Chromium bronze rings and their short-process forming preparation method

Abstract

This invention discloses a chromium bronze ring and its short-process forming method. By integrating solution treatment and hot forming into the same thermal cycle, upsetting, punching, and ring rolling are performed directly using the high-temperature residual heat after solution treatment. This eliminates the independent heating steps between hot forging and solution treatment, shortening the process flow and reducing the total number of heating cycles from three to two, significantly reducing energy consumption and cost, and improving production efficiency. It also avoids grain boundary precipitate coarsening and surface oxidation dechromiumization. Furthermore, by optimizing the Cr content and synergistically adding trace elements Ti, Mo, Sb, and B, a strengthening mechanism matching process adjustment and composition compensation is established, effectively solving the problem of insufficient precipitation strengthening driving force caused by direct forming after solution treatment. This invention has strong process adaptability and can adjust parameters for high-precision rings, large rings, and rings under special working conditions, achieving a balanced improvement in the comprehensive performance of chromium bronze rings, including high strength, high conductivity, and good plasticity.

Description

Technical Field

[0001] This invention belongs to the field of copper alloy preparation technology, and more specifically, relates to a chromium bronze ring and its short-process forming preparation method. Background Technology

[0002] Chromium bronze (such as TCr1 and C18150) is a typical high-strength, high-conductivity, and wear-resistant precipitation-strengthened copper alloy, which is widely used in the manufacture of key components such as motor rotor end rings, sealing rings and gaskets, bearing cages, and mechanical connectors.

[0003] Currently, the mature process route for manufacturing such high-performance chromium bronze rings in the industry is typically: "alloy smelting → semi-continuous casting → blanking → hot forging (upsetting, punching, ring rolling) → solution treatment → quenching → cold forging (or cold forming) → aging treatment." Research indicates that rapid cooling after solution treatment is crucial for obtaining a supersaturated solid solution. However, while the traditional "hot forging → solution treatment → aging" process can achieve good overall performance, its multiple independent heating steps generally result in high energy consumption, long cycles, and damage to the microstructure and properties.

[0004] To overcome the aforementioned shortcomings, some researchers have attempted to employ short-process technologies in other copper alloy systems. For example, patent CN107716885A discloses a short-process machining technology applied to beryllium copper and copper-nickel-silicon alloys, which can shorten the process flow by 40%–60% and reduce energy consumption by 40%–50%. In the field of beryllium bronze, patent CN118635490A applies liquid forging technology to the forming and manufacturing of beryllium bronze parts to overcome the disadvantages of the long process flow and high energy consumption of the "cast billet first, then forge" method. However, these short-process solutions are all for specific alloy systems (beryllium bronze, copper-nickel-silicon alloys). The precipitation strengthening mechanisms of different copper alloys are fundamentally different, and the thermoplasticity windows of each alloy are different. When applying the above-mentioned short-process technology to the chromium bronze system, the dynamic recrystallization during the high-temperature forming process will eliminate most of the dislocations, resulting in insufficient driving force for precipitation strengthening and a decrease in the strength of the final product. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a chromium bronze ring and its short-process forming method. By integrating solution treatment and hot forming into the same thermal cycle, upsetting, punching, and ring rolling are performed directly using the high-temperature residual heat after solution treatment. This eliminates the independent heating steps between hot forging and solution treatment, shortening the process flow and reducing the total number of heating cycles from three to two, significantly reducing energy consumption and costs, and improving production efficiency. Simultaneously, it avoids grain boundary precipitate coarsening and surface oxidation dechromiumization. Furthermore, by optimizing the Cr content and synergistically adding trace elements such as Ti, Mo, Sb, and B, a strengthening mechanism matching process adjustment and composition compensation is established, effectively solving the problem of insufficient precipitation strengthening driving force caused by direct forming after solution treatment. This invention has strong process adaptability, allowing parameter adjustments for high-precision rings, large rings, and rings under special working conditions, achieving a balanced improvement in the comprehensive performance of chromium bronze rings, including high strength, high conductivity, and good plasticity.

