Welding material powder, flux-cored wire and preparation method of flux-cored wire

Abstract

The invention discloses welding material powder which is used as an additive in welding operation, the welding material powder comprises agglomerated coating fine powder, the agglomerated coating fine powder is fine particles obtained by agglomerating and coating hard particles, and a coating layer formed by coating treatment is a metal film. The invention further discloses a flux-cored wire using the welding material powder and a preparation method of the flux-cored wire and the welding material powder. According to the method, the hard particles are agglomerated into the fine powder containing the coating structure by adopting the agglomeration and coating technology, and during welding, the performance change of the hard particles is reduced, so that the hard particles in a welding layer can be distributed more uniformly, and the performance of the welding layer is more stable.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to welding material powder, flux-cored welding wire and a preparation method thereof. Background Art

[0002] In the metallurgy, mining, petrochemical, cement, mechanical processing and other industries, the parts of mechanical equipment are often subject to wear caused by materials or processed parts. The parts of such mechanical equipment need to adopt surfacing welding process for surface wear resistance enhancement, so the wear resistance requirements for the weld / weld layer are also high.

[0003] Using hard phases such as carbides, nitrides and oxides to improve the strength and hardness of metal materials is one of the most commonly used and important methods. Therefore, in order to improve the wear resistance of the weld, hard phase components such as carbides, nitrides and oxides can be added to the weld pool.

[0004] For example, Chinese patent application CN116532754A discloses a method for preparing a wear-resistant cladding layer, which adopts MAG welding, and the welding gun injects hard particles into the molten pool while performing cladding.

[0005] For example, Chinese patent application CN105269183A discloses a nano-modified boron-containing high-chromium cast iron wear-resistant surfacing self-protective flux-cored welding wire, which uses high-chromium cast iron powder, electrolytic manganese powder, ferrosilicon powder, ferroboron powder, graphite powder and aluminum-magnesium alloy powder in the flux core, and forms chromium-iron carbide by adjusting the composition of the flux core to improve the wear resistance of the surfacing layer. Chinese patent application CN103381527 A discloses a tungsten carbide-reinforced iron-based wear-resistant surfacing flux-cored welding wire, which adds a large amount of cast tungsten carbide to the flux core powder and uses it as the main hard phase to play the role of a wear-resistant skeleton.

[0006] The formation of hard particles such as carbides, nitrides and oxides in the weld layer can be achieved through in-situ precipitation and external addition. However, these two methods of forming hard particles in the weld overlay layer have a common disadvantage: the morphology and distribution of carbides, nitrides and oxides in the metal microstructure cannot be efficiently regulated. For example, tungsten carbide is used in welding wire to improve the hardness of the weld layer. When tungsten carbide is precipitated in situ, the precipitation position and size of tungsten carbide are not only difficult to control, but also the generated tungsten carbide components generally deviate greatly from the design value; while when external addition is adopted, although the melting point of hard particles such as carbides, nitrides and oxides is much higher than the melting point of metals such as alloy steel, the temperature of the arc during welding can generally reach 1700℃ or even 2900℃, and the instantaneous temperature may be higher. Therefore, if the size of the added particles is too small, the hard particles will be melted or partially melted, and brittle materials will be formed in the molten area, which will reduce the adhesion ability of the particles and cause the performance of the hard particles to decline; and if the size of the added particles is too large, the particles will sink to the bottom, resulting in uneven hardness of the weld layer. Other metal compounds as hard phases, such as carbides, nitrides or oxides of metals such as tungsten and titanium, have similar problems of difficulty in controlling the generation and / or distribution of wear-resistant particles due to their respective characteristics.

[0007] Therefore, improving the distribution of the hard phase in the weld layer during welding operations, improving the stability and uniformity of the weld layer, and thus improving the performance of the weld layer has become a technical problem that needs to be solved now. Summary of the invention

[0008] The main technical problem solved by the present invention is to provide a welding material powder, a flux-cored welding wire and a preparation method thereof, which can improve the stability and distribution uniformity of hard particles in the welding layer during the cladding process, thereby improving the performance of the welding layer.

