An impact and wear resistant flux cored wire for welding high manganese steel liner plate and a surfacing method

Abstract

The invention discloses a kind of welding high manganese steel lining plate's impact wear resistant flux-cored wire and surfacing method, belong to surface engineering technical field, for the problem such as traditional high manganese steel lining plate brittle crack, surfacing layer peeling and deformation, flux-cored wire: high-carbon chromium iron powder, micro-carbon chromium iron powder, graphite powder, silicon iron powder, manganese iron powder, titanium iron powder, molybdenum iron powder, vanadium iron powder, boron iron powder, calcium fluoride powder, nickel powder, the balance is iron powder;Outer skin is low-carbon cold-rolled steel strip, diameter 2.4~3.2mm, filling rate 42~50%;Surfacing method: pretreatment, drying, adopt plasma arc automatic surfacing: current 135~180A, welding speed 350~650mm / min, wire feeding speed 1800~2200mm / min, compressed gas and protective gas are argon, control high manganese steel lining plate surface temperature;The invention realizes that surfacing layer hardness is high, wear resistance is strong, substrate deformation is small and there is no interface cracking by nickel powder solid solution, calcium fluoride powder weak self-protection.

Description

Technical Field

[0001] This invention belongs to the field of surface engineering technology, specifically relating to a flux-cored welding wire for welding high manganese steel liners with impact and wear resistance, and a welding method thereof. Background Technology

[0002] As a key piece of equipment in industries such as mining and metallurgy, ball mills are subjected to long-term intense impact and abrasive wear from steel balls, materials, and slurry on their inner walls, which are made of high-manganese steel. Traditional high-manganese steel liners, such as Mn13, with a thickness of 50-130mm, have excellent toughness (impact toughness ≥150J / cm²) and strong work hardening ability, with a hardness of up to HB500 after work hardening. However, in the initial stage of ball mill operation, the insufficient hardness leads to extremely rapid and severe impact and wear of the liner by the abrasive. This causes the liner dimensions to shrink prematurely, resulting in insufficient steel lifting capacity, which in turn leads to a decrease in ball mill efficiency and significantly substandard ball mill operating time. Therefore, frequent replacement of ball mill liners is necessary.

[0003] When existing open-arc automatic surfacing and submerged arc surfacing technologies are used for surfacing high-manganese steel, they often lead to carbide precipitation in the heat-affected zone, reducing impact toughness to <50J / cm², resulting in an extremely high risk of brittle fracture. The surfacing layer can also experience extensive cracking and spalling due to excessive welding stress. Furthermore, due to the large heat input, typically greater than 1.5kJ / mm, the substrate deformation is very severe and difficult to control. In addition, existing surfacing materials often focus on single wear resistance or impact resistance properties, making it difficult to meet the synergistic requirements of ball mill liners for a "high-strength and tough substrate + hardened wear-resistant layer."

[0004] Plasma cladding technology boasts advantages such as strong controllability of penetration depth, fast cladding speed, high production efficiency, and a metallurgically bonded interface between the substrate material and the cladding layer after cladding, resulting in high bonding strength. Furthermore, the cladding process is easily mechanized and automated. However, current research on plasma cladding technology for mining ball mill liners is limited, and most studies still utilize traditional Fe-Cr-C alloy systems for wear-resistant coatings, neglecting the issue of interface cracking between the high-manganese steel substrate and the cladding layer. Patent CN119057304A discloses a plasma cladding flux-cored wire resistant to high-stress impact wear and its preparation method. While the prepared cladding alloy exhibits high impact wear resistance, it does not address the impact of the cladding process on the deformation of the high-manganese steel liner and the cracking of the coating / substrate interface. In addition, although the plasma welding process uses full argon protection and does not require self-protection, in actual production, the large shielding gas pressure often hinders the deoxidation products from floating out of the molten pool, resulting in increased porosity. Therefore, a small amount of calcium fluoride can be used to exert a weak self-protection effect to offset some of the influence of external gas pressure. Summary of the Invention

[0005] The purpose of this invention is to provide a flux-cored welding wire and a welding method for welding high-manganese steel liners on the inner wall of a ball mill cylinder, which achieves low dilution rate, no peeling, and micro-deformation welding of the impact-wear resistant coating on the high-manganese steel liner. Furthermore, the welding wire formulation overcomes the problems of brittle fracture in the heat-affected zone of high-manganese steel and the difficulty of deoxidation products in the weld layer floating out of the molten pool in the prior art.

