A chromium-free wear-resistant self-protecting metal powder cored wire, a preparation device and method thereof

Abstract

This invention discloses a chromium-free, wear-resistant, self-protected metal-cored welding wire preparation device, welding wire, and preparation method. The device includes a mixing chamber, a feeding mechanism, a positioning plate, and a driving mechanism. The feeding mechanism is equipped with a dispensing rod and a metering plate. The positioning block on the positioning plate can change with the width of the low-carbon steel strip. Through a guide groove and a driven rod, the metering plate is moved, automatically adjusting the powder feeding amount to adapt to different specifications of steel strips. The driving mechanism uses an inclined groove and a moving rod to make the clamping plate first clamp the steel strip, move it, and then release and reset it. During reset, the dispensing rod is rotated 180° using a rack and gear to complete the fixed-distance, metered feeding, ensuring uniform and continuous powder filling. The welding wire powder is composed of C, Mn, Si, Ni, B, and Fe, etc. After welding, it forms a composite structure dominated by amorphous phase and dispersed nanocrystalline phase, exhibiting chromium-free self-protection, low cost, and good wear resistance.

Description

Technical Field

[0001] This invention relates to the technical field of metal powder-cored welding wire preparation equipment, specifically a chromium-free wear-resistant self-protected metal powder-cored welding wire, preparation device, and method. Background Technology

[0002] Chromium-free wear-resistant self-protected metal powder-cored welding wire is gradually replacing traditional chromium-containing flux-cored welding wire due to its lack of chromium contamination, self-protection for field use, low cost, high cladding efficiency, and excellent wear and impact resistance. It is widely used in machinery manufacturing, mining machinery, oil pipelines and other fields.

[0003] For example, Chinese Patent Publication No. CN120587754A discloses a high-quality preparation device for alloy welding wire, which belongs to the field of alloy welding wire technology. It includes a base, a movable structure at the center of the upper end face of the base, an operating table at the center of the upper end face of the connecting block, a connecting structure at the center of the upper end face of the operating table, three auxiliary structures arranged horizontally at the center of the upper end face of the operating table, a cutting structure at the front center of the center of the two side walls of the operating table, and a positioning structure at the center of the upper end face of the two first sliders.

[0004] In this scheme, during the preparation of alloy welding wire, the welding wire is guided by multiple gear transmissions and positioning wheels to ensure that it can maintain linear motion. However, during the preparation of the welding wire, flux-cored powder needs to be filled into the steel strip. The width of the steel strip used to prepare welding wires of different sizes is different, and the amount of flux-cored powder required is also different. Although it can drive welding wires of different sizes to move linearly, it cannot adaptively adjust the amount of flux-cored powder filling according to the width of different steel strips. Summary of the Invention

[0005] The purpose of this invention is to provide a chromium-free wear-resistant self-protective metal powder core welding wire, its preparation apparatus and method, in order to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A chromium-free wear-resistant self-protected metal powder-cored welding wire preparation device includes a base plate. A mixing chamber is fixedly connected to the upper middle part of the base plate. A feeding mechanism is provided at the lower end of the mixing chamber. A positioning plate is fixedly connected to the upper middle part of the base plate. A low-carbon steel strip is placed in the middle of the positioning plate. Both sides of the positioning plate are provided with driving mechanisms for driving the low-carbon steel strip to move horizontally. When the driving mechanism is horizontally close to the position of the mixing chamber, the feeding mechanism remains stationary. When the driving mechanism is away from the position of the mixing chamber, the feeding mechanism rotates 180° clockwise.

[0007] As a further aspect of the present invention: a stirring rod is rotatably connected to the top of the inner cavity of the mixing chamber, a feeding chamber is fixedly connected to the lower end of the mixing chamber, the feeding mechanism includes a distributing chamber, the outer walls of the distributing chamber and the feeding chamber are fixedly connected, a feeding hopper is fixedly connected to the lower end of the distributing chamber, the lower end face of the feeding hopper is perpendicular to the lower end face of the feeding chamber, and the lower end face of the feeding hopper is parallel to the low carbon steel strip.

[0008] As a further embodiment of the present invention: a distributing rod is rotatably connected to the connection between the distributing bin and the unloading bin; a rotating rod is fixedly connected to the center of both ends of the distributing rod; a support rod is rotatably connected to the outer wall of both ends of the rotating rod; the bottom of the support rod is fixedly connected to the bottom plate; a distributing groove is opened in the middle of the upper end of the distributing rod; and symmetrical metering plates are vertically slidably connected to the inner cavity of the distributing groove.

[0009] As a further aspect of the present invention: a groove is provided in the middle of the rotating rod, a connecting rod is slidably connected to the inner cavity of the groove, a driven ring is fixedly connected to one end of the connecting rod near the support rod, the driven ring is slidably connected to the outer wall of the rotating rod, a symmetrical mounting rod is fixedly connected to one side of the metering plate near the rotating rod, a guide plate is fitted to one side of the mounting rod away from the rotating rod, the symmetrical guide plate is fixedly connected to the connecting rod on the side away from the metering plate, a driven rod is fixedly connected to the middle of the end of the mounting rod away from the metering plate, and a guide groove is provided on the side wall of the guide plate to slide with the driven rod.

