High-toughness wear-resistant flux-cored wire and preparation method thereof

Abstract

The invention relates to the technical field of flux-cored wires, and particularly discloses a high-toughness wear-resistant flux-cored wire and a preparation method thereof.The preparation method comprises the steps that iron powder, nickel powder, modified boron nitride whiskers, manganese powder, chromium powder, molybdenum powder, titanium powder, a stabilizer and calcium fluoride are evenly mixed and then dried, and a flux core is obtained; the welding skin is rolled into a U shape, the flux core is added, then sealing and rolling are conducted to form an O shape, and the flux-cored wire is obtained through drawing and diameter reducing; according to the preparation method provided by the invention, the iron powder, the nickel powder, the modified boron nitride whiskers, the manganese powder, the chromium powder, the molybdenum powder, the titanium powder, the stabilizer and the calcium fluoride are reasonably compounded to form the flux-cored powder with high hardness and high toughness, so that the prepared flux-cored wire has excellent hardness after being welded, the wear resistance of the flux-cored wire is greatly improved, and the service life of the flux-cored wire is prolonged. Meanwhile, the excellent mechanical property is realized.

Description

Technical Field

[0001] The invention relates to the technical field of flux-cored welding wires, and in particular to a high-toughness and wear-resistant flux-cored welding wire and a preparation method thereof. Background Art

[0002] In the field of welding material technology, traditional welding processes mainly use welding rods and solid welding wires as filling materials, but they have significant limitations in welding efficiency, metallurgical properties and process adaptability. The welding rod achieves molten pool protection and alloy transition through the external coating, but its intermittent welding characteristics lead to low production efficiency and poor operating flexibility. The coating is easy to absorb moisture and the composition stability is insufficient, which makes it difficult to meet the needs of automated production. Although solid welding wire is suitable for continuous welding, its alloy elements can only be provided by the welding wire substrate, and the composition design is limited, and it is impossible to achieve complex metallurgical reaction regulation. Especially when dealing with high-strength steel, weathering steel or special working conditions (such as low temperature, corrosive environment), the mechanical properties and crack resistance of the weld are difficult to meet the requirements.

[0003] Flux-cored welding wire (also known as powder-cored welding wire) is a new generation of welding materials. It combines the metallurgical function of electrode coating and the continuous wire feeding advantage of solid welding wire through the composite structure of steel strip wrapped with powder. Its flux core composition can flexibly adjust alloy elements (such as Mn, Si, Ni, Mo, etc.), deoxidizers (such as ferrosilicon, ferromanganese), slag-forming agents (such as fluorite, titanium dioxide) and arc stabilizers (such as potassium and sodium compounds), forming gas-slag joint protection during the welding process, effectively isolating the oxidation and nitridation of the molten pool by air, and at the same time achieving desulfurization, dephosphorization and purification of the weld by floating slag. In addition, the continuous wire feeding characteristics of flux-cored welding wire support fully automatic or semi-automatic welding processes, significantly improve the deposition efficiency (up to 85%-90%), and reduce the amount of groove processing by increasing the weld cross-section, reducing the consumption of deposited metal, showing significant economy in the welding of large structural parts.

[0004] However, the welds welded by current flux-cored welding wires have problems of low tensile strength, poor toughness and poor wear resistance, which greatly limits the application of welded structural parts. Summary of the invention

[0005] In view of the deficiencies in the prior art, an object of the present invention is to provide a high-toughness and wear-resistant flux-cored welding wire and a preparation method thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A high-toughness, wear-resistant flux-cored welding wire comprises a welding skin and a flux core, wherein the flux core is composed of the following raw materials in parts by weight: 20-30 parts of iron powder, 5-10 parts of nickel powder, 10-15 parts of modified boron nitride whiskers, 3-6 parts of manganese powder, 3-6 parts of chromium powder, 2-4 parts of molybdenum powder, 0.4-0.8 parts of titanium powder, 1-2 parts of stabilizer, and 2-3 parts of calcium fluoride.

[0007] In the technical solution disclosed by the present invention, the number of parts of iron powder can be selected from 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0008] The iron powder provided by the present invention will melt and fill into the weld during the welding process, so it can increase the metal filling amount of the weld, thereby improving the welding speed and deposition rate.