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

[0007] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance includes an outer sheath and a flux core. The flux core is composed of the following raw materials in weight percentages, the sum of which is 100 wt%: 10-18 wt% high-carbon ferrochrome powder, 25-38 wt% micro-carbon ferrochrome powder, 0.5-2 wt% graphite powder, 1-2 wt% ferrosilicon powder, 1-4 wt% ferromanganese powder, 1.5-3 wt% ferrotitanium powder, 1-5 wt% ferromolybdenum powder, 1-4 wt% ferrovanadium powder, 0.5-5 wt% ferroboron powder, 0.3-1 wt% calcium fluoride powder, 0.5-2 wt% nickel powder, with the remainder being reduced iron 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 42–50%.

[0010] A welding method for welding high manganese steel liners, using the above-mentioned flux-cored welding wire for welding high manganese steel liners with impact and wear resistance;

[0011] Step 1: Pre-treat the surface of the high manganese steel liner to remove oil and rust from the workpiece surface;

[0012] Step 2: Place the above-mentioned flux-cored welding wire in a heating furnace for drying and dehumidification;

[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 350-650mm / min, wire feed speed 1800-2200mm / min; the wire feed method is off-axis wire feed.

[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, in step 3, both the compressed gas and the protective gas are argon with a purity of ≥99.99%, the flow rate of the compressed gas is 3-7 L / min, and the flow rate of the selected protective gas is 5-12 L / min.

[0016] Further, in step 2, the above-mentioned flux-cored welding wire is placed in a heating furnace at 150-250°C for 1-2 hours to dry and dehumidify.

[0017] Furthermore, the microstructure of the high-manganese steel liner after plasma cladding consists of an iron-based solid solution and a multi-component reinforcing phase uniformly distributed therein.

[0018] Furthermore, the hardness of the weld overlay of the high manganese steel liner after plasma welding reaches 55-62 HRC, and its wear resistance against impact wear is 1.44-1.88 times that of the original high manganese steel liner.

[0019] This invention addresses the interface compatibility issue between high-manganese steel liners and weld overlays by introducing 0.5–2 wt% nickel powder for solid solution strengthening. Nickel atoms dissolved in the γ-Fe matrix effectively reduce the coefficient of linear expansion of the weld overlay itself, alleviating interfacial stress generated during cooling due to the difference in thermal expansion between the coating and the substrate, thereby suppressing the tendency for interfacial cracking. However, excessive nickel powder addition increases manufacturing costs and leads to lower hardness in the weld overlay. Furthermore, the addition of 0.3–1 wt% calcium fluoride powder to the flux core decomposes at the high temperature of plasma welding, generating trace amounts of active gas, forming a weak self-protective effect. This partially offsets the hindering effect of the applied argon protective pressure on the flotation of deoxidation products in the molten pool, ensuring the smooth escape of Si and Mn deoxidation products and reducing the porosity of the weld overlay to 0.5–0.8%. The weld overlay microstructure consists of an iron-based solid solution and a uniformly distributed multi-component strengthening phase, resulting in good impact and wear resistance. By controlling the heat input of the welding process, the surface temperature of the high-manganese steel liner plate 5cm away from the molten pool is controlled at 150-280℃. The weld layer and the substrate are metallurgically bonded with no cracks at the interface. The overall deformation of the high-manganese steel liner plate is ≤2mm, achieving a balance between wear resistance improvement of more than 1.4 times and structural integrity.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] 1. This invention provides a flux-cored welding wire for welding high-manganese steel liners on the inner wall of a ball mill cylinder, which can fully utilize the solid solution strengthening effect of Fe and Ni to effectively alleviate cracking at the coating / substrate interface caused by the difference in linear expansion coefficients.

