A steel rolling shearing tool and manufacturing process

Abstract

This invention discloses a steel rolling shearing tool, the composition of which, by weight percentage, includes: C: 0.35~0.55%, W: 5.0~9.0%, Mo: 2.5~5.5%, Cr: 3.0~5.0%, V: 0.8~1.8%, Co: 2.5~6.0%, Nb: 0.05~0.30%, Si≤0.6%, Mn≤0.6%, with the balance being Fe and unavoidable impurities; wherein, Co / Nb=10~30; wherein, the tool contains 12~22% by volume of MC-type carbides and M6C-type carbides, the volume ratio of MC-type carbides to M6C-type carbides is controlled between 1:(1.2~2.5), and the average particle size of the carbides is ≤2.5μm. The manufacturing process and shearing machine using the tool were also disclosed, which can effectively solve the problems of steel sticking or wire pulling when existing tools are used for high-temperature shearing, and also solve the problem of not being able to balance red hardness and toughness.

Description

Technical Field

[0001] This invention belongs to the field of cutting tools, specifically a steel rolling shearing tool and its manufacturing process. Background Technology

[0002] Shearing machines are used for cutting sheet metal. The shearing machine blades, powered by a mechanical hydraulic system via the blade holder, cut the sheet metal up and down, thus completing the shearing action. The blades used in shearing machines generally require strong overall performance. If the performance is poor, it will be difficult to cut sheet metal, and deformation and chipping are likely to occur during the shearing process. The main factors affecting the performance of shearing machine blades are their manufacturing processes, including material selection, forging processes, and heat treatment processes. Different processes can significantly impact the performance of the blades.

[0003] In current steel mills, especially during the shearing of steel plates, the steel plates remain at high temperatures after rolling. If traditional materials (such as H13, M2 high-speed steel, or conventional powder metallurgy steel) are used, the emphasis is often solely on high-temperature hardness, neglecting the microscopic influence of carbide type on high-temperature adhesion behavior. Traditional materials, typically M6C or M7C3, are prone to steel adhesion or wire drawing at shearing temperatures of 800-1200℃ due to the mismatch in thermal properties between the carbides and the substrate. This problem is usually addressed with surface coating technology, which significantly increases tooling costs. Summary of the Invention

[0004] The technical problem to be solved by this invention is: how to solve the problem of steel sticking or wire pulling during high-temperature shearing, while also solving the problem of the inability to balance red hardness and toughness.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A steel rolling shearing tool, wherein the composition of the tool, by weight percentage, comprises: C: 0.35~0.55%, W: 5.0~9.0%, Mo: 2.5~5.5%, Cr: 3.0~5.0%, V: 0.8~1.8%, Co: 2.5~6.0%, Nb: 0.05~0.30%, Si ≤ 0.6%, Mn ≤ 0.6%, with the balance being Fe and unavoidable impurities;

[0007] Wherein, Co / Nb = 10~30;

[0008] The cutting tool contains 12-22% MC-type carbides and M6C-type carbides by volume, with the volume ratio of MC-type carbides to M6C-type carbides controlled between 1:(1.2-2.5), and the average particle size of the carbides is ≤2.5μm.

[0009] Co alone dissolves in the martensitic matrix, reducing stacking fault energy and inhibiting dislocation climb, thereby improving high-temperature strength (red hardness). However, it does not form carbides and cannot prevent other carbides (such as M6C and M7C3) on the grain boundaries from coarsening at high temperatures. During shearing at 800~1200℃, the coarse carbides on the grain boundaries become micro-viscosity sources—the softened ferrite in the steel sheet preferentially diffuses to these coarse sites and welds, leading to wire drawing. In addition, adding Co alone reduces the thermal conductivity of the material and exacerbates the local temperature rise at the cutting edge.

[0010] Adding Nb alone, as a strong carbide-forming element, forms high-melting-point, high-hardness NbC (MC type), which can pin grain boundaries and refine grains. However, NbC is very stable during high-temperature austenitization and is difficult to dissolve, so it cannot precipitate again during subsequent tempering. If there are not enough solid solution strengthening elements (such as Co) in the matrix, the matrix around NbC will soften first at high temperatures, resulting in a hard point + soft matrix structure. This makes it easier for particles to be pulled out during shearing, and the micro-pits left after the pull-out become new sticky points.

