High-temperature heat preservation diffusion annealing device and method for centrifugally casting steel parts or iron parts

Abstract

The invention discloses a high-temperature heat-preservation diffusion annealing device and method for centrifugally casting steel parts or iron parts. The space in the device is a sealed space; two longitudinal rails (1) are arranged at the top of the device; the track is provided with a travelling crane for hoisting centrifugal casting steel parts or iron parts; the side wall and the top of the device are filled with thermal insulation materials (such as pearl thermal insulation sand, thermal insulation cotton and the like); a plurality of air suction ports (3) are formed in the top of the device. The centrifugal casting high-temperature casting is placed in the device, the device is filled with efficient heat preservation materials (such as pearl heat preservation sand and heat preservation cotton), the casting is slowly cooled, high-temperature heat preservation diffusion annealing is carried out, the casting is taken out after 48 hours, and the purposes of structure refining, hardness reducing, no crack generation and no energy consumption are achieved.

Description

TECHNICAL FIELD

[0001] The application relates to a high-temperature heat preservation diffusion annealing device and method for centrifugal casting steel or iron parts. BACKGROUND

[0002] Centrifugal casting steel or iron parts are prone to the following problems due to high casting part temperature when being taken out of a mold, 800-900 DEG C.

[0003] 1. Cracks are easily generated and the parts are scrapped.

[0004] 2. The parts are quickly cooled in air, high surface hardness is formed, and machining is difficult.

[0005] 3. The parts have coarse grain structure.

[0006] The above three points need high-temperature annealing (annealing temperature 860-920 DEG C), a large amount of energy is required, and about 300-350 Kwh of power is consumed per ton of castings.

[0007] 4. Due to the need for annealing (loading into a furnace, heating, heat preservation, furnace cooling, and unloading), the production cycle is long, generally 7 days.

[0008] 5. The working environment is poor, and high-temperature radiation is generated.

[0009] Therefore, it is necessary to design a new type of high-temperature heat preservation diffusion annealing device and method for centrifugal casting steel or iron parts. SUMMARY

[0010] The application solves the technical problem of providing a high-temperature heat preservation diffusion annealing device and method for centrifugal casting steel or iron parts, which is easy to implement and can ensure smooth annealing.

[0011] The technical solution of the application is as follows:

[0012] A high-temperature heat preservation diffusion annealing device for centrifugal casting steel or iron parts, the space in the device is a sealed space;

[0013] The top of the device is provided with two longitudinal rails (1); a travelling crane for lifting centrifugal casting steel or iron parts is arranged on the rails;

[0014] The side walls and the top of the device are filled with heat preservation materials (such as pearl heat preservation sand, heat preservation cotton, etc.);

[0015] The top of the device is provided with a plurality of air suction ports (3).

[0016] The side walls on the longitudinal two sides of the device include an inclined surface (5) at the upper part, a fixed vertical plate (6) at the middle part, and a movable door (7) at the lower part.

[0017] The suction port is 10, and the diameter is 400mm.

[0018] The total length of the device is 12m, the total width is 3m, the height from the ground is 4.1m, and the depth of the sunken part is 0.9m.

[0019] The high-temperature heat preservation diffusion annealing device is externally connected with a waste heat recovery device; and the high-temperature heat preservation diffusion annealing device is internally provided with a temperature control module.

[0020] A high-temperature heat preservation diffusion annealing method for centrifugal casting steel or iron parts is provided.

[0021] The temperature of the casting is 800-900 DEG C, and the annealing time is not less than 48 hours.

[0022] Beneficial effects:

[0023] 1. The high-temperature heat preservation diffusion annealing device is designed, the centrifugal casting high-temperature casting is placed in the device, the device is filled with efficient heat preservation materials (such as pearl heat preservation sand, heat preservation cotton and the like), the casting is slowly cooled, high-temperature heat preservation diffusion annealing is carried out, and the casting is taken out after 48 hours, so that the organization is refined, the hardness is reduced, cracks are not generated, and energy consumption is not needed.

