Local stress relief annealing device and stress relief annealing method

Abstract

The invention relates to the technical field of destressing heat treatment of shaft parts, in particular to a local destressing annealing device. The invention provides a local stress relief annealing device which comprises a heat treatment cylinder, an electric control cabinet and a placement bracket, one axial end of the heat treatment cylinder is open, a plurality of temperature sensors are arranged in the heat treatment cylinder at intervals, the heat treatment cylinder and the plurality of temperature sensors are in signal connection with the electric control cabinet, and the heat treatment cylinder is transversely arranged on the placement bracket. The device is simple to operate, can avoid dependence on heat treatment furnace equipment, and also avoids bending deformation of the shaft parts when the shaft parts are transversely placed and heated under the participation of the external roller carrier.

Description

Technical Field

[0001] The invention relates to the technical field of stress relief heat treatment of shaft parts, and in particular to a local stress relief annealing device and a stress relief annealing method using the device. Background Art

[0002] Ultra-supercritical high and medium pressure rotors are made of steel with a chromium content of 9%-12%. The friction characteristics between the rotor and the bearing alloy are poor. This position is prone to wear during operation, resulting in "hair pulling" and abnormal vibration of the rotor shaft system. Therefore, it is often necessary to weld Cr-Mo low alloy steel at the rotor shaft diameter position and perform stress relief heat treatment to improve the friction characteristics between the rotor and the bearing alloy; due to power plant operation problems or production and processing factors that cause defects or lack of meat in the rotor, it is sometimes necessary to repair the rotor by means of welding plus stress relief heat treatment; some long shaft parts have complex size and structure, large processing volume, and are prone to cause large processing stress, and stress relief heat treatment is required to remove the processing stress.

[0003] At present, the commonly used heat treatment methods are whole furnace or local heat treatment. However, there are some problems with the several commonly used stress relief heat treatment methods: (1) If the traditional whole furnace heating stress relief heat treatment is adopted, the shaft parts need to be placed vertically in the pit furnace for heating, which is highly dependent on the heat treatment furnace equipment, has limited use conditions, and has high production costs; (2) Some shaft parts can only be placed horizontally for stress relief heat treatment due to the current situation. After long-term horizontal placement, it is easy to cause certain deformation of the shaft parts. For shaft parts with small or no margin, bending deformation should be avoided; (3) When the shaft parts have large external dimensions, the required power is also large. If local resistance heating is used for stress relief heat treatment, dozens of ceramic-lined resistance heating plates need to be laid and fixed, which is not only difficult to operate, but also difficult to ensure the heating quality. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a local stress relief annealing device which is simple to operate and can avoid dependence on heat treatment furnace equipment.

[0005] The present invention adopts the following technical solution:

[0006] The present invention provides a local stress relief annealing device, comprising a heat treatment cylinder, an electric control cabinet and a placement bracket. One axial end of the heat treatment cylinder is open, and a plurality of temperature sensors are arranged at intervals inside the heat treatment cylinder. The heat treatment cylinder and the plurality of temperature sensors are all connected to the electric control cabinet signal. The heat treatment cylinder is horizontally arranged on the placement bracket.

[0007] Preferably, the heat treatment cylinder comprises a heat preservation cylinder and a heating cylinder, the outer wall of the heating cylinder is in contact with the inner wall of the heat preservation cylinder, and the heating cylinder is connected to the electric control cabinet signal.

[0008] Preferably, the heat treatment cylinder is divided into two parts, an upper cylinder and a lower cylinder, which are split along the axial direction, and the upper cylinder and the lower cylinder are detachably connected.

[0009] Preferably, the outer wall of the upper cylinder and the outer wall of the lower cylinder are both installed with lifting ears, and the upper cylinder and the lower cylinder are fastened and fixed by the lifting ears.

[0010] Preferably, the temperature sensor is arranged on the inner wall of the heat treatment cylinder outside the open end.

