A center trough having a tungsten carbide reinforced wear layer and a method of making the same

Abstract

This invention proposes a central trough with a tungsten carbide-reinforced wear-resistant layer and its preparation method. The central trough body includes a shovel plate sidewall, a baffle plate sidewall, and a middle plate and a bottom plate for connecting the two sidewalls. Multiple first mounting grooves are provided on the upper surface of the middle plate, and a second mounting groove is provided on the inner side of the shovel plate sidewall, on the side in contact with the shovel plate. A tungsten carbide wear-resistant layer is provided in both the first and second mounting grooves. The tungsten carbide wear-resistant layer is metallurgically bonded to the central trough body, which is a casting. This invention avoids the problems of stress concentration and easy detachment of the wear-resistant layer in traditional cast-welded structures by metallurgically bonding the tungsten carbide wear-resistant layer to the central trough body. By providing the tungsten carbide wear-resistant layer in the coal transport and contact positions with the scraper, this invention can specifically solve the wear failure problem in the core area of ​​the central trough body.

Description

Technical Field

[0001] This invention relates to the field of mining machinery manufacturing technology, and in particular to a central groove with a tungsten carbide-reinforced wear-resistant layer and its preparation method. Background Technology

[0002] The central trough is the core load-bearing and material conveying component of the scraper conveyor, directly undertaking the functions of carrying, guiding, and conveying materials such as coal and gangue. Its wear resistance, structural strength, and service life directly determine the continuous production efficiency of the fully mechanized mining face, equipment operation and maintenance costs, and underground mining safety. The underground fully mechanized mining environment is extremely harsh. The inner side of the trough wall and the upper surface of the central plate are subjected to high-frequency impact and severe friction from materials for a long time, while also suffering from reciprocating scraping wear from the scraper. It is the key component of the scraper conveyor with the highest wear failure frequency and the most frequent replacement.

[0003] The existing middle sections are made of cast-welded or integral casting. The cast-welded sections use NM450 or NM500 high-strength alloy steel plates as the middle plate, which is welded to ZG30SiMn cast channel sides. The hardness of the middle plate (HB425-480) is insufficient for wear resistance under high gangue content conditions. At the same time, the weld seam of dissimilar materials is prone to become a weak area of ​​stress concentration, which poses a risk of cracking. The integrally cast middle sections are made of a single alloy cast iron and do not have targeted reinforcement design for key wear-prone parts such as the channel sides and middle plate. They only rely on conventional surface heat treatment to improve performance, resulting in insufficient overall wear resistance (hardness only HRC30-35). They cannot take into account both the overall structural strength and local wear resistance, and are prone to premature failure in core wear areas such as the edges of the channel sides and the middle of the middle plate. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] To achieve the above objectives, the present invention proposes a central groove with a tungsten carbide reinforced wear-resistant layer, comprising a central groove body, wherein the central groove body includes a shovel plate groove side, a baffle groove side, and a middle plate and a bottom plate for connecting the two side groove sides;

[0006] The upper surface of the middle plate is provided with a plurality of first mounting grooves, and the inner side of the shovel plate groove side that contacts the shovel plate is provided with a second mounting groove. Both the first mounting groove and the second mounting groove are provided with a tungsten carbide wear-resistant layer. The tungsten carbide wear-resistant layer is metallurgically bonded to the central tank body, which is a casting.

[0007] This invention avoids the problems of stress concentration and easy detachment of the wear-resistant layer in traditional cast and welded structures by metallurgically combining the tungsten carbide wear-resistant layer with the central tank body. The tungsten carbide wear-resistant layer is provided in the central tank body at the coal transport position and the contact position with the scraper, which can specifically solve the wear failure problem in the core area of ​​the central tank body.

[0008] Optionally, the tungsten carbide wear-resistant layer has a serrated surface on the side facing the central groove body; A guide groove is provided on the side of the tungsten carbide wear-resistant layer in the first mounting groove that faces away from the middle plate.

[0009] Furthermore, the thickness of the tungsten carbide wear-resistant layer in the first mounting groove is set to 8-12 mm, and the thickness of the tungsten carbide wear-resistant layer in the second mounting groove is set to 10-15 mm.

