Flux-cored wire for surfacing repair and preparation method of flux-cored wire

Abstract

The invention relates to the technical field of welding, and provides a flux-cored wire for surfacing repair and a preparation method of the flux-cored wire. The flux-cored wire for surfacing repair comprises a flux core and an outer skin, and the flux core is prepared from, by weight, 8-12 parts of aluminum powder, 2-5 parts of feldspar, 4-8 parts of silicon manganese, 10-17 parts of ferromolybdenum, 12-16 parts of ferrochromium, 8-14 parts of a reinforcing agent and 20-26 parts of iron powder; the reinforcing agent comprises sodium fluoborate, rare earth fluoride and tungsten carbide. By means of the technical scheme, the problem that the tensile strength of deposited metal is low in the prior art is solved.

Description

Technical Field

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

[0002] In the modern industrial system, the stable operation of mechanical equipment plays a decisive role in production efficiency and product quality. However, in actual operation, various types of equipment have to face complex, changeable and harsh working environments, which puts great pressure on key components and makes them prone to problems such as wear, corrosion and fatigue damage.

[0003] Taking the energy mining industry as an example, the drill pipes of oil drilling rigs have been operating in an underground environment with high temperature, high pressure and full of corrosive mud for a long time. Each drilling is accompanied by intense friction between the drill pipe and the rock and erosion of the mud. The surface of the drill pipe is severely worn and its service life is greatly shortened. In some areas with harsh mining conditions, drill pipes are frequently overhauled or replaced, which not only increases mining costs, but also often leads to interruptions in mining operations. In the field of steel smelting, the lining inside the blast furnace has been subjected to the scouring of high-temperature molten iron and the erosion of slag for a long time. The peeling and erosion of the lining material occur frequently, which not only affects the normal production cycle of the blast furnace, but may also cause safety accidents due to damage to the lining.

[0004] To solve these problems, surfacing repair technology has become a very promising solution. It not only restores the original size of the parts, but also gives them better wear resistance, corrosion resistance and other properties by depositing specific welding materials on the surface of damaged parts. However, traditional surfacing repair technology has obvious limitations. In the automotive manufacturing industry, some high-precision stamping dies have been restored to their appearance dimensions after traditional surfacing repair, but in subsequent high-intensity stamping operations, due to insufficient tensile strength of the deposited metal, fine cracks are prone to appear on the surface of the dies, affecting the precision and quality of the stamped parts. For example, in shipbuilding, propellers, as key components for ship propulsion, have been subjected to high loads in seawater environments for a long time. The tensile strength of propellers repaired by traditional surfacing is difficult to meet the needs of ocean voyages, and blades are prone to deformation or even breakage during navigation, which seriously threatens the safety of ship navigation.

[0005] With the rise of emerging industries such as intelligent manufacturing and high-end equipment manufacturing, the requirements for mechanical equipment performance have reached an unprecedented level. Whether it is precision processing equipment or large-scale heavy-duty machinery, parts need to have higher strength and stability. In this context, it is urgent to develop a flux-cored wire technology for surfacing repair that can significantly improve the tensile strength of the deposited metal. Summary of the invention

[0006] The invention provides a flux-cored welding wire for cladding repair and a preparation method thereof, which solves the problem of low tensile strength of deposited metal of the flux-cored welding wire for cladding repair in the related art.

[0007] The technical solution of the present invention is as follows: The invention provides a flux-cored welding wire for surfacing repair, comprising a flux core and an outer sheath, wherein the raw materials of the flux core comprise the following components in parts by weight: 8-12 parts of aluminum powder, 2-5 parts of feldspar, 4-8 parts of silicon manganese, 10-17 parts of ferromolybdenum, 12-16 parts of ferrochrome, 8-14 parts of a reinforcing agent, and 20-26 parts of iron powder; The reinforcing agents include sodium fluoroborate, rare earth fluoride and tungsten carbide.

[0008] As a further technical solution, the mass ratio of the sodium fluoroborate, rare earth fluoride and tungsten carbide is 3~5:6:11.

[0009] In the present invention, the tensile strength of the deposited metal is further improved by adjusting the mass ratio of sodium fluoroborate, rare earth fluoride and tungsten carbide to 3-5:6:11.

[0010] As a further technical solution, the mass ratio of the sodium fluoroborate, rare earth fluoride and tungsten carbide is 4:6:11.

[0011] In the present invention, the tensile strength of the deposited metal is further improved by adjusting the mass ratio of sodium fluoroborate, rare earth fluoride and tungsten carbide to 4:6:11.

[0012] As a further technical solution, the rare earth fluoride includes one or more of lanthanum fluoride, cerium fluoride and yttrium fluoride.