[0009] In the technical solution disclosed by the present invention, the number of parts of nickel powder can be selected from 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0010] The nickel powder provided by the present invention can moderately increase the strength of the welded joint through the ferrite solid solution strengthening effect. Nickel is an element that forms and stabilizes austenite and can exist in the ferrite and austenite in a mutually soluble form with iron in the weld, thereby strengthening the weld metal.

[0011] In the technical solution disclosed by the present invention, the number of parts of modified boron nitride whiskers can be selected from 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0012] Specifically, the preparation method of the modified boron nitride whiskers is as follows: Add soluble zirconium salt to deionized water, stir and dissolve it, then add boron nitride whiskers to it, disperse evenly, adjust the pH of the solution to 9 - 10, rotate and evaporate to remove the solvent water, then calcine it under a nitrogen atmosphere, and grind it after cooling to obtain the modified boron nitride whiskers.

[0013] More specifically, the mass ratio of the soluble zirconium salt to the boron nitride whiskers is 5 - 10:5 - 10. In some embodiments of the present invention, for example, it can be selected from 5:5, 5:8, 5:10, 8:5, 8:6, 8:10, 10:5, 10:8, 10:10, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0014] Preferably, the soluble zirconium salt is selected from zirconium oxychloride, zirconium sulfate or zirconium nitrate.

[0015] Preferably, the calcination temperature is 600 - 800 °C. In some embodiments of the present invention, for example, it can be selected from 600 °C, 650 °C, 700 °C, 750 °C, 800 °C; the calcination time is 1 - 2 h, for example, it can be selected from 1 h, 1.5 h, 2 h, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0016] Boron nitride whiskers are single-crystal materials with high strength and high modulus, having excellent mechanical properties. However, there are differences in the thermal expansion coefficients between boron nitride whiskers and the metal matrix, and there is a problem of easy peeling from the interface. In the present invention, zirconia is in-situ generated on the surface of boron nitride whiskers by the sol method. The thermal expansion coefficient of zirconia is close to that of the steel matrix. Through the intermediate transition effect of zirconia, the thermal expansion difference between boron nitride whiskers and the metal matrix is reduced, and the risk of its peeling from the interface is lowered; compared with the physical blending method, the technical solution of the present invention avoids the problem of uneven dispersion caused by density differences or surface energy mismatches. At the same time, the heterogeneous composite structure of boron nitride whiskers loaded with zirconia reduces the adsorption of impurities (such as oxygen and sulfur) during the metallurgical process by pre-constructing a stable interface, and optimizes the interfacial wettability; in addition, the loaded zirconia nanoparticles can serve as heterogeneous nucleation cores, promoting the refinement of the deposited metal grains and forming a composite wear-resistant structure of "high-hardness boron nitride + fine-grained matrix"; the combined action of the high hardness of boron nitride whiskers itself and the transformation toughening characteristics of zirconia improves the mechanical properties and wear resistance of the flux-cored wire.

[0017] In the technical solution disclosed in the present invention, the number of parts of manganese powder can be selected as 3 parts, 4 parts, 5 parts, 6 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0018] The addition of manganese powder can improve the welding process performance, such as stabilizing the arc, reducing spatter, making the welding process more stable, and can improve the strength and toughness of the weld metal. At the same time, manganese powder can effectively remove oxygen and sulfur in the weld during the welding process, reduce the oxide inclusions in the weld and the content of sulfur in the weld, and reduce the risk of hot cracks.

[0019] In the technical solution disclosed in the present invention, the number of parts of chromium powder can be selected as 3 parts, 4 parts, 5 parts, 6 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0020] The addition of chromium powder can significantly improve the corrosion resistance of the deposited metal, especially the pitting resistance; chromium forms a stable passive film in the deposited metal, thereby improving the corrosion resistance of the weld.

[0021] In the technical solution disclosed in the present invention, the number of parts of molybdenum powder can be selected as 2 parts, 3 parts, 4 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0022] The addition of molybdenum powder can not only improve the strength of the welded joint by solid solution strengthening, but also improve the toughness; molybdenum element has the effect of delaying the precipitation and growth of proeutectoid ferrite, which is beneficial to the formation of acicular ferrite tissue with a high density of dislocations in the weld.