[0010] Furthermore, the coverage area of ​​the tungsten carbide wear-resistant layer on the inner side of the second mounting groove extends from the end away from the middle plate toward the middle plate, the thickness of the tungsten carbide wear-resistant layer gradually increases from the top of the groove side downwards, and the coverage range of the tungsten carbide wear-resistant layer is set to 1 / 2-2 / 3 of the groove side height direction. The tungsten carbide wear-resistant layer in the first mounting groove fully covers the upper surface of the middle plate along the scraper movement direction.

[0011] Furthermore, the tungsten carbide wear-resistant layer is made of tungsten carbide particles with a purity of not less than 99.5%, and the particle size range of the tungsten carbide particles is 50-200μm, of which the proportion of tungsten carbide particles with a particle size of 100-150μm is not less than 60%. Furthermore, the tungsten carbide particles in the tungsten carbide wear-resistant layer comprise 30%-40% by mass.

[0012] Furthermore, the top corners of the inner side of the shovel groove and the top corners of the inner side of the baffle groove are both provided with an arc transition of R5-R8, and the tungsten carbide particle content in this area is increased by 5%-10%.

[0013] This application also provides a method for preparing a central groove with a tungsten carbide-reinforced wear-resistant layer as described above, comprising: S1. Based on the structural dimensions of the central groove, a lost foam mold is prepared, and a molding cavity is provided in the mold corresponding to the positions of the first and second mounting grooves. S2. Use tungsten carbide particles with a purity of not less than 99.5% and composite binder to prepare tungsten carbide particle preforms; S3. Place the prepared tungsten carbide particle preform into a lost foam mold, and sequentially perform substrate melting, casting, metallurgical bonding, and cooling. S4. After cooling is complete, open the box, remove the casting, and perform cleaning, grinding, non-destructive testing, and performance testing.

[0014] Furthermore, a serrated fixing groove is provided in the molding cavity corresponding to the serrated surface of the tungsten carbide wear-resistant layer.

[0015] Furthermore, in step S2, when preparing the tungsten carbide particle preform, a composite binder of phenolic resin and water glass is selected as the binder, wherein the mass ratio of phenolic resin to water glass is 1:1.

[0016] Furthermore, in step S2, the preparation of the tungsten carbide particle preform specifically includes: Add tungsten carbide particles and composite binder to a high-speed mixer at a mass ratio of 3:1-5:1, mix for ≥30 minutes, and the mixer speed is not less than 500 r / min; Tungsten carbide granule preforms are pressed into a molded cavity using a 50-80MPa hydraulic press. The density of the tungsten carbide granule preforms is controlled to be 3.5-4.0 g / cm³. The pressed tungsten carbide granule preforms are placed in a hot air drying oven and dried using a stepped drying process: the temperature is raised to 120°C at a rate of 50°C / h and held for 1 hour to remove surface moisture; then the temperature is raised to 180°C at a rate of 30°C / h and held for 2-4 hours to ensure that the binder is fully cured; after curing, the preforms have a compressive strength ≥15MPa, which meets the requirements for resisting the impact of molten steel during casting.

[0017] Furthermore, in step S3, during the base material melting process, the melting temperature is controlled at 1500–1550°C and held for 30–60 minutes; during the holding period, argon gas (flow rate 1.0–1.5 m³ / h) is introduced for stirring to remove impurities and gases from the molten steel and ensure the purity of the molten steel. The base material is ZG35CrMo alloy cast steel, and its chemical composition is strictly controlled as follows: C: 0.32%~0.38%, Cr: 0.8%~1.2%, Mo: 0.2%~0.3%, Si: 0.6%~0.8%, Mn 0.8%~1.0%, P≤0.03%, S≤0.02%.

[0018] Furthermore, in S3, during the casting operation, a bottom-pouring method is adopted, the casting speed is precisely controlled at 5-8 kg / s, the casting temperature is 1480-1520℃, and argon gas is introduced for protection throughout the casting process, with the argon gas flow rate controlled at 0.5-1.0 m³ / h to prevent oxidation of molten steel and secondary pollution. A riser is installed at the top of the mold corresponding to the thick part of the casting. The volume of the riser is 15% to 20% of the volume of the casting to ensure sufficient feeding of the casting.