[0010] As a further embodiment of the present invention: a symmetrical horizontal rod is slidably connected to the middle of the positioning plate, a positioning block is fixedly connected to the end of the horizontal rod near the hopper, a positioning rod is fixedly connected to the end of the horizontal rod away from the positioning block, the positioning rod and the support rod are elastically connected by a spring, and a symmetrical driven frame is rotatably connected to the outer wall of the driven ring, the lower ends of the symmetrical driven frames are fixedly connected to the positioning rod.

[0011] As a further aspect of the present invention: the driving mechanism includes a driving block, a guide rod is fixedly connected to the middle of one end of the driving block near the support rod, the guide rod is slidably connected to the lower middle of the positioning rod, a T-shaped plate is slidably connected to the side of the driving block away from the guide rod, a clamping plate is provided on the side of the driving block near the low carbon steel strip, the outer wall of the clamping plate near the driving block is slidably connected to the positioning plate, and the spacing between the symmetrical clamping plates is greater than the spacing between the symmetrical positioning blocks.

[0012] As a further embodiment of the present invention: a moving groove is provided in the middle of the side of the driving block near the positioning plate, the outer wall of the clamping plate away from the low carbon steel strip is slidably engaged with the moving groove, the inner cavity of the moving groove is provided with symmetrical inclined grooves, and a moving rod is fixedly connected to the middle of the end of the clamping plate near the driving block, the end of the moving rod is slidably connected to the inner cavity of the inclined groove.

[0013] As a further aspect of the present invention: an L-shaped rod is fixedly connected to the side of the guide rod away from the positioning plate, a fixed rod is fixedly connected to the top of the L-shaped rod, a gear is fixedly connected to the outer wall of the rotating rod near the support rod, the center position of the gear and the center position of the fixed rod are located in the same vertical plane, a receiving groove is provided in the middle of the upper end of the fixed rod away from the L-shaped rod, a rack is provided in the inner cavity of the receiving groove, and the rack and the receiving groove are rotatably connected by symmetrical connecting rods.

[0014] This invention also discloses a chromium-free wear-resistant self-protected metal powder core welding wire. The welding wire is made of core powder and low-carbon steel strip encasing the powder core. The core powder comprises the following components by mass percentage: C: 0.4%-0.6%; Mn: 1.8%-2.2%; Si: 1.0%-1.4%; Ni: 1.5%-1.9%; B: 3.7%-4.3%, with the balance being Fe and unavoidable impurities. After the metal wire is welded, a composite structure of amorphous phase and nanocrystalline phase is formed, with nanocrystalline particle size <100nm and amorphous phase being the performance-dominant phase.

[0015] This invention also discloses a method for preparing chromium-free wear-resistant self-protected metal powder cored welding wire, which is prepared using the aforementioned apparatus for preparing chromium-free wear-resistant self-protected metal powder cored welding wire, and includes the following steps: S1. Add the core powder to the mixing chamber, and use the motor to drive the stirring rod to rotate and fully mix the core powder. After mixing, turn on the switch to allow the mixed core powder to enter the inner cavity of the feeding hopper. S2. The low carbon steel strip is elastically clamped and positioned by symmetrical positioning blocks. Then, through the cooperation of the drive block, clamping plate and guide rod, the position of the clamping plate is automatically adjusted, and the low carbon steel strip is clamped by the clamping plate, which drives the low carbon steel strip to move horizontally with the drive block to complete the conveying of the low carbon steel strip. S3. During the reset process of the drive block, the clamping plate automatically releases the clamping plate from the low-carbon steel strip, and through the cooperation of the rack, receiving groove and connecting rod, the drive gear, rotating rod and distributing rod rotate 180° clockwise during the reset process, quantitatively adding core powder into the inner cavity of the low-carbon steel strip.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The chromium-free wear-resistant self-protected metal powder-cored welding wire preparation device of the present invention features a positioning block that moves a horizontal rod and a positioning rod according to the width of the low-carbon steel strip. This, in conjunction with a guide groove and a driven rod, moves a metering plate closer to / away from the center of the dispensing groove, changing the groove depth. This allows the amount of flux-cored powder added in a single batch to adapt to changes in the width of the low-carbon steel strip. During the welding wire preparation process, the amount of flux-cored powder required for low-carbon steel strips of different widths can be quickly adjusted, facilitating the preparation of chromium-free wear-resistant self-protected welding wires of different sizes. The self-protected metal-cored welding wire is ground; the electric push rod drives the drive block to make horizontal reciprocating motion, and the clamping plate first clamps the steel strip and then conveys it through the inclined groove and moving rod. When resetting, the clamp is first released; when resetting, the rack and gear mesh, driving the rotating rod and the material distribution rod to rotate 180° clockwise to complete the quantitative feeding. The steel strip remains stationary during feeding to ensure that the core powder can be evenly scattered on the steel strip. The intermittent movement distance of the steel strip is fixed to ensure that there is no gap between the filled core powders during the continuous filling process.

