A recyclable repairable alloy stud welding grinding roller and its preparation method

Abstract

This invention discloses a recyclable and repairable alloy stud-welded grinding roller and its preparation method, comprising a shaft, a grinding roller body, and alloy stud bodies. The grinding roller body is located outside the shaft, and the alloy stud bodies are located outside the grinding roller body. The alloy stud bodies are arranged in a ring shape and are connected to the outside of the grinding roller body by welding. This invention involves assembling new, qualified alloy studs into each positioning countersunk hole after the grinding roller has been in service in the industrial field for a certain period. Then, a complete set of processes is performed, including alloy stud assembly and positioning, overall gradient preheating of the component, localized welding of stud gaps, post-weld heat preservation and slow cooling, and subsequent precision machining. This process ultimately completes the regeneration and repair of the grinding roller. Using this repair process, the roller base can be repeatedly repaired by replacing the alloy studs multiple times, truly realizing the recycling and reuse of the roller base and significantly improving the utilization rate of the base material.

Description

Technical Field

[0001] This invention relates to the field of grinding roller manufacturing and remanufacturing repair technology for vertical mills and roller press mills, and in particular to a regenerable repairable alloy stud welded grinding roller and its preparation method. Background Technology

[0002] As a core piece of equipment in ore crushing, building material cement raw material production, coal powder preparation, and solid waste resource utilization, the vertical mill's grinding rollers are key vulnerable components that directly bear the pressure, impact, and abrasive cutting of materials. Operating under continuous heavy loads, the roller surface is subjected to long-term impact and grinding from high-hardness materials, making it highly susceptible to failure modes such as wear of the wear-resistant layer, localized peeling, roller surface pitting, and surface cracking. Once the grinding rollers fail, it directly leads to a decrease in grinding efficiency and unstable finished product particle size. In severe cases, it can cause equipment vibration shutdowns, significantly impacting the continuous production of the entire line.

[0003] The following problems exist in the use of alloy pin weld overlay grinding rollers on the market: When using traditional alloy pin weld overlay grinding rollers, the mainstream grinding roller processing methods in the industry are generally divided into two types. The first type is integrally cast wear-resistant alloy grinding rollers. This type of grinding roller has high overall cost and is extremely difficult to repair after wear. Most of them are directly scrapped, resulting in serious material waste. The second type is grinding rollers with integral wear-resistant layer overlay welding on the substrate surface. When repairing, it is necessary to grind and peel off the old wear-resistant layer and then re-weld it over a large area. Large-area welding results in concentrated heat input and uneven heating of the grinding roller substrate, easily leading to defects such as thermal deformation, substrate cracks, and excessive residual stress. Repeated welding repairs significantly degrade the substrate's performance, and the number of repairs is limited. Currently, some products use a stud-type grinding roller structure, placing carbide studs on the roller seat surface to improve wear resistance. However, existing processes mostly use interference fit followed by full welding or simple spot welding for fixation. Disassembly after stud wear is extremely difficult, and the removal of old studs easily damages the mounting holes of the roller seat. Once the holes deform or chip, the entire roller seat substrate is rendered unusable. Existing processes lack a complete and controllable preparation and regeneration repair process, resulting in low recycling rates for the roller seat substrate and high costs for spare parts procurement and on-site maintenance, failing to meet the actual needs of industrial production for cost reduction and efficiency improvement. Summary of the Invention

[0004] To address the shortcomings of the prior art, this invention provides a recyclable and repairable alloy stud welding grinding roller and its preparation method.

[0005] To address the aforementioned issues, this invention employs the following technical solution: a regenerable and repairable alloy stud welding grinding roller and its preparation method, comprising a shaft, a grinding roller body, and alloy stud bodies. The grinding roller body is disposed outside the shaft, and the alloy stud bodies are disposed outside the grinding roller body. The alloy stud bodies are arranged in a ring-shaped distribution and are connected to the outside of the grinding roller body by welding.

[0006] The production method includes the following: S1, Pre-treatment: Conduct comprehensive flaw detection on the roller seat base of incoming or repaired grinding rollers to screen out unqualified roller seats with through cracks or severe deformation; perform precision machining on the roller surface of qualified roller seats, and machine stepped positioning countersunk holes in an array according to process requirements; after machining, grind and clean the entire roller seat base and each positioning countersunk hole to remove residual burrs and iron filings from machining, and then use a combination of organic solvents and sandblasting to complete the degreasing and derusting treatment to ensure that the assembly working surface is clean and free of oxide scale.