[0023] In the technical solution disclosed by the present invention, the amount of titanium powder can be selected from 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0024] The addition of titanium powder can form more inclusions within the crystal grains, thus becoming nucleation cores, promoting the formation of acicular ferrite structure in the weld, refining the grains. Additionally, during the formation of the deposited metal, it also has the effect of capturing hydrogen, effectively reducing the diffusible hydrogen content in the deposited metal, and improving the mechanical properties of the welded joint.

[0025] In the technical solution disclosed by the present invention, the amount of stabilizer can be selected from 1 part, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0026] Specifically, the stabilizer is selected from at least one of potassium titanate, yttrium oxide, and lanthanum oxide.

[0027] The addition of the stabilizer can significantly improve the stability of the welding arc, make the arc softer and smoother, reduce spatter, thereby improving the welding process performance.

[0028] In the technical solution disclosed by the present invention, the amount of calcium fluoride can be selected from 2 parts, 2.2 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.8 parts, 3 parts, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0029] Calcium fluoride is a commonly used slag former, which can form slag during the welding process, cover the surface of the molten pool, and play a role in isolating air and protecting the molten pool from oxidation and contamination.

[0030] In the technical solution disclosed by the present invention, the flux cored wire accounts for 15 - 25% of the mass of the flux cored wire. In the technical solution disclosed by the present invention, for example, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25% can be selected, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] The present invention also provides a method for preparing the above-mentioned flux cored wire, which includes the following steps: S1. Mix iron powder, nickel powder, modified boron nitride whiskers, manganese powder, chromium powder, molybdenum powder, titanium powder, stabilizer, and calcium fluoride by weight, and dry them evenly to obtain the flux core; S2. Roll the welding skin into a U shape, add the flux core, then seal it and roll it into an O shape, and obtain the flux cored wire through drawing and reducing the diameter.

[0032] In the technical solution disclosed by the present invention, in step S1, the drying temperature is 100-120°C. For example, 100°C, 105°C, 110°C, 115°C, 120°C can be selected; the drying time is 1-3h. For example, 1h, 1.5h, 2h, 2.5h, 3h can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0033] In the technical solution disclosed by the present invention, in step S2, the diameter of the flux-cored wire is 1.2-1.8mm. For example, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0034] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, zirconia is in-situ generated on the surface of boron nitride whiskers by the sol-gel method. The thermal expansion coefficient of zirconia is close to that of the steel matrix. Through the intermediate transition of zirconia, the thermal expansion difference between the boron nitride whiskers and the metal matrix is reduced, and the risk of its peeling off from the interface is lowered; compared with the physical blending method, the technical solution of the present invention avoids the problem of uneven dispersion caused by density difference or surface energy mismatch. At the same time, the heterogeneous composite structure of boron nitride whiskers loaded with zirconia reduces the adsorption of impurities (such as oxygen and sulfur) during the metallurgical process by pre-constructing a stable interface and optimizes the interfacial wettability; in addition, the loaded zirconia nanoparticles can serve as heterogeneous nucleation cores to promote the refinement of the deposited metal grains and form a composite wear-resistant structure of "high-hardness boron nitride + fine-grained matrix"; the combined action of the high hardness of the boron nitride whiskers themselves and the transformation toughening characteristics of zirconia improves the mechanical properties and wear resistance of the flux-cored wire.

[0035] (2) The present invention provides a flux-cored wire with high toughness and wear resistance and its preparation method. After uniformly mixing iron powder, nickel powder, modified boron nitride whiskers, manganese powder, chromium powder, molybdenum powder, titanium powder, stabilizer and calcium fluoride and drying, a flux is obtained; the welding skin is rolled into a U shape, the flux is added, and then it is sealed and rolled into an O shape, and after drawing and reducing the diameter, the flux-cored wire is obtained; the preparation method provided by the present invention reasonably compounds iron powder, nickel powder, modified boron nitride whiskers, manganese powder, chromium powder, molybdenum powder, titanium powder, stabilizer and calcium fluoride to form a flux powder with high hardness and high toughness, so that the prepared flux-cored wire has excellent hardness after welding, its wear resistance is greatly improved, and it also has excellent mechanical properties. Specific Embodiments

[0036] The following further details the present invention through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0037] It should be noted that unless otherwise specified, the chemical reagents involved in the present invention are all purchased through commercial channels.