[0013] As a further technical solution, the particle size of the tungsten carbide is 100~200nm.

[0014] The invention improves the yield strength of the deposited metal by controlling the particle size of tungsten carbide to be 100-200nm.

[0015] As a further technical solution, the material of the outer skin is steel, and the steel is composed of the following elements in weight percentage: carbon 0.05%~0.08%, manganese 0.40%~0.70%, silicon 0.03%~0.05%, chromium 0.32%~0.44%, sulfur 0.0008%~0.012%, phosphorus 0.0002%~0.015%, and the remainder is iron and inevitable impurities.

[0016] As a further technical solution, the mass ratio of the drug core to the outer skin is 1.5~2.5:7.

[0017] The present invention also provides a method for preparing a flux-cored welding wire for cladding repair, which is used to prepare the flux-cored welding wire for cladding repair, comprising the following steps: S1, ball-milling the components except the core enhancer, adding the enhancer, mixing until uniform, and drying to obtain the core powder; S2, rolling the steel into a U-shaped groove, adding the flux core powder into the U-shaped groove, sealing, reducing the diameter, and drawing to obtain a flux cored welding wire for surfacing repair.

[0018] As a further technical solution, during the ball milling, the rotation speed is 200-300 rpm and the time is 3-4 hours.

[0019] As a further technical solution, during the drying, the temperature is 800-900° C. and the time is 8-12 hours.

[0020] As a further technical solution, the diameter of the flux-cored welding wire for surfacing repair is 1.5~3mm.

[0021] The working principle and beneficial effects of the present invention are: In the present invention, sodium fluoroborate, rare earth fluoride and tungsten carbide are added as reinforcing agents. During welding, sodium fluoroborate and rare earth fluoride decompose fluorine element, and form hydrogen fluoride with hydrogen element in the weld, thereby improving the performance of the cladding layer. Tungsten carbide is a hard phase with high hardness. Sodium fluoroborate, rare earth fluoride and tungsten carbide work synergistically, thereby improving the tensile strength of the deposited metal of the flux-cored welding wire for cladding repair. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 are within the scope of protection of the present invention.

[0023] In the following embodiments and comparative examples, the sodium fluoroborate has a particle size of 100 mesh and a purity of 99wt%, the lanthanum fluoride has a particle size of 8 μm and a purity of 99.99wt%, cerium fluoride is purchased from Shandong Xinghai Chemical Co., Ltd. with the article number XH-181, the purity of yttrium fluoride is 99.99wt%, the purity of tungsten carbide with a particle size of 50nm is 99.9wt%, the purity of tungsten carbide with a particle size of 100nm is 99.9wt%, the purity of tungsten carbide with a particle size of 200nm is 99.9wt%, the purity of tungsten carbide with a particle size of 300nm is 99.9wt%, the silicon content in silicon manganese is 17wt%, the molybdenum content in ferromolybdenum is 60wt%, the chromium content in ferrochrome is 65.1wt%, and the purity of iron powder is 99wt%.

[0024] Example 1 A flux-cored welding wire for surfacing repair, comprising a flux core and a sheath with a mass ratio of 2.5:7, wherein the raw materials of the flux core include the following components in parts by weight: 12 parts of aluminum powder, 5 parts of feldspar, 8 parts of silicon manganese, 17 parts of ferromolybdenum, 16 parts of ferrochrome, 14 parts of a reinforcing agent, and 26 parts of iron powder; The enhancer includes sodium fluoroborate, lanthanum fluoride and tungsten carbide in a mass ratio of 8:6:11; The particle size of tungsten carbide is 300nm; The material of the outer skin is steel, which is composed of the following elements in percentage by weight: carbon 0.08%, manganese 0.70%, silicon 0.05%, chromium 0.44%, sulfur 0.012%, phosphorus 0.015%, and the balance is iron and inevitable impurities; The preparation method of flux-cored welding wire for surfacing repair comprises the following steps: S1, ball mill the components except the core enhancer at 300 rpm for 3 h, add the enhancer, mix until uniform, and dry at 900 ° C for 8 h to obtain the core powder; S2. Roll the steel into a U-shaped groove, add flux core powder into the U-shaped groove, seal, reduce the diameter, and draw the wire to obtain a flux cored welding wire with a diameter of 3 mm for surfacing repair.