[0011] The present invention also provides a stress relief annealing method, which uses the local stress relief annealing device as described in the third or fourth item above, and comprises the following steps:

[0012] S1: Arrange the axial placement of the roller frame and the heat treatment cylinder according to the size of the shaft parts;

[0013] S2: Lift the shaft parts onto the roller frame and adjust the height of the roller frame to make the clearance between the shaft parts and the heat treatment cylinder uniform in the circumferential direction;

[0014] S3: After the part to be treated of the shaft parts enters the heat treatment cylinder, the gap between the shaft parts and the opening of the heat treatment cylinder is sealed with a heat insulation material;

[0015] S4: Start the roller frame to drive the shaft parts to rotate, and make the heat treatment cylinder execute the preset heating program;

[0016] S5: After the heating program is completed, the heat-insulating material blocking the opening of the heat treatment cylinder is removed, the upper cylinder part of the heat treatment cylinder is lifted off, and then the shaft parts are vertically moved out of the heat treatment cylinder and lifted off.

[0017] Preferably, in step S4, the heating and cooling speed of the heat treatment barrel to heat the to-be-treated part of the shaft-type part is within 40°C / h.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] When the local stress relief annealing device of the present invention is in use, shaft parts of different sizes can be placed at the radial center of the heat treatment cylinder by adjusting the height and position of the roller frame, and the gap between the shaft parts and the opening of the heat treatment cylinder can be sealed with a heat-insulating material. After that, the shaft parts can be placed horizontally and heated in a rotating state by starting the roller frame. The operation is simple and can avoid dependence on heat treatment furnace equipment. At the same time, with the participation of the external roller frame, bending deformation of the shaft parts when placed horizontally and heated is also avoided.

[0020] The stress relief annealing method of the present invention naturally has the above-mentioned beneficial effects due to the use of the above-mentioned local stress relief annealing device and roller frame, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of a first specific application of a local stress relief annealing device in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of a second specific application of the local stress relief annealing device in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a third specific application of the local stress relief annealing device in an embodiment of the present invention.

[0024] Figure 4 It is a schematic front view of the upper and lower barrels of the local stress relief annealing device in an embodiment of the present invention.

[0025] Figure 5 It is a bottom view schematic diagram of the upper and lower cylinders of the local stress relief annealing device in the embodiment of the present invention.

[0026] The reference numerals are described as follows:

[0027] 1. Heat treatment cylinder 3. Temperature sensor

[0028] 11. Insulation cylinder 4. Roller frame

[0029] 12. Heating cylinder 5. Lifting lug

[0030] 2. Place the bracket DETAILED DESCRIPTION

[0031] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0035] See also Figure 1 The present embodiment provides a local stress relief annealing device, comprising a heat treatment cylinder 1, an electric control cabinet and a placement bracket 2. One axial end of the heat treatment cylinder 1 is open, and a plurality of temperature sensors 3 are arranged at intervals inside the heat treatment cylinder 1. The heat treatment cylinder 1 and the plurality of temperature sensors 3 are all connected to the electric control cabinet signal. The heat treatment cylinder 1 is horizontally arranged on the placement bracket 2.

[0036] When the local stress relief annealing device of this embodiment is in use, the height of the heat treatment cylinder 1 can be adjusted by the roller frame 4, and the gap between the shaft parts and the opening of the heat treatment cylinder 1 can be sealed with insulation material. After that, the shaft parts can be placed horizontally and heated in a rotating state by starting the roller frame 4 and the heat treatment cylinder 1. The operation is simple and can avoid dependence on the heat treatment furnace equipment. At the same time, with the participation of the external roller frame 4, the bending deformation of the shaft parts when placed horizontally and heated is also avoided.

[0037] Among them, the heat treatment cylinder 1 is used to heat the part to be treated of the shaft parts; the opening on one side of the heat treatment cylinder 1 enables various shaft parts with diameters smaller than the opening diameter of the heat treatment cylinder 1 to be subjected to local stress relief heat treatment, and has good versatility; necessary switchgear, control equipment, measuring instruments, protective electrical appliances and auxiliary equipment are pre-installed inside the electric control cabinet; the bracket 2 is placed to enable the heat treatment cylinder 1 to be raised a certain distance from the ground, and cooperate with the roller frame 4 to facilitate the heat treatment operation of the shaft parts.

[0038] Preferably, see Figure 1 The heat treatment cylinder 1 includes a heat preservation cylinder 11 and a heating cylinder 12. The outer wall of the heating cylinder 12 is in contact with the inner wall of the heat preservation cylinder 11, and the heating cylinder 12 is connected to the electric control cabinet signal. The electric control cabinet controls the heating cylinder 12 to heat, and the heat preservation cylinder 11 can keep the shaft parts warm, so as to ensure the heat treatment effect of the heat treatment cylinder 1 on the shaft parts.