[0017] Furthermore, the welding wire of this invention is a metal powder core wire, which is basically slag-free and has higher cladding efficiency; it contains no precious elements, resulting in lower cost; it achieves wear resistance by forming a composite structure of high proportion of amorphous phase + dispersed nanocrystalline phase; and it adopts self-protection, making it more convenient for on-site use. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the motion state of the low-carbon steel strip in this invention.

[0020] Figure 3 This is a schematic diagram of the mixing chamber in this invention.

[0021] Figure 4 This is a schematic diagram of the feeding mechanism in this invention.

[0022] Figure 5 This is a schematic diagram of the material distribution bin in this invention.

[0023] Figure 6 This is a schematic diagram of the material distribution trough in this invention.

[0024] Figure 7 For the present invention Figure 6 A schematic diagram of the structure of area B in the middle.

[0025] Figure 8 For the present invention Figure 1 A schematic diagram of the structure of area A in the middle.

[0026] Figure 9 This is a schematic diagram of the drive mechanism in this invention.

[0027] Figure 10 This is a schematic diagram of the structure of the fixing rod in this invention.

[0028] In the diagram: 1. Base plate; 2. Mixing bin; 3. Feeding bin; 4. Distribution bin; 5. Positioning plate; 6. Low carbon steel strip; 7. Stirring rod; 8. Feeding hopper; 9. Distribution rod; 10. Rotating rod; 11. Support rod; 12. Metering plate; 13. Distribution trough; 14. Mounting rod; 15. Guide plate; 16. Guide groove; 17. Connecting rod; 18. Slide groove; 19. Driven ring; 20. Driven frame; 21. Driven rod; 22. Positioning rod; 23. Horizontal rod; 24. Positioning block; 25. Guide rod; 26. Drive block; 27. Clamping plate; 28. T-shaped plate; 29. ​​Moving groove; 30. Inclined groove; 31. Moving rod; 32. L-shaped rod; 33. Fixed rod; 34. Gear; 35. Rack; 36. Receiving groove; 37. Connecting rod. Detailed Implementation Example

[0029] Please see Figure 1-3 This embodiment discloses a preparation device for chromium-free wear-resistant self-protected metal powder core welding wire as described in Embodiment 1. It includes a base plate 1, a mixing chamber 2 fixedly connected to the upper middle part of the base plate 1, a feeding mechanism provided at the lower end of the mixing chamber 2, a positioning plate 5 fixedly connected to the upper middle part of the base plate 1, a low carbon steel strip 6 placed in the middle of the positioning plate 5, and driving mechanisms for driving the low carbon steel strip 6 to move horizontally on both sides of the positioning plate 5. When the driving mechanism is horizontally close to the position of the mixing chamber 2, the feeding mechanism remains stationary. When the driving mechanism is far away from the position of the mixing chamber 2, the feeding mechanism rotates 180° clockwise.

[0030] Please see Figure 1-5 A stirring rod 7 is rotatably connected to the top of the inner cavity of mixing chamber 2. A servo motor is driven to the middle of the upper end of mixing chamber 2, and the output end of the servo motor is fixedly connected to the top of the stirring rod 7. The stirring rod 7 is driven to rotate by the servo motor. A feed inlet is opened at the upper end of mixing chamber 2. Drug core powder is added into the inner cavity of mixing chamber 2 through the feed inlet, and the drug core powder is stirred and mixed by the stirring rod 7. A discharge chamber 3 is fixedly connected to the lower end of mixing chamber 2. An electric opening is provided between the discharge chamber 3 and mixing chamber 2. The opening and closing of the mixing chamber 2 and the feeding chamber 3 are controlled by an electric switch, thereby ensuring that the core powder enters the inner cavity of the feeding chamber 3 only after it is well mixed. The feeding mechanism includes a distributing chamber 4, which is fixedly connected to the outer wall of the feeding chamber 3. A feeding hopper 8 is fixedly connected to the lower end of the distributing chamber 4. The lower end face of the feeding hopper 8 is perpendicular to the lower end face of the feeding chamber 3 and parallel to the low carbon steel strip 6. The servo motor and the electric switch are both commonly used technologies in the prior art.

[0031] A distributing rod 9 is rotatably connected to the connection between the distributing bin 4 and the feeding bin 3. A rotating rod 10 is fixedly connected to the center of both ends of the distributing rod 9. A support rod 11 is rotatably connected to the outer wall of both ends of the rotating rod 10. The bottom of the support rod 11 is fixedly connected to the bottom plate 1. A distributing groove 13 is opened in the middle of the upper end of the distributing rod 9. A symmetrical metering plate 12 is vertically slidably connected to the inner cavity of the distributing groove 13. The symmetrical metering plate 12 can block and isolate the inner cavity of the distributing groove 13, thereby forming a groove in the inner cavity of the distributing groove 13 for receiving the drug core powder. Through the cooperation of the distributing groove 13 and the metering plate 12, the drug core powder mixed in the inner cavity of the feeding bin 3 is received. The rotation of the distributing rod 9 throws the drug core powder received by the metering plate 12 above into the inner cavity of the feeding hopper 8, and the feeding hopper 8 adds the drug core powder to the middle of the upper end of the low carbon steel belt 6.

