Wear-resistant flux-cored wire for welding high-manganese steel lining plate and surfacing method

Abstract

The invention discloses a wear-resistant flux-cored wire for welding a high-manganese steel lining plate and a surfacing method, and belongs to the technical field of surface strengthening of mining machinery. A flux core of the welding wire is composed of high-carbon ferrochrome powder, graphite powder and a small amount of ferrosilicon, ferromanganese, ferrotitanium, ferroboron and nickel powder, an outer skin is a low-carbon cold-rolled steel strip, the diameter of the outer skin ranges from 2.4 mm to 3.2 mm, and the filling rate of the outer skin ranges from 38% to 50%. According to the surfacing method, plasma arc automatic surfacing is adopted during welding, paraxial wire feeding is conducted, and argon protection is conducted; controlling the surface temperature of the high-manganese steel lining plate; the thickness of a single-layer surfacing layer is about 3 mm, the hardness is 58-65 HRC, the single-layer surfacing layer is metallurgically bonded with high manganese steel without cracks, the longitudinal deformation of the lining plate is smaller than or equal to 1.9 mm, and the wear resistance is improved to 2.0-3.3 times that of a base material. The high-carbon ferro-chrome serves as a main raw material, the raw material particle size range is wide, the welding wire cost is low, the process is stable, and the method is suitable for on-site rapid repairing and new piece strengthening of the ball mill end cover high-manganese steel lining plate.

Description

Technical Field

[0001] This invention belongs to the field of surface strengthening of high manganese steel liner plates for mining machinery, and specifically relates to a wear-resistant flux-cored welding wire for welding high manganese steel liner plates and a welding method thereon. Background Technology

[0002] As a key piece of equipment in industries such as mining and metallurgy, ball mills suffer from severe friction and wear on the high-manganese steel liners of their end caps due to long-term use by steel balls, materials, and slurry. Traditional high-manganese steel liners, such as Mn13, typically have a thickness of 50–130 mm. While possessing excellent strength and toughness (yield strength ≥350 MPa, impact toughness ≥150 J / cm²) and strong work-hardening ability (reaching a hardness of HB500 after work hardening), they experience extremely rapid and severe wear from the abrasives in the initial stages of service because they haven't yet developed sufficient hardness. After just one month of use, the wear can exceed 10 mm, causing the high-manganese steel liner's dimensions to shrink prematurely, resulting in insufficient steel lifting capacity and further reducing ball mill efficiency. This leads to significantly substandard operating times, necessitating frequent liner replacements and causing substantial economic losses for enterprises.

[0003] Functional coatings prepared based on surface engineering technology can improve the mechanical properties of material surfaces, such as wear resistance, corrosion resistance, and resistance to biofouling. However, existing open arc automatic surfacing and submerged arc surfacing technologies often result in severe substrate deformation due to excessive heat input when surfacing on the substrate material surface.

[0004] Patent CN119115301A discloses a plasma-coated flux-cored wire resistant to abrasive wear and its preparation method, mainly for surface strengthening of agricultural machinery. The flux-cored wire contains expensive tungsten carbide powder and nano-rare earth powder, leading to increased costs. Patent CN119159279A discloses a plasma-coated flux-cored wire resistant to medium-stress abrasive wear and its preparation method, adding a large amount of vanadium iron powder (45%–65%) to the flux-cored wire. Patent CN119057304A discloses a plasma-coated flux-cored wire resistant to high-stress impact wear and its preparation method, with chromium carbide powder as the main additive. Furthermore, none of the above three patents address the control of substrate material deformation during the welding process. Patent CN 106041359A discloses an in-situ generated composite hard phase stepped reinforced wear-resistant surfacing flux-cored wire and its preparation method. Although each flux powder is composed of two particle sizes in a 1:1 ratio, it still uses powders of a single particle size, thus inevitably leading to high manufacturing costs. Furthermore, both patents use open-arc surfacing to prepare three layers of surfacing material before achieving a hardness of approximately 60 HRC, increasing the amount of flux used and the surfacing time, further increasing the overall cost. Therefore, from the perspective of cost saving and deformation control, developing a low-cost plasma surfacing wear-resistant flux-cored wire and a low-deformation surfacing process for high-manganese steel end caps of ball mills is particularly important. Summary of the Invention