[0011] This application utilizes the composite addition of Co and Nb (Co / Nb = 10~30) to improve red hardness with Co and simultaneously utilize Nb to form highly stable NbC to pin grain boundaries, which is the key to solving high-temperature viscosity.

[0012] If the carbide volume fraction is <12% and the mean free path between carbides is >5μm, the high-temperature softened matrix cannot effectively support shear stress, and the steel plate material will embed into the matrix, forming a cold weld; if the carbide volume fraction is >22%, the carbides begin to contact and form a skeleton, and the fracture toughness K... IC The temperature drops sharply, making it unable to withstand the dynamic impact of steel rolling shearing.

[0013] This application strictly limits the volume fraction (12-22%) of the MC and M6C composite phases in the cutting tool and the relationship between their volume ratios. Coarse MC pins grain boundaries, resisting abrasive wear during shearing and preventing direct contact between the steel plate and the matrix. Fine M6C particles disperse and precipitate during tempering, filling the matrix regions between MC particles, inhibiting dislocation movement, and maintaining high-temperature hardness. MC (especially NbC) has extremely high chemical inertness and does not react with Fe. At the shear interface, MC particles protrude from the matrix, directly preventing the diffusion of Fe atoms from the softened steel plate to the tool surface. W and Mo in M6C diffuse to the surface at high temperatures, forming a dense WO3 and MoO2 oxide film. This film has solid lubrication properties, reducing the affinity between the steel plate and the tool, further inhibiting adhesion. With an MC:M6C ratio between 1:1.2 and 2.5, MC provides physical barrier properties, while M6C provides chemical lubrication. The spacing between the physical barrier points can be controlled within 1-2 μm, and the chemical lubrication film is continuous and free of pores.

[0014] In the aforementioned steel rolling shearing tool, the composition by weight percentage is as follows: C: 0.35~0.50%, W: 5.5~8.2%, Mo: 3.0~4.7%, Cr: 3.2~4.7%, V: 1.0~1.6%, Co: 2.5~5.5%, Nb: 0.13~0.26%, Si ≤0.5%, Mn ≤0.5%, with the balance being Fe and unavoidable impurities.

[0015] In the aforementioned steel rolling shearing tool, the composition by weight percentage is: C: 0.42%, W: 6.5%, Mo: 3.5%, Cr: 4.0%, V: 1.2%, Co: 3.5%, Nb: 0.15%, Si: 0.3%, Mn: 0.4%, with the balance being Fe and unavoidable impurities.

[0016] In the aforementioned steel rolling shearing tool, the composition by weight percentage is: C: 0.50%, W: 8.0%, Mo: 4.5%, Cr: 4.5%, V: 1.6%, Co: 5.5%, Nb: 0.25%, Si: 0.4%, Mn: 0.4%, with the balance being Fe and unavoidable impurities.

[0017] In the aforementioned steel rolling shearing tool, the composition by weight percentage is: C: 0.38%, W: 5.5%, Mo: 3.0%, Cr: 3.5%, V: 1.0%, Co: 2.8%, Nb: 0.10%, Si: 0.3%, Mn: 0.4%, with the balance being Fe and unavoidable impurities.

[0018] A manufacturing process for a steel rolling shearing tool includes the following steps:

[0019] Step 1: Smelt and cast the ingots according to the tool component ratio described above;

[0020] Step 2: Perform high-temperature homogenization treatment on the ingot at a temperature of 1180~1250℃ for 8~20 hours.

[0021] Step 3: Perform multi-directional forging or rolling for billet preparation, with a final forging temperature ≥950℃ and a total deformation ratio ≥5;

[0022] Step 4: Perform spheroidizing annealing at a temperature of 820~880℃, hold at the temperature, and then slowly cool to ≤550℃.

[0023] Step 5: Perform rough machining and shaping;

[0024] Step 6, perform final heat treatment:

[0025] Step 61, Quenching: Preheat in stages to 800~850℃, then raise the temperature to 1100~1180℃ for austenitization, hold for heat and then quench in oil or under high pressure.

[0026] Step 62, cryogenic treatment: keep warm at -80℃ to -150℃ for 1~4 hours;

[0027] Step 63, tempering: temper at 530~600℃ 2~4 times, holding for 1~3 hours each time;

[0028] Step 7: Perform finishing to the final cutting edge size.

[0029] In the steel rolling shearing tool, the austenitizing temperature in step (6) is 1130~1160℃, and the holding time is 15~40min;

[0030] The tempering temperature is 560~590℃, and the tempering is performed 3 times. After each tempering, the temperature is cooled to room temperature before the next tempering is performed.