[0038] In the examples of the present invention, the purity of iron powder, manganese powder, chromium powder, molybdenum powder, titanium powder, and calcium fluoride used is ≥99.9%, and the particle size is 200 - 300 mesh; The purity of nickel powder is ≥99.8%, and the particle size is 150 mesh; The diameter of boron nitride whiskers is 1 μm, and the length is 10 - 20 μm; The welding skin is an H08A alloy steel strip, with a width of 10 mm and a thickness of 0.3 mm.

[0039] Example 1 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 25 parts of iron powder, 8 parts of nickel powder, 12 parts of modified boron nitride whiskers, 6 parts of manganese powder, 4 parts of chromium powder, 4 parts of molybdenum powder, 0.8 part of titanium powder, 1 part of stabilizer potassium titanate, and 3 parts of calcium fluoride evenly, and dry at 120°C for 1 h to obtain the flux core; Among them, the preparation method of the modified boron nitride whiskers is as follows: Add 5 g of zirconium oxychloride to 100 mL of deionized water, stir to dissolve, then add 5 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 9 with 0.5 mol / L NaOH solution, rotate and evaporate to remove the solvent water, then calcine in a nitrogen atmosphere, the calcination temperature is 800°C, the calcination time is 1 h, and grind after cooling to obtain the modified boron nitride whiskers.

[0040] S2. Roll the welding skin into a U shape, add the flux core, then seal and roll it into an O shape, and obtain the flux-cored wire through drawing and reducing the diameter. The flux core accounts for 20% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0041] Example 2 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 30 parts of iron powder, 5 parts of nickel powder, 15 parts of modified boron nitride whiskers, 3 parts of manganese powder, 6 parts of chromium powder, 2 parts of molybdenum powder, 0.5 part of titanium powder, 2 parts of stabilizer potassium titanate, and 2 parts of calcium fluoride evenly, and dry at 120°C for 1 h to obtain the flux core; Among them, the preparation method of the modified boron nitride whiskers is as follows: Add 5 g of zirconium oxychloride to 100 mL of deionized water, stir to dissolve, then add 8 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 9 with 0.5 mol / L NaOH solution, rotate and evaporate to remove the solvent water, then calcine in a nitrogen atmosphere, the calcination temperature is 800°C, the calcination time is 1 h, and grind after cooling to obtain the modified boron nitride whiskers.

[0042] S2. Roll the welding skin into a U shape, add the flux-cored wire, then seal it and roll it into an O shape. After drawing and reducing the diameter, the flux-cored wire is obtained. The flux-cored wire accounts for 20% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0043] Example 3 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 20 parts of iron powder, 10 parts of nickel powder, 10 parts of modified boron nitride whiskers, 6 parts of manganese powder, 3 parts of chromium powder, 3 parts of molybdenum powder, 0.4 part of titanium powder, 1.5 parts of potassium titanate as a stabilizer, and 2.5 parts of calcium fluoride evenly, and dry them at 120 °C for 1 h to obtain the flux-cored wire. Among them, the preparation method of the modified boron nitride whiskers is as follows: Add 5 g of zirconium oxychloride to 100 mL of deionized water, stir and dissolve it, then add 10 g of boron nitride whiskers to it, disperse evenly, adjust the pH of the solution to 9 with 0.5 mol / L of NaOH solution, rotate and evaporate to remove the solvent water, then calcine it under a nitrogen atmosphere, the calcination temperature is 800 °C, the calcination time is 1 h, and grind it after cooling to obtain the modified boron nitride whiskers.

[0044] S2. Roll the welding skin into a U shape, add the flux-cored wire, then seal it and roll it into an O shape. After drawing and reducing the diameter, the flux-cored wire is obtained. The flux-cored wire accounts for 15% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0045] Example 4 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 28 parts of iron powder, 6 parts of nickel powder, 14 parts of modified boron nitride whiskers, 4 parts of manganese powder, 4 parts of chromium powder, 4 parts of molybdenum powder, 0.4 part of titanium powder, 1 part of yttrium oxide as a stabilizer, and 2 parts of calcium fluoride evenly, and dry them at 120 °C for 1 h to obtain the flux-cored wire. Among them, the preparation method of the modified boron nitride whiskers is as follows: Add 5 g of zirconium oxychloride to 100 mL of deionized water, stir and dissolve it, then add 10 g of boron nitride whiskers to it, disperse evenly, adjust the pH of the solution to 9 with 0.5 mol / L of NaOH solution, rotate and evaporate to remove the solvent water, then calcine it under a nitrogen atmosphere, the calcination temperature is 800 °C, the calcination time is 1 h, and grind it after cooling to obtain the modified boron nitride whiskers.