[0022] 2. The present invention adds a small amount of calcium fluoride powder (≤1wt%) to the flux-cored welding wire to achieve a weak self-protection effect. This can generate a protective gas in the molten pool to offset part of the external protective gas pressure and ensure that the deoxidation products float out of the molten pool normally, while also effectively preventing the porosity of the molten pool from exceeding 1%.

[0023] 3. By controlling the welding process, this invention ensures a low deformation of the high-manganese steel substrate (≤2mm), which facilitates its subsequent installation inside the ball mill cylinder.

[0024] 4. The single-layer (approximately 3 mm thick) plasma overlay coating prepared by this invention exhibits a good metallurgical bond with the substrate, and the coating hardness reaches 55-62 HRC, thereby improving the impact and wear resistance of the liner material. Attached Figure Description

[0025] Figure 1 This is a microstructure diagram of the impact-wear resistant coating surface prepared by plasma cladding in Example 1 of the present invention.

[0026] Figure 2 This is a microstructure image of the impact-wear resistant coating / substrate interface prepared by plasma cladding in Example 2 of the present invention.

[0027] Figure 3 This is a comparison diagram of the weight loss of the high-manganese steel liner with impact and wear resistant coating in Embodiment 3 of the present invention and the original high-manganese steel liner.

[0028] Figure 4 This image shows the longitudinal deformation of a high-manganese steel liner after plasma welding, as shown in Embodiment 5 of the present invention.

[0029] Figure 5 This is a picture showing the longitudinal deformation of a high-manganese steel liner after plasma welding, which is a comparative example of the present invention.

[0030] Figure 6 Image of a high-manganese steel liner plate before plasma welding.

[0031] Figure 7 The image shows the metallographic structure of the impact-wear resistant coating of Comparative Example 4 without added calcium fluoride powder.

[0032] Figure 8 Metallographic diagram of the impact and wear resistant coating of Comparative Example 5 with added excess calcium fluoride powder.

[0033] Figure 9 This is a metallographic diagram of the impact-wear resistant coating of Example 4.

[0034] Figure 10 The image shows the microstructure of the impact-resistant coating without nickel powder in Comparative Example 6. Detailed Implementation

[0035] 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.

[0036] The raw materials used in this invention are:

[0037] The high manganese steel liner is made of ZGMn13 high manganese steel. Before plasma cladding, the edges of the high manganese steel liner are warped upwards by 20.0mm from the horizontal line.

[0038] High-carbon ferrochrome contains 7% to 9% C and ≥60% Cr, with a powder particle size range of 60 to 325 mesh;

[0039] Micro-carbon ferrochrome contains 3% to 6% C and ≥55% Cr, with a powder particle size range of 60 to 325 mesh;

[0040] Graphite powder contains ≥98% C, and the powder particle size ranges from 60 to 200 mesh;

[0041] Ferrosilicon powder contains ≥72% Si, and the powder particle size ranges from 60 to 200 mesh;

[0042] The manganese-iron powder contains 65%–72% Mn and 1–1.5% C, with a particle size range of 60–200 mesh.

[0043] The titanium iron powder contains 35% to 45% Ti and ≤8% Al, and the powder particle size ranges from 60 to 200 mesh.

[0044] The ferromolybdenum powder contains ≥60% Mo, and the powder particle size ranges from 60 to 200 mesh.

[0045] The vanadium-iron powder contains 40% to 55% V, and the powder particle size ranges from 60 to 200 mesh.

[0046] Boron iron powder contains 9-25% B and ≤0.1% C, and the powder particle size ranges from 60 to 200 mesh.

[0047] The nickel powder contains ≥98% Ni, and the powder particle size ranges from 60 to 200 mesh;

[0048] Calcium fluoride powder contains ≥96% CaF2, and the powder particle size ranges from 60 to 200 mesh;

[0049] Reduced iron powder contains ≥98% Fe, and the powder particle size ranges from 60 to 325 mesh.