[0006] To achieve the above objectives, according to one aspect of the present invention, a short-process forming method for manufacturing chromium bronze rings is provided, which integrates solution treatment and hot forming into the same thermal cycle, comprising the following steps: Step 1: Heat the chromium bronze billet to 950 ℃~1020 ℃ and hold for 1~3 hours to allow the alloying elements to fully dissolve, forming a supersaturated solid solution and high concentration of vacancy defects; Step 2: After solution treatment, without intermediate cooling, the billet's high-temperature residual heat is used to directly perform upsetting, punching, and ring rolling within 300 seconds. The initial upsetting temperature is not lower than 900℃, the upsetting deformation is 20%~30%, and the strain rate is ≤0.1 / s. The punching deformation is 10%~15%. The final ring rolling temperature is not lower than 750℃, the ring rolling deformation is 50%~60%, and the strain rate is 0.5~2 / s. The transfer time between adjacent processes does not exceed 30 seconds. Step 3: After the ring rolling is completed, keep it at 800 ℃~850 ℃ for 1~2 minutes to make the temperature of the ring cross section uniform; Step 4: After the isothermal treatment, perform water quenching or polymer aqueous solution quenching within 60 seconds to lock the high-temperature microstructure to room temperature. Step 5: Hold at 400 ℃~500 ℃ for 4~8 hours for artificial aging to promote uniform precipitation of the dispersion-strengthened phase; The chromium bronze comprises, by mass percentage: Cr 1.0%~1.5%, Ti 0.1%~0.3%, Mo 0.5%~1.0%, Sb 0.005%~0.01%, B 0.05%~0.1%, with the balance being Cu and unavoidable impurities.

[0007] Preferably, before step 1, alloy batching and melting, semi-continuous casting and blanking are also included.

[0008] Preferably, in step 1, the heat preservation time is extended to 3-5 hours when processing large ring parts with an outer diameter >1m.

[0009] Preferably, in step 2, the rolled ring is a radial rolled ring or a axial rolled ring.

[0010] Preferably, during the high-precision ring processing, micro-tension control technology is used to control the rolling tension.

[0011] Preferably, in step 4, the quenching uses water or a polymer aqueous solution with a concentration of 3% to 5%, wherein the polymer is selected from one or a combination of polyvinyl alcohol or polyethylene glycol.

[0012] Preferably, the chromium bronze of the special working condition ring also contains 0.05%~0.1% Ag element, and a phosphating treatment step is included after step 5 to make it suitable for high temperature or corrosive special working conditions.

[0013] Preferably, the specific grade of the chromium bronze is TCr1 or C18150.

[0014] Preferably, the ring is a motor end ring or a sealing ring.

[0015] According to a second aspect of the present invention, a chromium bronze ring is provided, which is prepared by the method described above.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. This invention integrates solution treatment and hot forming into the same thermal cycle, constructing a short-process processing system of "one-time heating and continuous forming". In this system, after solution treatment, there is no intermediate cooling; the high-temperature residual heat is directly used for upsetting, punching, and ring rolling, effectively eliminating the independent heating steps between hot forging and solution treatment. This reduces the total number of heating cycles from three to two, significantly reducing energy consumption and production costs, while avoiding grain boundary coarsening and surface oxidation dechromiuming caused by the cooling-reheating process in traditional processes, providing a process guarantee for high-quality ring forming.

[0017] 2. This invention utilizes optimized Cr content and synergistic addition of trace elements Ti, Mo, Sb, and B to establish a strengthening mechanism that matches process adjustment with compositional compensation. Specifically, the dynamic recrystallization structure during direct thermoforming after solution treatment is significantly refined, and the high-melting-point dispersed phases formed by Ti and Mo pinning the grain boundaries exhibit excellent resistance to high-temperature softening. Under the grain boundary segregation effect of Sb and the grain refinement effect of B, the material exhibits good thermoplasticity and deformation uniformity during high-temperature deformation, effectively solving the problem of insufficient precipitation strengthening driving force caused by direct forming after solution treatment.