[0019] Furthermore, in step S3, the metallurgical bonding and cooling process includes the following steps: Thermal insulation and fusion: After casting, place the mold in the insulation pit and maintain the temperature at 800-900℃ for 2-3 hours to allow the molten steel base material to fully fuse with the tungsten carbide particle precast block, forming a dense metallurgical bonding layer with a thickness of 1-2mm, ensuring a bonding strength ≥350Mpa. Step-cooling: A controllable step-cooling process is adopted. In the first stage, the temperature is cooled to 500℃ at a rate of 50-80℃ / h. In the second stage, the temperature is cooled to 200℃ at a rate of 30-50℃ / h. In the third stage, the temperature is naturally cooled to room temperature. During the cooling process, the cooling rate is precisely controlled by wrapping the outer wall of the mold with thermal insulation cotton to avoid thermal cracks caused by excessive temperature difference. Dehydrogenation treatment: When cooled to 500℃, hold for 1 hour to perform dehydrogenation treatment, reduce the hydrogen content inside the casting, control the oxygen content to ≤2ppm, improve the stability of the tank structure, and avoid hydrogen-induced cracks during later use.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall structure of a central groove with a tungsten carbide-reinforced wear-resistant layer according to the present invention; Figure 2 This is a schematic diagram of the central groove body structure of a central groove with a tungsten carbide reinforced wear-resistant layer according to the present invention; Figure 3 This is a schematic diagram of a carbide wear-resistant layer structure with a central groove having a tungsten carbide reinforced wear-resistant layer according to the present invention. Figure 4 This is a schematic diagram of the method steps for preparing a central groove with a tungsten carbide-reinforced wear-resistant layer according to the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. Central trough body; 2. Shovel plate trough side; 3. Baffle plate trough side; 4. Middle plate; 5. Bottom plate; 6. First mounting trough; 7. Second mounting trough; 8. Tungsten carbide wear-resistant layer; 9. Serrated surface; 10. Guide trough. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] This invention proposes a central groove with a tungsten carbide-reinforced wear-resistant layer, as described below. Figures 1 to 3 Please provide a detailed explanation.

[0025] A central groove with a tungsten carbide reinforced wear-resistant layer includes a central groove body 1, the central groove body 1 including a shovel groove side 2, a baffle groove side 3, and a middle plate 4 and a bottom plate 5 for connecting the two side groove sides. Multiple first mounting grooves 6 are provided on the upper surface of the middle plate 4. A second mounting groove 7 is provided on the inner side of the shovel plate groove 2 that contacts the shovel plate. A tungsten carbide wear-resistant layer 8 is provided in both the first mounting groove 6 and the second mounting groove 7. The tungsten carbide wear-resistant layer 8 is metallurgically combined with the central tank body 1, which is a casting.

[0026] This invention metallurgically combines the tungsten carbide wear-resistant layer 8 with the central tank body 1. The central tank body 1 is integrally cast without welding seams, and the metallurgical bonding strength between the wear-resistant layer and the substrate is ≥350 MPa. This avoids the problems of stress concentration and easy detachment of the wear-resistant layer in traditional cast-welded structures. The tungsten carbide wear-resistant layer 8 is provided in the central tank body 1 at the coal transport position and at the contact position with the scraper, which can specifically solve the wear failure problem in the core area of ​​the central tank body 1. The hardness of the tungsten carbide reinforced wear-resistant layer is ≥HRC60, which is more than twice as wear-resistant as the traditional central tank (HRC30~35), significantly reducing the replacement frequency of the central tank.

[0027] In some embodiments, considering that the casting process of the central tank body 1 requires the use of lost foam, and the tungsten carbide wear-resistant layer 8 is placed in the lost foam to integrally prepare the tungsten carbide wear-resistant layer 8 and the central tank body 1, in order to better metallurgically bond the central tank body 1 and the tungsten carbide wear-resistant layer 8 and avoid the tungsten carbide wear-resistant layer 8 from shifting during the casting process of the central tank body 1, a serrated surface 9 is provided on the side of the tungsten carbide wear-resistant layer 8 facing the central tank body 1, and a serrated groove that interlocks with the serrated surface 9 is provided in the lost foam. The tungsten carbide wear-resistant layer 8 is fixed by the interlocking between the serrated groove and the serrated surface 9.