[0025] Example 2 A flux-cored welding wire for surfacing repair, comprising a flux core and a sheath with a mass ratio of 1.5:7, wherein the raw materials of the flux core include the following components in parts by weight: 8 parts of aluminum powder, 2 parts of feldspar, 4 parts of silicon manganese, 10 parts of ferromolybdenum, 12 parts of ferrochrome, 8 parts of a reinforcing agent, and 20 parts of iron powder; The reinforcing agent includes sodium fluoroborate, cerium fluoride and tungsten carbide in a mass ratio of 1:6:11; The particle size of tungsten carbide is 300nm; The material of the outer skin is steel, which is composed of the following elements in percentage by weight: carbon 0.05%, manganese 0.40%, silicon 0.03%, chromium 0.32%, sulfur 0.0008%, phosphorus 0.0002%, and the balance is iron and inevitable impurities; The preparation method of flux-cored welding wire for surfacing repair comprises the following steps: S1. Ball mill the components except the core enhancer at 200 rpm for 4 h, add the enhancer, mix until uniform, and dry at 800 °C for 12 h to obtain core powder; S2. Roll the steel into a U-shaped groove, add flux core powder into the U-shaped groove, seal, reduce the diameter, and draw the wire to obtain a flux cored welding wire with a diameter of 1.5 mm for surfacing repair.

[0026] Example 3 A flux-cored welding wire for surfacing repair, comprising a flux core and an outer sheath, wherein the raw materials of the flux core comprise the following components in parts by weight: 10 parts of aluminum powder, 4 parts of feldspar, 6 parts of silicon manganese, 15 parts of ferromolybdenum, 14 parts of ferrochrome, 12 parts of a reinforcing agent, and 24 parts of iron powder; The reinforcing agent includes sodium fluoroborate, yttrium fluoride and tungsten carbide in a mass ratio of 6:6:11; The particle size of tungsten carbide is 300nm; The material of the outer skin is steel, which is composed of the following elements in percentage by weight: carbon 0.06%, manganese 0.50%, silicon 0.04%, chromium 0.38%, sulfur 0.001%, phosphorus 0.0015%, and the balance is iron and inevitable impurities; The mass ratio of the core to the sheath is 2:7; The preparation method of flux-cored welding wire for surfacing repair comprises the following steps: S1. Ball mill the components other than the core enhancer at a speed of 250 rpm for 3.5 h, add the enhancer, mix until uniform, and dry at 850° C. for 10 h to obtain a core powder; S2. Roll the steel into a U-shaped groove, add flux core powder into the U-shaped groove, seal, reduce the diameter, and draw the wire to obtain a flux cored welding wire with a diameter of 2 mm for surfacing repair.

[0027] Example 4 The only difference between this embodiment and embodiment 3 is that the reinforcing agent in this embodiment includes sodium fluoroborate, yttrium fluoride and tungsten carbide in a mass ratio of 2:6:11.

[0028] Example 5 The only difference between this embodiment and embodiment 3 is that the reinforcing agent in this embodiment includes sodium fluoroborate, yttrium fluoride and tungsten carbide in a mass ratio of 3:6:11.

[0029] Example 6 The only difference between this embodiment and embodiment 3 is that the reinforcing agent in this embodiment includes sodium fluoroborate, yttrium fluoride and tungsten carbide in a mass ratio of 4:6:11.

[0030] Example 7 The only difference between this embodiment and embodiment 3 is that the reinforcing agent in this embodiment includes sodium fluoroborate, yttrium fluoride and tungsten carbide in a mass ratio of 5:6:11.

[0031] Example 8 The only difference between this embodiment and embodiment 6 is that the particle size of tungsten carbide in this embodiment is 50 nm.

[0032] Example 9 The only difference between this embodiment and embodiment 6 is that the particle size of tungsten carbide in this embodiment is 100 nm.

[0033] Example 10 The only difference between this embodiment and embodiment 6 is that the particle size of tungsten carbide in this embodiment is 200 nm.

[0034] Comparative Example 1 The only difference between this comparative example and Example 3 is that the reinforcing agent in this comparative example is sodium fluoroborate and yttrium fluoride in a ratio of 1:1.

[0035] Comparative Example 2 The only difference between this comparative example and Example 3 is that the reinforcing agent in this comparative example is sodium fluoroborate and tungsten carbide in a ratio of 6:11.

[0036] Comparative Example 3 The only difference between this comparative example and Example 3 is that the reinforcing agent in this comparative example is yttrium fluoride and tungsten carbide in a ratio of 6:11.

[0037] Comparative Example 4 The only difference between this comparative example and Example 3 is that this comparative example does not contain a reinforcing agent.

[0038] Experimental Example 1 The flux-cored welding wires for surfacing repair prepared in Examples 1 to 7 and Comparative Examples 1 to 4 were used for butt joint welding of T22 pearlite heat-resistant steel, with a welding current of 250A, a welding voltage of 28A, an argon shielding gas, and a gas flow rate of 5L / min. The tensile strength of the deposited metal was tested according to the method specified in GB / T 2652-2022 "Destructive Test of Metallic Material Welds - Longitudinal Tensile Test of Fusion Welded Joint Weld Metal". The test results are shown in Table 1.