[0009] In order to solve the above technical problems, the present invention provides a welding material powder used as an additive in welding operations, wherein the welding material powder includes agglomerated coated fine powder; the agglomerated coated fine powder is fine particles of hard particles that have been agglomerated and coated; wherein the coating layer formed by the coating treatment is a metal film.

[0010] The present invention also provides a method for preparing welding material powder, wherein the welding material powder is used as an additive in welding operations, and the preparation method comprises:

[0011] The hard particles are agglomerated and coated to form agglomerated coated fine powder; wherein the coating layer formed by the coating is a metal film

[0012] The agglomerated coated fine powder is used to prepare welding material powder.

[0013] The present invention also provides a flux-cored welding wire, comprising an outer skin and a flux core, wherein the outer skin is a metal strip, and the flux core comprises agglomerated coated fine powder, the agglomerated coated fine powder is fine particles of hard particles that have been agglomerated and coated, and the coating layer formed by the coating treatment is a metal film.

[0014] The present invention also provides a method for preparing a flux-cored welding wire, the method comprising:

[0015] The method comprises the following steps: agglomerating and coating hard particles to form agglomerated coated fine powder; wherein the coating layer formed by the coating process is a metal film;

[0016] preparing a drug core containing the agglomerated coated fine powder;

[0017] Filling the core into the U-shaped metal belt;

[0018] The U-shaped metal strip filled with flux core is rolled and then formed by a drawing process to produce flux cored welding wire of the required specifications.

[0019] The beneficial effect of the present invention is that the embodiment of the present invention adopts agglomeration and coating technology to agglomerate hard particles into fine powder with a coating structure, which can make the distribution of hard particles in the welding layer more uniform and the performance more stable during welding. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0021] The welding material powder of the embodiment of the present invention comprises agglomerated coated fine powder. The agglomerated coated fine powder is fine particles obtained by agglomerating and coating hard particles. The particle size of the agglomerated coated fine powder is 100nm to 100μm.

[0022] The hard particles can be at least one of tungsten carbide, chromium carbide, titanium carbide, niobium carbide, chromium oxide, aluminum oxide, rare earth metal oxide, silicon nitride, and gallium nitride, or a combination of several thereof. The hard particles are micro-nano particles with a particle size of 20nm to 20μm.

[0023] The agglomeration technology of the embodiment of the present invention includes a technology of bonding powders together by a binder, for example, rotary spray granulation, etc.

[0024] The coating technology of the embodiment of the present invention includes uniformly depositing a metal film on the surface of the particles through physical or chemical reactions, such as magnetron sputtering, chemical deposition, etc. The coating layer material includes at least one of nickel, chromium, molybdenum, and copper.

[0025] The agglomerated coated fine powder can be a fine powder obtained by forming a metal film on the surface of the agglomerated particles by forming hard particles into agglomerated particles through a coating technology.

[0026] The agglomerated coated fine powder can also be obtained by first coating hard particles to form a metal film on the surface of the hard particles, and then using agglomeration technology to form agglomerated particles.

[0027] The welding material powder of the embodiment of the present invention can be produced by drying the agglomerated coated fine powder.

[0028] The welding material powder of the embodiment of the present invention can be used as an additional powder in welding operation and directly used in welding operation. During welding operation, the welding material powder is added to the weld pool to form a welding layer.

[0029] Hard particles with a particle size distribution of 20nm to 20μm, after agglomeration technology to become large-particle powder, the particle size is several to hundreds of times that of the original powder, but the appearance and performance of the hard particles after agglomeration will not change. Micro-nano powders are small in size, and such carbides, nitrides and oxides have a stronger bonding force with the metal lattice. Under the condition of unchanged physical properties and uniform distribution, the strength and hardness of metal materials will be significantly improved. However, micro-nano powders are small in size, the van der Waals force between powders is obvious, and the fluidity is poor, which makes it inconvenient to transport them on pipelines or conveyor belts later. In addition, micro-nano powders are easily melted after being heated by welding heat sources, so that the performance changes and the original strengthening effect is lost.