[0028] It should be noted that after the central tank body 1 is poured, a serrated interlocking structure will be formed between the tungsten carbide wear-resistant layer 8 and the central tank body 1. Through the serrated transition design, the impact resistance of the central tank body 1 and the tungsten carbide wear-resistant layer 8 can be improved.

[0029] In some embodiments, a guide groove 10 is provided on the side of the tungsten carbide wear-resistant layer 8 in the first mounting groove 6 away from the middle plate 4. When transporting coal blocks, the coal blocks can move in the guide groove 10, thereby restricting the position of the coal blocks after they have moved, so that the coal blocks can fully contact the tungsten carbide wear-resistant layer 8 during the movement, and reducing the friction between the coal blocks and the middle groove body 1.

[0030] In some embodiments, the thickness of the tungsten carbide wear-resistant layer 8 in the first mounting groove 6 is set to 8-12 mm, and the thickness of the tungsten carbide wear-resistant layer 8 in the second mounting groove 7 is set to 10-15 mm. Differentiating the thickness of the tungsten carbide wear-resistant layer 8 in different mounting grooves can specifically improve the wear resistance of the tungsten carbide wear-resistant layer 8 in different wear areas. During operation, the scraper in the scraper conveyor will abut against the inner wall of the second mounting groove 7 under the tension of the iron chain. Since the scraper is generally made of steel, significant wear is easily generated between the scraper and the tungsten carbide wear-resistant layer 8. However, the tungsten carbide wear-resistant layer 8 in the first mounting groove 6 mainly rubs against the coal block. Therefore, the thickness of the tungsten carbide wear-resistant layer 8 in the second mounting groove 7 is set to be greater than that in the first mounting groove 6.

[0031] In some embodiments, as mentioned above, during operation, the scraper in the scraper conveyor will abut against the upper side and middle of the inner wall of the second mounting groove 7 under the tension of the iron chain. In order to ensure that the tungsten carbide wear-resistant layer 8 completely covers the scraper abutment position, the coverage area of ​​the tungsten carbide wear-resistant layer 8 on the inner side of the second mounting groove 7 extends from the end away from the middle plate 4 toward the middle plate 4, and the coverage range of the tungsten carbide wear-resistant layer 8 is set to 1 / 2-2 / 3 of the groove height direction; thereby ensuring that the tungsten carbide wear-resistant layer 8 can completely cover the scraper abutment position in the second mounting groove 7, effectively reducing the wear and consumption at the contact position between the middle groove body 1 and the scraper. The tungsten carbide wear-resistant layer 8 in the first mounting groove 6 fully covers the upper surface of the middle plate 4 along the scraper movement direction. That is, on the middle plate 4 of each middle groove body 1, several first mounting grooves 6 are arranged through the length of the middle plate 4, so that the tungsten carbide wear-resistant layer 8 in each first mounting groove 6 can be completely covered in the corresponding first mounting groove 6 along the length of the middle plate 4.

[0032] Furthermore, considering that during use, when the scraper pushes the coal block for transportation, the bottom of the scraper will come into contact with the inner side of the two sides of the trough due to the resistance of the coal block, that is, during long-term operation, the area with greater wear on the inner side of the trough is the area in contact with the bottom of the scraper. Therefore, the thickness of the tungsten carbide wear-resistant layer 8 is gradually increased from the top of the trough to the bottom.

[0033] In some embodiments, the tungsten carbide wear-resistant layer 8 is made of tungsten carbide particles with a purity of not less than 99.5%, and the particle size range of the tungsten carbide particles is 50-200μm, of which the proportion of tungsten carbide particles with a particle size of 100-150μm is not less than 60%; this particle size ratio can ensure the density of the wear-resistant layer and improve the impact wear resistance. Furthermore, the tungsten carbide particles in the tungsten carbide wear-resistant layer 8 have a mass percentage content of 30%-40%, balancing wear resistance and impact toughness, and avoiding excessive particle content that could lead to brittleness of the wear-resistant layer.