[0005] The purpose of this invention is to improve the wear resistance of the high manganese steel liner plate of the ball mill end cover, and to provide a low-cost wear-resistant flux-cored welding wire for plasma cladding with high carbon ferrochrome powder as the main raw material, and to overcome the large deformation of the high manganese steel liner plate caused by thermal expansion and contraction by controlling the cladding process.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A wear-resistant flux-cored welding wire for welding high-manganese steel liners includes an outer sheath and a flux core, wherein the flux core is composed of the following raw materials in weight percentage: 75-89 wt% high-carbon ferrochrome powder, 2-8 wt% graphite powder, 1-4 wt% ferrosilicon powder, 1-4 wt% ferromanganese powder, 0.5-3 wt% ferrotitanium powder, 0.5-5 wt% ferroboron powder, and 0.5-2 wt% nickel powder.

[0008] Furthermore, the outer sheath is a low-carbon cold-rolled steel strip, and the welding wire is made by cold-rolling and drawing to wrap the flux core with the outer sheath.

[0009] Furthermore, its diameter is 2.4–3.2 mm, and its filling rate is 38–50%.

[0010] A method for surfacing high-manganese steel liners, using wear-resistant flux-cored welding wire for welding high-manganese steel liners;

[0011] Step 1: Pre-treat the surface of the high-manganese steel;

[0012] Step 2: Dry and dehumidify the flux-cored welding wire;

[0013] Step 3: The welding equipment used is an automatic plasma arc welding machine. The welding process parameters include: welding current 135-180A, welding speed 300-720mm / min, wire feed speed 1500-2400mm / min; the wire feed method is off-axis wire feed; both the compressed gas and the shielding gas are argon with a purity ≥99.99%, the selected compressed gas flow rate is 1-10L / min, and the selected shielding gas flow rate is 10-20L / min.

[0014] Step 4: During the plasma cladding process, the surface temperature of the high manganese steel liner plate 5cm away from the molten pool needs to be controlled within the range of 150-280℃.

[0015] Furthermore, the hardness of the weld overlay of the high manganese steel liner after plasma welding reaches 58-65 HRC, and its wear resistance is 2.01-3.29 times that of the high manganese steel liner.

[0016] Furthermore, the microstructure of the high-manganese steel liner after plasma cladding mainly consists of iron-based solid solution and (Cr,Fe)7C3 reinforcing phase distributed within it.

[0017] This invention addresses the challenges of rapid early wear, large deformation, and high cost associated with traditional welding methods for high-manganese steel liners in ball mill end caps. It proposes a low-cost flux-cored wire primarily composed of 75–89 wt% high-carbon ferrochrome and supplemented with multi-element microalloying, coupled with a low-heat-input plasma arc process. By controlling the surface temperature of the high-manganese steel liner at 150–280 °C at 5 cm from the molten pool, carbide precipitation in the heat-affected zone and liner warping (longitudinal deformation ≤1.9 mm) are suppressed, while also ensuring a crack-free metallurgical bond between the weld overlay and the substrate. A single 3 mm cladding layer achieves a high hardness of 58–65 HRC and a uniform (Cr,Fe)7C3 strengthening phase, improving wear resistance and achieving a balance between high hardness, low deformation, and low cost.

[0018] Beneficial effects

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] 1. The present invention provides a wear-resistant flux-cored welding wire for welding high-manganese steel liners, which uses low-cost high-carbon ferrochrome as the main raw material, and the particle size distribution powder used is cheaper than single-particle-size powder, thereby reducing the manufacturing cost of the welding wire and enabling it to fully realize huge economic benefits in the field of mining machinery manufacturing.

[0021] 2. The plasma surfacing process for high manganese steel liners for ball mill end caps provided by this invention solidifies the surfacing parameters. By controlling parameters such as welding current, wire feeding speed, and surface temperature of the high manganese steel liner, a low deformation of the high manganese steel liner is ensured.