[0030] In the preparation of the welding material powder of the embodiment of the present invention, the hard particles are formed into agglomerated coated fine powder through agglomeration technology and coating technology, and the small particles become larger and the fluidity is enhanced. When the agglomerated particles pass through the high-temperature welding heat source, the metal film melts and absorbs heat, reducing the heat received by the hard particles inside the agglomerated particles, avoiding the melting or performance degradation of the hard particles, and maintaining their original performance to the greatest extent. Among them, the binder in the agglomerated particles decomposes and volatilizes into the environment under the action of high temperature, and the hard particles return to a loose state and are evenly distributed in the weld metal in a state close to the original appearance and performance.

[0031] The welding material powder of the embodiment of the present invention improves the fluidity of hard particles through agglomeration and coating processes, is suitable for industrial production, and reduces the damage to the performance of hard particles caused by welding heat, thereby improving the strengthening effect of hard particles in the welding layer.

[0032] The flux-cored welding wire of the embodiment of the present invention comprises an outer sheath and a flux core. The outer sheath is a metal strip.

[0033] The core contains agglomerated coated fine powder, which is a fine powder formed by agglomeration and metal coating of hard particles, and contains hard particles with agglomerated structure and metal film structure.

[0034] In addition, the flux core may also contain conventional fluxes such as deoxidizers, slag formers, and alloy components. For example, the deoxidizer may be manganese, ferrosilicon, etc., the alloy component may include graphite, high carbon ferrochrome, metallic chromium, metallic nickel, etc., and the slag former may include rutile, calcium fluoride, marble, etc.

[0035] The weight of the agglomerated coated fine powder in the core is 30% to 60%, and the particle size is 100nm to 100μm.

[0036] The hard particles can be at least one of tungsten carbide, chromium carbide, titanium carbide, niobium carbide, chromium oxide, aluminum oxide, rare earth metal oxide, silicon nitride, and gallium nitride, or a combination of several thereof. The hard particles are micro-nano-level fine particles with a particle size of 20nm to 20μm.

[0037] The agglomeration technology of the embodiment of the present invention includes a technology of bonding powders together by a binder, for example, rotary spray granulation, etc.

[0038] The coating technology of the embodiment of the present invention includes uniformly depositing a metal film on the surface of the particles through physical or chemical reactions, such as magnetron sputtering, chemical deposition, etc. The coating layer material includes at least one of nickel, chromium, molybdenum, and copper.

[0039] The agglomerated coated fine powder can be a fine powder obtained by forming a metal film on the surface of the agglomerated particles by forming hard particles into agglomerated particles through a coating technology.

[0040] The agglomerated coated fine powder can also be obtained by first coating hard particles to form a metal film layer on the surface of the hard particles, and then using agglomeration technology to form agglomerated particles.

[0041] In the preparation of flux-cored welding wire, the steel strip is rolled into a U-shaped cross-section shape, and then the flux core containing agglomerated coated fine powder is filled into the U-shaped steel strip; the U-shaped steel strip filled with the flux core is compacted by a rolling mill and then formed by a drawing process to produce the flux-cored welding wire of the required specifications.

[0042] Hard particles with a particle size distribution of 20nm to 20μm, after agglomeration technology to become large-particle powder, the particle size is several to hundreds of times that of the original powder, but the appearance and performance of the hard particles after agglomeration will not change. Micro-nano powders are small in size, and such carbides, nitrides and oxides have a stronger bonding force with the metal lattice. Under the condition of unchanged physical properties and uniform distribution, the strength and hardness of metal materials will be significantly improved. However, micro-nano powders are small in size, the van der Waals force between powders is obvious, and the fluidity is poor, which makes it inconvenient to transport them on pipelines or conveyor belts later. In addition, micro-nano powders are easily melted after being heated by welding heat sources, so that the performance changes and the original strengthening effect is lost.