[0031] In the steel rolling shearing tool, in the spheroidizing annealing in step (4), after holding at 820~880℃ for 4~8h, it is slowly cooled to below 550℃ at a cooling rate of ≤20℃ / h, and then furnace cooled or air cooled to room temperature.

[0032] In the steel rolling shearing tool, the multi-directional forging in step (3) is upsetting and drawing in at least two directions, and the forging ratio is ≥6.

[0033] High-temperature homogenization: Severe dendritic segregation and network carbides (especially coarse M6C and M7C3) exist in the as-cast microstructure. These coarse carbides are the root cause of insufficient toughness and viscosity in subsequent processes. At high temperatures, the diffusion coefficients of elements such as W, Mo, V, and Nb increase dramatically, causing segregated elements to diffuse into lower concentration regions, eliminating compositional differences between dendrites. Unstable M7C3 and some coarse M6C dissolve, while C and alloying elements dissolve into austenite. Stable MC (especially NbC) is partially retained and spheroidized. In the as-cast state, continuous network carbides transform into discrete, spheroidized carbide particles, providing uniform raw materials for subsequent forging. If the temperature is below 1180℃, W and Mo diffusion is too slow to effectively eliminate segregation; if the temperature is above 1250℃, excessive grain growth occurs, even leading to localized overheating. A reasonable diffusion time of 8-20 hours is sufficient to complete diffusion while avoiding abnormal grain coarsening.

[0034] Multi-directional forging: Although the homogenized carbides are spheroidized, coarse primary carbides (5-15 μm in size) still exist and are unevenly distributed. Multi-directional upsetting and drawing apply triaxial compressive stress, mechanically breaking the coarse carbides into fine particles (1-3 μm). During forging, the carbides rearrange along the deformation direction, changing from a clustered structure to a dispersed distribution. During high-temperature deformation, austenite grains undergo dynamic recrystallization, refining the grains while new grain boundaries pin the carbides, preventing their re-aggregation. Unidirectional forging (drawing only) results in a streamlined banded distribution of carbides, with extremely poor transverse toughness, making them prone to cracking along the streamlines during shearing. Multi-directional forging produces equiaxed, dispersed, and isotropic carbides, significantly improving toughness. However, below 950℃, the deformation resistance increases sharply, carbide crushing efficiency decreases, and forging cracks are easily generated. When the temperature is kept above 950℃, the material is in the austenitic region, has good plasticity, and can undergo large deformations without cracking.

[0035] Cryogenic treatment: After quenching, 15%-30% of retained austenite remains. During shearing, this austenite undergoes stress-induced phase transformation (transforming into brittle martensite), leading to volume expansion, microcrack initiation, and reduced red hardness. Cryogenic treatment provides greater undercooling, allowing retained austenite below the M3 point (the martensitic transformation termination temperature) to continue transforming into martensite. During cryogenic treatment, the matrix shrinks, generating high-density dislocations. These dislocations become nucleation sites for M6C precipitation during subsequent tempering, resulting in a more dispersed carbide distribution. When conventionally quenched and cooled to room temperature, some austenite stops transforming due to "thermal stabilization." Cryogenic treatment breaks this stable state, promoting continued phase transformation. The retained austenite content decreases from 15-30% to ≤5%, eliminating the risk of stress-induced phase transformation and providing more carbide nucleation sites for subsequent tempering.

[0036] High-temperature tempering and quenching followed by deep cooling results in "supersaturated carbon martensite," which has high hardness but poor toughness and lacks high-temperature strength. During tempering at 530-600℃, the supersaturated martensite decomposes, precipitating dispersed M6C and MC-type carbides (0.1-0.5µm in size), resulting in significant precipitation strengthening. After each tempering and cooling to room temperature, the remaining small amount of austenite transforms into martensite, which is then gradually eliminated during the next tempering process. The quenching stress is also released, dislocation density decreases, and toughness is restored.

[0037] A shearing machine includes a steel rolling shearing cutter as described above and a cutter holder for mounting the cutter.

[0038] The tool has hook holes on both sides, and a mounting groove and insertion holes distributed on both sides of the mounting groove are opened on the top of the tool. The mounting groove has a T-shaped groove with a smaller top and a larger bottom. The insertion holes and the bottom space of the T-shaped groove are connected.