[0022] 3. The single-layer plasma overlay coating prepared by this invention has good formation and a thickness of about 3 mm. The coating has a good metallurgical bond with the high manganese steel liner and a hardness of 58~65 HRC, which significantly improves the wear resistance of the high manganese steel liner material. Attached Figure Description

[0023] Figure 1 This is a microstructure diagram of the interface between the plasma-welded wear-resistant layer and the substrate in Embodiment 1 of the present invention.

[0024] Figure 2 This is a microscopic wear morphology diagram of the original high-manganese steel liner plate in Example 2 of the present invention.

[0025] Figure 3 This is a microscopic wear morphology image of a high-manganese steel liner with a plasma-welded wear-resistant coating according to Embodiment 2 of the present invention.

[0026] Figure 4 This is a diagram of the original high-manganese steel liner plate before plasma welding.

[0027] Figure 5 This is a diagram showing the longitudinal deformation after plasma welding on a high-manganese steel liner in Embodiment 3 of the present invention.

[0028] Figure 6 This is a diagram showing the longitudinal deformation of a high-manganese steel liner after plasma welding, as shown in Comparative Example 1 of the present invention. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0030] The raw materials used in this invention are:

[0031] The high manganese steel liner is made of ZGMn13 high manganese steel. Before plasma cladding, the edges and corners of the high manganese steel liner are warped upwards by 15.0mm from the horizontal line.

[0032] High-carbon ferrochrome contains 7% to 9% C and ≥60% Cr, with a powder particle size range of 60 to 325 mesh;

[0033] Graphite powder contains ≥98% C, and the powder particle size ranges from 60 to 200 mesh;

[0034] Ferrosilicon powder contains ≥72% Si, and the powder particle size ranges from 60 to 200 mesh;

[0035] The manganese-iron powder contains 65%–72% Mn and 1–1.5% C, with a particle size range of 60–200 mesh.

[0036] The titanium iron powder contains 35% to 45% Ti and ≤8% Al, and the powder particle size ranges from 60 to 200 mesh.

[0037] Boron iron powder contains 9-25% B and ≤0.1% C, and the powder particle size ranges from 60 to 200 mesh.

[0038] The nickel powder contains ≥98% Ni, and the particle size ranges from 60 to 200 mesh.

[0039] Example 1

[0040] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 76.5 wt%, graphite 7.8 wt%, ferrosilicon 3.9 wt%, ferromanganese 3.5 wt%, ferrotitanium 2.6 wt%, ferroboron 4.1 wt%, and nickel powder 1.6 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 2.4 mm and a filler content of 43%.

[0041] A method for surfacing high-manganese steel liners involves pre-treating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 140A, the welding speed is 350mm / min, and the wire feed speed is 1650mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 4L / min and a selected shielding gas flow rate of 12L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 167℃.

[0042] The microstructure and interfacial bonding of the wear-resistant coating prepared by plasma welding are shown in the figure. Figure 1 The interface exhibits a good metallurgical bonding state and no cracks are observed.

[0043] The longitudinal deformation before and after plasma welding is 1.2 mm.

[0044] The coating hardness, measured using a Rockwell hardness tester, is 59.6 HRC.

[0045] Wear tests were conducted on high-manganese steel liners and welded high-manganese steel liners using a dry sand rubber wheel friction and wear tester, according to ASTM G65 standard. The load was 130 N, the rubber wheel speed was 200 r / min, the abrasive flow rate was 350 g / min, and the test duration was 10 min. The mass loss of the samples before and after wear was measured using an analytical balance with an accuracy of 0.1 mg. The results showed that the high-manganese steel liner lost 0.7861 g, while the wear-resistant coating on the welded high-manganese steel liner lost only 0.3912 g, indicating that the latter's wear resistance was 2.01 times that of the former.

[0046] Example 2

[0047] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 81.3 wt%, graphite 6.5 wt%, ferrosilicon 2.8 wt%, ferromanganese 3.1 wt%, ferrotitanium 1.8 wt%, ferroboron 3.4 wt%, and nickel powder 1.1 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 2.4 mm and a filler content of 45%.

[0048] A method for surfacing high-manganese steel liners involves pre-treating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 140A, the welding speed is 380mm / min, and the wire feed speed is 1730mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 6L / min and a selected shielding gas flow rate of 15L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 191℃.

