Partition controlled rapid cooling method for quenching of complex cross-section members

Abstract

A partition controllable rapid cooling method for quenching of complex cross-section components belongs to the field of rapid cooling of large and complex workpiece heat treatment. By designing the up and down arrangement of air tank and water tank, the uniform purpose of gas flow and water flow at each nozzle outlet is realized, and uniform and dense spray is generated at the top of the nozzle; according to the requirements of the processing object, the multi-tank structure can be designed in the air tank and water tank, and the uniform and rapid cooling of the complex high-temperature workpiece is realized. Through the principle of spray generation, the flow ratio of water flow and air flow is designed, and the uniform and effective spray is generated by the method of designing the nozzle structure to ensure that the gas outlet surrounds the water flow outlet, the present application can avoid Leidenfrost phenomenon, and has faster cooling speed than traditional cooling pool cooling or spray cooling. Compared with the air blowing cooling, the spray improves the heat exchange capacity, greatly improves the cooling speed, and at the same time, by adopting different nozzle height and nozzle gap, the distance between the nozzle and the workpiece can be controlled to realize more uniform and rapid cooling of the complex high-temperature workpiece.

Description

Technical Field

[0001] This invention belongs to the field of heat treatment of large and complex cross-section components, and relates to the field of high-temperature zoned controllable rapid cooling of complex cross-section workpieces, and particularly to a zoned controllable rapid cooling method for quenching complex cross-section components. Background Technology

[0002] Metal quenching heat treatment is a process in which metal or alloy workpieces are heated to above the critical temperature in the solid state, held at that temperature for a certain time, and then rapidly cooled to change the internal microstructure of the workpiece, thereby obtaining the desired physical, mechanical, and technological properties.

[0003] The cooling rate has a crucial impact on the properties of workpieces after quenching heat treatment. To achieve rapid cooling, common methods include: cooling in a cooling pool, which results in an excessively fast and uncontrollable cooling rate, easily leading to significant residual stress within the workpiece, as well as wasting a large amount of coolant and causing environmental pollution; spray cooling, which leads to uneven cooling, easily causing significant residual stress and workpiece cracking; and air cooling, while effectively reducing quenching costs and protecting the environment, uses air as the sole medium, resulting in a slow cooling rate and affecting quenching quality. Furthermore, to meet the increasingly demanding requirements of engineering applications, the development of graded dual-performance or even multi-performance components necessitates precise control of the cooling rate at different locations during solution treatment quenching.

[0004] Therefore, it is necessary to invent a method for controlled and rapid cooling of complex cross-section components in a partitioned manner to solve the above problems. Summary of the Invention

[0005] To address the above problems, this invention proposes a zoned, controllable, and rapid cooling method for complex cross-section components.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A zoned, controllable, rapid cooling method for quenching complex cross-section components is disclosed. This method achieves regionalized, uniform, and rapid cooling of the complex cross-section component by generating uniform and dense sprays in different zones. The specific implementation is as follows:

[0008] The first step is to design the structure of nozzle 5 and the mold 1 for placing nozzle 5.

[0009] The nozzle 5 is a two-stage stepped cylindrical structure, and a through hole A is arranged in the middle part, and the nozzle 5 includes a thick cylindrical structure and a thin cylindrical structure, and the thick cylindrical structure is provided with a through hole B which is arranged in the axial direction. The mold 1 is a hollow disc structure, and the internal space is divided into an upper gas storage chamber 2 and a lower water storage chamber 3 by a partition plate 4 which is arranged in the middle part in the transverse direction, and according to actual conditions, the gas storage chamber 2 and the water storage chamber 3 can be further provided with a vertically arranged annular partition plate 6 which is arranged in the longitudinal direction and penetrates the gas storage chamber 2 and the water storage chamber 3, and the gas storage chamber 2 and the water storage chamber 3 are divided into a plurality of chamber bodies in the longitudinal direction. The upper surface of the mold 1 is provided with a plurality of through holes which are arranged at intervals and correspond to the positions of the partition plate 4, and the through holes are used for mounting the nozzle 5, wherein the through hole A of the partition plate 4 is used for mounting the thin cylindrical structure of the nozzle 5, the bottom of the through hole A is a water inlet which is communicated with the water storage chamber 3, the through hole of the upper surface of the mold 1 is used for mounting the thick cylindrical structure of the nozzle 5, and the bottom of the through hole B is an air inlet which is communicated with the gas storage chamber 2. The installation position of the partition plate 6 is determined according to the cooling rate requirement of the workpiece area, and one or more air inlets are arranged in each chamber body of the gas storage chamber 2, and one or more water inlets are arranged in each chamber body of the water storage chamber 3.