[0039] A traction motor is mounted on the tool holder, and a drum is installed at the output end of the traction motor. A connecting steel rope is wound on the drum, and a connector is installed at the free end of the connecting steel rope for connecting to the hook hole. A hook is installed in the middle of the bottom surface of the tool holder, and the hook and mounting groove are adapted to each other. The hook includes a connecting part located in the middle and mounting parts distributed on both sides of the bottom of the connecting part. The bottom sides of the connecting part are inclined structures with sliding grooves. The side of the mounting part that contacts the connecting part is an inclined structure with a T-shaped slider. The slider and the slide groove are compatible. The middle part of the connecting part is provided with a waist-shaped hole. A connecting rod is slidably installed in the waist-shaped hole. A through hole is provided on the hanging part. The through hole is set perpendicular to the connecting part, and the size of the through hole at the end away from the connecting part is larger than the size at the end near the connecting part. The connecting rod is inserted into the through hole and a limit block is connected in the end of the through hole away from the connecting part. A spring is installed in the end of the through hole away from the connecting part. The spring is sleeved on the outside of the connecting rod and located on the side of the limit block near the connecting part. An insertion hole is provided on the hanging part.

[0040] The tool holders on both sides of the hook are provided with built-in slots. Hydraulic cylinders and insert rods installed at the output end of the hydraulic cylinders are installed in the built-in slots. The free end of the insert rod is conical and passes through the built-in slots and extends to the bottom of the tool holder. The insert rod is inserted into the insert hole and is adapted to the insert hole.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] This invention defines the types, volume fractions, volume ratios, and particle sizes of carbides (MC and M6C). MC typically forms in the early stages of forging and heat treatment, with a relatively coarse size (1-2.5 μm), serving as the primary framework. M6C precipitates diffusely during the tempering stage, with an extremely fine size (<0.5 μm), serving as a secondary strengthening phase. The coarse MC resists wear, while the fine M6C resists softening. When shearing high-temperature steel plates, the viscous nature is due to the diffusion bonding between the atoms on the tool surface and the atoms in the steel plate. MC, due to its extremely high chemical inertness (especially...),... NbC and VC can block the diffusion between Fe atoms. W and Mo elements in M6C easily form a dense oxide film (WO3, MoO2) at high temperatures, which plays a solid lubricating role and further reduces the adhesion tendency. At the same time, MC consumes C and strong carbide-forming elements, reducing the C content in the matrix. Thus, after quenching, it obtains lath martensite with good toughness rather than brittle granular martensite. M6C consumes W and Mo in the matrix during tempering, purifying the matrix and improving the tempering brittleness resistance. Based on the precise ratio of Co and Nb (Co / Nb = 10~30), if the volume fraction of carbides is <12%, it is insufficient to provide adequate red hardness and wear resistance. At high temperatures, the matrix is ​​directly exposed and quickly becomes sticky. If the volume fraction is >22%, excessive carbides will form a continuous network or large-size aggregates, leading to tool chipping (insufficient toughness). If the particle size is >2.5um, large-size carbides will become crack sources, easily cracking from the inside or interface of the carbides under shear impact loads, leading to tool chipping. At the same time, coarse carbides are prone to adhering to the steel plate.

[0043] This invention achieves a synergistic effect through high-temperature homogenization, multi-directional forging, cryogenic treatment, and high-temperature tempering. High-temperature homogenization eliminates as-cast segregation and provides a uniform microstructure for forging; multi-directional forging breaks coarse carbides down to ≤2.5μm and disperses them; cryogenic treatment reduces retained austenite to ≤5% and introduces high-density dislocations; high-temperature tempering disperses M6C carbides on the dislocations, achieving secondary hardening; all four processes together enable the cutting tool to possess both a red hardness of ≥52HRC (650℃) and ≥28 MPa·m when shearing at 800-1200℃. 1 / 2 The fracture toughness. These four processes are not a simple "heat treatment process", but an effective solution to the chain of problems of carbide segregation → coarseness → retained austenite → supersaturated solid solution. Each process solves the problems left over from the previous process, while creating better conditions for the next process, and finally achieves the synergy of fine carbides, stable microstructure, high red hardness and high toughness. Attached Figure Description

[0044] Figure 1 This is a diagram showing the connection relationship between the blade holder and the blade of the shearing machine of the present invention.

[0045] Figure 2This is a diagram showing the positional relationship between the blade holder and the blade of the shearing machine of the present invention when they are not installed.

