A wear-resistant welding wire and its application method

Abstract

This invention discloses a wear-resistant welding wire and its application method. The welding wire contains Co: 0.1-7.0%, Cr: 5.0-9.0%, and C: 0.15-0.4%, with (Cr,Fe)7C3 type carbides dispersed throughout. The average particle size of the (Cr,Fe)7C3 type carbides is 0.2-10 μm, and the mass ratio of Cr to C in the welding wire is 20-50. The manufacturing process of the welding wire includes: smelting and alloying, casting and rolling, heat treatment, drawing, and surface treatment. This invention solves the technical problems of uneven carbide distribution, insufficient wear resistance, and difficulty in balancing wear resistance and toughness in existing wear-resistant welding wires.

Description

Technical Field

[0001] This invention relates to the field of welding materials technology, and more specifically, to a wear-resistant welding wire and a method for manufacturing and using the welding wire. Background Technology

[0002] In industries such as mining machinery, cement manufacturing, steel metallurgy, and power generation, many pieces of equipment and components operate under conditions of high wear and high impact for extended periods. Examples include crusher hammers, excavator bucket teeth, and coal mill roller sleeves, which suffer from severe surface wear and short service lives. Using wear-resistant welding technology to repair failed components or to pre-protect new products is an effective way to extend equipment lifespan and reduce production costs.

[0003] The welding wire used for wear-resistant surfacing is a key factor determining the wear resistance of the weld overlay. Existing wear-resistant welding wires typically employ a high-chromium cast iron alloy system, improving wear resistance by forming a large number of high-hardness M7C3 carbides in the weld overlay. However, traditional high-chromium cast iron welding wires have the following shortcomings: firstly, the carbides are coarse and unevenly distributed, affecting the toughness and impact resistance of the weld overlay; secondly, their high-temperature wear resistance is insufficient, with a significant decrease in hardness under high-temperature conditions; and thirdly, the alloy system design is not optimized enough, making it difficult to balance good welding process performance and excellent wear resistance.

[0004] In the metal heat treatment industry, because the heat treatment temperature is higher than 850℃, the wear resistance and toughness of the weld after heat treatment are difficult to meet production requirements.

[0005] Therefore, developing a wear-resistant welding wire with good wear resistance, toughness, and welding process performance has important practical application value. Summary of the Invention

[0006] Technical problems to be solved The present invention aims to solve the technical problems of uneven carbide distribution, insufficient high-temperature wear resistance, and difficulty in balancing wear resistance and toughness in the existing wear-resistant welding wire, and provides a wear-resistant welding wire and its preparation method.

[0007] Technical solution To achieve the above objectives, the present invention provides a wear-resistant welding wire, which, by mass percentage, contains Co: 0.1-7.0%, Cr: 5.0-9.0%, C: 0.15-0.4%, and Fe, with (Cr,Fe) 7C3 type carbides dispersed in the welding wire.

[0008] Furthermore, the welding wire also contains W: 0.1-5.0% by mass percentage, wherein W exists in a solid solution state and in the form of WC.

[0009] Furthermore, by mass percentage, the welding wire also contains Ni: 6.0-9.0%, Mn: 1.0-2.0%, and Si: 0.1-1.0%.

[0010] Furthermore, the average particle size of the (Cr,Fe)7C3 type carbide is 0.2-10 μm, and the mass ratio of Cr to C in the welding wire is 20-50.

[0011] Furthermore, the average particle size of the WC is 0.5-10 μm.

[0012] Furthermore, by mass percentage, the welding wire also contains at least one of the following elements: V: 0.1-2.0%, Nb: 0.05-1.0%, Mo: 0.01-1.5%; and, apart from unavoidable impurities, it does not contain any other intentionally added alloying elements.

[0013] Furthermore, the wear-resistant welding wire is a solid welding wire.

[0014] Furthermore, the solid welding wire manufacturing process includes: melting and alloying, casting and rolling, heat treatment, drawing, and surface treatment.