[0032] Please see Figure 1 and Figure 4-6 During the preparation of welding wire, the width of the low-carbon steel strip 6 used for different sizes of welding wire is different, and the amount of flux-cored powder required for low-carbon steel strip 6 of different widths is also different. A symmetrical horizontal rod 23 is slidably connected to the middle of the positioning plate 5. A positioning block 24 is fixedly connected to the end of the horizontal rod 23 near the hopper 8. Both ends of the positioning block 24 have arc-shaped edges to facilitate the positioning of the low-carbon steel strip 6. A positioning rod 22 is fixedly connected to the end of the horizontal rod 23 away from the positioning block 24. The positioning rod 22 is elastically connected to the support rod 11 via a spring, allowing the positioning rod to... 22. The horizontal bar 23 and the positioning block 24 provide elastic clamping and positioning for the low carbon steel strip 6. The middle part of the rotating rod 10 is provided with a sliding groove 18. The inner cavity of the sliding groove 18 is slidably connected to the connecting rod 17. The end of the connecting rod 17 near the support rod 11 is fixedly connected to the driven ring 19. The driven ring 19 is slidably connected to the outer wall of the rotating rod 10. The metering plate 12 is fixedly connected to the side of the rotating rod 10 with symmetrical mounting rods 14. The side of the mounting rod 14 away from the rotating rod 10 is fitted with a guide plate 15. The side of the symmetrical guide plate 15 away from the metering plate 12 is fixedly connected to the connecting rod 17.

[0033] Please see Figure 6-7A driven rod 21 is fixedly connected to the middle of the end of the mounting rod 14 away from the metering plate 12. A guide groove 16 is provided on the side wall of the guide plate 15, which slides with the driven rod 21. When the driven ring 19 drives the connecting rod 17 to move horizontally, it will also drive the symmetrical guide plate 15 to move horizontally synchronously. That is, as the driven ring 19 drives the connecting rod 17 and the guide plate 15 to move horizontally closer to the support rod 11, it can drive the symmetrical driven rod 21, the mounting rod 14, and the metering plate 12 to move synchronously closer to the center of the dispensing groove 13, thereby increasing the depth of the groove and increasing the amount of drug core powder that the groove cavity can accommodate. A symmetrical driven frame 20 is rotatably connected to the outer wall of the driven ring 19. The lower end of the 0 is fixedly connected to the positioning rod 22. When the symmetrical positioning block 24 elastically clamps and positions the low carbon steel strip 6 of different widths, the symmetrical positioning block 24 will drive the horizontal rod 23 and the positioning rod 22 to move synchronously closer to the position of the support rod 11. During the horizontal movement of the positioning rod 22, it will drive the driven ring 19 and the connecting rod 17 to move horizontally through the driven frame 20, thereby completing the adjustment of the position of the metering plate 12. This allows the amount of flux core powder added at one time to adapt to changes in the width of the low carbon steel strip 6. During the preparation of the welding wire, the amount of flux core powder required for low carbon steel strips 6 of different widths can be quickly adjusted.

[0034] Please see Figure 1 and Figure 9 The driving mechanism includes a driving block 26. A guide rod 25 is fixedly connected to the middle of the end of the driving block 26 near the support rod 11. The guide rod 25 is slidably connected to the lower middle of the positioning rod 22. The side of the driving block 26 near the low carbon steel strip 6 is slidably connected to the outer wall of the positioning plate 5. A T-shaped plate 28 is slidably connected to the side of the driving block 26 away from the guide rod 25. A symmetrical electric push rod is driven to the upper side of the base plate 1. The output end of the electric push rod is fixedly connected to the middle of the side of the T-shaped plate 28 away from the driving block 26. That is, the electric push rod pushes the T-shaped plate 28, the driving block 26 and the guide rod 25 to move horizontally synchronously, thereby driving the driving block 26 to move horizontally closer to or away from the position of the positioning rod 22. The positioning rod 22 can only move horizontally closer to or away from the position of the positioning plate 5, while the driving block 26 can move horizontally closer to or away from the position of the positioning plate 5 and also move horizontally closer to or away from the position of the positioning rod 22.

[0035] When the width of the low-carbon steel strip 6 increases, the symmetrical positioning blocks 24 elastically clamp and position the low-carbon steel strip 6, and the positioning rod 22 will move horizontally closer to the position of the support rod 11. Due to the sliding cooperation between the guide rod 25 and the positioning rod 22, during the horizontal movement of the positioning rod 22, the guide rod 25 will drive the drive block 26 to move horizontally synchronously. At this time, under the action of the electric push rod, the T-shaped plate 28 remains stationary. That is, during the horizontal movement of the drive block 26 with the positioning rod 22, the T-shaped plate 28 will balance and guide the drive block 26.