[0049] The longitudinal deformation before and after plasma cladding is 1.4 mm.

[0050] The coating hardness, measured using a Rockwell hardness tester, is 60.4 HRC.

[0051] Wear tests were conducted on high-manganese steel liners and welded high-manganese steel liners using a dry sand rubber wheel friction and wear testing machine according to ASTM G65 standard. The load was 130 N, the rubber wheel speed was 200 r / min, the abrasive flow rate was 350 g / min, and the test duration was 10 min. The mass loss of the samples before and after wear was measured using an analytical balance with an accuracy of 0.1 mg. The results showed that the high-manganese steel liner lost 0.7673 g, while the welded high-manganese steel liner lost only 0.3021 g. The latter's wear resistance was 2.54 times that of the former. The surface wear morphologies of both are shown in [Figure showing...]. Figure 2 and Figure 3 .

[0052] Example 3

[0053] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 85.3 wt%, graphite 5.3 wt%, ferrosilicon 1.9 wt%, ferromanganese 2.6 wt%, ferrotitanium 1.2 wt%, ferroboron 2.9 wt%, and nickel powder 0.8 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 2.8 mm and a filler content of 47%.

[0054] A method for surfacing high-manganese steel liners involves pre-treating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 155A, the welding speed is 480mm / min, and the wire feed speed is 1950mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 6L / min and a selected shielding gas flow rate of 16L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 216℃.

[0055] The longitudinal deformation before and after plasma welding is 1.5 mm, as shown in the attached figure. Figure 5 and Figure 4 As shown in the comparison.

[0056] The coating hardness, measured using a Rockwell hardness tester, is 62.5 HRC.

[0057] Wear tests were conducted on high-manganese steel liners and welded high-manganese steel liners using a dry sand rubber wheel friction and wear tester, according to ASTM G65 standard. The load was 130 N, the rubber wheel speed was 200 r / min, the abrasive flow rate was 350 g / min, and the test duration was 10 min. The mass loss of the samples before and after wear was measured using an analytical balance with an accuracy of 0.1 mg. The results showed that the high-manganese steel liner lost 0.7735 g, while the welded high-manganese steel liner lost only 0.2843 g, indicating that the latter's wear resistance was 2.72 times that of the former.

[0058] Example 4

[0059] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 86.9 wt%, graphite 4.9 wt%, ferrosilicon 2.0 wt%, ferromanganese 2.3 wt%, ferrotitanium 0.9 wt%, ferroboron 2.3 wt%, and nickel powder 0.7 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 2.8 mm and a filler content of 47%.

[0060] A method for surfacing high-manganese steel liners involves pre-treating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 160A, the welding speed is 540mm / min, and the wire feed speed is 2050mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 5L / min and a selected shielding gas flow rate of 17L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 247℃.

[0061] The longitudinal deformation before and after plasma cladding is 1.7 mm.

[0062] The coating hardness, measured using a Rockwell hardness tester, is 63.8 HRC.

[0063] Wear tests were conducted on high-manganese steel liners and welded high-manganese steel liners using a dry sand rubber wheel friction and wear tester, according to ASTM G65 standard. The load was 130 N, the rubber wheel speed was 200 r / min, the abrasive flow rate was 350 g / min, and the test duration was 10 min. The mass loss of the samples before and after wear was measured using an analytical balance with an accuracy of 0.1 mg. The results showed that the high-manganese steel liner lost 0.7596 g, while the welded high-manganese steel liner lost only 0.2533 g, indicating that the latter's wear resistance was 2.99 times that of the former.

[0064] Example 5

[0065] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 88.6 wt%, graphite 4.6 wt%, ferrosilicon 1.5 wt%, ferromanganese 2.2 wt%, ferrotitanium 0.9 wt%, ferroboron 1.8 wt%, and nickel powder 0.5 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 3.2 mm and a filler content of 49%.

[0066] A method for surfacing high-manganese steel liners involves pre-treating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 175A, the welding speed is 630mm / min, and the wire feed speed is 2150mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 7L / min and a selected shielding gas flow rate of 15L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 272℃.

[0067] The longitudinal deformation before and after plasma cladding is 1.9 mm.