[0046] Figure 3 This is a schematic diagram of the hook and hanger (unhooked state) of the present invention.

[0047] Figure 4 This is a structural schematic diagram of the hook and hanger (hook and hang state) of the present invention.

[0048] Figure 5 This is a side view of the shearing machine of the present invention after the blade holder and the blade are connected.

[0049] Figure 6 for Figure 5 A magnified view of a portion of point A in the middle.

[0050] Figure 7 , Figure 8 This is a schematic diagram of the tool structure of the present invention.

[0051] Figure 9 This is a schematic diagram of the connection part of the present invention.

[0052] Figure 10 This is a schematic diagram of the mounting part of the present invention.

[0053] In the diagram: 10. Cutting tool; 11. Hook hole; 12. Hanging groove; 13. Insertion hole; 20. Tool holder; 21. Traction motor; 22. Drum; 23. Connecting steel rope; 24. Connector; 25. Hook; 251. Connecting part; 252. Hanging part; 253. Slide groove; 254. T-shaped slider; 255. Waist-shaped hole; 256. Connecting rod; 257. Through hole; 258. Limiting block; 259. Spring; 2510. Insertion hole; 26. Internal groove; 27. Hydraulic cylinder; 28. Insertion rod. Detailed Implementation

[0054] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0055] 1. The components of Examples 1, 2, and 3 are as follows:

[0056]

[0057] Example 1: Balanced type, with moderate performance in all aspects, suitable for general steel rolling shearing conditions.

[0058] Example 2: High Co, high C, high W, pursuing ultimate red hardness and wear resistance, suitable for continuous high temperature heavy load shearing.

[0059] Example 3: Low C, low Co, low Nb, prioritizing toughness, suitable for impact loads or high-speed shearing of thin plates.

[0060] 2. The components of Comparative Examples 1, 2, and 3 are as follows:

[0061]

[0062] 3. Standardized process parameters (used in all examples and comparative examples)

[0063] The manufacturing process of the knife is as follows:

[0064] Step 1: Smelt and cast the cutting tool components according to the proportions described in the embodiments or comparative examples into ingots;

[0065] Step 2: Perform high-temperature homogenization treatment on the ingot at a temperature of 1200±10℃ for 12 hours.

[0066] Step 3: Perform multi-directional forging and three-directional upsetting, with a total deformation ratio of 6 and a final forging temperature of 980℃;

[0067] Step 4: Perform spheroidizing annealing at a temperature of 850±10℃, hold for 6 hours, and then slowly cool to ≤500℃.

[0068] Step 4: Perform rough machining and shaping;

[0069] Step 6, perform final heat treatment:

[0070] Step 61, Quenching: Preheat in stages to 820±10℃, then raise the temperature to 1150±10℃ for austenitization, hold for 25 minutes, and then quench in oil or under high pressure.

[0071] Step 62, cryogenic treatment: keep warm at -120±10℃ for 2 hours;

[0072] Step 63, Tempering: Temper at 570±10℃ 3 times, holding for 2 hours each time;

[0073] Step 7: Perform finishing to the final cutting edge size.

[0074] 4. Performance Parameter Comparison

[0075] 4.1 Microstructure parameters

[0076]

[0077] As shown in the table above, in Comparative Example 2, the MC volume fraction was only 3.2%, and the carbide was severely coarsened (3.1 μm); in Comparative Example 3, the MC / M6C ratio was reversed (too much MC), and the carbide was generally coarser.

[0078] 4.2 Mechanical Property Analysis

[0079]

[0080] As shown in the table above, the hardness of Comparative Example 1 at 650℃ is only 46.5 HRC, which is 6.7 HRC lower than that of Example 1, demonstrating the crucial role of Co in red hardness. Comparative Example 2's K... IC Only 24.5, 22% lower than in Example 1, demonstrating the contribution of Nb to toughness (grain refinement). Strength-toughness matching: K in Comparative Example 3 IC With a hardness of only 22.0, Example 1 showed a 43% improvement in toughness at a comparable hardness, demonstrating the importance of proportion matching.

[0081] 4.3 High-temperature shearing performance (simulated steel rolling conditions: 850℃ steel plate, shearing speed 5 times / min)

[0082]

[0083] As shown in the table above, after 1000 cycles, the adhesion area of ​​Examples 1-3 was ≤7%, while that of Comparative Example 2 was as high as 55%, proving the key role of Nb in inhibiting adhesion. After 1000 cycles, the edge wear of Example 2 was only 0.04 mm, while that of Comparative Example 2 was 0.35 mm, proving the synergistic anti-wear effect of Co+Nb. Comparative Examples 2 and 3 showed chipping after 600-800 cycles, which was due to coarse carbides (no Nb) or an imbalanced ratio (too much MC) leading to insufficient toughness.