[0018] 3. The process adaptability and application scope of the method of this invention are significantly enhanced. For high-precision ring components, micro-tension control technology is used to achieve precision rolling; for large ring components, the solution treatment and holding time is extended and a staged reduction process is adopted to effectively solve the problems of uneven cooling of the core and grain coarsening; for ring components under special working conditions, Ag element is added and stress-relief annealing and phosphating treatment steps are added to obtain excellent high-temperature softening resistance and corrosion resistance. This invention achieves a balanced improvement in the overall performance of chromium bronze ring components, providing a stable and scalable material and process foundation for the green and efficient manufacturing of key components such as motor end rings and sealing rings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the short-process forming preparation method according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the short-process heat treatment curve according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the heat treatment curve of the conventional process in Comparative Example 1 of the present invention; Figure 4 This is a finished product image of the large chromium bronze ring according to Embodiment 7 of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] An embodiment of the present invention is a chromium bronze ring and its short-process forming preparation method, comprising the following steps: Example 1 This embodiment uses a short-process technology to prepare chromium bronze rings. The specific steps are as follows: (1) Alloying and smelting: The composition of the chromium bronze casting rod, by mass percentage, consists of the following elements: 1.0% Cr, 0.1% Ti, 0.5% Mo, 0.005% Sb, 0.05% B, with the balance being Cu. In the smelting process, electrolytic copper, Mo blocks and Cr blocks are added to a medium-frequency induction furnace and smelted at 1250 ℃ for 40 min under nitrogen. After the matrix melts, CuTi30, CuB10 master alloy and Sb blocks are added, and the temperature is further increased to 1280 ℃ and held for 15 min. A rotating graphite rotor is used for degassing and refining at a speed of 400 r / min for 10 min. After refining, the rod is allowed to stand for 5 min, the surface slag is removed, and semi-continuous casting is carried out at 1260 ℃ to prepare the chromium bronze casting rod.

[0022] (2) Blanking: Peel the surface of the cast rod to remove the surface oxide layer and defects, and then use a band saw to cut it into cylindrical blanks.

[0023] (3) Solution treatment: The sawn billet is placed into a box-type resistance furnace and heated to 990°C at a rate of 10°C / min. After reaching the temperature, it is kept at the temperature for 2 hours to allow strengthening elements such as Cr and Mo to fully dissolve in the copper matrix and form a supersaturated solid solution.

[0024] (4) Hot forming: After solution treatment, without intermediate cooling, the billet is directly upset, punched and rolled into a ring within 300 seconds using the high temperature residual heat. After the billet exits the furnace, it is quickly transferred to the fast forging press station. The initial upset temperature is not lower than 900℃, the upset deformation is 20%~30%, the strain rate is ≤0.1 / s, and the upset is upset to a height of 160mm. Then punching is performed, and the punching deformation is 10%~15%. The prepared ring blank is sent into the CNC radial axial ring rolling mill. The temperature is controlled at 900℃~950℃, the final rolling temperature is not lower than 750℃, the ring deformation is 50%~60%, the strain rate is 0.5~2 / s, the main roll speed is set to 0.5 r / s, the feed speed is 0.8 mm / s, and the transfer time between adjacent processes does not exceed 30 seconds. Finally, it is rolled into a ring with a wall thickness of 100mm.

[0025] (5) Quenching and aging: After the ring is rolled, it is immediately immersed in a flowing water tank for water quenching. The water temperature is controlled at 30 ℃~40 ℃ to ensure that the supersaturated solid solution is fixed and the workpiece does not crack. The quenched ring is placed in an aging furnace and held at 450 ℃ for 6 hours, and then air-cooled to room temperature to finally obtain the chromium bronze ring.

[0026] Example 2 This embodiment uses the method of Example 1 to prepare chromium bronze rings. The smelting process is the same as in Example 1. The difference is that the composition of the chromium bronze casting rod is composed of the following elements by mass percentage: 1.1% Cr, 0.15% Ti, 0.65% Mo, 0.0065% Sb, 0.065% B, and the balance element is Cu.

[0027] Example 3 This embodiment uses the method of Example 1 to prepare chromium bronze rings. The smelting process is the same as in Example 1. The difference is that the composition of the chromium bronze casting rod is composed of the following elements by mass percentage: 1.2% Cr, 0.2% Ti, 0.8% Mo, 0.008% Sb, 0.08% B, and the balance element is Cu.

[0028] Example 4 This embodiment uses the method of Example 1 to prepare chromium bronze rings. The smelting process is the same as in Example 1. The difference is that the composition of the chromium bronze casting rod is composed of the following elements by mass percentage: 1.35% Cr, 0.25% Ti, 0.9% Mo, 0.009% Sb, 0.09% B, and the balance element is Cu.