[0036] A clamping plate 27 is provided on the side of the driving block 26 near the low carbon steel strip 6. The side of the clamping plate 27 away from the low carbon steel strip 6 is slidably connected to the upper outer wall of the positioning plate 5. That is, when the driving block 26 approaches the positioning rod 22, it will drive the clamping plate 27 to approach the position of the positioning rod 22. That is, when the driving block 26 approaches the position of the support rod 11 as the positioning rod 22 approaches the position of the support rod 11, it will also drive the clamping plate 27 to move in the direction of the support rod 11. The distance between the symmetrical clamping plates 27 is greater than the distance between the symmetrical positioning blocks 24. Therefore, when the positioning block 24 clamps and positions the low carbon steel strip 6, the clamping plate 27 and the low carbon steel strip 6 remain separated. A moving groove 29 is provided in the middle of the side of the driving block 26 near the positioning plate 5. A symmetrical inclined groove 30 is provided in the inner cavity of the moving groove 29. A moving rod 31 is fixedly connected to the middle of the end of the clamping plate 27 near the driving block 26. The end of the moving rod 31 is slidably connected in the inner cavity of the inclined groove 30.

[0037] Therefore, during the process of the electric push rod pushing the drive block 26 horizontally closer to the positioning rod 22, the clamping plate 27 will not immediately move synchronously with the drive block 26 to the position of the positioning rod 22. At this time, relative movement occurs between the drive block 26 and the clamping plate 27. Under the sliding cooperation of the inclined groove 30 and the moving rod 31, the clamping plate 27 will immediately move towards the direction of the low carbon steel strip 6. After the clamping plate 27 and the low carbon steel strip 6 are in close contact, the clamping plate 27 will move synchronously with the drive block 26 to the position of the positioning rod 22, thereby driving the low carbon steel strip 6 to move horizontally synchronously.

[0038] Please see Figure 1 and Figure 9-10During the resetting process of the drive block 26, the clamping plate 27 immediately separates from the outer wall of the low-carbon steel strip 6. Then, as the drive block 26 resets, the electric push rod continuously pushes the drive block 26 to perform horizontal reciprocating motion, thereby continuously conveying the low-carbon steel strip 6 to the bottom of the hopper 8, and continuously filling the inner cavity of the low-carbon steel strip 6 with core powder. An L-shaped rod 32 is fixedly connected to the side of the guide rod 25 away from the positioning plate 5. A fixing rod 33 is fixedly connected to the top of the L-shaped rod 32. A gear 34 is fixedly connected to the outer wall of the rotating rod 10 near the support rod 11. The center position of the gear 34 and the center position of the fixing rod 33 are located in the same vertical plane. Therefore, during the synchronous horizontal movement of the guide rod 25 driven by the drive block 26, the L-shaped rod 32 and the fixed rod 33 will move towards the position of the positioning rod 22 until the outer wall of the L-shaped rod 32 is in contact with the outer wall of the positioning rod 22. At this time, the fixed rod 33 is located below the gear 34 and does not contact the gear 34. A receiving groove 36 is provided in the middle of the side of the upper end of the fixed rod 33 away from the L-shaped rod 32. A rack 35 is provided in the inner cavity of the receiving groove 36. The rack 35 and the receiving groove 36 are rotatably connected by a symmetrical connecting rod 37. That is, the upper end of the connecting rod 37 is rotatably connected to the bottom of the rack 35, and the lower end of the connecting rod 37 is rotatably connected to the bottom of the inner cavity of the receiving groove 36.

[0039] The end of the rack 35 away from the L-shaped rod 32 is attached to the side of the cavity of the receiving groove 36 away from the L-shaped rod 32, and the length of the receiving groove 36 is greater than the length of the rack 35. As the rack 35 moves closer to the positioning rod 22 along with the L-shaped rod 32, the rack 35 will gradually approach the gear 34 and contact its outer wall. Since there is no fixed support on the side of the rack 35 close to the L-shaped rod 32, the rack 35 will rotate in the direction of the L-shaped rod 32 under the guidance of the connecting rod 37, and eventually retract into the cavity of the receiving groove 36. The rack 35 and the bottom of the cavity of the receiving groove 36 are elastically connected by symmetrical springs. The springs are tilted in the direction away from the L-shaped rod 32. After the L-shaped rod 32 is attached to the outer wall of the positioning rod 22, the springs will drive the rack 35 to reset.

[0040] During the process of the drive block 26 resetting the L-shaped rod 32, the fixed rod 33 and the rack 35, the rack 35 will contact the gear 34 again. At this time, the rack 35 will be stably supported and will no longer rotate. Then the rack 35 will mesh with the gear 34, thereby driving the gear 34 to rotate 180° clockwise, thereby driving the rotating rod 10 and the distributing rod 9 to rotate 180° clockwise, completing the quantitative feeding of the core powder. By continuously driving the drive block 26 to reciprocate horizontally, the low carbon steel belt 6 can be continuously pushed to the bottom of the feeding hopper 8, and a quantitative amount of powder can be added to the inner cavity of the feeding hopper 8. During the powder feeding process, the low carbon steel belt 6 remains stationary. Example

[0041] This embodiment discloses a chromium-free wear-resistant self-protected metal powder core welding wire. The welding wire includes a core powder and a low-carbon steel strip 6 encasing the powder core. The core powder comprises the following components by mass percentage: C: 0.4%-0.6%; Mn: 1.8%-2.2%; Si: 1.0%-1.4%; Ni: 1.5%-1.9%; B: 3.7%-4.3%, with the balance being Fe and unavoidable impurities. After the metal powder core welding wire is deposited, it forms a composite structure of amorphous phase and nanocrystalline phase, with the nanocrystalline particle size <100nm and the amorphous phase being the performance-dominant phase.