[0024] 2. The device is a sealed space, and is provided with dust removal equipment, so that the environmental protection requirements are met.

[0025] 3. The device is simple and convenient to operate, the production efficiency is high, and the high-temperature heat preservation diffusion annealing time is 48 hours.

[0026] The beneficial effects of the present application are:

[0027] The centrifugal casting is subjected to 48-hour high-temperature heat preservation diffusion annealing scheme, and the following problems are solved:

[0028] 1. The problem of casting cracks is solved.

[0029] 2. The problem of high surface hardness of the casting and difficult machining is solved.

[0030] 3. The organization of the casting is refined, and heating annealing treatment is no longer needed, so that energy is saved.

[0031] 4. The working environment is improved, and no heat radiation is generated.

[0032] 5. The production efficiency is improved, the casting no longer needs to be loaded into the furnace and unloaded, and the labor intensity of workers is reduced. The diffusion annealing process only needs 48 hours, and the production cycle is reduced. Since annealing (loading into the furnace, heating, heat preservation, furnace cooling, and unloading) is needed, the production cycle is long, and generally needs 7 days.

[0033] In addition, the temperature in the annealing device can be kept constant by using the temperature control module, which is beneficial to the implementation of the annealing process. In addition, the waste heat recovery device can fully utilize the waste heat through the heat exchanger, thereby avoiding energy waste. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a schematic view of the device (top view) ;

[0035] Figure 2 is a schematic view of the side wall structure of the device (front view) ;

[0036] Figure 3 is a schematic view of the end face of the device (side view) ;

[0037] Figure 4 is a schematic view of the travelling crane in the device (longitudinal Figure 1 ) ;

[0038] Figure 5 is a schematic view of the travelling crane in the device (transverse view) ;

[0039] Figure 6 is a schematic view of the travelling crane in the device (longitudinal Figure 2 ) ;

[0040] Figure 7 is a block diagram of the temperature control module;

[0041] Figure 8 is a schematic view of the waste heat recovery module.

[0042] Reference signs: 1 - rail, 2 - gantry crane, 3 - air inlet, 4 - box side wall, 5 - inclined surface, 6 - fixed vertical plate, 7 - movable door. DETAILED DESCRIPTION

[0043] The application will be further described in detail below in combination with the drawings and specific examples:

[0044] Example 1: As Figures 1-6 A high-temperature holding diffusion annealing device for centrifugal cast steel or iron parts, the space in the device is a sealed space;

[0045] The top of the device is provided with two longitudinal rails 1; the rails are provided with travelling cranes for lifting the centrifugal cast steel or iron parts;

[0046] The side wall and the top of the device are both filled with heat preservation materials (such as pearl heat preservation sand, heat preservation cotton, etc.) ;

[0047] The top of the device is provided with multiple air inlets 3.

[0048] The side walls on the longitudinal sides of the device include an inclined surface 5 at the upper part, a fixed vertical plate 6 at the middle part, and a movable door 7 at the lower part.

[0049] The suction port is 10, diameter 400mm.

[0050] The total length of the device is 12m, the total width is 3m, the height from the ground is 4.1m, and the depth of the sunken part is 0.9m. The total height of the internal space is 5m.

[0051] A high-temperature heat preservation diffusion annealing method for centrifugal casting steel or iron parts, the casting is transferred to the device by a crane for annealing.

[0052] The casting temperature is 800-900℃, and the annealing time is not less than 48 hours.

[0053] Specifically: after the cast steel or cast iron part is centrifugally cast out of the mold (the casting temperature is 800-900℃), it is quickly transferred to the heat preservation annealing device for diffusion annealing for 48 hours by covering the heat preservation material, so that the carbide is decomposed and the organization is refined. After 48 hours, the casting is taken out of the device, and the temperature is about 600℃, which meets the annealing process requirements (the original electric furnace annealing process is: after the casting is loaded into the electric furnace, it is heated to 860℃, and then it is cooled to a temperature of about 600℃, and then it is taken out of the furnace and air cooled), and then it is air cooled to room temperature for machining.