[0007] S2, Pin Assembly and Positioning: Pre-screened and inspected qualified alloy pins are sequentially pressed into each positioning countersunk hole. During the assembly process, ensure that the limiting boss at the tail of the alloy pin is fully engaged in the limiting groove of the countersunk hole. After assembly, each point is inspected to strictly control the exposed height of the head of each alloy pin to be consistent and avoid height differences. After assembly, a knocking test is performed to check for problems such as loose or incomplete pin installation.

[0008] S3, Overall Preheating: The grinding roller with the assembled alloy pins is sent into the heat treatment furnace for gradient heating preheating treatment. The preheating temperature is controlled at 220-350℃. A segmented gradient heating mode is adopted to avoid local thermal stress concentration caused by rapid heating.

[0009] S4, Welding and Post-processing: Local welding is performed at the gap between the roller seats and roller surfaces of adjacent alloy studs to form a transition weld layer. After the welding is completed, the process is immediately transferred to the heat preservation process for slow cooling to eliminate the residual welding stress generated by the welding. After cooling, grinding and precision machining are carried out to smooth the transition weld layer, so that the surface of the transition weld layer and the head of the alloy stud are smoothly connected, eliminating the step edges and corners, and completing the preparation of the grinding roller.

[0010] As a further preferred embodiment of the present invention, in step S1, ultrasonic flaw detection is used to comprehensively check for hidden cracks, pores, and slag inclusions inside the roller base. After the positioning countersink is machined, the countersink step surface and inner wall are ground and polished to completely remove machining burrs and tool marks, prevent the alloy studs from being scratched during assembly, and ensure that the hole position is not easily damaged during subsequent stud disassembly and assembly.

[0011] As a further preferred embodiment of the present invention, in step S2, the pressing is performed using hydraulic tooling for static pressure pressing, with the pressing pressure controlled at 8-15MPa. Impact and hammering during assembly are strictly prohibited to avoid micro-cracks inside the studs. After assembly, each alloy stud is hammered to inspect it. The standard for qualified assembly is that the studs are not loose and have no radial or axial movement.

[0012] As a further preferred embodiment of the present invention, in step S3, preheating is carried out by overall gradient heating in the furnace, with the heating rate strictly controlled at 40-60℃ / h. After reaching the target preheating temperature, the temperature is maintained for 2-4 hours to ensure that the overall temperature of the grinding roller base, positioning countersunk hole, and alloy stud is uniform and consistent, eliminating the temperature difference between the components, providing a uniform temperature field for subsequent welding operations, and reducing the risk of welding cold cracks.

[0013] As a further preferred embodiment of the present invention, in step S4, the welding is carried out using an open arc automatic welding process, and the welding is performed in a multi-layer, multi-pass, segmented skip welding manner to avoid local heat concentration. After the welding is completed, the grinding roller is quickly transferred into a heat preservation furnace and kept at 300-380℃ for 4-6 hours. Then, it is slowly cooled to room temperature with the furnace. After cooling, rough grinding and precision machining are carried out in sequence to ensure that the transition weld layer surface and the alloy stud head are smoothly connected, without protrusions or gaps, and the overall circular runout of the roller surface meets the equipment assembly requirements.

[0014] This invention addresses the issue that after a certain period of service in industrial settings, the alloy studs on the working surface of grinding rollers gradually wear down and erode due to material impacts and grinding friction, leading to a decline in the roller's performance. During the regeneration and repair process, the original transitional weld overlay layer on the roller surface is first removed using grinding equipment, completely stripping away the surface weld material to fully expose the alloy studs. Then, a specialized ejection tool is used, applying force from the bottom of the countersunk hole to smoothly eject the worn-out alloy studs. The entire process avoids impact methods such as hammering or striking to prevent secondary damage to the roller base and countersunk hole walls. After stud removal, the roller base and all countersunk hole areas undergo visual inspection and non-destructive testing to comprehensively check for cracks in the base material. If defects such as hole wall deformation, hole edge chipping, and local fatigue damage are confirmed by inspection that the roller base substrate has no cracking defects and that the positioning countersunk holes have no deformation, chipping, or fatigue damage, the roller base substrate can continue to be used for cyclic repair. If defects exceeding the standard are found by inspection, corresponding treatment is carried out according to the defect level. After confirming that the substrate condition is qualified, new qualified alloy studs are installed in each positioning countersunk hole. Then, the entire set of processes, including alloy stud assembly and positioning, overall gradient preheating of the component, local overlay welding of stud gaps, post-weld heat preservation and slow cooling, and subsequent precision machining, are completed in sequence to finally complete the regeneration and repair of the grinding roller. Using this repair process, the roller base substrate can be repeatedly repaired by replacing alloy studs multiple times, truly realizing the cyclic reuse of the roller base substrate and greatly improving the utilization rate of substrate materials. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram illustrating the manufacturing steps of the present invention.