[0029] Example 5 This embodiment uses the method of Example 1 to prepare chromium bronze rings. The smelting process is the same as in Example 1. The difference is that the composition of the chromium bronze casting rod is composed of the following elements by mass percentage: 1.5% Cr, 0.3% Ti, 1.0% Mo, 0.01% Sb, 0.1% B, and the balance element is Cu.

[0030] Example 6 This embodiment describes the fabrication of a high-precision chromium bronze ring, and the specific steps are as follows: (1) Alloy smelting: Electrolytic copper, Mo briquettes and Cr blocks are added to a medium-frequency induction furnace and smelted at 1250℃ for 40 min under nitrogen. After the matrix is ​​melted, CuTi30, CuB10, CuAg10 intermediate alloys and Sb blocks are added and the temperature is raised to 1280℃ and held for 15 min. Degassing and refining are carried out using a rotating graphite rotor at a speed of 400 r / min for 10 min. After refining, the mixture is allowed to stand for 5 min, the surface slag is removed, and semi-continuous casting is carried out at 1260℃ to prepare chromium bronze casting rods.

[0031] (2) Blanking: Peel the surface of the cast rod to remove the surface oxide layer and defects, and then use a band saw to cut it into cylindrical blanks.

[0032] (3) Solution treatment: The sawn billet is placed into a box-type resistance furnace and heated to 990°C at a rate of 10°C / min. After reaching the temperature, it is kept at the temperature for 2 hours to allow strengthening elements such as Cr and Mo to fully dissolve in the copper matrix and form a supersaturated solid solution.

[0033] (4) Hot forming: After the heat preservation is completed, the billet is quickly transferred to the high-speed forging press station. Since the billet is in a fully recrystallized high-temperature softened state, it is directly upset, punched and rolled into a ring. Among them, after the billet exits the furnace, it is quickly transferred to the forging press and upset to a height of 160 mm in the range of 960 ℃~980 ℃, and then punched to form a billet. The rolling tension control steps are as follows: turn on the micro-tension control mode on the CNC panel, set the tension target value to 12 kN, and the tension dead zone to ±2kN. Set the feed speed of the mandrel to 1.0 mm / s and the initial speed of the main roll to 7 rpm. Through the frequency converter coordinated control, lock the linear velocity of the metal flowing out of the roll to 0.28 m / s. During the implementation process, it is necessary to monitor the tension sensor feedback value in real time during the rolling process. If the tension feedback is >14 kN, the rolling mill speed is slightly slowed down to 6.5 rpm; if the tension feedback is <14 kN, the rolling mill speed is slightly increased to 7.5 rpm. The rolling speed is adjusted in a coordinated manner; if the speed is too fast, it is slightly slowed down, and if it is too slow, it is slightly accelerated, to ensure that the ring is formed in a state of near-no tension but tightness, so as to achieve high precision requirements.

[0034] (5) Quenching and aging: After the ring is rolled, it is immediately immersed in a 3%~5% polyvinyl alcohol aqueous solution. The solution temperature is controlled at 30℃~40℃ to ensure that the supersaturated solid solution is fixed and the workpiece does not crack. The quenched ring is placed in an aging furnace and held at 450℃ for 6 hours, and then air-cooled to room temperature to finally obtain a high-precision chromium bronze ring.

[0035] Example 7 This embodiment describes the preparation of a large chromium bronze ring with an outer diameter >1m. The preparation process uses the same formula blank as in Example 3, and the specific steps are as follows: (1) Alloy smelting: Electrolytic copper, Mo briquettes and Cr blocks are added to a medium-frequency induction furnace and heated to 1250℃ under nitrogen for 40 min. After the matrix is ​​melted, CuTi30, CuB10 intermediate alloy and Sb blocks are added and the temperature is raised to 1280℃ and held for 15 min. A rotating graphite rotor is used for degassing and refining at a speed of 400 r / min for 10 min. After refining, the mixture is allowed to stand for 5 min, the surface slag is removed, and semi-continuous casting is carried out at 1260℃ to prepare chromium bronze casting rods.

[0036] (2) Blanking: Peel the surface of the cast rod to remove the surface oxide layer and defects, and then use a band saw to cut it into cylindrical blanks.