[0010] During installation, the height of the water inlets of the nozzles 5 in the water storage chamber 3 is consistent, and the height of the air inlets of the nozzles 5 in the gas storage chamber 2 is consistent, so that the water output and the air output of each nozzle are consistent, and the purpose of uniformly cooling the workpiece is achieved.

[0011] Second step, using the structure designed in the first step to cool the workpiece

[0012] 2.1) Connect the gas storage chamber 2 of the mold 1 with a gas pump, connect the water storage chamber 3 with a water pump, heat the workpiece to be processed to a predetermined temperature, and place the workpiece at a suitable height from the nozzle 5, and the range of the nozzle 5 completely covers the workpiece;

[0013] 2.2) Open the water pump to fill the water storage chamber 3, ensure that the nozzles 5 are filled with water, and spray liquid at the outlet of the nozzle 5; open the gas pump to generate gas at the outlet of the nozzle 5, and adjust the parameters of the water pump and the gas pump to make the liquid flow at a low speed and the gas flow at a high speed, so that the liquid is torn by the high-speed gas to form a water mist, and the workpiece is cooled.

[0014] Further, in order to ensure uniform cooling, the present application adopts a dot matrix nozzle arrangement, and the distance between adjacent nozzles 5 is 2-3 times the diameter of the thick cylindrical structure of the nozzle 5, and the distance between the nozzle 5 and the workpiece is maintained between 20-30 mm.

[0015] Further, in the first step, the number of air inlets and water inlets arranged in each chamber body is determined according to the number of nozzles 5 in the chamber body, and one air inlet and one water inlet are arranged for every 10-15 nozzles 5, so as to ensure sufficient air output and water output.

[0016] Further, when facing complex workpieces, only the height of the nozzle and the gap between the nozzles need to be designed to meet the cooling requirements of complex workpieces.

[0017] Further, when the cooling rate of the workpiece needs to be different in each region, only the water inflow and air inflow of each region of the warehouse body need to be changed to control the ratio of gas flow and water flow in each region to be 1-30:1, so as to achieve different cooling rates in each region.

[0018] The principle of the present application is that the spray is generated due to the contact of low-speed flowing liquid with high-speed airflow, and the liquid is torn by high-speed air to form water mist. The gas outlet of the nozzle is in the form of a ring surrounding the water outlet to ensure the atomization effect of the water flow, and a nozzle cap is arranged to gather the spray to increase the cooling rate, and a regionally divided gas storage warehouse and water storage warehouse are arranged to realize the controllable rapid cooling of complex cross-section components.

[0019] The present application has the beneficial effects of:

[0020] (1) The present application cools the workpiece in the form of spray, avoiding the problem that the cooling rate of the ordinary cooling pool is too fast and uncontrollable, which easily causes a large residual stress in the workpiece.

[0021] (2) The present application cools the workpiece in the form of spray, avoiding the problem that the spray cooling is not uniform, which easily causes a large residual stress and cracking of the workpiece.

[0022] (3) The present application can easily realize the cooling of complex cross-section components by designing the mold and the nozzle.

[0023] (4) The present application can realize uniform and rapid cooling of complex cross-section components by controlling the distance between the nozzle and the nozzle and the distance between the workpiece and the nozzle.

[0024] (5) The present application can easily realize the regionally controllable cooling rate of complex cross-section components by arranging the partition and partition plate structure of the water storage warehouse and the gas storage warehouse. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic view of the mold and nozzle assembly structure.

