%, TiC: 12wt%-16wt%, NbC: 5wt%-7wt%, Cr2C3: 1wt%-2wt%, rare earth Ce: 0.6wt%-1.2wt%, and the rest is Co; The soft metal is Cu-Ni-Zn-Mn system material powder.

2. The rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 1, characterized in that: The soft metal comprises Cu: 76wt%-80wt%, Ni: 4wt%-8wt%, Mn: 5wt%-8wt%, and the rest is Zn.

3. The rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 1, characterized in that: The hard alloy particles are of a polygonal structure.

4. A method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of oil well repair tools as claimed in claim 1, characterized in that: include, S1, wet-grinding and mixing the components of the hard alloy particles in an oxygen-free environment, adding a binder after drying and mixing evenly, pressing and molding the alloy material through a polygonal mold to obtain a polygonal alloy material, and sintering the pressed alloy material under high temperature conditions to obtain hard alloy particles; S2. Spread the hard alloy particles in proportion in the mold, place the mold in a hydrogen environment and heat it to 500±50℃, then spread the soft metal in proportion around the hard alloy particles in the mold, place the mold in a hydrogen environment again and heat it to 1200±50℃, keep it warm for 10-15 minutes, place it in a 200±50℃ environment and cool it to obtain a rare earth-containing hard alloy sintered welding rod.

5. The method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 4, characterized in that: The temperature during the wet grinding and mixing process does not exceed 26° C., and the wet grinding time is 25 h-30 h.

6. The method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 4, characterized in that: Anhydrous alcohol is added during the wet grinding and mixing process to maintain humidity and temperature.

7. The method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 4, characterized in that: The hardness of the hard alloy particles is HV1600-HV1800.

8. The method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 4, characterized in that: The multi-faceted mold is a triangular prism, a seven-pointed star or an eight-pointed star.

9. The method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 4, characterized in that: The specific process of sintering the pressed alloy material under high temperature conditions is: firstly put the pressed alloy material into the sintering equipment to form a vacuum environment, then heat it from room temperature to 400±50°C, keep it warm for 1h±0.2h, then heat it to 1000±50°C, keep it warm for 1h±0.2h, and finally heat it to the sintering temperature of 1400±50°C, and keep it warm for 8h±1h.

10. The method for manufacturing a rare earth-containing hard alloy sintered welding rod for surface welding of petroleum well repair tools according to claim 4, characterized in that: Before spreading the hard alloy particles, a layer of borax release agent is first spread on the bottom of the mold.

Images