[0034] Specifically, when setting the thickness of the tungsten carbide wear-resistant layer 8, the thickness and particle content of the wear-resistant layer can be adjusted according to different coal seam thicknesses, mining intensity and material characteristics, adapting to different scenarios such as mines with high gangue content and thin coal seams, making it highly versatile.

[0035] In some embodiments, the top corners of the inner side of the scraper groove 2 and the top corners of the inner side of the baffle groove 3 are provided with an arc transition of R5-R8, and the tungsten carbide particle content in this area is increased by 5%-10%. This specifically enhances the impact and wear resistance of the corners, preventing impacts on the corners during scraper operation and avoiding corner breakage.

[0036] This invention proposes a precise reinforcement scheme for easily worn parts. By differentiating the thickness, particle content, and coverage of the tungsten carbide wear-resistant layer 8, as well as the sawtooth transition structure and the rounded corner reinforcement design, it specifically solves the wear failure problem in the core area and significantly reduces the wear-resistant blind zone.

[0037] This application also provides a method for preparing the above-mentioned central groove with a tungsten carbide reinforced wear-resistant layer, as described below. Figure 4 Please provide a detailed explanation.

[0038] A method for preparing a central groove with a tungsten carbide-reinforced wear-resistant layer as described above, comprising: S1. Based on the structural dimensions of the central groove, a lost foam mold is prepared, and a molding cavity is provided in the mold at the positions corresponding to the first mounting groove 6 and the second mounting groove 7. S2. Use tungsten carbide particles with a purity of not less than 99.5% and composite binder to prepare tungsten carbide particle preforms; S3. Place the prepared tungsten carbide particle preform into a lost foam mold, and sequentially perform substrate melting, casting, metallurgical bonding, and cooling. S4. After cooling is complete, open the box, remove the casting, and perform cleaning, grinding, non-destructive testing, and performance testing.

[0039] In some embodiments, in S1, according to the structural dimensions of the central groove design, a lost foam casting is prepared (foam density ≥ 0.03 g / cm³, ensuring molding accuracy); a molding cavity is precisely machined at the position corresponding to the first mounting groove 6 and the second mounting groove 7 of the mold, and a serrated fixing groove (groove depth 2-3 mm, spacing 5-8 mm) is machined on the inner wall of the molding cavity to engage with the serrated surface 9 of the tungsten carbide wear-resistant layer 8, positioning and fixing the tungsten carbide particle preform, ensuring that the position of the tungsten carbide particle preform is accurate and tightly fitted to the inner wall of the mold, avoiding displacement during casting.

[0040] In some embodiments, during S2, when preparing the tungsten carbide particle preform, a composite binder of phenolic resin and water glass is selected as the binder, wherein the mass ratio of phenolic resin to water glass is 1:1. This composite binder combines high-temperature stability and bonding strength, and can prevent the generation of harmful gases when the preform melts at high temperatures.

[0041] In some embodiments, S2, the preparation of tungsten carbide particle preforms specifically includes: Mixing and pressing: Put tungsten carbide particles and composite binder into a high-speed mixer at a mass ratio of 3:1-5:1, mix for ≥30 minutes, and the mixer speed is not less than 500 r / min to ensure uniform mixing; Tungsten carbide granule preforms are pressed into a molded cavity using a 50-80MPa hydraulic press. The density of the tungsten carbide granule preforms is controlled at 3.5-4.0 g / cm³ to avoid excessive porosity of the wear-resistant layer due to low density. Drying and curing: The pressed tungsten carbide granule preforms are placed in a hot air drying oven and a step drying process is adopted: the temperature is raised to 120℃ at a rate of 50℃ / h and kept at the temperature for 1 hour to remove surface moisture. Then, raise the temperature to 180℃ at a rate of 30℃ / h and hold for 2-4 hours to ensure that the adhesive is fully cured; after curing, the compressive strength of the precast block is ≥15MPa, which meets the requirements for resisting the impact of molten steel during casting.

[0042] The use of phenolic resin-water glass composite binder and stepped drying and curing process ensures the high-temperature stability and molding accuracy of the precast blocks, providing a foundation for metallurgical bonding.