[0026] Figure 2 is a spray cooling temperature-time curve graph of Example 1.

[0027] Figure 3 is a schematic view of a disc-shaped workpiece structure.

[0028] Figure 4 is a spray generation principle diagram.

[0029] In the diagram: 1. Mold; 2. Air storage chamber; 3. Water storage chamber; 4. Divider; 5. Nozzle; 6. Partition plate.

[0030] Specific implementation form

[0031] The technical solution of the invention will be further described in detail below with reference to the embodiments.

[0032] Example 1

[0033] This embodiment provides a zoned, controllable, rapid cooling method for quenching complex cross-section components, including the following specific steps:

[0034] The first step is to design the structure of nozzle 5 and the mold 1 for placing nozzle 5.

[0035] The nozzle 5 is a two-stage stepped cylindrical structure with a through hole A in its center. It consists of two cylindrical parts, a coarse one and a thin one, with a through hole B extending axially around the coarse cylinder. The mold 1 is a hollow disc structure, its internal space divided into an upper air storage chamber 2 and a lower water storage chamber 3 by a horizontally arranged partition 4 in the middle. In this embodiment, an annular partition 6 is not provided. Multiple through holes are spaced at intervals on the upper surface of the mold 1 corresponding to the partition 4 for mounting the nozzles 5. Through hole A on the partition 4 is used to mount the thin cylinder of the nozzle 5, with the bottom of through hole A serving as a water inlet connected to the water storage chamber 3. Through holes on the upper surface of the mold 1 are used to mount the coarse cylinder of the nozzle 5, with the bottom of through hole B serving as an air inlet connected to the air storage chamber 2. During installation, the height of the water inlets of each nozzle 5 in the water storage chamber 3 and the height of the air inlets of each nozzle 5 in the air storage chamber 2 are ensured to be consistent in terms of water and air output from each nozzle, achieving uniform cooling of all parts of the workpiece.

[0036] The second step is to heat the disc-shaped workpiece to the specified temperature.

[0037] In this example, the selected workpiece is a 304 stainless steel disc-shaped part with a radius of 105mm and a height of 26mm. The workpiece is heated to 700 degrees Celsius.

[0038] The third step is to turn on the water pump and fill the water tank until the water flow from the nozzle is observed to be uniform.

[0039] The water pump is a self-priming pump with a flow rate of 1500L / min. Mold 1 has 6 water inlets, which are evenly distributed in a ring and the diameter of the water inlets is 6mm.

[0040] The third step is to remove the heated workpiece and place it on the support.

[0041] The distance between the workpiece and nozzle 5 is controlled by the bracket to be 25mm, and the spray range 5 completely covers the disc-shaped workpiece.

[0042] Fourthly, open the air pump to produce spray to cool the workpiece.

[0043] The device adopts two air pumps, the pressure of the air pump is 0.8Mpa, the number of air inlet is 6 and presents annular uniform distribution, the ratio of gas flow and liquid flow of each nozzle 5 outlet is 30:1, the temperature of the workpiece to be cooled is reduced from 676℃ to 347℃ within 20s, realizing the rapid and uniform cooling of the workpiece.

[0044] Example 2

[0045] The embodiment provides a partition controllable rapid cooling method for quenching of a complex cross-section component, comprising the following specific steps:

[0046] Firstly, the structure of the nozzle 5 is designed, and a mold 1 for placing the nozzle 5 is designed