[0037] (3) Solution treatment: The sawn billet is placed into a box-type resistance furnace and heated to 990°C at a rate of 10°C / min. After reaching the temperature, it is kept at the temperature for 4 hours to allow strengthening elements such as Cr and Mo to fully dissolve in the copper matrix and form a supersaturated solid solution.

[0038] (4) Hot forming: After the heat preservation is completed, the billet is quickly transferred to the high-speed forging press station. Since the billet is in a fully recrystallized, high-temperature softened state, it is directly upset, punched, and rolled into a ring. Specifically, after the billet exits the furnace, it is quickly transferred to the forging press and upset to a height of 160 mm in the range of 960 ℃~980 ℃, followed by punching to form the billet. In the ring rolling process, a staged pressing system is adopted, which is divided into the bite stage → rough rolling stage → finish rolling stage. The rolling process is divided into several stages: The biting stage uses a low speed (1.0~1.5 m / s) for stable biting, with a reduction rate controlled at 10%~20%; the roughing stage uses a medium-high speed (2~3 m / s) to fully utilize equipment capacity, with a single reduction rate of 20%~30%, accounting for 60%~70% of the total reduction; and the finishing stage uses a low speed (1.0~1.5 m / s) to improve control accuracy, with a single reduction rate of 5%~15%, accounting for 20%~30% of the total reduction.

[0039] (5) Quenching and aging: After the ring is rolled, it is immediately immersed in a 3%~5% polyvinyl alcohol aqueous solution. The solution temperature is controlled at 30℃~40℃ to ensure that the supersaturated solid solution is fixed and the workpiece does not crack. The quenched ring is placed in an aging furnace and held at 450℃ for 6 hours, and then air-cooled to room temperature to finally obtain a large chromium bronze ring.

[0040] Example 8 This embodiment describes the fabrication of a chromium bronze ring under special working conditions. This workpiece can operate in harsh environments with high temperatures and corrosive media. The specific steps are as follows: (1) Alloying and Smelting: The composition of the chromium bronze casting rod, by mass percentage, consists of the following elements: 1.0% Cr, 0.1% Ti, 0.5% Mo, 0.005% Sb, 0.05% B, 0.05% Ag, with the balance being Cu. In the smelting process, electrolytic copper, Mo briquettes, and Cr blocks are added to a medium-frequency induction furnace and smelted at 1250 ℃ for 40 min under nitrogen. After the matrix melts, CuTi30, CuB10 master alloys, and Sb blocks are added, and the temperature is further increased to 1280 ℃ and held for 15 min. A rotating graphite rotor is used for degassing and refining at a speed of 400 r / min for 10 min. After refining, the rod is allowed to stand for 5 min, the surface slag is removed, and semi-continuous casting is carried out at 1260 ℃ to prepare the chromium bronze casting rod.

[0041] (2) Blanking: Peel the surface of the cast rod to remove the surface oxide layer and defects, and then use a band saw to cut it into cylindrical blanks.

[0042] (3) Solution treatment: The sawn billet is placed into a box-type resistance furnace and heated to 1000 ℃ at a rate of 10 ℃ / min. After reaching the temperature, it is kept at the temperature for 2 hours to allow strengthening elements such as Cr and Mo to fully dissolve in the copper matrix and form a supersaturated solid solution.

[0043] (4) Hot forming: After the heat preservation is completed, the billet is quickly transferred to the high-speed forging press station, and forging and rolling are carried out directly using the high-temperature residual heat of the billet after it exits the furnace. Specifically, after the billet exits the furnace, it is quickly transferred to the forging press and upset to a height of 160 mm in the range of 960 ℃~980 ℃, and then punched to form a billet. The prepared ring blank is fed into a CNC radial axial ring rolling mill, with the temperature controlled at 900 ℃~950 ℃, the main roll speed set at 0.5 r / s, and the feed speed at 0.8 mm / s, and finally rolled into a ring with a wall thickness of 100 mm.

[0044] (5) Quenching and aging: After the ring is rolled, it is immediately immersed in a flowing water tank for water quenching. The water temperature is controlled at 30 ℃~40 ℃ to ensure that the supersaturated solid solution is fixed and the workpiece does not crack. The quenched ring is placed in an aging furnace and held at 450 ℃ for 6 hours. After the ring is cooled down, a stress-relieving annealing process is added to the ring, which is held at 350 ℃ for 2 hours, and then air-cooled to room temperature.