[0050] Example 1

[0051] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 12.3 wt% high-carbon ferrochrome powder, 28.5 wt% low-carbon ferrochrome powder, 1.3 wt% graphite powder, 1.2 wt% ferrosilicon powder, 2.5 wt% ferromanganese powder, 1.6 wt% ferrotitanium powder, 2.7 wt% ferromolybdenum powder, 1.4 wt% ferrovanadium powder, 0.8 wt% ferroboronium powder, 1.1 wt% nickel powder, 0.8 wt% calcium fluoride powder, and the balance being reduced iron powder. 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%.

[0052] A welding method for welding high manganese steel liners involves placing the flux-cored welding wire in a heating furnace at 150°C for 2 hours to dry and dehumidify.

[0053] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0054] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 140A, the welding speed was 380mm / min, and the wire feed speed was 1850mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.99% pure argon gas, with a selected compressed gas flow rate of 4L / min and a selected shielding gas flow rate of 8L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool was 169℃.

[0055] like Figure 1 The microstructure of the impact and wear resistant coating prepared by plasma cladding shows that various hard phases are evenly distributed on the iron matrix, which plays a key role in improving wear resistance, and the porosity is 0.8%.

[0056] The longitudinal deformation before and after plasma cladding is 1.4 mm.

[0057] The coating hardness, measured using a Rockwell hardness tester, is 56.2 HRC.

[0058] Impact wear tests were conducted using an MLD-10 impact wear testing machine. The impact hammer mass was 10 kg, the impact load was 5 J, and the grinding pair was made of 45# steel. The test sample was loaded onto the impact hammer head and impacted downwards at a rate of 200 impacts / min and a grinding pair rotation speed of 200 r / min. The abrasive added was refined silica sand (particle size 1.50–2.36 mm) at a flow rate of 40 kg / h. The impact wear time was 5 h. The mass loss of the sample 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 1.1273 g of mass during impact wear, while the high-manganese steel liner with a weld overlay lost only 0.7831 g. The impact wear resistance of the high-manganese steel liner in this embodiment was 1.44 times that of the high-manganese steel liner in this example.

[0059] Example 2

[0060] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 14.2 wt% high-carbon ferrochrome powder, 30.1 wt% micro-carbon ferrochrome powder, 1.7 wt% graphite powder, 1.5 wt% ferrosilicon powder, 3.1 wt% ferromanganese powder, 2.2 wt% ferrotitanium powder, 4.5 wt% ferromolybdenum powder, 2.5 wt% ferrovanadium powder, 1.6 wt% ferroboronium powder, 0.7 wt% nickel powder, 0.5 wt% calcium fluoride powder, and the balance being reduced iron powder. 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%.

[0061] A welding method for welding high manganese steel liner plates involves placing the flux-cored welding wire in a heating furnace at 175°C for 1.75 hours to dry and dehumidify.

[0062] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0063] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 160A, the welding speed was 420mm / min, and the wire feed speed was 1890mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.99% pure argon gas, with a selected compressed gas flow rate of 5L / 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 was 183℃.

[0064] The plasma-bonded coating / substrate interface exhibits a good metallurgical bond, with no cracking observed at the interface. Figure 2 As shown.

[0065] The longitudinal deformation before and after plasma cladding is 1.5 mm.

[0066] The coating hardness, measured using a Rockwell hardness tester, was 57.8 HRC, and the porosity was 0.7%.

[0067] The impact wear test was the same as in Example 1. The results showed that the high manganese steel liner lost 1.1090g of weight during impact wear, while the high manganese steel liner with the weld overlay lost only 0.7165g of weight during impact wear. The wear resistance of the high manganese steel liner in this example was 1.55 times that of the high manganese steel liner in this example.

[0068] Example 3

[0069] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 15.8 wt% high-carbon ferrochrome powder, 32.2 wt% micro-carbon ferrochrome powder, 0.8 wt% graphite powder, 1.2 wt% ferrosilicon powder, 3.6 wt% ferromanganese powder, 2.5 wt% ferrotitanium powder, 3.7 wt% ferromolybdenum powder, 3.2 wt% ferrovanadium powder, 2.5 wt% ferroboronium powder, 1.1 wt% nickel powder, 0.9 wt% calcium fluoride powder, and the balance being reduced iron powder. 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%.