[0047] The nozzle 5 is a two-stage stepped cylindrical structure, a through hole A is arranged in the middle, and the nozzle 5 comprises a thick cylindrical structure and a thin cylindrical structure, and a through hole B is arranged in the thick cylindrical structure in the circumferential direction and penetrates in the axial direction. The mold 1 is a hollow disc structure, the internal space of the mold 1 is divided into an upper gas storage bin 2 and a lower water storage bin 3 by a partition plate 4 arranged in the middle in the transverse direction, and a ring-shaped partition plate 6 arranged in the longitudinal direction and penetrating the upper gas storage bin 2 and the lower water storage bin 3 is arranged in the upper gas storage bin 2 and the lower water storage bin 3, so that the upper gas storage bin 2 and the lower water storage bin 3 are divided into two bin bodies, including an internal bin body surrounded by the partition plate 6 and an external bin body surrounded by the partition plate 6 and the mold. A through hole is arranged on the upper surface of the mold 1 and corresponds to the position of the partition plate 4, and is used for mounting the nozzle 5, wherein the through hole A of the partition plate 4 is used for mounting the thin cylindrical body of the nozzle 5, the bottom of the through hole A is a water inlet and is communicated with the water storage bin 3, the through hole on the upper surface of the mold 1 is used for mounting the thick cylindrical body of the nozzle 5, and the bottom of the through hole B is an air inlet and is communicated with the gas storage bin 2. During installation, the height of the water inlet of each nozzle 5 in the water storage bin 3 is consistent, and the height of the air inlet of each nozzle 5 in the gas storage bin 2 is consistent, so that the water flow and the gas flow of each nozzle are consistent, so that the purpose of uniform cooling of the workpiece is achieved.

[0048] Secondly, heat the workpiece to a specified temperature.

[0049] In this example, the selected workpiece is 304 stainless steel, as shown in the figure, the size is a disc-shaped part with a bottom surface diameter a = 410mm, a height b = 35mm, a convex diameter c = 200mm and a height d = 25mm, and the workpiece is heated to 900 degrees Celsius. Figure 3

[0050] Thirdly, open the water pump to fill the water bin with water to the nozzle port.

[0051] ​The water inlets in the inner chamber within the partition 6 are 8, each corresponding to 12 nozzles 5, and the water pump adopts a self-priming pump with a flow rate of 2000 L / min; the water inlets in the outer chamber composed of the partition 6 and the mold periphery are 4, each corresponding to 12 nozzles 5, and the water pump adopts a self-priming pump with a flow rate of 1500 L / min; and the water inlets are uniformly distributed, with a diameter of 6 mm; and the positions corresponding to the water inlets are provided with air inlets in the gas storage chamber.

[0052] In the third step, the heated workpiece is taken out and placed on the support.

[0053] The support controls the distance between the workpiece and the nozzle 5 to be 25 mm, to ensure this distance, the nozzle 5 is designed to have a coarse cylindrical height of 24 mm, 26 mm, and 33 mm, other dimensions are the same, and the spray range completely covers the workpiece.

[0054] In the fourth step, the air pump is turned on to generate spray for cooling.

[0055] The pressure of the air pump is 1 Mpa, three air pumps are adopted, the number of air inlets in the inner chamber within the partition 6 is 8, and the number of air inlets in the outer chamber composed of the partition 6 and the mold periphery is 4 and is uniformly distributed in a ring shape, the ratio of gas flow rate to liquid flow rate at the nozzle outlet of the inner chamber is 25:1, and the ratio of gas flow rate to liquid flow rate at the nozzle outlet of the outer chamber is 30:1.

[0056] The temperature of the cooled workpiece is reduced from 850℃ to 530℃ within 20s on the outside and from 850℃ to 516℃ on the inside, realizing the rapid and uniform cooling of the workpiece in different regions.

[0057] The above-described embodiments only express the implementation of the present application, but cannot be interpreted as a limitation on the scope of the patent of the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application.