[0043] In some embodiments, a serrated surface 9 is provided on the side of the tungsten carbide particle preform facing the molding cavity. The serrated surface 9 is designed according to the serrated fixing groove (groove depth 2-3mm, spacing 5-8mm) in the molding cavity to ensure that the serrated surface 9 can be fully engaged with the serrated fixing groove to avoid displacement of the carbide preform.

[0044] The dried tungsten carbide granule preforms are embedded into the molding cavity of the mold, ensuring a tight fit. Following the lost foam casting assembly process, the upper mold, lower mold, core, and end baffles are installed sequentially. The mold joints are sealed with sealant to ensure a good seal and prevent leakage of molten steel during pouring. The lost foam casting assembly process is a relatively mature existing technology and will not be described in detail here.

[0045] In some embodiments, during S3, when the base material is smelted, the base material is put into a 1.5-ton medium-frequency induction furnace for smelting, the smelting temperature is controlled at 1500-1550℃, and the temperature is held for 30-60 minutes; during the holding period, argon gas (flow rate 1.0-1.5m³ / h) is introduced for stirring to remove impurities and gases from the molten steel and ensure the purity of the molten steel (oxygen content ≤50ppm). The base material is ZG35CrMo alloy cast steel, and its chemical composition is strictly controlled as follows: C: 0.32%~0.38%, Cr: 0.8%~1.2%, Mo: 0.2%~0.3%, Si: 0.6%~0.8%, Mn: 0.8%~1.0%, P≤0.03%, S≤0.02%. This material combines high strength (tensile strength ≥650MPa) with excellent casting fluidity, making it suitable for integral casting requirements.

[0046] In some embodiments, in S3, when performing the casting operation, a bottom-pouring method is adopted, the casting speed is precisely controlled at 5-8 kg / s, and the casting temperature is 1480-1520℃. Too high a temperature can easily cause the tungsten carbide particles to decompose, while too low a temperature will affect the metallurgical bonding effect. Argon gas is introduced for protection throughout the casting process, and the argon gas flow rate is controlled at 0.5-1.0 m³ / h to prevent the steel liquid from oxidizing and causing secondary pollution. A riser is set at the top of the mold corresponding to the thick part of the casting. The volume of the riser is 15% to 20% of the volume of the casting to ensure sufficient feeding of the casting and avoid internal defects such as shrinkage cavities and porosity.

[0047] In some embodiments, S3, metallurgical bonding and cooling includes the following processes: Thermal insulation and fusion: After casting, place the mold in the insulation pit and maintain the temperature at 800-900℃ for 2-3 hours to allow the molten steel base material to fully fuse with the tungsten carbide particle precast block, forming a dense metallurgical bonding layer with a thickness of 1-2mm, ensuring a bonding strength ≥350Mpa. Step-cooling: A controllable step-cooling process is adopted. In the first stage, the temperature is cooled to 500℃ at a rate of 50-80℃ / h. In the second stage, the temperature is cooled to 200℃ at a rate of 30-50℃ / h. In the third stage, the temperature is naturally cooled to room temperature. During the cooling process, the cooling rate is precisely controlled by wrapping the outer wall of the mold with thermal insulation cotton to avoid thermal cracks caused by excessive temperature difference. Dehydrogenation treatment: When cooled to 500℃, hold for 1 hour to perform dehydrogenation treatment, reduce the hydrogen content inside the casting, control the oxygen content to ≤2ppm, improve the stability of the tank structure, and avoid hydrogen-induced cracks during later use.

[0048] By using an integrated process of "melting-heat preservation fusion-step cooling", the temperature, cooling rate and argon protection parameters are precisely controlled to achieve a dense metallurgical bond between the wear-resistant layer and the substrate, while avoiding defects such as thermal cracking and hydrogen-induced cracking.