[0070] A welding method for welding high manganese steel liner plates involves placing the flux-cored welding wire in a heating furnace at 200°C for 1.5 hours to dry and dehumidify.

[0071] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0072] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 165A, the welding speed was 480mm / min, and the wire feed speed was 2020mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.999% pure argon gas, with a selected compressed gas flow rate of 6L / min and a selected shielding gas flow rate of 8L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool was 212℃.

[0073] The longitudinal deformation before and after plasma cladding is 1.7 mm.

[0074] The coating hardness, measured using a Rockwell hardness tester, was 59.4 HRC, and the porosity was 0.6%.

[0075] The impact wear test was the same as in Example 1. The results showed that the impact wear loss of the high-manganese steel liner was 1.0895g, while that of the high-manganese steel liner with the weld overlay was only 0.6042g. The impact wear resistance of the high-manganese steel liner in this example was 1.80 times that of the liner in this example. The impact wear loss of the two is as follows: Figure 3 .

[0076] Example 4

[0077] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 16.5 wt% high-carbon ferrochrome powder, 35.5 wt% micro-carbon ferrochrome powder, 1.4 wt% graphite powder, 1.5 wt% ferrosilicon powder, 1.8 wt% ferromanganese powder, 1.8 wt% ferrotitanium powder, 2.1 wt% ferromolybdenum powder, 1.3 wt% ferrovanadium powder, 4.6 wt% ferroboronium powder, 1.5 wt% nickel powder, 0.7 wt% calcium fluoride powder, and the balance being reduced iron powder. The flux-cored welding wire prepared by cold rolling and drawing process has a diameter of 2.8 mm and a filler content of 48%.

[0078] A welding method for welding high manganese steel liner plates involves placing the flux-cored welding wire in a heating furnace at 225°C for 1.25 hours to dry and dehumidify.

[0079] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0080] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 170A, the welding speed was 520mm / min, and the wire feed speed was 2050mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.999% pure argon gas, with a selected compressed gas flow rate of 6L / min and a selected shielding gas flow rate of 8L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool was 256℃.

[0081] The longitudinal deformation before and after plasma cladding is 1.8 mm.

[0082] The coating hardness, measured using a Rockwell hardness tester, was 60.5 HRC, and the porosity was 0.5%. Figure 9 As shown.

[0083] The impact wear test was the same as in Example 1. The results showed that the high manganese steel liner lost 1.1141g of weight during impact wear, while the high manganese steel liner with the weld overlay lost only 0.5986g. The impact wear resistance was 1.86 times that of the high manganese steel liner in this example.

[0084] Example 5

[0085] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 17.3 wt% high-carbon ferrochrome powder, 37.2 wt% low-carbon ferrochrome powder, 1.8 wt% graphite powder, 1.7 wt% ferrosilicon powder, 2.8 wt% ferromanganese powder, 1.8 wt% ferrotitanium powder, 4.4 wt% ferromolybdenum powder, 3.8 wt% ferrovanadium powder, 4.1 wt% ferroboronium powder, 0.9 wt% nickel powder, 0.5 wt% calcium fluoride powder, and the balance being reduced iron powder. 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%.

[0086] A welding method for welding high manganese steel liner plates involves placing the above-mentioned flux-cored welding wire in a heating furnace at 250°C for 1 hour to dry and dehumidify.

[0087] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0088] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 175A, the welding speed was 580mm / min, and the wire feed speed was 2130mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.999% pure argon gas, with a selected compressed gas flow rate of 6L / min and a selected shielding gas flow rate of 7L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool was 271℃.

[0089] The longitudinal deformation before and after plasma cladding is 1.9 mm.

[0090] The coating hardness, measured using a Rockwell hardness tester, was 61.4 HRC, and the porosity was 0.5%.

[0091] The impact wear test was the same as in Example 1. The results showed that the high manganese steel liner lost 1.0764g of weight during impact wear, while the high manganese steel liner with the weld overlay lost only 0.5739g of weight during impact wear. The wear resistance of the high manganese steel liner in this example was 1.88 times that of the high manganese steel liner in this example.