[0015] Furthermore, the wear-resistant welding wire is deposited onto a steel plate or steel part using a gas shielded self-fusion welding method, wherein the welding current is 100-240A, the welding voltage is 20-30V, the welding speed is 3-6mm / s, and the shielding gas is a mixture of 80%Ar and 20%CO2.

[0016] A method for using wear-resistant welding wire, characterized by comprising: butt-jointing the edges of at least two steel plates, the thickness of the steel plates being 0.5-5.0 mm; using the wear-resistant welding wire to perform laser filler welding at the butt joint of the steel plate edges to form a weld seam, thereby obtaining a welded steel plate, wherein the welding speed is 30-140 mm / s, the wire feed speed is 20-150 mm / s, and the laser power is 2-10 kW; heating the welded steel plate to 850-950℃ to fully austenitize it; then hot pressing and quenching; after quenching, the elongation of the welded steel plate is greater than 4%.

[0017] The present invention also provides a wear-resistant weld overlay layer, which is formed by weld overlay using the wear-resistant welding wire described in any of the above claims.

[0018] The present invention also provides a high-temperature resistant and wear-resistant weld, wherein laser welding is performed at the joint of at least two steel plates, and the welding wire is filled during the welding process to form a weld between the edge of the plate and the welding wire, and the weld can withstand a high temperature of 850°C to 950°C.

[0019] Beneficial effects Compared with the prior art, the present invention has the following beneficial effects: 1. By optimizing the ratio of elements such as Co, Cr, and C, the occurrence of coarse carbides is avoided, and the toughness of the weld overlay and weld is improved while ensuring high hardness.

[0020] 2. Excellent high-temperature wear resistance: By adding an appropriate amount of Co, the high-temperature hardness and wear resistance of the weld overlay and weld are improved; at the same time, W is added and exists in the form of solid solution and WC. WC particles act as a hard phase to further improve wear resistance, and solid solution W plays a solid solution strengthening role, so that the welding wire still maintains excellent wear resistance under high-temperature conditions.

[0021] 3. Excellent welding process performance: By adding Ni, Mn and Si elements, welding spatter is reduced, making the welding wire suitable for various welding processes such as gas shielded autogenous welding and laser welding. Mn can play a role in solid solution strengthening, Mn and Si can play a role in deoxidation, and Ni plays a crucial role in improving toughness.

[0022] 4. Excellent comprehensive mechanical properties: By controlling the Cr / C mass ratio to 20-50, the quantity and morphology of carbides are optimized; through the synergistic effect of multiple elements such as Co, Ni, Mn, and Si, the weld overlay and weld have high hardness, good toughness, and excellent wear resistance. Attached Figure Description

[0023] Figure 1 The image shows the welded steel plate obtained in Embodiment 2 of the present invention, with the weld seam in the center.

[0024] Figure 2 This is a schematic diagram of the dispersed distribution of (Cr,Fe)7C3 type carbides.

[0025] Figure 3 This is a schematic diagram showing the uneven distribution of coarse carbides. Detailed Implementation

[0026] To further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0027] The present invention provides a wear-resistant welding wire, which contains, by mass percentage, Co: 0.1-7.0%, Cr: 5.0-9.0%, C: 0.15-0.4%, and Fe, and (Cr,Fe)7C3 type carbides are dispersed in the welding wire.

[0028] Furthermore, the welding wire also contains W: 0.1-5.0% by mass percentage, wherein W exists in a solid solution state and in the form of WC, and the mass ratio of W to C is 4-12.

[0029] Furthermore, by mass percentage, the welding wire also contains Ni: 6.0-9.0%, Mn: 1.0-2.0%, and Si: 0.1-1.0%.

[0030] Furthermore, the average particle size of the (Cr,Fe)7C3 type carbide is 0.2-10 μm, and the mass ratio of Cr to C in the welding wire is 20-50.

[0031] Furthermore, the average particle size of the WC is 0.5-10 μm.

[0032] Furthermore, the mass ratio of W to C is 6-10.

[0033] Furthermore, by mass percentage, the welding wire also contains at least one of the following elements: V: 0.1-2.0%, Nb: 0.05-1.0%, Mo: 0.01-1.5%; and, apart from unavoidable impurities, it does not contain any other intentionally added alloying elements.