[0042] Based on the above technical solution, the optimal composition of the core powder is: B: 4.0%, C: 0.5%, Mn: 2.0%, Si: 1.2%, Ni: 1.7%.

[0043] The core innovation of this invention lies in the composition design based on the principle of amorphous formation, combined with a rapid cooling process for welding, to achieve the controllable formation of an amorphous-nanocrystalline composite structure in the weld overlay. Simultaneously, through the synergistic effect of various alloying elements, it balances amorphous formation capability, weldability, wear resistance, and toughness. The roles of each element and the overall synergistic principle are as follows: Core amorphous forming elements B+C: As the primary amorphous forming element in iron-based amorphous materials, boron (B) has an atomic radius much smaller than that of iron atoms. This allows it to fill the interatomic gaps in Fe, significantly increasing melt viscosity, suppressing long-range atomic ordering, and reducing the critical cooling rate of Fe-based alloys, thus lowering the conventional cooling rate for weld overlay (10). 2 -10 4 A large amount of amorphous phase can be precipitated at K / s; at the same time, B and Fe form a mixed covalent-metallic bond, which improves the intrinsic hardness and wear resistance of the amorphous phase and is the core source of the high hardness of the composite structure.

[0044] If B < 3.7 wt%, the amorphous formation ability decreases significantly, the proportion of amorphous phase after welding is < 50%, and the hardness is < 60 HRC; if B > 4.3 wt%, the brittleness of the weld layer increases dramatically, making it prone to cracking and failure under impact and wear. As a trace element for regulating amorphous structure, a small amount of carbon can further enhance the amorphous formation ability, expand the supercooled liquid phase region, and at the same time inhibit the formation of coarse crystals during crystallization, promoting the precipitation of dispersed nanocrystals with a particle size of <100nm. However, carbon should not be excessive to avoid the formation of crystalline carbides such as Fe3C, which would damage the integrity of the amorphous structure.

[0045] If C < 0.4wt%, nanocrystals cannot be effectively refined, and the brittleness of pure amorphous materials increases; if C > 0.6%, Fe3C crystalline carbides precipitate, destroying the amorphous structure and reducing wear resistance. 2. Amorphous formation strengthening and toughening elements Mn+ Ni: The atomic radius of manganese (Mn) differs from that of iron (Fe), which can disrupt the ordered arrangement of Fe atoms, further increasing the disorder of the melt structure and enhancing the amorphous formation capability. Simultaneously, as an austenite stabilizing element, it refines nanocrystalline grains, improves the toughness of the composite structure, and avoids the brittleness problem of pure amorphous materials. Furthermore, Mn can combine with harmful impurities such as sulfur (S) in the molten pool to form MnS, reducing the negative impact of impurities on amorphous formation and improving weldability. If Mn < 1.8 wt%: insufficient melt disorder, increased critical cooling rate for amorphous materials, and severe crystallization after welding; if Mn > 2.2 wt%: reduced thermal stability of the amorphous phase, leading to crystallization of the amorphous phase during multi-layer welding. Ni is a strong austenite stabilizing element that significantly improves the hardenability of the alloy and ensures uniform cooling rate across the entire thickness of the weld overlay. At the same time, as a toughening element, Ni effectively improves the impact toughness of the amorphous-nanocrystalline composite structure, making it suitable for impact and wear scenarios of heavy-duty wear-resistant components. In addition, Ni can lower the melting point of the alloy, expand the supercooled liquid phase region, improve the thermal stability of the amorphous phase, and avoid amorphous crystallization caused by heat input in subsequent welding processes.

[0046] If Ni < 1.5 wt%, the hardenability of the weld overlay is insufficient and the hardness is uneven; if Ni > 1.9 wt%, the melt viscosity is reduced, the formation of amorphous phase is suppressed, and the proportion of amorphous phase decreases.

[0047] 3. Si, an element for amorphous protection and weldability optimization: Strong deoxidation effect: During the smelting and welding of metal wire, Si preferentially combines with free oxygen in the molten pool to generate SiO2, which completely eliminates the damage of oxygen element to the formation of amorphous phase (oxygen will form oxide inclusions, which become crystal nuclei and induce crystallization), ensuring the purity of the molten pool composition and providing an undisturbed metallurgical environment for the formation of amorphous phase.

[0048] Assisting amorphous formation: Si atoms have small atomic radii, which can fill the interatomic gaps between Fe and B atoms, further increasing the melt viscosity and enhancing the amorphous formation capability; at the same time, it expands the supercooled liquid phase region and improves the thermal stability of the amorphous phase.

[0049] Welding process optimization: Si can adjust the viscosity and fluidity of the slag, and with the self-protection design, improve arc stability, reduce welding spatter, make the surfacing process smoother, and optimize weld bead formation.

[0050] If Si < 1.0 wt%: insufficient deoxidation, increased O content in the molten pool, inducing amorphous crystallization; if Si > 1.4 wt%: excessive solid solution strengthening, increased hardness of the weld overlay but decreased toughness. 4. Matrix element Fe: As the core element of the amorphous-nanocrystalline composite structure, Fe provides a carrier for the dissolution and reaction of all alloying elements, forming an Fe-based amorphous matrix. At the same time, as the nucleus substrate of nanocrystals, it promotes the precipitation of dispersed nanocrystalline phases, achieving a synergistic effect of "amorphous phase dominating hardness and wear resistance, and nanocrystalline phase improving toughness".