Claims

1. A method for partitioned controlled rapid cooling of quenching of complex cross-section components, characterized in that, The partition controllable rapid cooling method realizes the uniform purposes of the gas flow and the water flow at the nozzle outlet by designing the up-down arrangement of the air warehouse and the water warehouse, and generates uniform and dense spray at the top of the nozzle; meanwhile, the multiple warehouse body structures are designed in the air warehouse and the water warehouse according to the processing object requirements, and finally the uniform and rapid cooling of the complex high-temperature workpiece is realized; the specific implementation manner is as follows: Firstly, the structure of the nozzle (5) is designed, and the mold (1) for placing the nozzle (5) is designed The nozzle (5) is a two-stage stepped cylindrical structure, a through hole A is arranged in the middle, and the nozzle (5) comprises an upper thick cylindrical structure and a lower thin cylindrical structure, and a through hole B is arranged in the thick cylindrical structure in the circumferential direction and penetrates in the axial direction; the mold (1) is a hollow disc structure, the internal space of the mold (1) is divided into an upper air storage warehouse (2) and a lower water storage warehouse (3) by a partition piece (4) arranged in the transverse direction in the middle, annular partition plates (6) are arranged in the corresponding positions in the air storage warehouse (2) and the water storage warehouse (3) in the longitudinal direction, the air storage warehouse (2) and the water storage warehouse (3) are divided into multiple warehouse bodies, air inlet holes and water inlet holes are respectively arranged on the outer circumferential surfaces of the air storage warehouse (2) and the water storage warehouse (3); a plurality of through holes are arranged at the corresponding positions of the upper surface of the mold (1) and the partition piece (4) and are used for mounting the nozzle (5), wherein the through hole of the partition piece (4) is used for mounting the thin cylindrical body of the nozzle (5), the bottom of the through hole A of the nozzle (5) is connected with the water inlet of the nozzle and the water storage warehouse (3), the through hole of the upper surface of the mold (1) is used for mounting the thick cylindrical body of the nozzle (5), and the bottom of the through hole B of the nozzle (5) is connected with the air inlet of the nozzle and the air storage warehouse (2); during installation, the heights of the water inlets of the nozzles in the water storage warehouse (3) are consistent, and the heights of the air inlets of the nozzles in the air storage warehouse (2) are consistent; The height of the nozzle (5) and the gap between the nozzles (5) are designed to meet the cooling and temperature reduction requirements of the complex workpiece; The distance between the nozzle (5) and the workpiece to be processed is kept between 20-30mm; Secondly, the workpiece is cooled by using the structure designed in the first step 2.1) The air storage warehouse (2) of the mold (1) is connected with the air pump through the air inlet hole, the water storage warehouse (3) is connected with the water pump through the water inlet hole, the workpiece to be processed is heated to a predetermined temperature, and is placed at a suitable height from the nozzle (5), and the spray range completely covers the workpiece; 2.2) The water pump is opened, the water storage warehouse (3) is filled with water, the nozzle (5) is filled with water, liquid is sprayed at the top outlet of the nozzle (5), the air pump is opened, gas is generated at the top outlet of the nozzle (5), the parameters of the water pump and the air pump are adjusted, the low-speed flowing liquid is contacted with the high-speed gas flow, the liquid is torn by the high-speed gas to form water mist, and the workpiece is cooled.

2. A method for partition controlled rapid cooling of quenching of complex cross-section members according to claim 1, characterized in that, The installation positions of the partition plates (6) are determined according to the cooling rate requirements of the workpiece area, one or more air inlets are arranged in each warehouse body of the air storage warehouse (2), one or more water inlets are arranged in each warehouse body of the water storage warehouse (3), and the positions of the air inlets and the water inlets correspond.

3. A method for partition controlled rapid cooling of quenching of complex cross-section members according to claim 2, characterized in that, The number of air inlet and water inlet arranged in each bin body is determined according to the number of nozzles (5) in the bin body, wherein one water inlet and air inlet is arranged for every 10-15 nozzles (5).

4. A method for partition controlled rapid cooling of quenching of complex cross-section members according to claim 1, characterized in that, In order to ensure uniform cooling, a dot matrix nozzle arrangement is adopted, and the distance between adjacent nozzles (5) is 2-3 times the diameter of the thick cylinder of the nozzle (5).

5. A method for partition controlled rapid cooling of quenching of complex cross-section members according to claim 1, characterized in that, Since the cooling rate of the workpiece needs to be different in different regions, the ratio of the gas flow rate to the water flow rate is controlled to be 1-50:1 by changing the water inlet amount and air inlet amount of each region bin body, so as to achieve different cooling rates in different regions.

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