[0034] Furthermore, the wear-resistant welding wire is a solid welding wire.

[0035] Furthermore, the solid welding wire manufacturing process includes: melting and alloying, casting and rolling, heat treatment, drawing, and surface treatment.

[0036] Furthermore, the wear-resistant welding wire is deposited onto a steel plate or steel part using a gas shielded self-fusion welding method, wherein the welding current is 100-240A, the welding voltage is 20-30V, the welding speed is 3-6mm / s, and the shielding gas is a mixture of 80%Ar and 20%CO2.

[0037] A method for using wear-resistant welding wire, characterized by comprising: butt-jointing the edges of at least two steel plates, the thickness of which is 0.5-5.0 mm; using the wear-resistant welding wire to perform laser filler welding at the butt joint of the steel plates to form a weld seam, thereby obtaining a welded steel plate, wherein the welding speed is 30-140 mm / s, the wire feed speed is 20-150 mm / s, and the laser power is 2-10 kW; heating the welded steel plate to 850-950℃, the heating temperature needing to be higher than the complete austenitizing temperature of the welded steel plate to achieve complete austenitization; then hot pressing and quenching; after quenching, the elongation of the welded steel plate is greater than 4%.

[0038] Methods for measuring the full austenitizing temperature (AC3): The full austenitizing temperature of a steel plate or weld is measured by thermal expansion method (DIL) or differential scanning calorimetry (DSC).

[0039] Optionally, the complete austenitizing temperature (AC3) of the steel plate or weld can be calculated using an empirical formula: AC3 = 854 - 180°C + 44Si - 14Mn - 17Cr - 18Ni, where C, Si, Mn, Cr, and Ni are the contents of each element in the steel plate or weld expressed as a mass percentage, and elements not present are counted as having a content of 0.

[0040] The method for manufacturing solid welding wire of the present invention: (1) Smelting and alloying Raw materials are weighed according to the designed proportions. These raw materials include industrial pure iron, metallic cobalt, metallic chromium, carbon, ferrotungsten, nickel, ferromanganese, ferrosilicon, and the required ferrovanadium, ferroniobium, or ferromolybdenum. The raw materials are sequentially fed into a vacuum induction melting furnace for melting. The melting temperature is controlled at 1600-1650℃. After the raw materials are completely melted, deoxidation and desulfurization refining are carried out to obtain an alloy melt.

[0041] The order and method of adding alloying elements during smelting are as follows: Step 1 involves adding a portion of nickel, all pure iron, all metallic chromium, and all metallic cobalt, then loading the mixture into a vacuum induction melting furnace to form the molten pool base. The furnace temperature is 1450 - 1550°C.

[0042] Step 2: Add ferrotungsten, ferromolybdenum, ferrovanadium, and ferroniobium, and heat the furnace to 1450-1550°C.

[0043] Step 3: Add the remaining nickel, which should be added gradually during the melting of the furnace charge.

[0044] Step 4: After all the furnace charge has been melted and cleared, it is refined at a temperature of 1500-1580℃ and a vacuum degree of ≤10Pa for 20-40 minutes to remove gaseous impurities such as O, N, and H.

[0045] Step 5: Lower the temperature of the molten pool and add carbon, ferrosilicon, and ferromanganese for final deoxidation.

[0046] In the above order and method of adding elements, elements not present in the target welding wire do not need to be added.

[0047] (2) Casting and rolling The alloy melt obtained in step (1) is cast into steel ingots or continuous casting billets, and the casting temperature is controlled at 1500-1550℃. After heating the billet to 1100-1200℃, it is rolled into a wire rod with a diameter of 5.0-6.5mm. The initial rolling temperature is not lower than 1050℃, and the final rolling temperature is controlled at 850-900℃.

[0048] (3) Heat treatment The rolled wire rod is subjected to softening annealing treatment at a temperature of 700-800℃ and a holding time of 0.5-6 hours. It is then cooled to room temperature in the furnace to eliminate rolling stress, reduce hardness, and facilitate subsequent drawing.