[0017] Explanation of markings in the diagram: 1. Shaft body; 11. Grinding roller body; 12. Alloy stud body. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1

[0019] like Figure 1-2 As shown, the present invention provides a technical solution: a regenerable repairable alloy stud welding grinding roller and its preparation method, comprising a shaft body 1, a grinding roller body 11, and an alloy stud body 12. The grinding roller body 11 is provided on the outside of the shaft body 1, and the alloy stud body 12 is provided on the outside of the grinding roller body 11. The alloy stud body 12 is arranged in a ring shape and is connected to the outside of the grinding roller body 11 by welding.

[0020] The production method includes the following: S1, Pre-treatment: Ultrasonic testing is performed on the roller base to be processed to remove workpieces with internal cracks and defects. The qualified roller base surface is machined to obtain an array of stepped positioning countersunk holes. The inner wall of the positioning countersunk holes and the stepped surface are polished to remove tool marks and burrs. The whole is sandblasted and cleaned with organic solvents to remove oil and rust, ensuring that the assembly work surface is clean.

[0021] S2, Staple assembly and positioning: The alloy staples are statically pressed using hydraulic tooling, with the pressing pressure set to 10MPa to ensure that the tail limiting boss of the alloy staple is fully engaged in the countersunk hole limiting groove. After assembly, the exposed height of the staples is checked to ensure uniform height. All staples are tapped to check for looseness or movement.

[0022] S3, Overall Preheating: Gradual heating in the heat treatment furnace at a rate of 50℃ / h, and holding at 260℃ for 3 hours to ensure uniform heating of the grinding roller.

[0023] S4, Welding and Post-processing: Open arc automatic welding is adopted, and multi-layer and multi-pass skip welding is used to complete the transition wear-resistant layer welding at the gap position. After the welding is completed, it is immediately sent to the heat preservation furnace and kept at 320℃ for 5 hours. It is then slowly cooled to room temperature with the furnace. After cooling, rough grinding and precision machining are carried out to ensure a smooth transition between the transition weld layer and the alloy stud head, and the roller surface runout meets the standard.

[0024] During the regeneration and repair process, the old transition weld layer is removed by grinding. A special ejection tool is used to eject the worn alloy pins. The roller base and positioning countersunk holes are thoroughly inspected. If the base and holes are undamaged, new alloy pins are installed. Steps S2-S4 are repeated in sequence to complete the regeneration and repair of the grinding roller. Under this process, the roller base can be repaired at least 6 times. Example 2

[0025] This invention provides a technical solution: a regenerable repairable alloy stud welding grinding roller and its preparation method, comprising a shaft body 1, a grinding roller body 11, and alloy stud bodies 12. The grinding roller body 11 is provided on the outside of the shaft body 1, and the alloy stud bodies 12 are provided on the outside of the grinding roller body 11. The alloy stud bodies 12 are arranged in a ring shape and are connected to the outside of the grinding roller body 11 by welding.

[0026] The production method includes the following: S1, Pre-treatment: Ultrasonic testing is performed on the roller base to be processed to remove workpieces with internal cracks and defects. The qualified roller base surface is machined to obtain an array of stepped positioning countersunk holes. The inner wall of the positioning countersunk holes and the stepped surface are polished to remove tool marks and burrs. The whole is sandblasted and cleaned with organic solvents to remove oil and rust, ensuring that the assembly work surface is clean.

[0027] S2, Staple assembly and positioning: The alloy staples are statically pressed using hydraulic tooling, with the pressing pressure set to 10MPa to ensure that the tail limiting boss of the alloy staple is fully engaged in the countersunk hole limiting groove. After assembly, the exposed height of the staples is checked to ensure uniform height. All staples are tapped to check for looseness or movement.