[0051] 5. Formation mechanism of amorphous-nanocrystalline composite structure of weld overlay The metal wire of this invention is self-protected. When using the DCEP (Direct Current Electrode Positive) welding process, the molten pool volume is small, and the low-carbon steel substrate has fast thermal conductivity, allowing the molten pool to cool at a rate of 10²~10⁻⁶. 4 K / s, close to the critical cooling rate of Fe-B system amorphous materials; combined with the composition design of the metal wire with high amorphous forming ability, during the cooling process of the molten pool, atoms cannot form a long-range ordered crystalline structure, and a large amount of amorphous phase is precipitated; in the small crystallization region, due to the regulation effect of C, Mn and Ni, only dispersed nanocrystals with a particle size of <100nm are precipitated, and finally a composite structure with a high proportion of amorphous phase + dispersed nanocrystal phase is formed.

[0052] 6. The principle of synergistic performance of composite structures The amorphous-nanocrystalline composite structure of the weld overlay combines the advantages of both amorphous and nanocrystalline phases, which is the fundamental reason for achieving high hardness, ultra-low wear, and uniform performance across the entire thickness. Amorphous phases are free from crystal defects such as grain boundaries and dislocations. They have high intrinsic hardness and excellent wear resistance. The wear process is a uniform micro-cutting process, without the problems of preferential wear at grain boundaries and shedding of hard phases. The dispersed nanocrystalline phase can effectively improve the brittleness of pure amorphous materials, enhance the impact toughness and crack resistance of composite structures, and make them suitable for impact and wear scenarios such as buckets and crushers. Unlike existing technologies, the metal-cored welding wire in this embodiment is virtually slag-free and has higher cladding efficiency; it contains no precious elements, resulting in lower costs; it achieves wear resistance by forming a composite structure with a high proportion of amorphous phase and dispersed nanocrystalline phase; and it employs self-protection, making it more convenient for on-site use.

[0053] Sample testing: A 6mm thick substrate was selected, and a 6mm thick metal-cored wire was welded to its surface. Dry sand abrasion tests were conducted according to JB / T 7705 (ASTM G65 Abrasion Test Procedure A). The test results are shown in the table below.

[0054] The Rockwell hardness (HRC) of five points on the surface of the welding wire were 67.5, 68, 69, 67.5, and 68, with an average of 68. This invention also protects the application of the aforementioned metal wires. It employs a self-protected DCEP positive electrode welding process and utilizes water-cooled heat conduction on the back of the substrate to achieve rapid cooling of the weld pool, thereby forming an amorphous-nanocrystalline composite structure in the weld layer. This method is suitable for the preparation of wear-resistant plates of various specifications. Example

[0055] This embodiment protects a method for preparing a chromium-free wear-resistant self-protected metal powder-cored welding wire of Example 2 using the preparation apparatus of Example 1, including the following steps: S1. Add the core powder to the mixing chamber 2, and use the motor to drive the stirring rod 7 to rotate and fully mix the core powder. After mixing, turn on the switch so that the mixed core powder enters the inner cavity of the feeding chamber 3. S2. The low carbon steel strip 6 is elastically clamped and positioned by the symmetrical positioning block 24. Then, through the cooperation of the drive block 26, the clamping plate 27 and the guide rod 25, the position of the clamping plate 27 is automatically adjusted, and the low carbon steel strip 6 is clamped by the clamping plate 27, which drives the low carbon steel strip 6 to move horizontally with the drive block 26 to complete the conveying of the low carbon steel strip 6. S3. During the reset process of the drive block 26, the clamping plate 27 automatically releases the clamping plate 27 from the low carbon steel strip 6, and through the cooperation of the rack 35, the receiving groove 36 and the connecting rod 37, the drive gear 34, the rotating rod 10 and the distributing rod 9 rotate 180° clockwise during the reset process, and quantitatively add the core powder into the inner cavity of the low carbon steel strip 6.

[0056] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A device for preparing chromium-free, wear-resistant, self-protective metal powder-cored welding wire, characterized in that, The device includes a base plate, a mixing chamber fixedly connected to the upper center of the base plate, a feeding mechanism at the lower end of the mixing chamber, a positioning plate fixedly connected to the upper center of the base plate, a low-carbon steel strip placed in the center of the positioning plate, and driving mechanisms for driving the low-carbon steel strip to move horizontally on both sides of the positioning plate. When the driving mechanism is horizontally close to the position of the mixing chamber, the feeding mechanism remains stationary. When the driving mechanism is far away from the position of the mixing chamber, the feeding mechanism rotates 180° clockwise.

2. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 1, characterized in that, A stirring rod is rotatably connected to the top of the inner cavity of the mixing chamber, and a feeding chamber is fixedly connected to the lower end of the mixing chamber. The feeding mechanism includes a distributing chamber, and the outer walls of the distributing chamber and the feeding chamber are fixedly connected. A feeding hopper is fixedly connected to the lower end of the distributing chamber. The lower end face of the feeding hopper is perpendicular to the lower end face of the feeding chamber, and the lower end face of the feeding hopper is parallel to the low carbon steel strip.

3. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 2, characterized in that, The material distribution bin and the unloading bin are connected together by a material distribution rod. Rotating rods are fixedly connected to the center of both ends of the material distribution rod. Support rods are rotatably connected to the outer walls of both ends of the rotating rod. The bottom of the support rods is fixedly connected to the bottom plate. A material distribution groove is opened in the middle of the upper end of the material distribution rod. Symmetrical metering plates are vertically slidably connected to the inner cavity of the material distribution groove.

4. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 3, characterized in that, A groove is provided in the middle of the rotating rod, and a connecting rod is slidably connected to the inner cavity of the groove. A driven ring is fixedly connected to one end of the connecting rod near the support rod. The driven ring is slidably connected to the outer wall of the rotating rod. A symmetrical mounting rod is fixedly connected to one side of the metering plate near the rotating rod. A guide plate is fitted to the side of the mounting rod away from the rotating rod. The symmetrical guide plate is fixedly connected to the connecting rod on the side away from the metering plate. A driven rod is fixedly connected to the middle of the end of the mounting rod away from the metering plate. A guide groove is provided on the side wall of the guide plate to slide with the driven rod.

5. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 4, characterized in that, The positioning plate has symmetrical horizontal rods slidably connected to its middle part. A positioning block is fixedly connected to the end of the horizontal rod near the hopper, and a positioning rod is fixedly connected to the end of the horizontal rod away from the positioning block. The positioning rod and the support rod are elastically connected by a spring. The outer wall of the driven ring is rotatably connected to symmetrical driven frames. The lower ends of the symmetrical driven frames are fixedly connected to the positioning rods.

6. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 5, characterized in that, The driving mechanism includes a driving block. A guide rod is fixedly connected to the middle of one end of the driving block near the support rod. The guide rod is slidably connected to the lower middle of the positioning rod. A T-shaped plate is slidably connected to the side of the driving block away from the guide rod. A clamping plate is provided on the side of the driving block near the low carbon steel strip. The outer wall of the clamping plate near the driving block is slidably connected to the positioning plate. The spacing between the symmetrical clamping plates is greater than the spacing between the symmetrical positioning blocks.

7. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 6, characterized in that, A moving groove is provided in the middle of the side of the drive block near the positioning plate. The outer wall of the clamping plate away from the low carbon steel strip is slidably engaged with the moving groove. A symmetrical inclined groove is provided in the inner cavity of the moving groove. A moving rod is fixedly connected to the middle of the end of the clamping plate near the drive block. The end of the moving rod is slidably connected in the inner cavity of the inclined groove.

8. The apparatus for preparing chromium-free wear-resistant self-protective metal powder-cored welding wire according to claim 7, characterized in that, An L-shaped rod is fixedly connected to the side of the guide rod away from the positioning plate. A fixed rod is fixedly connected to the top of the L-shaped rod. A gear is fixedly connected to the outer wall of the rotating rod near the support rod. The center of the gear and the center of the fixed rod are located in the same vertical plane. A receiving groove is provided in the middle of the upper end of the fixed rod away from the L-shaped rod. A rack is provided in the inner cavity of the receiving groove. The rack and the receiving groove are rotatably connected by symmetrical connecting rods.

9. A chromium-free, wear-resistant, self-protecting metal powder-cored welding wire prepared by the preparation apparatus according to any one of claims 1 to 8, characterized in that, The welding wire is made of a core powder and a low-carbon steel strip encasing the powder core; the core powder comprises the following components by mass percentage: C: 0.4%-0.6%; Mn: 1.8%-2.2%; Si: 1.0%-1.4%; Ni: 1.5%-1.9%; B: 3.7%-4.3%, with the balance being Fe and unavoidable impurities; after the metal wire is welded, a composite structure of amorphous phase and nanocrystalline phase is formed, with nanocrystalline particle size <100nm, and the amorphous phase is the performance-dominant phase.

10. A method for preparing a chromium-free wear-resistant self-protected metal powder-cored welding wire, comprising using the apparatus for preparing a chromium-free wear-resistant self-protected metal powder-cored welding wire as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Add the core powder to the mixing chamber, and use the motor to drive the stirring rod to rotate and fully mix the core powder. After mixing, turn on the switch to allow the mixed core powder to enter the inner cavity of the feeding hopper. S2. The low carbon steel strip is elastically clamped and positioned by symmetrical positioning blocks. Then, through the cooperation of the drive block, clamping plate and guide rod, the position of the clamping plate is automatically adjusted, and the low carbon steel strip is clamped by the clamping plate, which drives the low carbon steel strip to move horizontally with the drive block to complete the conveying of the low carbon steel strip. S3. During the reset process of the drive block, the clamping plate automatically releases the clamping plate from the low-carbon steel strip, and through the cooperation of the rack, receiving groove and connecting rod, the drive gear, rotating rod and distributing rod rotate 180° clockwise during the reset process, quantitatively adding core powder into the inner cavity of the low-carbon steel strip.

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