[0049] (4) Pulling The annealed wire rod is drawn in multiple passes, 6-12 passes in total. After every 2-4 passes, an intermediate annealing treatment is performed. The annealing temperature is controlled between AC1+20℃ and AC1+50℃, where AC1 is the temperature at which pearlite begins to transform into austenite. AC1 = 750.2 - 26.6 × C + 17.6 × Si - 11.6 × Mn - 22.9 × Cu - 23 × Ni + 24.1 × Cr + 22.5 × Mo - 39.7 × V - 5.7 × Ti + 232. 4×Nb-169.4×Al, where C, Si, Mn, Cu, Ni, Cr, Mo, V, Ti, Nb, and Al are the contents of each element in the welding wire expressed as a mass percentage, and elements not contained are calculated as 0; the holding time is 0.5-6 hours, and after cooling in the furnace to below 300℃, it is air-cooled to room temperature, with a total diameter reduction rate of 70-90%, and the diameter reduction rate of each pass is controlled at 15-25%, with a drawing speed of 3-8m / s, and finally drawn to a welding wire with a diameter of 1.0mm-1.6mm.

[0050] (5) Surface treatment The drawn welding wire is surface treated to obtain the finished wear-resistant welding wire.

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below with reference to specific embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0052] Example 1 This embodiment provides a wear-resistant welding wire with the following chemical composition by mass percentage: Co: 3.5%, Cr: 7.2%, C: 0.28%, W: 2.5%, Ni: 7.5%, Mn: 1.5%, Si: 0.5%, V: 0.8%, with the balance being iron and unavoidable impurities. The W / C mass ratio is 8.9, and the Cr / C mass ratio is 25.7.

[0053] The welding wire is a solid welding wire with a diameter of 1.2 mm.

[0054] The above-mentioned wear-resistant welding wire was used to perform gas shielded self-fusion welding on 45# steel plate. The welding current was 220A, the welding voltage was 28V, the welding speed was 5mm / s, and the shielding gas was 80%Ar+20%CO2.

[0055] Performance testing of the weld overlay: Hardness of weld overlay (HRC): 62; Relative wear resistance (relative to Q235 steel): 8.5; Average particle size of carbides: 3.2 μm; Metallographic observation shows that the (Cr,Fe)7C3 type carbides are diffusely and uniformly distributed, with no large carbide aggregates observed.

[0056] Example 2 This embodiment provides a wear-resistant welding wire with the following chemical composition by mass percentage: Co: 5.0%, Cr: 6.5%, C: 0.22%, W: 1.2%, Ni: 8.0%, Mn: 1.2%, Si: 0.4%, Mo: 0.03%, with the balance being iron and unavoidable impurities. The W / C mass ratio is 5.5, and the Cr / C mass ratio is 29.5.

[0057] The welding wire is a solid welding wire, which is prepared by vacuum melting, rolling, heat treatment, drawing and surface treatment processes, and the final diameter is 1.2mm.

[0058] Laser welding was performed on two 34MnB5 steel plates using the aforementioned wear-resistant welding wire, forming a weld at the butt joint of the two plates. The plate thickness was 1.6 mm. The laser power was 5.5 kW, the wire feed speed was 65 mm / s, the welding speed was 70 mm / s, and the shielding gas was argon. After welding, the steel plates were heated to 860℃ and held for 5 minutes, followed by hot pressing and quenching. An A80 specimen was cut from the quenched steel plate, with the weld located in the middle of the specimen and perpendicular to its length. The performance requirements for the quenched 34MnB5 steel plate were: tensile strength greater than 1800 MPa and elongation greater than 4%.

[0059] Performance testing of the weld: Weld hardness (HRC): 60; Relative wear resistance (relative to Q235 steel): 7.8; Average particle size of carbides: 2.8 μm; Tensile test: Failure occurs in the base material, elongation is greater than 4%, and tensile strength is greater than 1800 MPa.

[0060] Metallographic observation shows that the (Cr,Fe)7C3 type carbides are diffusely and uniformly distributed, with no large carbide aggregates observed.