[0045] (6) Surface treatment: The ring obtained after the above steps is immersed in phosphating solution at room temperature for 5 to 15 minutes to generate a phosphate protective film to prevent rust. Then it is washed and dried to finally obtain the chromium bronze ring.

[0046] Comparative Example 1 This comparative example uses a traditional process to prepare chromium bronze rings. The specific steps are as follows: (1) Blanking: Select TCr1 chromium bronze cast bar and cut it into cylindrical blanks on a band saw.

[0047] (2) Hot forging heating: The billet is loaded into a trolley-type resistance heating furnace and heated to 930 ℃. It is kept at the temperature for 2.5 hours to make the overall temperature of the billet uniform and reach the thermoplastic forming window.

[0048] (3) Hot forging: The heated billet is transferred to the high-speed forging press station for upsetting and punching, and then rolled into a ring on a ring rolling mill. After forming, the ring is taken out and air-cooled to room temperature.

[0049] (4) Solution treatment: After air cooling, the ring is put back into the furnace, heated to 990 ℃, and held for 2 hours to allow chromium to fully dissolve in the copper matrix and form a supersaturated solid solution.

[0050] (5) Quenching: After the solution heat preservation is completed, the ring is quickly taken out and water quenched and cooled to room temperature.

[0051] (6) Aging treatment: The quenched ring is placed in an aging furnace, heated to 450 ℃, held for 6 hours, and then removed from the furnace and air-cooled.

[0052] Comparative Example 2 This comparative example is used to verify the effect of changing only the process flow (omitting the hot forging heating step) on the performance of the ring. The experiment uses TCr1 chromium bronze cast bar containing 1.2% Cr element for processing. No trace elements such as Ti, Mo, Sb, and B are added to the material.

[0053] Performance testing of chrome bronze ring components The tensile strength, yield strength, electrical conductivity and elongation of the chromium bronze rings prepared in the above embodiments and comparative examples were tested respectively, and the test results are shown in Table 1.

[0054] Table 1 Performance tests of chromium bronze rings prepared in each embodiment and comparative example

[0055] The performance tests of the chromium bronze rings obtained in each embodiment and comparative example are shown in Table 1. Comparative Example 1 uses the traditional "hot forging → solution treatment → aging" process, while Comparative Example 2 uses the new process of this invention but uses traditional TCr1 chromium bronze (containing only 1.2% Cr, excluding Ti, Mo, Sb, and B). Comparing the performance of the chromium bronze rings obtained by the two processes, it can be seen that the tensile strength, yield strength, and elongation of Comparative Example 2 all decreased to varying degrees compared to Comparative Example 1. This proves that simply changing the process sequence (pre-solution treatment) leads to insufficient precipitation strengthening driving force and overall performance degradation. Example 3 uses the same process as Comparative Example 2, but increases the Cr content to 1.2% and synergistically adds Ti, Mo, Sb, and B, resulting in improved performance of the obtained rings. This proves that the combination of process adjustment and composition compensation in this invention has a significant synergistic effect, and neither can be omitted.

[0056] Examples 1-5 explored and verified the material formulation range in the short-process technology, revealing a clear trend in material properties: tensile strength and yield strength increased, while conductivity and elongation decreased. This indicates that the composition ranges in Examples 1-5 have significant criticalities; below these ranges, the strength is insufficient to meet the requirements of load-bearing components such as motor end rings; above these ranges, conductivity and plasticity are excessively sacrificed, which is unfavorable for applications requiring good conductivity and processing toughness. Among these, the chromium bronze ring obtained in Example 3 achieved the best balance between strength, conductivity, and elongation in the test results, making it the optimal solution in terms of overall performance.