[0084] In summary, the following conclusions are drawn: (1) Co and Nb are indispensable. If either element is missing, the red hardness or adhesion performance will be significantly deteriorated; (2) The Co:Nb ratio needs to be strictly controlled. In Comparative Example 3, the Co / Nb ratio deviated significantly. Although both Co and Nb are present, the performance is even worse than that of the comparative example that lacks a single element; (3) The synergistic effect of Co and Nb far exceeds that of simple addition. Example 1 is significantly better than any comparative example in terms of red hardness, toughness and anti-adhesion, which proves that the composite addition of Co+Nb produces an excellent synergistic effect.

[0085] like Figures 1 to 10 As shown, a shearing machine includes a steel rolling shearing cutter 10 as described in the above embodiment and a cutter holder 20 for mounting the cutter 10.

[0086] The tool 10 has hook holes 11 installed on both sides, and a mounting groove 12 and insertion holes 13 distributed on both sides of the mounting groove 12 are provided on the top of the tool 10. The mounting groove 12 has a T-shaped groove with a smaller top and a larger bottom. The insertion holes 13 and the bottom space of the T-shaped groove are connected.

[0087] A traction motor 21 is mounted on the tool holder 20. A drum 22 is mounted on the output end of the traction motor 21. A connecting steel rope 23 is wound on the drum 22, and a connector 24 is mounted on the free end of the connecting steel rope 23 for connecting to the hook hole 11. A hook 25 is mounted in the middle of the bottom surface of the tool holder 20. The hook 25 is adapted to the mounting groove 12. The hook 25 includes a connecting part 251 located in the middle and mounting parts 252 distributed on both sides of the bottom of the connecting part 251. The bottom sides of the connecting part 251 are inclined structures with grooves 253. The side of the mounting part 252 that contacts the connecting part 251 is an inclined structure with a T-shaped slider 254. The T-shaped slider 254 is adapted to the groove 253. A waist-shaped hole 255 is provided in the middle of the connecting part 251. A connecting rod 256 is slidably installed in the waist-shaped hole 255. A through hole 257 is provided on the hanging part 252. The through hole 257 is perpendicular to the connecting part 251, and the size of the end of the through hole 257 away from the connecting part 251 is larger than the size of the end near the connecting part 251. The connecting rod 256 is inserted into the through hole 257 and a limit block 258 is connected in the end of the through hole 257 away from the connecting part 251. A spring 259 is installed in the end of the through hole 257 away from the connecting part 251. The spring 259 is fitted on the outside of the connecting rod 256 and is located on the side of the limit block 258 near the connecting part 251. An insertion hole 2510 is provided on the hanging part 252.

[0088] The tool holder 20 located on both sides of the hook 25 is provided with an internal groove 26. A hydraulic cylinder 27 and an insert rod 28 installed at the output end of the hydraulic cylinder 27 are installed in the internal groove 26. The free end of the insert rod 28 is conical and passes through the internal groove 26 and extends to the bottom of the tool holder 20. The insert rod 28 is inserted into the insert hole 13 and is adapted to the insertion hole 2510.

[0089] In practice, the connector 24 is connected to the hook holes 11 on both sides of the cutter 10. The traction motor 21 drives the drum 22 to rotate, which in turn drives the cutter 10 upward via the connecting steel rope 23. At this state, both mounting parts 252 are attached to the side wall of the connector 251, and the distance between them is minimal. During the upward movement of the cutter 10, the two mounting parts 252 will enter the upper area of ​​the mounting groove 12 and eventually enter the bottom area. When they contact the bottom area, the two mounting parts 252 are obstructed, and the bottom area is attached to the connecting part 251. 51 moves outward until it matches the mounting slot 12. After the matching is completed, the hydraulic cylinder 27 drives the insertion rod 28 downward to insert it into the insertion hole 2510. At this time, the tool 10 is installed. When it needs to be replaced, the hydraulic cylinder 27 drives the insertion rod 28 upward. After it is disengaged from the insertion hole 2510, the traction motor 21 slowly moves through the drum 22 and the connecting steel rope 23. At the same time, as the two mounting parts 252 move downward relative to the connecting part 251, the distance between them will gradually decrease. This is because the spring 259 will act to bring the mounting part 252 closer to the connecting part 251.