[0061] Example 3 This embodiment provides a wear-resistant welding wire with the following chemical composition by mass percentage: Co: 6.5%, Cr: 5.8%, C: 0.18%, Ni: 7.0%, Mn: 1.4%, Si: 0.3%, with the balance being iron and unavoidable impurities. The Cr / C mass ratio is 32.2.

[0062] The welding wire is a solid welding wire with a diameter of 1.0 mm.

[0063] Laser welding was performed on two 34MnB5 steel plates using the aforementioned wear-resistant welding wire, forming a weld at the butt joint of the two plates. The plates were 1.6 mm thick and had an alloy protective layer on their surfaces. The laser power was 5.2 kW, the wire feed speed was 80 mm / s, the welding speed was 70 mm / s, and the shielding gas was argon. After welding, the steel plates were heated to 860℃ and held for 5 minutes, followed by hot pressing and quenching. An A80 specimen was cut from the quenched steel plate, with the weld located in the middle of the specimen and perpendicular to its length.

[0064] Performance testing of the weld: Weld hardness (HRC): 58; Relative wear resistance (relative to Q235 steel): 7.2; Average particle size of carbides: 2.5 μm; Tensile test: Failure occurs in the base material, elongation is greater than 4%, and tensile strength is greater than 1800 MPa.

[0065] Metallographic observation shows that the (Cr,Fe)7C3 type carbides are diffusely and uniformly distributed, with no large carbide aggregates observed.

[0066] Comparative Example 1 This comparative example provides a wear-resistant welding wire with the following chemical composition by mass percentage: Cr: 12%, C: 0.45%, Ni: 4.5%, Mn: 1.2%, Si: 0.6%, with the balance being iron and unavoidable impurities. It does not contain Co or W. The welding wire is a solid wire with a diameter of 1.6 mm.

[0067] The above-mentioned wear-resistant welding wire was used to perform gas shielded self-fusion welding on 45# steel plate. The welding current was 220A, the welding voltage was 28V, the welding speed was 3.5mm / s, and the shielding gas was 80%Ar+20%CO2.

[0068] Performance testing of the weld overlay: Hardness of weld overlay (HRC): 55; Relative wear resistance (relative to Q235 steel): 5.6; Average particle size of carbides: 12.5 μm; Metallographic observation shows that the carbides are coarse and unevenly distributed, with obvious carbide agglomeration.

[0069] Comparative Example 2 This comparative example provides a wear-resistant welding wire with the following chemical composition by mass percentage: Co: 8.5%, Cr: 7.0%, C: 0.30%, W: 6.5%, Ni: 7.2%, Mn: 1.6%, Si: 0.5%, with the balance being iron and unavoidable impurities. The W / C mass ratio is 21.7. The welding wire is a solid wire with a diameter of 1.2 mm.

[0070] Laser welding was performed on two 34MnB5 steel plates using the aforementioned wear-resistant welding wire, forming a weld at the butt joint of the two plates. The plate thickness was 1.6 mm. The laser power was 5.5 kW, the wire feed speed was 65 mm / s, the welding speed was 70 mm / s, and the shielding gas was argon. After welding, the steel plates were heated to 860℃ and held for 5 minutes, followed by hot pressing and quenching. An A80 specimen was cut from the quenched steel plate, with the weld located in the middle of the specimen and perpendicular to the length of the specimen.

[0071] Performance testing of the weld: Weld hardness (HRC): 66; Relative wear resistance (relative to Q235 steel): 8.1; Average particle size of carbides: 5.8 μm; Tensile test: The failure location was in the weld, the tensile strength was 1560 MPa, and the elongation was 2%.

[0072] Although the hardness and wear resistance are high, the weld overlay shows obvious cracking tendency, poor welding process performance, poor weld formation, tensile strength of less than 1800 MPa, elongation of less than 4%, and the failure location of the tensile test is in the weld, and the tensile test results are unqualified.

