A heat treatment method and treatment device for FV520(B) steel for centrifugal compressor impeller

Abstract

The invention relates to a heat treatment method and device for FV520 (B) steel for centrifugal compressor impellers. The method is to carry out solid solution aging treatment after rough processing of the material; the solid solution aging treatment is to place the rough processed parts in an insulation barrel, then load the furnace, fill with argon, and gradually heat up to 1050±10℃ after a certain period of time, keep warm for 1 hour, take the insulation barrel out of the furnace, and uncover; increase the amount of gas filling, and when the temperature is about to reach 400℃, reduce the amount of gas filling, and when the temperature is about to reach below 200℃, close the argon filling, and cool to room temperature. Aging treatment, the insulation barrel with the workpiece is loaded into the furnace, argon is passed, and when it is filled for a certain period of time, the temperature is gradually raised to 600℃, and the temperature is kept warm for 4 hours, the insulation barrel is taken out of the furnace, uncovered, and when the temperature is about to reach below 300℃, close the argon filling, and cool to room temperature; the invention simplifies the heat treatment process system, shortens the production cycle, and reduces the energy consumption of the factory while ensuring the mechanical performance indicators of the impeller.

Description

Technical Field

[0001] The invention relates to a heat treatment method and a treatment device for FV520 (B) steel for a centrifugal compressor impeller. Specifically, a precipitation hardened martensitic material is placed in an insulation barrel and filled with argon gas for protection throughout the whole process to reduce the generation of oxide scale. At the same time, the material is cooled by air cooling and subjected to solid solution aging treatment so that the material meets the mechanical performance requirements of the centrifugal compressor impeller. Background Art

[0002] FV520(B) material is currently widely used in high-speed rotating machinery, such as turbine blades, centrifugal compressor impellers, bolts, etc., and its material has the characteristics of weldability, corrosion resistance, and good mechanical properties. Due to the confidentiality of heat treatment technology, the information that can be found in online literature is limited, and the specific key parameters are unknown. In addition, the heat treatment method mentioned in the information is cumbersome, the production cycle is long, and the heat treatment equipment and site may not meet the actual production requirements of the company's factory. For this reason, a heat treatment method and treatment device for FV520(B) steel for centrifugal compressor impellers are designed to overcome the above problems. After solution treatment and aging treatment by the method, the ideal mechanical performance requirements for centrifugal compressor impellers can be obtained at room temperature. Summary of the invention

[0003] The purpose of the present invention is to provide a heat treatment method and a treatment device for FV520 (B) steel for centrifugal compressor impellers, so that the mechanical performance indicators of the steel at room temperature meet the technical requirements for centrifugal compressor impellers; at the same time, the heat treatment process is simplified, the production cycle is shortened, and the energy consumption of the factory is reduced.

[0004] To achieve the above object, the present invention provides a heat treatment method for FV520(B) steel for centrifugal compressor impeller, the method comprising the following steps:

[0005] (1) Solution treatment

[0006] 1) Place the rough-machined impeller blank in a heat preservation barrel and attach a thermocouple to the workpiece;

[0007] 2) The insulation barrel needs to be reserved for connecting the argon filling and thermocouple;

[0008] 3) The electric furnace used for heat treatment needs to reserve an installation port for placing the pipe;

[0009] 4) At room temperature, place the insulation barrel containing the impeller blank into an electric furnace, and fill the barrel with argon at a flow rate of 10L / min;

[0010] 5) After 30 minutes, gradually heat to 1050±10℃ at a rate of ≤200℃ / h while keeping the amount of argon unchanged, and keep warm for 1 hour;

[0011] 6) Move the insulation barrel out of the electric furnace to an open area, open the cover of the insulation barrel, adjust the argon filling amount, and connect it at 60L / min;

[0012] 7) When the temperature drops below 400°C, adjust the amount of argon gas to 10L / min;

[0013] 8) When the temperature drops below 50°C, cut off the argon gas and cool to room temperature;

[0014] (2) Aging treatment

[0015] 1) At room temperature, place the insulation barrel containing the impeller blank into an electric furnace, and fill the barrel with argon at a flow rate of 10L / min;

[0016] 2) After 30 minutes, gradually heat to 600±10℃ at a rate of ≤150℃ / h while keeping the amount of argon unchanged, and keep warm for 4 hours;

[0017] 3) Move the insulation barrel out of the electric furnace to an open area, open the cover of the insulation barrel, and keep the argon filling amount unchanged;

[0018] 4) When the temperature drops to 300°C or below, cut off the argon gas injection and wait for the impeller blank to naturally cool to room temperature.