[0046] S2. Roll the welding skin into a U shape, add the flux-cored wire, then seal it and roll it into an O shape. After drawing and reducing the diameter, the flux-cored wire is obtained. The flux-cored wire accounts for 18% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0047] Example 5 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 24 parts of iron powder, 8 parts of nickel powder, 12 parts of modified boron nitride whiskers, 3 parts of manganese powder, 3 parts of chromium powder, 2 parts of molybdenum powder, 0.4 part of titanium powder, 1 part of yttrium oxide as a stabilizer and 2 parts of calcium fluoride uniformly, and then dry at 120 °C for 1 h to obtain a flux core; Among them, the preparation method of the modified boron nitride whiskers is as follows: Add 5 g of zirconium oxychloride to 100 mL of deionized water, stir and dissolve it, then add 10 g of boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 9 with 0.5 mol / L NaOH solution, rotate and evaporate to remove the solvent water, and then calcine in a nitrogen atmosphere. The calcination temperature is 800 °C, the calcination time is 1 h, and after cooling, grind to obtain the modified boron nitride whiskers.

[0048] S2. Roll the welding skin into a U shape, add the flux core, then seal and roll it into an O shape, and obtain the flux-cored wire through drawing and reducing the diameter. The flux core accounts for 25% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.2 mm.

[0049] Comparative Example 1 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 25 parts of iron powder, 8 parts of nickel powder, 12 parts of boron nitride whiskers, 6 parts of manganese powder, 4 parts of chromium powder, 4 parts of molybdenum powder, 0.8 part of titanium powder, 1 part of potassium titanate as a stabilizer and 3 parts of calcium fluoride uniformly, and then dry at 120 °C for 1 h to obtain a flux core; S2. Roll the welding skin into a U shape, add the flux core, then seal and roll it into an O shape, and obtain the flux-cored wire through drawing and reducing the diameter. The flux core accounts for 20% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0050] Compared with Example 1, the boron nitride whiskers in Comparative Example 1 were not subjected to modification treatment.

[0051] Comparative Example 2 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 25 parts of iron powder, 8 parts of nickel powder, 8 parts of boron nitride whiskers, 4 parts of zirconium oxide, 6 parts of manganese powder, 4 parts of chromium powder, 4 parts of molybdenum powder, 0.8 part of titanium powder, 1 part of potassium titanate as a stabilizer and 3 parts of calcium fluoride uniformly, and then dry at 120 °C for 1 h to obtain a flux core; S2. Roll the welding skin into a U shape, add the flux core, then seal and roll it into an O shape, and obtain the flux-cored wire through drawing and reducing the diameter. The flux core accounts for 20% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0052] Compared with Example 1, in Comparative Example 2, the boron nitride whiskers and zirconium oxide were directly blended.

[0053] Comparative Example 3 A method for preparing a flux-cored wire, comprising the following steps: S1. Mix 25 parts of iron powder, 8 parts of nickel powder, 12 parts of modified boron nitride, 6 parts of manganese powder, 4 parts of chromium powder, 4 parts of molybdenum powder, 0.8 part of titanium powder, 1 part of potassium titanate as a stabilizer and 3 parts of calcium fluoride evenly, and dry at 120°C for 1 h to obtain a flux core; Among them, the preparation method of the modified boron nitride is as follows: Add 5 g of zirconium oxychloride to 100 mL of deionized water, stir and dissolve it, then add 5 g of boron nitride powder thereto, disperse evenly, adjust the pH of the solution to 9 with 0.5 mol / L NaOH solution, rotate and evaporate to remove the solvent water, and then calcine in a nitrogen atmosphere. The calcination temperature is 800°C, the calcination time is 1 h, and after cooling, grind to obtain the modified boron nitride.