[0073] Performance Comparison Analysis The performance test results of each embodiment and comparative example are summarized below: project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Hardness (HRC) 62 60 58 55 66 Relative abrasion resistance 8.5 7.8 7.2 5.6 8.1 Average particle size of carbides (μm) 3.2 2.8 2.5 12.5 5.8 Welding process performance good good good generally Poor (cracked) As can be seen from the above comparison, the (Cr,Fe)7C3 type carbides in the embodiments of the present invention are dispersedly distributed, with fine and uniform carbide particle size. The weld overlay and weld have high hardness and excellent wear resistance, while the welding process performance is good, and the tensile strength and elongation meet the requirements. Comparative Example 1, due to its high Cr and C content and the absence of Co and W, has coarse and unevenly distributed carbides, resulting in lower hardness and wear resistance. Although Comparative Example 2 has higher hardness and wear resistance, its Co and W content exceeds the range of the present invention, and the W / C ratio is too high, leading to deterioration of welding process performance, weld cracks, and tensile strength and elongation not meeting the requirements.

[0074] Industrial applicability The wear-resistant welding wire of this invention can be widely used for surfacing repair and pre-protection of easily worn parts in industries such as mining machinery, cement equipment, iron and steel metallurgy, and power, including crusher hammers, roller surfaces of roller presses, coal mill roller sleeves, and excavator bucket teeth. Surfacing treatment using the welding wire of this invention can significantly extend the service life of equipment, reduce maintenance costs, and has broad market application prospects.

[0075] Meanwhile, the wear-resistant welding wire of the present invention can also be applied to laser filler wire welding, so that the weld has wear resistance and toughness, and is especially suitable for hot stamping laser welding plate welding.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wear-resistant welding wire, characterized in that, The welding wire contains, by mass percentage, Co: 0.1-7.0%, Cr: 5.0-9.0%, C: 0.15-0.4%, and Fe, with (Cr,Fe) 7C3 type carbides dispersed in the welding wire.

2. The wear-resistant welding wire according to claim 1, characterized in that, The welding wire also contains W by weight percentage: 0.1-5.0%, wherein W exists in a solid solution state and in the form of WC.

3. The wear-resistant welding wire according to claim 1 or 2, characterized in that, The welding wire also contains, by mass percentage, Ni: 6.0-9.0%, Mn: 1.0-2.0%, and Si: 0.1-1.0%.

4. The wear-resistant welding wire according to claim 1, characterized in that, The average particle size of the (Cr,Fe)7C3 type carbide is 0.2-10μm, and the mass ratio of Cr to C in the welding wire is 20-50.

5. The wear-resistant welding wire according to claim 2, characterized in that, The average particle size of the WC is 0.5-10 μm.

6. The wear-resistant welding wire according to claim 3, characterized in that, The welding wire, by weight percentage, also contains at least one of the following elements: V: 0.1-2.0%, Nb: 0.05-1.0%, Mo: 0.01-1.5%; and, except for unavoidable impurities, does not contain any other intentionally added alloying elements.

7. The wear-resistant welding wire according to claim 3, characterized in that, The wear-resistant welding wire is a solid welding wire.

8. The wear-resistant welding wire according to claim 7, characterized in that, The manufacturing process of the solid welding wire includes: melting and alloying, casting and rolling, heat treatment, drawing, and surface treatment.

9. The wear-resistant welding wire according to any one of claims 4 to 8, characterized in that, The wear-resistant welding wire is deposited onto a steel plate or steel part using a gas shielded self-fusion welding method, wherein the welding current is 100-240A, the welding voltage is 20-30V, the welding speed is 3-6mm / s, and the shielding gas is a mixture of 80%Ar and 20%CO2.

10. A method of using the wear-resistant welding wire according to any one of claims 4 to 8, characterized in that, include: At least two steel plates are joined at their edges, the steel plates having a thickness of 0.5-5.0 mm. Laser filler wire welding is performed at the joined edges of the steel plates using the wear-resistant welding wire to form a weld, resulting in a welded steel plate. The welding speed is 30-140 mm / s, the wire feed speed is 20-150 mm / s, and the laser power is 2-10 kW. The welded steel plate is heated to 850-950℃ to fully austenitize it. Then, it undergoes hot pressing and quenching. After quenching, the elongation of the welded steel plate is greater than 4%.

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