[0039] Table 1 Tensile strength test results

[0040] Comparing Examples 3 to 7 with Comparative Examples 1 to 4, it is shown that the sodium fluoroborate, rare earth fluoride and tungsten carbide in the present invention work synergistically to improve the tensile strength of the deposited metal.

[0041] Experimental Example 2 The flux-cored welding wires for surfacing repair prepared in Examples 6 and 8-10 were used for butt joint welding of T22 pearlite heat-resistant steel, with a welding current of 250A, a welding voltage of 28A, an argon shielding gas, and a gas flow rate of 5L / min. The yield strength of the deposited metal was tested according to the method specified in GB / T 2652-2022 "Destructive Test of Metallic Material Welds - Longitudinal Tensile Test of Fusion Welded Joint Weld Metal". The test results are shown in Table 2.

[0042] Table 2 Yield strength test results

[0043] Comparing Examples 9 and 10 with Examples 6 and 8, it is shown that when the tungsten carbide particle size is adjusted to 100 to 200 nm, the yield strength of the deposited metal is improved.

[0044] Experimental Example 3 The flux-cored welding wire for surfacing repair prepared in Example 3 was used for butt joint welding of T22 pearlite heat-resistant steel, with a welding current of 250A, a welding voltage of 28A, an argon shielding gas, and a gas flow rate of 5L / min. The impact absorption energy of the deposited metal was tested at room temperature according to the method specified in GB / T 229-2020 "Metallic Materials Charpy Pendulum Impact Test Method", and the notch was a V-notch. The test results are shown in Table 3.

[0045] Table 3 Absorption energy test results

[0046] It can be seen from Table 3 that the flux-cored welding wire for cladding repair in the present invention is suitable for cladding repair.

[0047] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flux-cored welding wire for cladding repair, characterized in that: It includes a core and a sheath, wherein the raw materials of the core include the following components in parts by weight: 8-12 parts of aluminum powder, 2-5 parts of feldspar, 4-8 parts of silicon manganese, 10-17 parts of ferromolybdenum, 12-16 parts of ferrochrome, 8-14 parts of reinforcing agent, and 20-26 parts of iron powder; The reinforcing agents include sodium fluoroborate, rare earth fluoride and tungsten carbide.

2. A flux-cored welding wire for cladding repair according to claim 1, characterized in that: The mass ratio of the sodium fluoroborate, rare earth fluoride and tungsten carbide is 3-5:6:

11.

3. A flux-cored welding wire for cladding repair according to claim 2, characterized in that: The mass ratio of the sodium fluoroborate, rare earth fluoride and tungsten carbide is 4:6:

11.

4. The flux-cored welding wire for cladding repair according to claim 1, characterized in that: The rare earth fluoride includes one or more of lanthanum fluoride, cerium fluoride and yttrium fluoride.

5. The flux-cored welding wire for surfacing repair according to claim 1, characterized in that: The particle size of the tungsten carbide is 100-200 nm.

6. The flux-cored welding wire for cladding repair according to claim 1, characterized in that: The material of the outer skin is steel, and the steel is composed of the following elements in weight percentage: carbon 0.05%~0.08%, manganese 0.40%~0.70%, silicon 0.03%~0.05%, chromium 0.32%~0.44%, sulfur 0.0008%~0.012%, phosphorus 0.0002%~0.015%, and the remainder is iron and inevitable impurities.

7. The flux-cored welding wire for cladding repair according to claim 1, characterized in that: The mass ratio of the drug core to the outer skin is 1.5-2.5:

7.

8. A method for preparing a flux-cored welding wire for cladding repair, used for preparing a flux-cored welding wire for cladding repair as claimed in claim 6, characterized in that: The following steps are involved: S1. Ball-mill all the components of the drug core except the reinforcing agent, add the reinforcing agent, mix until uniform, and dry to obtain drug core powder; S2, rolling the steel into a U-shaped groove, adding the flux core powder into the U-shaped groove, sealing, reducing the diameter, and drawing to obtain a flux cored welding wire for surfacing repair.

9. The method for preparing a flux-cored welding wire for cladding repair according to claim 8, characterized in that: During the drying, the temperature is 800-900° C. and the time is 8-12 hours.

10. The method for preparing a flux-cored welding wire for cladding repair according to claim 8, characterized in that: The diameter of the flux-cored welding wire for surfacing repair is 1.5-3 mm.

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