[0054] S2. Roll the welding skin into a U shape, add the flux core, then seal it and roll it into an O shape, and obtain the flux-cored wire through drawing and reducing the diameter. The flux core accounts for 20% of the mass of the flux-cored wire, and the diameter of the flux-cored wire is 1.5 mm.

[0055] Compared with Example 1, in Comparative Example 3, 800-mesh boron nitride powder is used to replace boron nitride whiskers.

[0056] Weld the flux-cored wires prepared in Examples 1-2 and Comparative Examples 1-3. The shielding gas is argon. The welding steel plate is a Q235B steel plate (350 mm×150 mm×20 mm). The welding voltage is 18 - 20 V, the welding current is 130 - 150 A, the welding speed is 25 cm / min, and the wire feeding speed is 150 cm / min. Measure various properties of the deposited metal of the welded parts. Among them, the hardness (HRC) is measured according to the national standard GB / T 230.1-2018 "Metallic materials - Rockwell hardness test - Part 1: Test method", the wear resistance is measured according to the national standard GB / T 12444-2006, and the impact toughness is measured according to the national standard GB / T 2650-2022. The test results are shown in Table 1.

[0057] Table 1 Performance test results of different groups As can be seen from Table 1, in Comparative Example 3, boron nitride powder was used to replace boron nitride whiskers, and its performance was inferior to that of the examples of the present invention. The reason may be that compared with the powder, the long fibrous structure of the whiskers is more likely to provide stable nucleation sites, thereby refining the grains and improving the performance of the deposited metal. At the same time, the long fibrous structure of the boron nitride whiskers can form a tighter bond with the matrix through mechanical interlocking, thereby improving the stability of the performance. Compared with Comparative Examples 1-3, the flux-cored wire prepared in the examples of the present invention has higher hardness, excellent mechanical properties and wear resistance.

[0058] Finally, it should be noted that the above embodiments do not limit the present invention in any form. For those skilled in the art, based on the present invention, some modifications and improvements can be made. Therefore, any modification or improvement made without departing from the spirit of the present invention falls within the scope of the present invention claimed.

Claims

1. A flux-cored wire with high toughness and wear resistance, characterized in that, The flux-cored wire includes a weld coating and a flux core, and the flux core is composed of the following raw materials in parts by weight: 20-30 parts of iron powder, 5-10 parts of nickel powder, 10-15 parts of modified boron nitride whiskers, 3-6 parts of manganese powder, 3-6 parts of chromium powder, 2-4 parts of molybdenum powder, 0.4-0.8 parts of titanium powder, 1-2 parts of stabilizer, and 2-3 parts of calcium fluoride.

2. The flux-cored wire according to claim 1, characterized in that, The preparation method of the modified boron nitride whiskers is as follows: Add soluble zirconium salt to deionized water, stir to dissolve, then add boron nitride whiskers thereto, disperse evenly, adjust the pH of the solution to 9-10, rotary evaporate to remove the solvent water, then calcine in a nitrogen atmosphere, and grind after cooling to obtain the modified boron nitride whiskers.

3. The flux-cored wire according to claim 2, characterized in that, The mass ratio of the soluble zirconium salt to the boron nitride whiskers is 5-10:5-10.

4. The flux-cored wire according to claim 2, characterized in that, The soluble zirconium salt is selected from zirconium oxychloride, zirconium sulfate or zirconium nitrate.

5. The flux-cored wire according to claim 2, characterized in that, The calcination temperature is 600-800 °C, and the calcination time is 1-2 h.

6. The flux cored wire according to claim 1, wherein The stabilizer is selected from at least one of potassium titanate, yttrium oxide, and lanthanum oxide.

7. The flux-cored wire according to claim 1, wherein, The flux core accounts for 15-25% of the mass of the flux-cored wire.

8. The preparation method of the flux-cored wire according to any one of claims 1-7, characterized in that, It includes the following steps: S1. Mix iron powder, nickel powder, modified boron nitride whiskers, manganese powder, chromium powder, molybdenum powder, titanium powder, stabilizer and calcium fluoride evenly in parts by weight and then dry to obtain the flux core; S2. Roll the weld coating into a U shape, add the flux core, then seal and roll it into an O shape, and obtain the flux-cored wire through drawing and reducing the diameter.

9. The preparation method according to claim 8, wherein In step S2, the diameter of the flux-cored wire is 1.2-1.8 mm.

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