[0019] Preferably, the treatment device adopted by the heat treatment method is composed of an insulation barrel and a thermocouple, an impeller blank, an isolation ring, and a heightening block arranged inside the insulation barrel. A barrel cover is arranged on the top of the insulation barrel, and a heightening block is placed on the bottom of the insulation barrel. An isolation ring is arranged directly above the heightening block, and an impeller blank is placed on the isolation ring. The impeller blank is connected to one end of the thermocouple in the insulation barrel, and the other end of the thermocouple passes through a first through hole arranged on the side of the insulation barrel from below the isolation ring, and is connected to an external device for use after passing through a thermocouple pipe connected to the first through hole.

[0020] Preferably, a second through hole is provided on the side of the insulation barrel, to which an argon gas connecting pipe is connected. The argon gas connecting pipe is connected to an argon gas tank arranged outside the insulation barrel through a connecting pipe. The vertical heights of the argon gas connecting pipe and the thermocouple connecting pipe are both lower than the vertical height of the isolation ring, so that the argon gas can fully cool the impeller blank.

[0021] Preferably, a handle is provided on the lid at the top of the heat preservation barrel, and the lid is an openable and closable structure.

[0022] The invention discloses a heat treatment method and a treatment device for FV520 (B) steel for centrifugal compressor impellers, so that the mechanical performance indexes of the steel at room temperature meet the technical requirements for centrifugal compressor impellers; at the same time, the heat treatment process is simplified, the production cycle is shortened, and the energy consumption of the factory is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention.

[0024] Figure 2 The relationship diagram of the heat treatment temperature, argon flow rate and time of the present invention. DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the following embodiments are used to illustrate the present invention. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] In the description of the present invention, unless otherwise specified, “plurality” means two or more than two; the orientations or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “inside”, “outside”, “front end”, “rear end”, “head” and “tail” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] like Figure 1 As shown, a heat treatment method of FV520(B) steel for a centrifugal compressor impeller comprises the following steps:

[0028] (1) Solution treatment

[0029] 1) Place the rough-machined impeller blank in a heat preservation barrel and attach a thermocouple to the workpiece;

[0030] 2) The insulation barrel needs to be reserved for connecting the argon filling and thermocouple;

[0031] 3) The electric furnace used for heat treatment needs to reserve an installation port for placing the pipe;

[0032] 4) At room temperature, place the insulation barrel containing the impeller blank into an electric furnace, and fill the barrel with argon at a flow rate of 10L / min;

[0033] 5) After 30 minutes, gradually heat to 1050±10℃ at a rate of ≤200℃ / h while keeping the amount of argon unchanged, and keep warm for 1 hour;

[0034] 6) Move the insulation barrel out of the electric furnace to an open area, open the cover of the insulation barrel, adjust the argon filling amount, and connect it at 60L / min;

[0035] 7) When the temperature drops below 400°C, adjust the amount of argon gas to 10L / min;

[0036] 8) When the temperature drops below 50°C, cut off the argon gas and cool to room temperature;

[0037] (2) Aging treatment

[0038] 1) At room temperature, place the insulation barrel containing the impeller blank into an electric furnace, and fill the barrel with argon at a flow rate of 10L / min;

[0039] 2) After 30 minutes, gradually heat to 600±10℃ at a rate of ≤150℃ / h while keeping the amount of argon unchanged, and keep warm for 4 hours;

[0040] 3) Move the insulation barrel out of the electric furnace to an open area, open the cover of the insulation barrel, and keep the argon filling amount unchanged;

[0041] 4) When the temperature drops to 300°C or below, cut off the argon gas injection and wait for the impeller blank to naturally cool to room temperature.