[0049] In some embodiments, during S4, subsequent processing and inspection specifically include: Cleaning and Grinding: After unpacking and removing the casting, shot blasting (shot diameter 1.5~2.0mm, pressure 0.6~0.8MPa) is used to remove surface oxide scale, burrs and riser residue; the wear-resistant layer surface is ground to ensure uniform thickness (deviation ±0.5mm) and surface roughness Ra≤25μm; Non-destructive testing: Ultrasonic testing (UT, testing frequency 2-5MHz) is used to comprehensively inspect the interface between the tungsten carbide wear-resistant layer 8 and the substrate to ensure that there are no defects such as peeling or lack of fusion; magnetic particle testing (MT) is used to inspect the tank body to eliminate surface and near-surface defects such as cracks and inclusions. Performance testing: One finished product is randomly selected from each batch for performance testing: the wear resistance is tested using an MLD-100 impact wear tester to simulate downhole working conditions (wear amount ≤0.5g / h), the bond strength is tested using a tensile shear test (≥350MPa), and the hardness of the wear-resistant layer is tested using a Rockwell hardness tester (≥HRC60) to ensure that the product performance meets the standards.

[0050] A full-process performance control system has been established, combining non-destructive testing and targeted performance testing to ensure stable product quality. It can be adapted to mining conditions with high gangue content, long cycle and high intensity, and its service life is more than twice that of traditional products.

[0051] Through a comprehensive system of precise temperature control, non-destructive testing, and performance sampling, we ensure a product qualification rate of ≥98%. Dehydrogenation treatment and stepped cooling processes avoid internal defects, reducing the failure rate by more than 50% during product use and improving the continuous production efficiency of fully mechanized mining faces.

[0052] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A central groove with a tungsten carbide-reinforced wear-resistant layer, characterized in that, It includes a central trough body, which includes a shovel plate trough side, a baffle plate trough side, and a middle plate and a bottom plate for connecting the two side trough sides; The upper surface of the middle plate is provided with a plurality of first mounting grooves, and the inner side of the shovel plate groove side that contacts the shovel plate is provided with a second mounting groove. Both the first mounting groove and the second mounting groove are provided with a tungsten carbide wear-resistant layer. The tungsten carbide wear-resistant layer is metallurgically bonded to the central tank body, which is a casting.

2. A central groove with a tungsten carbide-reinforced wear-resistant layer as described in claim 1, characterized in that, The tungsten carbide wear-resistant layer has a serrated surface on the side facing the central groove body; A guide groove is provided on the side of the tungsten carbide wear-resistant layer in the first mounting groove that faces away from the middle plate.

3. A central groove with a tungsten carbide-reinforced wear-resistant layer as described in claim 1, characterized in that, The thickness of the tungsten carbide wear-resistant layer in the first mounting groove is set to 8-12 mm, and the thickness of the tungsten carbide wear-resistant layer in the second mounting groove is set to 10-15 mm.

4. A central groove with a tungsten carbide-reinforced wear-resistant layer as described in claim 3, characterized in that, The coverage area of ​​the tungsten carbide wear-resistant layer on the inner side of the second mounting groove extends from the end away from the middle plate toward the middle plate. The thickness of the tungsten carbide wear-resistant layer gradually increases from the top of the groove side downwards, and the coverage range of the tungsten carbide wear-resistant layer is set to 1 / 2-2 / 3 of the groove side height direction. The tungsten carbide wear-resistant layer in the first mounting groove fully covers the upper surface of the middle plate along the scraper movement direction.

5. A central groove with a tungsten carbide-reinforced wear-resistant layer as described in any one of claims 1-4, characterized in that, The tungsten carbide wear-resistant layer is made of tungsten carbide particles with a purity of not less than 99.5%, and the particle size range of the tungsten carbide particles is 50-200μm, of which the proportion of tungsten carbide particles with a particle size of 100-150μm is not less than 60%. Furthermore, the tungsten carbide particles in the tungsten carbide wear-resistant layer comprise 30%-40% by mass.

6. A central groove with a tungsten carbide-reinforced wear-resistant layer as described in claim 5, characterized in that, The top corners of the inner side of the shovel groove and the top corners of the inner side of the baffle groove are both provided with an arc transition of R5-R8, and the tungsten carbide particle content in this area is increased by 5%-10%.