[0092] Example 6

[0093] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 10.1 wt% high-carbon ferrochrome powder, 37.2 wt% micro-carbon ferrochrome powder, 0.5 wt% graphite powder, 2 wt% ferrosilicon powder, 1.1 wt% ferromanganese powder, 3 wt% ferrotitanium powder, 0.9 wt% ferromolybdenum powder, 4.1 wt% ferrovanadium powder, 0.5 wt% ferroboronium powder, 2.1 wt% nickel powder, 0.3 wt% calcium fluoride powder, and the balance being reduced iron powder. 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%.

[0094] A welding method for welding high manganese steel liner plates involves placing the above-mentioned flux-cored welding wire in a heating furnace at 250°C for 1 hour to dry and dehumidify.

[0095] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0096] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 155A, the welding speed was 550mm / min, and the wire feed speed was 2060mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.999% pure argon gas, with a selected compressed gas flow rate of 5L / min and a selected shielding gas flow rate of 8L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool was 252℃.

[0097] Example 7

[0098] A flux-cored welding wire for welding high-manganese steel liners with impact and wear resistance comprises a low-carbon cold-rolled steel strip outer sheath and flux powder. The flux powder composition and proportions are as follows: 18.1 wt% high-carbon ferrochrome powder, 24.8 wt% low-carbon ferrochrome powder, 2.2 wt% graphite powder, 0.9 wt% ferrosilicon powder, 4.1 wt% ferromanganese powder, 1.5 wt% ferrotitanium powder, 5.1 wt% ferromolybdenum powder, 0.9 wt% ferrovanadium powder, 4.9 wt% ferroboronium powder, 0.5 wt% nickel powder, 0.6 wt% calcium fluoride powder, and the balance being reduced iron powder. 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%.

[0099] A welding method for welding high manganese steel liner plates involves placing the flux-cored welding wire in a heating furnace at 200°C for 1.5 hours to dry and dehumidify.

[0100] Pre-treat the surface of the high manganese steel liner (grind with an angle grinder or sandblasting) to remove oil and rust from the workpiece surface.

[0101] Plasma cladding was performed on a high-manganese steel liner using this flux-cored welding wire. The welding current was 175A, the welding speed was 500mm / min, and the wire feed speed was 2100mm / min. The wire feed method was off-axis wire feed. Both the compressed gas and the shielding gas were 99.999% pure argon gas. The selected flow rate of the compressed gas was 6L / min, and the selected flow rate of the shielding gas was 9L / min. The surface temperature of the high-manganese steel liner at a distance of 5cm from the molten pool was 231℃.

[0102] Comparative Example

[0103] Three comparative experiments were conducted, namely Comparative Example 1, Comparative Example 2, and Comparative Example 3, using the welding wire formulation of Example 5, to verify the effects of welding current, wire feed speed, and high manganese steel liner surface temperature control on the process of this invention. Generally, wire feed speed and welding speed are positively correlated, that is, a higher wire feed speed will result in a higher welding speed. Therefore, the welding speed is not listed. The other parameters are the same as in Example 5. The comparative results are shown in the table below:

[0104]

[0105] like Figure 4 and Figure 5 The figures show the longitudinal deformation of the high-manganese steel liner before and after plasma welding in Embodiment 5 and Comparative Example 1, respectively. Comparative Example 1 shows a larger deformation. Before plasma welding, the original high-manganese steel liner's edges were warped upwards by 20.0 mm from the horizontal line. Figure 6 As shown.

[0106] Comparative Example 4

[0107] No calcium fluoride powder was added; otherwise, it was the same as in Example 1.

[0108] The longitudinal deformation before and after plasma cladding is 1.4 mm.

[0109] The coating hardness, measured using a Rockwell hardness tester, is 53.2 HRC.

[0110] like Figure 7 As shown, the porosity of the weld overlay is 2.7%.