[0090] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A steel rolling shearing tool, characterized in that, The composition of the cutting tool, by weight percentage, includes: C: 0.35~0.55%, W: 5.0~9.0%, Mo: 2.5~5.5%, Cr: 3.0~5.0%, V: 0.8~1.8%, Co: 2.5~6.0%, Nb: 0.05~0.30%, Si ≤ 0.6%, Mn ≤ 0.6%, with the balance being Fe and unavoidable impurities; Wherein, Co / Nb = 10~30; The cutting tool contains 12-22% MC-type carbides and M6C-type carbides by volume, with the volume ratio of MC-type carbides to M6C-type carbides controlled between 1:(1.2-2.5), and the average particle size of the carbides is ≤2.5μm.

2. The steel rolling shearing tool according to claim 1, characterized in that, The composition, by weight percentage, is as follows: C: 0.35~0.50%, W: 5.5~8.2%, Mo: 3.0~4.7%, Cr: 3.2~4.7%, V: 1.0~1.6%, Co: 2.5~5.5%, Nb: 0.13~0.26%, Si ≤ 0.5%, Mn ≤ 0.5%, with the balance being Fe and unavoidable impurities.

3. The steel rolling shearing tool according to claim 1, characterized in that, The composition, by weight percentage, is as follows: C: 0.42%, W: 6.5%, Mo: 3.5%, Cr: 4.0%, V: 1.2%, Co: 3.5%, Nb: 0.15%, Si: 0.3%, Mn: 0.4%, with the balance being Fe and unavoidable impurities.

4. The steel rolling shearing tool according to claim 2, characterized in that, The composition, by weight percentage, is as follows: C: 0.50%, W: 8.0%, Mo: 4.5%, Cr: 4.5%, V: 1.6%, Co: 5.5%, Nb: 0.25%, Si: 0.4%, Mn: 0.4%, with the balance being Fe and unavoidable impurities.

5. The steel rolling shearing tool according to claim 2, characterized in that, The composition, by weight percentage, is as follows: C: 0.38%, W: 5.5%, Mo: 3.0%, Cr: 3.5%, V: 1.0%, Co: 2.8%, Nb: 0.10%, Si: 0.3%, Mn: 0.4%, with the balance being Fe and unavoidable impurities.

6. A manufacturing process for a steel rolling shearing tool, characterized in that, Includes the following steps: Step 1: Smelt and cast into ingots according to the tool component ratio as described in any one of claims 1 to 5; Step 2: Perform high-temperature homogenization treatment on the ingot at a temperature of 1180~1250℃ for 8~20 hours. Step 3: Perform multi-directional forging or rolling for billet preparation, with a final forging temperature ≥950℃ and a total deformation ratio ≥5; Step 4: Perform spheroidizing annealing at a temperature of 820~880℃, hold at the temperature, and then slowly cool to ≤550℃. Step 5: Perform rough machining and shaping; Step 6, perform final heat treatment: Step 61, Quenching: Preheat in stages to 800~850℃, then raise the temperature to 1100~1180℃ for austenitization, hold for heat and then quench in oil or under high pressure. Step 62, cryogenic treatment: keep warm at -80℃ to -150℃ for 1~4 hours; Step 63, tempering: temper at 530~600℃ 2~4 times, holding for 1~3 hours each time; Step 7: Perform finishing to the final cutting edge size.

7. The manufacturing process according to claim 6, characterized in that, The austenitizing temperature in step (6) is 1130~1160℃, and the holding time is 15~40min; The tempering temperature is 560~590℃, and the tempering is performed 3 times. After each tempering, the temperature is cooled to room temperature before the next tempering is performed.

8. The manufacturing process according to claim 6, characterized in that, In the spheroidizing annealing process described in step (4), after holding at 820~880℃ for 4~8h, the temperature is slowly cooled to below 550℃ at a cooling rate of ≤20℃ / h, and then furnace cooled or air cooled to room temperature.

9. The manufacturing process according to claim 6, characterized in that, The multi-directional forging described in step (3) involves upsetting and drawing in at least two directions, and the forging ratio is ≥6.

10. A shearing machine comprising a steel rolling shearing cutter as described in any one of claims 1 to 5 and a cutter holder for mounting the cutter.

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