[0028] S3, Overall Preheating: Gradual heating in the heat treatment furnace at a rate of 50℃ / h, and holding at 260℃ for 3 hours to ensure uniform heating of the grinding roller.

[0029] S4, Welding and Post-processing: Open arc automatic welding is adopted, and multi-layer and multi-pass skip welding is used to complete the transition wear-resistant layer welding at the gap position. After the welding is completed, it is immediately sent to the heat preservation furnace and kept at 320℃ for 5 hours. It is then slowly cooled to room temperature with the furnace. After cooling, rough grinding and precision machining are carried out to ensure a smooth transition between the transition weld layer and the alloy stud head, and the roller surface runout meets the standard.

[0030] The regeneration and repair process is carried out in accordance with the regeneration and repair process of the present invention. Under the conditions of this process, the roller base can be cyclically repaired no less than 5 times. Example 3

[0031] This invention provides a technical solution: a regenerable repairable alloy stud welding grinding roller and its preparation method, comprising a shaft body 1, a grinding roller body 11, and alloy stud bodies 12. The grinding roller body 11 is provided on the outside of the shaft body 1, and the alloy stud bodies 12 are provided on the outside of the grinding roller body 11. The alloy stud bodies 12 are arranged in a ring shape and are connected to the outside of the grinding roller body 11 by welding.

[0032] The production method includes the following: S1, Pre-treatment: Ultrasonic testing is performed on the roller base to be processed to remove workpieces with internal cracks and defects. The qualified roller base surface is machined to obtain an array of stepped positioning countersunk holes. The inner wall of the positioning countersunk holes and the stepped surface are polished to remove tool marks and burrs. The whole is sandblasted and cleaned with organic solvents to remove oil and rust, ensuring that the assembly work surface is clean.

[0033] S2, Staple assembly and positioning: The alloy staples are statically pressed using hydraulic tooling, with the pressing pressure set to 10MPa to ensure that the tail limiting boss of the alloy staple is fully engaged in the countersunk hole limiting groove. After assembly, the exposed height of the staples is checked to ensure uniform height. All staples are tapped to check for looseness or movement.

[0034] S3, Overall Preheating: Gradual heating in the heat treatment furnace at a rate of 50℃ / h, and holding at 260℃ for 3 hours to ensure uniform heating of the grinding roller.

[0035] S4, Welding and Post-processing: Open arc automatic welding is adopted, and multi-layer and multi-pass skip welding is used to complete the transition wear-resistant layer welding at the gap position. After the welding is completed, it is immediately sent to the heat preservation furnace and kept at 320℃ for 5 hours. It is then slowly cooled to room temperature with the furnace. After cooling, rough grinding and precision machining are carried out to ensure a smooth transition between the transition weld layer and the alloy stud head, and the roller surface runout meets the standard.

[0036] The regeneration and repair process is carried out in accordance with the regeneration and repair process of the present invention. Under the conditions of this process, the roller base can be cyclically repaired no less than 4 times.

[0037] The process parameters for this invention are shown in the table below: project Example 1 Example 2 Example 3 Press-fit pressure (MPa) 10 12 14 Preheating rate (°C / h) 50 45 55 Preheating temperature (°C) 260 300 330 Preheating and heat preservation time (h) 3 2.5 4 Insulation temperature after welding (°C) 320 350 370 Post-weld heat preservation time (h) 5 4 6 Roller seat repair cycles ≥6 times ≥5 times ≥4 times In summary, this invention, through non-destructive testing and screening in the pretreatment stage, high-precision machining, and a complete cleanroom process, identifies and eliminates inherent defects in the base material at the source of component manufacturing. This fundamentally avoids early failure risks caused by inherent defects such as porosity, inclusions, and cracks within the base material. The assembly stage employs a static pressure fitting process to assemble the alloy studs, abandoning the traditional impact assembly method and completely eliminating latent internal defects such as microcracks and dislocation damage caused by impact loads, ensuring a complete and reliable bonding state at the assembly interface. A gradient heating preheating process is implemented before the welding operation to create a uniformly distributed temperature field within the grinding roller component, effectively mitigating sudden temperature changes during welding and reducing the risk of cold cracking in the weld layer from a process perspective. The welding process only performs localized welding on the gaps between the alloy studs, unlike large-area full-coverage welding, which significantly reduces the overall heat input of the component. This method effectively suppresses thermal deformation of the grinding roller base and reduces the continuous accumulation of welding residual stress, avoiding problems such as base cracking and spalling caused by stress concentration. After the grinding roller enters the wear failure stage, this repair process does not require large-scale melting and cutting of the roller base. Only the worn alloy stud components are removed, and the entire process of stud press-fitting, gradient preheating, local gap welding, and post-weld treatment is re-executed to complete the regeneration and repair of the grinding roller. The roller base can be reused multiple times without frequent replacement of the entire grinding roller base. Compared with the traditional whole-body welding repair process for grinding rollers, this technology can significantly extend the overall service life of grinding roller components, greatly reduce the procurement cost of grinding roller base spare parts for enterprises, and shorten the on-site downtime maintenance cycle. It has outstanding engineering application value and high promotion and practical value for reducing equipment operation and maintenance costs and increasing efficiency in the mining and building material grinding industries.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0039] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A regeneratively repairable alloy stud pin overlay roll and method of making the same, characterized by, It includes a shaft (1), a grinding roller body (11), and an alloy pin body (12). The grinding roller body (11) is provided on the outside of the shaft (1), and the alloy pin body (12) is provided on the outside of the grinding roller body (11). The alloy pin body (12) is distributed in a ring shape and is connected to the outside of the grinding roller body (11) by welding.