[0043] In the preparation of the flux-cored welding wire of the embodiment of the present invention, the hard particles are formed into agglomerated coated fine powders through agglomeration technology and coating technology, and the small particles become larger and the fluidity is enhanced. When the agglomerated coated fine powder passes through the high-temperature welding heat source, the metal film on the surface of the hard particles melts and absorbs heat, reducing the heat absorbed by the hard particles inside the agglomerated particles, and reducing the risk of melting or performance degradation of the hard particles. Among them, the binder in the agglomerated particles decomposes and volatilizes into the environment under the action of high temperature, and the hard particles return to a loose state and are evenly distributed in the weld metal in a state close to the original appearance and performance.

[0044] The agglomerated coated fine powder in the embodiment of the present invention improves the fluidity of hard particles through agglomeration and coating processes, and is suitable for industrial production. At the same time, it reduces the damage to the performance of hard particles caused by welding heat and improves the strengthening effect of hard particles in the weld layer. When welding, using a flux-cored welding wire containing agglomerated coated fine powder can obtain a weld layer with better wear resistance.

[0045] The outer skin of the flux-cored welding wire in the specific embodiment is a low-carbon steel strip, and the components include: C <0.1%, Si, Mn, Cr, Ni <1%; the balance is Fe. The components of the flux core in the specific embodiment of the flux-cored welding wire may include: metal manganese, 4% to 8%; 75# ferrosilicon, 3% to 6%; metal chromium, 6% to 10%; graphite, 1% to 4%; high carbon ferrochrome (wherein the components of high carbon ferrochrome are: C, 7.5% to 8.0%; Cr, 70% to 75%; the balance is Fe), 30% to 50%; metal nickel, 5% to 9%; agglomerated coating fine powder, 30% to 60%; rutile, 3% to 7%; calcium fluoride, 2% to 4%; marble, 3% to 7%; the balance is iron. The above percentages are weight percentages. The weight coefficient of the flux core, that is, the weight proportion of the flux core in the flux-cored welding wire, is 25% to 30%.

[0046] The outer skin of another specific embodiment of the flux-cored welding wire is a nickel-chromium alloy strip, and the components include: Cr, 19% to 21%; the balance is Ni. The components of the flux core in the specific embodiment of the flux-cored welding wire may include: metal manganese, 2% to 7%; 75# ferrosilicon, 1% to 3%; metal chromium, 15% to 30%; high carbon ferrochrome (wherein the components of high carbon ferrochrome are: C, 7.5% to 8.0%; Cr, 70% to 75%; the balance is Fe), 30% to 50%; ferromolybdenum (wherein Mo accounts for 60%, and the balance is Fe), 6% to 10%; agglomerated coated micro-nano powder, 30% to 60%; calcium fluoride, 2% to 4%; marble, 3% to 7%; the balance is metal nickel. The above percentages are weight percentages. The weight coefficient of the flux core, that is, the weight proportion of the flux core in the flux-cored welding wire, is 25% to 30%.

[0047] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A welding material powder used as an additive in welding operations, characterized in that: The welding material powder includes agglomerated coated fine powder; the agglomerated coated fine powder is fine particles of hard particles that have been subjected to agglomeration and coating treatments; wherein the coating layer formed by the coating treatment is a metal film.

2. The welding material powder according to claim 1, characterized in that: The particle size of the agglomerated coating fine powder is 100nm~100μm.

3. The welding material powder according to claim 1, characterized in that: The hard particles include at least one of tungsten carbide, chromium carbide, titanium carbide, niobium carbide, chromium oxide, aluminum oxide, rare earth metal oxide, silicon nitride, and gallium nitride.