[0068] The coating hardness, measured using a Rockwell hardness tester, is 64.1 HRC.

[0069] Wear tests were conducted on high-manganese steel liners and welded high-manganese steel liners using a dry sand rubber wheel friction and wear tester, according to ASTM G65 standard. The load was 130 N, the rubber wheel speed was 200 r / min, the abrasive flow rate was 350 g / min, and the test duration was 10 min. The mass loss of the samples before and after wear was measured using an analytical balance with an accuracy of 0.1 mg. The results showed that the high-manganese steel liner lost 0.7738 g, while the welded high-manganese steel liner lost only 0.2347 g, indicating that the latter's wear resistance was 3.29 times that of the former.

[0070] Example 6

[0071] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 75.3 wt%, graphite 8.1 wt%, ferrosilicon 2.9 wt%, ferromanganese 3.9 wt%, ferrotitanium 3.1 wt%, ferroboron 4.8 wt%, and nickel powder 1.9 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 2.4 mm and a filler content of 38%.

[0072] A method for surfacing high-manganese steel liners involves pretreating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 135A, the welding speed is 300mm / min, and the wire feed speed is 1500mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 1L / min and a selected shielding gas flow rate of 10L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 152℃.

[0073] Example 7

[0074] A wear-resistant flux-cored welding wire for welding high-manganese steel liners comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: high-carbon ferrochrome 89.4 wt%, graphite 2.2 wt%, ferrosilicon 1.1 wt%, ferromanganese 4.1 wt%, ferrotitanium 0.6 wt%, ferroboron 0.5 wt%, and nickel powder 2.1 wt%. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 3.2 mm and a filler content of 50%.

[0075] A method for surfacing high-manganese steel liners involves pretreating the surface of the high-manganese steel liner to remove oil and rust. The flux-cored welding wire is then placed in a heating furnace for drying and dehumidification. Plasma surfacing is performed on the high-manganese steel liner using this flux-cored welding wire. The welding current is 180A, the welding speed is 720mm / min, and the wire feed speed is 2400mm / min. The wire feed method is off-axis feeding. Both the compressed gas and the shielding gas are 99.99% pure argon, with a selected compressed gas flow rate of 10L / min and a selected shielding gas flow rate of 20L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool is 281℃.

[0076] Comparative Example 1: Using the wear-resistant flux-cored welding wire prepared in Example 5, a single-layer wear-resistant coating was prepared on a high-manganese steel liner using an open arc welding method with a welding current of 400A, a welding voltage of 32V, and a welding speed of 0.4m / min. The rest was the same as in Example 5. However, due to excessive heat input in the comparative example, the substrate was severely diluted, resulting in uneven edges on both sides of the wear-resistant coating due to reduced viscosity. The single-layer height was only 1.8mm, and the coating hardness measured using a Rockwell hardness tester was 56.4 HRC. Furthermore, as... Figure 6 The high-manganese steel liner shown has a longitudinal deformation of 5.6 mm due to overheating, which far exceeds the deformation control amount in Example 5.

[0077] Comparative Example 2 used a high-stress impact wear resistant plasma welding flux-cored wire (patent CN119057304A) with the following composition: 2.1 wt% graphite powder, 2.5 wt% high-carbon ferrochrome powder, 24.3% micro-carbon ferrochrome powder, 16.2 wt% chromium carbide powder, 2.3 wt% ferromolybdenum powder, 3.5 wt% ferrovanadium powder, 4.1% ferroniobium, 1.4 wt% silicon carbide powder, 7.3% ferroboron, 1.1% titanium carbide powder, 1.3 wt% electrolytic manganese powder, and the balance being reduced iron powder. The flux-cored wire was then used to prepare a wear-resistant layer on a high-manganese steel liner using the welding method described in Example 1. The hardness of the coating in Comparative Example 2, measured using a Rockwell hardness tester, was 57.1 HRC. According to the ASTM G65 standard, a dry sand-type rubber wheel friction and wear test was conducted. The results showed that the wear-resistant coating of Comparative Example 2 had a weight loss of 0.4784g, and its wear resistance was 1.64 times that of the high manganese steel substrate. The wear resistance was obviously lower than that of the wear-resistant coating prepared in Example 1 of this invention.