[0057] Based on the use of a short-process technology and formula adjustments, the universality of the process of this invention was further verified in the preparation of high-precision rings, large rings, and rings for special working conditions. For high-precision rings, micro-tension control technology was used in the ring rolling process to strictly control the rolling speed and roll gap. Since Sb element improves the fluidity of the alloy and B refines the grains, the material is not prone to cracking during precision rolling. For large rings with an outer diameter >1 m, by extending the solution heat treatment time to 4 hours and adopting a staged reduction system, the problems of uneven cooling in the core of large cross-sections and grain coarsening were effectively solved. The finished product has a tensile strength of 434 MPa and an elongation of 25.4%, which meets the requirements for the use of large rings. For special working condition rings that need to operate in high temperature or corrosive media, by adding 0.05% Ag to the formula and adding stress-relief annealing and phosphating treatment steps, the finished product has a tensile strength of 441 MPa and an conductivity of 76% IACS. Although the conductivity is slightly sacrificed, excellent high-temperature softening resistance and corrosion resistance are obtained in return. This indicates that the technical solution of the present invention has a good process window and adaptability, and the parameters can be adjusted for different application scenarios to meet diverse engineering needs.

[0058] Figure 1This is a schematic diagram of the heat treatment curve for the short-process of this invention. Figure 2 This is a schematic diagram of the heat treatment curve of the conventional process in Comparative Example 1 of the present invention. Through comparison... Figure 1 and Figure 2 As can be seen, this invention integrates solution treatment and hot forming into the same thermal cycle, eliminating the separate heating steps between hot forging and solution treatment in traditional processes, thus shortening the total production cycle from billet to finished product by about 20% to 40%, and significantly improving production efficiency and equipment utilization.

[0059] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A short-process forming method for manufacturing chromium bronze rings, characterized in that, Integrating solution treatment and thermoforming into the same thermal cycle includes the following steps: Step 1: Heat the chromium bronze billet to 950℃~1020℃ and hold for 1~3 hours to allow the alloying elements to fully dissolve, forming a supersaturated solid solution and high concentration of vacancy defects; Step 2: After solution treatment, without intermediate cooling, the billet's high-temperature residual heat is used to directly perform upsetting, punching, and ring rolling within 300 seconds. The initial upsetting temperature is not lower than 900℃, the upsetting deformation is 20%~30%, and the strain rate is ≤0.1 / s. The punching deformation is 10%~15%. The final ring rolling temperature is not lower than 750℃, the ring rolling deformation is 50%~60%, and the strain rate is 0.5~2 / s. The transfer time between adjacent processes does not exceed 30 seconds. Step 3: After the ring rolling is completed, keep it at 800℃~850℃ for 1~2 minutes to make the temperature of the ring cross section uniform. Step 4: After the isothermal treatment, perform water quenching or polymer aqueous solution quenching within 60 seconds to lock the high-temperature microstructure to room temperature. Step 5: Hold at 400℃~500℃ for 4~8 hours for artificial aging to promote uniform precipitation of the dispersion-strengthened phase; The chromium bronze ring, by mass percentage, contains: Cr 1.0%~1.5%, Ti 0.1%~0.3%, Mo 0.5%~1.0%, Sb 0.005%~0.01%, B 0.05%~0.1%, with the balance being Cu and unavoidable impurities.

2. The short-process forming method for preparing chromium bronze rings according to claim 1, characterized in that, The process preceding step 1 also includes alloy batching and smelting, semi-continuous casting, and blanking.

3. The short-process forming method for preparing chromium bronze rings according to claim 1 or 2, characterized in that, In step 2, the rolled ring is either a radially axial rolled ring or a radially rolled ring.

4. The short-process forming method for preparing chromium bronze rings according to claim 3, characterized in that, In step 2, during the high-precision ring processing, micro-tension control technology is used to control the rolling tension.

5. The short-process forming method for manufacturing chromium bronze rings according to claim 1 or 2, characterized in that, In step 4, the quenching is performed using water or a polymer aqueous solution with a concentration of 3% to 5%, wherein the polymer is selected from one or a combination of polyvinyl alcohol or polyethylene glycol.

6. The short-process forming method for manufacturing chromium bronze rings according to claim 1 or 2, characterized in that, The chromium bronze ring also contains 0.05%~0.1% Ag element, and after step 5, a phosphating treatment step is also included to make it suitable for high temperature or corrosive special working conditions.

7. The short-process forming method for preparing chromium bronze rings according to claim 1 or 2, characterized in that, The ring component is either a motor end ring or a sealing ring.

8. A chromium bronze ring, characterized in that, It is prepared by the short-process forming method of the chromium bronze ring as described in any one of claims 1-7.

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