4. The welding material powder according to claim 1, characterized in that: The particle size of the hard particles is 20 nm to 20 μm.

5. The welding material powder according to claim 1, characterized in that: Agglomeration treatments include rotary spray granulation.

6. The welding material powder according to claim 1, characterized in that: The material of the metal film includes at least one of nickel, chromium, molybdenum and copper.

7. A method for preparing welding material powder, wherein the welding material powder is used as an additive in welding operations, characterized in that: The preparation method comprises: Agglomerating and coating the hard particles to form agglomerated coated fine powder; wherein the coating layer formed by the coating treatment is a metal film; The agglomerated coated fine powder is used to prepare welding material powder.

8. The method for preparing welding material powder according to claim 7, characterized in that: The steps of agglomerating and coating the hard particles include: forming agglomerated particles from the hard particles, and then forming a metal film on the surface of the agglomerated particles by coating technology.

9. The method for preparing welding material powder according to claim 7, characterized in that: The steps of agglomerating and coating the hard particles include: coating the hard particles to form a metal film on the surface of the hard particles, and then agglomerating the coated hard particles to form agglomerated particles.

10. The method for preparing welding material powder according to claim 7, characterized in that: The particle size of the agglomerated coating fine powder is 100nm~100μm.

11. The method for preparing welding material powder according to claim 7, characterized in that: The hard particles include at least one of tungsten carbide, chromium carbide, titanium carbide, niobium carbide, chromium oxide, aluminum oxide, rare earth metal oxide, silicon nitride, and gallium nitride.

12. The method for preparing welding material powder according to claim 7, characterized in that: The particle size of the hard particles is 20 nm to 20 μm.

13. The method for preparing welding material powder according to claim 7, characterized in that: Agglomeration treatments include rotary spray granulation.

14. The method for preparing welding material powder according to claim 7, characterized in that: The material of the metal film includes at least one of nickel, chromium, molybdenum and copper.

15. A flux-cored welding wire, comprising an outer sheath and a flux core, wherein the outer sheath is a metal strip, characterized in that: The core comprises agglomerated coated fine powder, which is fine particles of hard particles that have been agglomerated and coated, and the coating layer formed by the coating treatment is a metal film.

16. The flux-cored welding wire according to claim 15, characterized in that: The particle size of the agglomerated coating fine powder is 100nm~100μm.

17. The flux-cored welding wire according to claim 15, characterized in that: The hard particles include at least one of tungsten carbide, chromium carbide, titanium carbide, niobium carbide, chromium oxide, aluminum oxide, rare earth metal oxide, silicon nitride, and gallium nitride.

18. The flux-cored welding wire according to claim 15, characterized in that: The particle size of the hard particles is 20 nm to 20 μm.

19. The flux-cored welding wire according to claim 15, characterized in that: Agglomeration treatments include rotary spray granulation.

20. The flux-cored welding wire according to claim 15, characterized in that: The material of the metal film includes at least one of nickel, chromium, molybdenum and copper.

21. The flux-cored welding wire according to claim 15, characterized in that: The flux core also includes powders of deoxidizer, slag forming agent, alloy components, etc.

22. The flux-cored welding wire according to claim 21, characterized in that: The metal strip is a low-carbon steel strip, and the weight percentage of each component in the low-carbon steel strip is as follows: C, 0-0.1%; Si, Mn, Cr, Ni, 0-1%; and the balance Fe.

23. The flux-cored welding wire according to claim 22, characterized in that The composition of the flux core includes: metallic manganese, 4% to 8%; 75# ferrosilicon, 3% to 6%; metallic chromium, 6% to 10%; graphite, 1% to 4%; high carbon ferrochrome, 30% to 50%; metallic nickel, 5% to 9%; agglomerated coating fine powder, 30% to 60%; rutile, 3% to 7%; calcium fluoride, 2% to 4%; marble, 3% to 7%; and the balance is iron.