[0054] The suction port is used as the interface of the dust collector connected to the heat preservation device, and is used for dust suction.

[0055] The movable door is convenient for lifting and transferring the casting for heat preservation operation. The heat preservation device is relatively long, and the movable door is a sliding door. When lifting and transferring the casting for heat preservation operation at a certain position, the movable door at this position is opened for operation, and when not in use, it is closed. When lifting and transferring the casting for heat preservation operation at another position, the movable door at this position is opened for operation, and so on. It is very convenient, has good sealing performance, and has good dust removal effect.

[0056] As shown in Figure 7 , the annealing device is provided with a heater (the heater is a 0Cr21Al6Nb electric heating wire) and a temperature sensor; a circulating fan is also provided, which functions to ensure that the temperature in the device is relatively uniform, and a heat exchanger fan (used for docking with an external heat recovery device) is also provided; the heater, temperature sensor, heat exchanger fan and circulating fan are all controlled by an MCU.

[0057] The working process is as follows:

[0058] The circulating fan is kept working to make the temperature in the space uniform;

[0059] When the temperature in the annealing device is detected by the temperature sensor to be lower than the preset annealing temperature, the heater is turned on and heated to the predetermined temperature;

[0060] When the current temperature is detected to be higher than the preset annealing temperature, the heater is turned off;

[0061] When the annealing is finished, the heat exchange fan is opened, and the waste heat recovery process is started.

[0062] As Figure 8 The waste heat recovery device comprises a heat exchange fan, a heat exchanger, a water tank and a water pump; the heat exchange fan and the water pump are controlled by the MCU.

[0063] One end of the gas heat exchange channel of the heat exchanger is connected with the heat exchange fan through an air pipe, and the other end of the gas passage of the heat exchanger is connected with the air inlet in the device; a circulating air duct is formed;

[0064] The water heat exchange channel of the heat exchanger, the water pipe, the water pump and the water tank form a water circulation passage; the water pump is a circulating pump;

[0065] When the water pump and the circulating fan are opened, the heat exchanger starts heat exchange, the recovered waste heat heats the water in the water tank, and the waste heat recovery is realized.

[0066] Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-temperature heat preservation diffusion annealing device for centrifugally cast steel or iron parts, characterized in that, The space within the device is a sealed space; The top of the device is provided with two longitudinal rails (1); the rails are provided with a crane for hoisting centrifugally cast steel or iron parts; The side walls and top of the device are filled with thermal insulation material; The device has multiple air intake ports on top (3).

2. The high-temperature heat preservation diffusion annealing device for centrifugally cast steel or iron parts according to claim 1, characterized in that, The side walls on both sides of the longitudinal direction of the device include an upper inclined surface (5), a middle fixed upright plate (6), and a lower movable door (7).

3. The high-temperature heat preservation diffusion annealing device for centrifugally cast steel or iron parts according to claim 1, characterized in that, There are 10 air intakes, each with a diameter of 400mm.

4. The high-temperature heat preservation diffusion annealing apparatus for centrifugally cast steel or iron parts according to any one of claims 1-3, characterized in that, The device has a total longitudinal length of 12m, a total width of 3m, a height of 4.1m above the ground, and a depth of 0.9m in the sunken section.

5. The high-temperature heat preservation diffusion annealing device for centrifugally cast steel or iron parts according to claim 4, characterized in that, The high-temperature heat preservation diffusion annealing device is externally connected to a waste heat recovery device; the high-temperature heat preservation diffusion annealing device is equipped with a temperature control module.

6. A high-temperature diffusion annealing method for centrifugally cast steel or iron parts, characterized in that, The casting is transferred by a crane to the apparatus according to any one of claims 1-4 for annealing.

7. The high-temperature heat treatment diffusion annealing method for centrifugally cast steel or iron parts according to claim 5, characterized in that, The casting temperature is 800-900℃, and the annealing time is not less than 48 hours.

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