7. A method for preparing a central groove with a tungsten carbide-reinforced wear-resistant layer as described in claim 6, characterized in that, include: S1. Based on the structural dimensions of the central groove, a lost foam mold is prepared, and a molding cavity is provided in the mold corresponding to the positions of the first and second mounting grooves. S2. Use tungsten carbide particles with a purity of not less than 99.5% and composite binder to prepare tungsten carbide particle preforms; S3. Place the prepared tungsten carbide particle preform into a lost foam mold, and sequentially perform substrate melting, casting, metallurgical bonding, and cooling. S4. After cooling is complete, open the box, remove the casting, and perform cleaning, grinding, non-destructive testing, and performance testing.

8. The preparation method according to claim 7, characterized in that, In step S1, a sawtooth fixing groove is provided on the sawtooth surface corresponding to the tungsten carbide wear-resistant layer inside the molding cavity.

9. The preparation method according to claim 7, characterized in that, In step S2, when preparing tungsten carbide particle preforms, a composite binder of phenolic resin and water glass is selected as the binder, wherein the mass ratio of phenolic resin to water glass is 1:

1.

10. The preparation method according to claim 9, characterized in that, In step S2, the preparation of tungsten carbide particle preforms specifically includes: Add tungsten carbide particles and composite binder to a high-speed mixer at a mass ratio of 3:1-5:1, mix for ≥30 minutes, and the mixer speed is not less than 500 r / min; Tungsten carbide granule preforms are pressed into a molded cavity using a 50-80MPa hydraulic press. The density of the tungsten carbide granule preforms is controlled to be 3.5-4.0 g / cm³. The pressed tungsten carbide granule preforms are placed in a hot air drying oven and dried using a stepped drying process: the temperature is raised to 120°C at a rate of 50°C / h and held for 1 hour to remove surface moisture; then the temperature is raised to 180°C at a rate of 30°C / h and held for 2-4 hours to ensure that the binder is fully cured; after curing, the preforms have a compressive strength ≥15MPa, which meets the requirements for resisting the impact of molten steel during casting.

11. The preparation method according to claim 7, characterized in that, In step S3, during the base material melting process, the melting temperature is controlled at 1500–1550°C and held for 30–60 minutes. During the holding period, argon gas (flow rate 1.0–1.5 m³ / h) is introduced for stirring to remove impurities and gases from the molten steel and ensure the purity of the molten steel. The base material is ZG35CrMo alloy cast steel, and its chemical composition is strictly controlled as follows: C: 0.32%~0.38%, Cr: 0.8%~1.2%, Mo: 0.2%~0.3%, Si: 0.6%~0.8%, Mn 0.8%~1.0%, P≤0.03%, S≤0.02%.

12. The preparation method according to claim 7, characterized in that, In S3, during the casting operation, a bottom-pouring method is adopted, the casting speed is precisely controlled at 5-8 kg / s, the casting temperature is 1480-1520℃, and argon gas is introduced for protection throughout the casting process, with the argon gas flow rate controlled at 0.5-1.0 m³ / h to prevent steel oxidation and secondary pollution. A riser is installed at the top of the mold corresponding to the thick part of the casting. The volume of the riser is 15% to 20% of the volume of the casting to ensure sufficient feeding of the casting.

13. The preparation method according to claim 7, characterized in that, In step S3, the metallurgical bonding and cooling process includes the following steps: Thermal insulation and fusion: After casting, place the mold in the insulation pit and maintain the temperature at 800-900℃ for 2-3 hours to allow the molten steel base material to fully fuse with the tungsten carbide particle precast block, forming a dense metallurgical bonding layer with a thickness of 1-2mm, ensuring a bonding strength ≥350Mpa. Step-cooling: A controllable step-cooling process is adopted. In the first stage, the temperature is cooled to 500℃ at a rate of 50-80℃ / h. In the second stage, the temperature is cooled to 200℃ at a rate of 30-50℃ / h. In the third stage, the temperature is naturally cooled to room temperature. During the cooling process, the cooling rate is precisely controlled by wrapping the outer wall of the mold with thermal insulation cotton to avoid thermal cracks caused by excessive temperature difference. Dehydrogenation treatment: When cooled to 500℃, hold for 1 hour to perform dehydrogenation treatment, reduce the hydrogen content inside the casting, control the oxygen content to ≤2ppm, improve the stability of the tank structure, and avoid hydrogen-induced cracks during later use.

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