24. The flux-cored welding wire according to claim 21, characterized in that: The metal strip is a nickel-chromium alloy strip, and its components include: Cr, 19% to 21%; and the balance is Ni.

25. The flux-cored welding wire according to claim 24, characterized in that: The composition of the core includes: metallic manganese, 2% to 7%; 75# ferrosilicon, 1% to 3%; metallic chromium, 15% to 30%; high carbon ferrochrome, 30% to 50%; ferromolybdenum, 6% to 10%; agglomerated coated micro-nano powder, 30% to 60%; calcium fluoride, 2% to 4%; marble, 3% to 7%; and the balance is metallic nickel.

26. The flux-cored welding wire according to claim 15, characterized in that: The weight coefficient of the drug core is 25% to 30%.

27. A method for preparing a flux-cored welding wire, characterized in that: The preparation method comprises: The method comprises the following steps: agglomerating and coating hard particles to form agglomerated coated fine powder; wherein the coating layer formed by the coating process is a metal film; preparing a drug core containing the agglomerated coated fine powder; Filling the core into the U-shaped metal belt; The U-shaped metal strip filled with flux core is rolled and then formed by a drawing process to produce flux cored welding wire of the required specifications.

28. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The steps of agglomerating and coating the hard particles include: forming agglomerated particles from the hard particles, and then forming a metal film on the surface of the agglomerated particles by coating technology.

29. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The steps of agglomerating and coating the hard particles include: coating the hard particles to form a metal film on the surface of the hard particles, and then agglomerating the coated hard particles to form agglomerated particles.

30. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The particle size distribution of the agglomerated coating fine powder is 100nm~100μm.

31. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The hard particles include at least one of tungsten carbide, chromium carbide, titanium carbide, niobium carbide, chromium oxide, aluminum oxide, rare earth metal oxide, silicon nitride, and gallium nitride.

32. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The particle size distribution of the hard particles is 20 nm to 20 μm.

33. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: Agglomeration treatments include rotary spray granulation.

34. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The material of the metal film includes at least one of nickel, chromium, molybdenum and copper.

35. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The flux core also includes deoxidizer, slag forming agent, alloy component and other powders; the step of preparing the flux core containing the agglomerated coated fine powder includes mixing the agglomerated coated fine powder with deoxidizer, slag forming agent, alloy component and other powders.

36. The method for preparing a flux-cored welding wire according to claim 35, characterized in that: The U-shaped metal strip is a low-carbon steel strip, and the weight percentage of each component in the low-carbon steel strip is as follows: C, 0-0.1%; Si, Mn, Cr, Ni, 0-1%; and the balance Fe.

37. The method for preparing a flux-cored welding wire according to claim 35, characterized in that: The composition of the flux core includes: metallic manganese, 4% to 8%; 75# ferrosilicon, 3% to 6%; metallic chromium, 6% to 10%; graphite, 1% to 4%; high carbon ferrochrome, 30% to 50%; metallic nickel, 5% to 9%; agglomerated coating fine powder, 30% to 60%; rutile, 3% to 7%; calcium fluoride, 2% to 4%; marble, 3% to 7%; and the balance is iron.

38. The method for preparing a flux-cored welding wire according to claim 35, characterized in that: The U-shaped metal strip is a nickel-chromium alloy strip, and its components include: Cr, 19% to 21%; and the balance is Ni.

39. The method for preparing a flux-cored welding wire according to claim 38, characterized in that: The composition of the core includes: metallic manganese, 2% to 7%; 75# ferrosilicon, 1% to 3%; metallic chromium, 15% to 30%; high carbon ferrochrome, 30% to 50%; ferromolybdenum, 6% to 10%; agglomerated coated micro-nano powder, 30% to 60%; calcium fluoride, 2% to 4%; marble, 3% to 7%; and the balance is metallic nickel.

40. The method for preparing a flux-cored welding wire according to claim 27, characterized in that: The weight coefficient of the drug core is 25% to 30%.