2. A regeneratively repairable alloy stud pile weld build-up roll and its manufacturing method according to claim 1, characterized in that, The production steps include the following: S1, Pre-treatment: The grinding roller base is subjected to flaw detection, the roller surface is machined and an array of stepped positioning countersunk holes are machined, and the roller base and positioning countersunk holes are cleaned by degreasing and rust removal. S2, stud assembly and positioning: Press the alloy studs into each positioning countersunk hole in sequence to ensure that the alloy stud limit boss is engaged in the countersunk hole limit slot and control the consistent exposed height of the alloy stud head. S3, Overall Preheating: The grinding roller with assembled alloy pins is preheated at a temperature of 220-350℃. S4, Welding and Post-processing: Welding is performed on the roller surface of the roller seat between adjacent alloy studs to form a transition weld layer. After welding is completed, the roller is kept warm and cooled slowly. The transition weld layer is then machined to smooth it out, thus completing the preparation of the grinding roller.

3. A regeneratively repairable alloy stud pile weld build up grinding roller and method of making the same according to claim 1, wherein, In step S1, ultrasonic testing is used to check for internal cracks, pores, and slag inclusions in the roller base. After the countersunk hole is machined, the inner wall of the countersunk hole and the step surface are ground and polished to remove machining burrs and tool marks.

4. A regeneratively repairable alloy stud pile weld build up grinding roller and method of making the same according to claim 1, wherein, In step S2, hydraulic static pressure is used for press fitting, and the press fitting pressure is controlled at 8-15MPa. After assembly, the alloy studs are tapped to test them. If the studs are not loose or move, they are considered qualified.

5. A regeneratively repairable alloy stud pile weld build up grinding roller and method of making the same according to claim 1, wherein, In step S3, preheating is carried out by overall gradient heating in the furnace, with the heating rate controlled at 40-60℃ / h; after reaching the preheating temperature, the temperature is maintained for 2-4 hours to achieve uniform temperature in all parts of the grinding roller.

6. A regeneratively restorable alloy stud pile weld build-up roll and a method of manufacturing the same according to claim 1, wherein, In step S4, the welding process adopts an open arc automatic welding process and a multi-layer, multi-pass, segmented skip welding method. After the welding is completed, the grinding roller is sent into the holding furnace and held at 300-380℃ for 4-6 hours. Then it is slowly cooled with the furnace and processed by a grinding machine after cooling to ensure that the transition weld layer surface and the alloy stud head are smoothly connected.

7. A regeneratively repairable alloy stud pile weld build up grinding roller and method of making the same according to claim 1, wherein, The process includes a regeneration and repair step. When the alloy studs on the working surface of the grinding roller are worn out, the surface transition weld layer is removed by grinding. The worn alloy studs are then ejected from the positioning countersunk holes using an ejector tool. The roller base and positioning countersunk holes are subjected to flaw detection and visual inspection. If there is no damage, new alloy studs are installed. Steps S2-S4 are repeated in sequence to complete the regeneration and repair, allowing the roller base to be reused multiple times.

Images