[0078] Comparative Example 3 used a high-stress impact wear resistant plasma welding flux-cored wire (CN119057304A) with the following composition: 2.1 wt% graphite powder, 2.5 wt% high-carbon ferrochrome powder, 24.3% micro-carbon ferrochrome powder, 16.2 wt% chromium carbide powder, 2.3 wt% ferromolybdenum powder, 3.5 wt% ferrovanadium powder, 4.1% ferroniobium, 1.4 wt% silicon carbide powder, 7.3% ferroboron, 1.1% titanium carbide powder, 1.3 wt% electrolytic manganese powder, and the balance being reduced iron powder. The flux-cored wire was then used to prepare a wear-resistant layer on a high-manganese steel liner using the welding method described in Example 5 of this patent. The coating hardness of Comparative Example 2 was measured to be 58.9 HRC using a Rockwell hardness tester. According to the ASTM G65 standard, a dry sand-type rubber wheel friction and wear test was conducted. The results showed that the wear-resistant coating of Comparative Example 3 had a weight loss of 0.3943g, and its wear resistance was 1.96 times that of the high manganese steel substrate. The wear resistance was obviously lower than that of the wear-resistant coating prepared in Example 5 of this invention.

[0079] The above description is merely a preferred embodiment of the present invention. It should be noted that the present invention is not limited to the above embodiments. Various changes can be made without departing from the technical principles of the present invention. Any alterations, modifications, substitutions, combinations, or simplifications made based on the spirit and principles of the technical solution of the present invention should be considered equivalent substitutions, and these changes also fall within the protection scope of the present invention. Furthermore, the plasma-cored welding wire formulation and welding process of the present invention are only effective when used synergistically on the surface of the high-manganese steel liner plate of the ball mill end cap; otherwise, both welding efficiency and quality cannot be achieved simultaneously.

Claims

1. A wear-resistant flux-cored welding wire for welding high-manganese steel liners, characterized in that, It includes an outer sheath and a core, the core being composed of the following raw materials in weight percentage: 75-89 wt% high-carbon ferrochrome powder, 2-8 wt% graphite powder, 1-4 wt% ferrosilicon powder, 1-4 wt% ferromanganese powder, 0.5-3 wt% ferrotitanium powder, 0.5-5 wt% ferroboron powder, and 0.5-2 wt% nickel powder.

2. The wear-resistant flux-cored welding wire for welding high-manganese steel liners according to claim 1, characterized in that, The outer sheath is made of low-carbon cold-rolled steel strip, and the welding wire is made by cold-rolling and drawing to wrap the flux core with the outer sheath.

3. The wear-resistant flux-cored welding wire for welding high-manganese steel liners according to claim 2, characterized in that, Its diameter is 2.4–3.2 mm, and its filling rate is 38–50%.

4. A method for surfacing high-manganese steel liners, using the wear-resistant flux-cored welding wire for welding high-manganese steel liners as described in claim 1, characterized in that... ； Step 1: Pre-treat the surface of the high manganese steel liner; Step 2: Dry and dehumidify the flux-cored welding wire; Step 3: The welding equipment used is an automatic plasma arc welding machine. The welding process parameters include: welding current 135-180A, welding speed 300-720mm / min, and wire feed speed 1500-2400mm / min. The wire feeding method is off-axis wire feeding; both the compressed gas and the protective gas are argon with a purity of ≥99.99%, the selected compressed gas flow rate is 1~10L / min, and the selected protective gas flow rate is 10~20L / min; Step 4: During the plasma cladding process, the surface temperature of the high manganese steel liner plate 5cm away from the molten pool needs to be controlled within the range of 150-280℃.

5. The method for overlaying high-manganese steel lining plates according to claim 4, characterized in that, The hardness of the weld overlay of the high manganese steel liner after plasma welding reaches 58-65 HRC, and its wear resistance is 2.01-3.29 times that of the original high manganese steel liner.

6. The method for overlaying high-manganese steel liner plates according to claim 4, characterized in that, The microstructure of the high-manganese steel liner after plasma cladding mainly consists of iron-based solid solution and (Cr,Fe)7C3 reinforcing phase distributed within it.

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