[0042] The treatment device used in the heat treatment method is composed of an insulation barrel 1 and a thermocouple 2, an impeller blank 3, an isolation ring 4, and a padding block 5 arranged inside the insulation barrel 1. The top of the insulation barrel 1 is provided with a barrel cover 6 with a handle 10 that can be opened and closed. The padding block 5 is placed at the bottom of the insulation barrel 1. The isolation ring 4 is set just above the padding block 5. The impeller blank 3 is placed on the isolation ring 4. The impeller blank 3 is connected to one end of the thermocouple 2 in the insulation barrel 1, and the other end of the thermocouple 2 is connected from the isolation ring 4. A first through hole 11 is provided on the side of the heat preservation barrel 1 and is connected to an external device (electric meter) for use through a thermocouple pipe 9 connected to the first through hole 11. A second through hole 12 is also provided on the side of the heat preservation barrel 1. An argon pipe 8 is connected to the second through hole 12. The argon pipe 8 is connected to an argon tank 8 provided outside the heat preservation barrel 1 through a connecting pipe 13. The vertical heights of the argon pipe 8 and the thermocouple pipe 9 are both lower than the vertical height of the isolation ring 4, so that the argon gas can fully cool the impeller blank 3.

[0043] The specific data are shown in Table 1 below:

[0044]

[0045] Table 1 Mechanical properties of FV520(B) steel at room temperature

[0046] In order to make the present invention more convenient and intuitive to understand, Figure 2 This is a relationship diagram of the heat treatment temperature, argon gas flow rate and time of the present invention.

[0047] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A heat treatment method for FV520(B) steel for centrifugal compressor impeller, characterized in that: The method comprises the following steps: (1) Solution treatment 1) Place the rough-machined impeller blank in a heat preservation barrel and attach a thermocouple to the workpiece; 2) The insulation barrel needs to be reserved for connecting the argon filling and thermocouple; 3) The electric furnace used for heat treatment needs to reserve an installation port for placing the pipe; 4) At room temperature, place the insulation barrel containing the impeller blank into the electric furnace, and fill the barrel with argon at a flow rate of 10L / min; 5) After 30 minutes, gradually heat to 1050±10℃ at a rate of ≤200℃ / h while keeping the argon filling volume unchanged, and keep warm for 1 hour; 6) Move the insulation barrel out of the electric furnace to an open area, open the cover of the insulation barrel, adjust the argon filling amount, and connect it at 60L / min; 7) When the temperature drops below 400°C, adjust the amount of argon gas to 10L / min; 8) When the temperature drops below 50°C, cut off the argon gas and cool to room temperature; (2) Timeliness treatment 1) At room temperature, place the insulation barrel containing the impeller blank into an electric furnace, and fill the barrel with argon at a flow rate of 10L / min; 2) After 30 minutes, gradually heat to 600±10℃ at a rate of ≤150℃ / h while keeping the argon filling volume unchanged, and keep warm for 4 hours; 3) Move the insulation barrel out of the electric furnace to an open area, open the cover of the insulation barrel, and keep the argon filling amount unchanged; 4) When the temperature drops to 300°C or below, cut off the argon gas injection and wait for the impeller blank to naturally cool to room temperature.

2. The heat treatment method according to claim 1, characterized in that: The treatment device used in the heat treatment method comprises a heat preservation barrel (1), a thermocouple (2), an impeller blank (3), an isolating ring (4), and a padding block (5) arranged inside the heat preservation barrel (1). The heat preservation barrel (1) is provided with a barrel cover (6) on the top, and a padding block (5) is placed on the bottom of the heat preservation barrel (1). An isolating ring (4) is arranged directly above the padding block (5), and an impeller blank (3) is placed on the isolating ring (4). The impeller blank (3) is connected to one end of the thermocouple (2) in the heat preservation barrel (1), and the other end of the thermocouple (2) passes through a first through hole (11) arranged on the side of the heat preservation barrel (1) from the bottom of the isolating ring (4), and is connected to an external device for use after passing through a thermocouple pipe (9) connected to the first through hole (11).

3. The heat treatment method according to claim 2, characterized in that: The heat preservation barrel (1) is also provided with a second through hole (12) on the side thereof, and an argon gas pipe (8) is connected to the second through hole (12). The argon gas pipe (8) is connected to an argon gas tank (8) arranged outside the heat preservation barrel (1) through a connecting pipe (13). The vertical heights of the argon gas pipe (8) and the thermocouple pipe (9) are both lower than the vertical height of the isolation ring (4), so that the argon gas can fully cool the impeller blank (3).

4. The heat treatment method according to claim 3, characterized in that: A handle (10) is provided on the barrel cover (6) at the top of the heat-insulating barrel (1), and the barrel cover (6) is an openable and closable structure.

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