[0111] The impact wear test was the same as in Example 1. The results showed that the high manganese steel liner lost 1.1198g of weight during impact wear, while the high manganese steel liner with the weld overlay lost 0.8875g of weight during impact wear. The wear resistance of the impact wear was only 1.26 times that of the original. This is because the substrate around the pores in the weld overlay is more susceptible to abrasive particles and peels off during the wear process.

[0112] Comparative Example 5

[0113] Add 2.8 wt% calcium fluoride powder, and the rest is the same as in Example 1.

[0114] The longitudinal deformation before and after plasma cladding is 1.4 mm.

[0115] The coating hardness, measured using a Rockwell hardness tester, is 54.7 HRC.

[0116] like Figure 8 As shown, the porosity of the weld overlay is 2.3%.

[0117] The impact wear test was the same as in Example 1. The results showed that the impact wear loss of the high manganese steel liner was 1.1207g, while that of the high manganese steel liner with the weld overlay was 0.8336g. The impact wear resistance was only 1.34 times that of the original.

[0118] Comparative Example 6

[0119] Without adding nickel powder, the rest is the same as in Example 2. Figure 10 As shown in the comparison of the weld overlay / substrate interface in Example 6, cracks can be seen at the interface, which is related to... Figure 2 The contrasting weld overlay / substrate interface in Example 2 demonstrates the effectiveness of adding nickel powder.

[0120] The above comparative experiments demonstrate the beneficial effects of the welding process provided by this invention in preparing well-formed coatings and controlling deformation of high-manganese steel liners.

[0121] The above-described embodiments are merely preferred embodiments of the present invention. It should be noted that the present invention is not limited to the above embodiments. Various changes can be made to the present invention without departing from the technical principles of the present invention. All changes, modifications, substitutions, combinations, and simplifications made based on the spirit and principles of the technical solution of the present invention should be considered as equivalent substitutions, and these changes also fall within the protection scope of the present invention.

Claims

1. A method for surfacing high-manganese steel liners, 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. The flux-cored welding wire includes an outer sheath and a flux core. The flux core is composed of the following raw materials in weight percentage: 10-18 wt% high-carbon ferrochrome powder, 25-38 wt% micro-carbon ferrochrome powder, 0.5-2 wt% graphite powder, 1-2 wt% ferrosilicon powder, 1-4 wt% ferromanganese powder, 1.5-3 wt% ferrotitanium powder, 1-5 wt% ferromolybdenum powder, 1-4 wt% ferrovanadium powder, 0.5-5 wt% ferroboron powder, 0.3-1 wt% calcium fluoride powder, 0.5-2 wt% nickel powder, and the remainder is reduced iron powder. Step 3: The welding equipment used is an automatic plasma arc welding machine. The welding process parameters include: welding current 135-180A, welding speed 350-650mm / min, wire feeding speed 1800-2200mm / min, and wire feeding method is off-axis wire feeding. 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℃.

2. The welding method for high-manganese steel lining plates 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 welding method for high-manganese steel lining plates according to claim 2, characterized in that, The diameter of the flux-cored welding wire is 2.4–3.2 mm, and the filler ratio is 42–50%.

4. The welding method for high-manganese steel liners according to claim 1, characterized in that, In step 3, both the compressed gas and the protective gas are argon with a purity of ≥99.99%. The flow rate of the compressed gas is 3-7 L / min, and the flow rate of the selected protective gas is 5-12 L / min.

5. The welding method for high-manganese steel lining plates according to claim 1, characterized in that, In step 2, the above-mentioned flux-cored welding wire is placed in a heating furnace at 150-250°C for 1-2 hours to dry and dehumidify.

6. The welding method for high-manganese steel liners according to claim 1, characterized in that, The microstructure of the high-manganese steel liner after plasma cladding consists of an iron-based solid solution and a multi-component reinforcing phase uniformly distributed within it.

7. The welding method for high-manganese steel liners according to claim 1, characterized in that, The hardness of the weld overlay of the high manganese steel liner after plasma welding reaches 55-62 HRC, and its wear resistance against impact wear is 1.44-1.88 times that of the original high manganese steel liner.

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