[0039] Preferably, the heat treatment cylinder 1 is an upper cylinder and a lower cylinder that are split in the axial direction, and the upper cylinder and the lower cylinder are detachably connected. When heat treating shaft parts, the upper and lower parts of the heat treatment cylinder 1 can be separated first, and then the upper and lower parts of the heat treatment cylinder 1 can be closed after the shaft parts are placed, which is conducive to improving the convenience of operation.

[0040] Preferably, see Figure 4 and Figure 5 The outer wall of the upper cylinder and the outer wall of the lower cylinder are both provided with lifting ears 5, and the upper cylinder and the lower cylinder are fastened and fixed by the lifting ears 5. The arrangement of the lifting ears 5 can facilitate the lifting of the upper cylinder and the lower cylinder by an external crane.

[0041] Preferably, see Figure 1 , the temperature sensor 3 is arranged on the inner wall outside the opening end of the heat treatment cylinder 1. The temperature sensor 3 is set to monitor the internal temperature of the heat treatment cylinder 1 and feed it back to the electric control cabinet to control the temperature according to the preset program. Temperature sensors can also be arranged in key areas such as the surfacing area and sharp corners of shaft parts to monitor the temperature to ensure the accurate execution of the process temperature and insulation time.

[0042] It should be noted that the specific location and number of the temperature sensors 3 are determined according to the appearance characteristics of the shaft parts and the surfacing locations.

[0043] Preferably, in this embodiment, the temperature sensor 3 is preferably a thermocouple.

[0044] Specifically, in this embodiment, see Figure 1 Four temperature sensors 3 are provided, two of which are spaced apart on the inner wall of the end of the heat treatment cylinder 1 opposite to the opening end, and the other two temperature sensors 3 are respectively provided on the top inner wall and the bottom inner wall of the heat treatment cylinder 1.

[0045] It should be noted that, in order to ensure the accurate execution of the process temperature and the holding time, temperature sensors 3 may also be placed on the shaft parts. These temperature sensors 3 are connected to external instruments and are only used to monitor the temperature.

[0046] This embodiment also provides a stress relief annealing method, which uses the above-mentioned local stress relief annealing device and includes the following steps:

[0047] S1: Arrange the axial placement positions of the roller frame 4 and the heat treatment cylinder 1 according to the size of the shaft parts;

[0048] S2: hoist the shaft parts onto the roller frame 4, and adjust the height of the roller frame 4 so that the gap between the shaft parts and the heat treatment cylinder 1 is uniform in the circumferential direction;

[0049] S3: After the part to be treated of the shaft part enters the heat treatment cylinder 1, a heat-insulating material is used to seal the gap between the shaft part and the opening of the heat treatment cylinder 1;

[0050] S4: Start the roller frame 4 to drive the shaft parts to rotate, and make the heat treatment cylinder 1 execute the preset heating program;

[0051] S5: After the heating program is completed, the heat-insulating material blocking the opening of the heat treatment cylinder 1 is removed, the upper cylinder part of the heat treatment cylinder 1 is lifted off, and then the shaft parts are vertically moved out of the heat treatment cylinder 1 and lifted off.

[0052] The stress relief annealing method of this embodiment naturally has the above-mentioned beneficial effects due to the use of the above-mentioned local stress relief annealing device and roller frame 4, which will not be described in detail here. In step S3, the gap between the shaft parts and the opening of the heat treatment cylinder 1 is sealed with a heat-insulating material to prevent heat loss.

[0053] Preferably, in step S4, the heat treatment barrel 1 heats the to-be-treated portion of the shaft-type part at a heating and cooling rate within 40°C / h to ensure the heat treatment effect.

[0054] The following are the specifications of the heat treatment cylinder 1: (Unit: mm), a local stress relief annealing device with a total power of 200KW (the power of the upper cylinder and the lower cylinder is 100KW each), several specific embodiments of the stress relief annealing method of the present invention: 1. See Figure 1 , local heat treatment of the surfacing parts of shaft parts, where the material of the shaft parts is 12Cr10Mo1W1NiVNbN, the welding wire used for surfacing is Cr-Mo low alloy steel, heating the surfacing parts of the shaft parts within a reasonable temperature range of 650℃-705℃ can achieve local stress relief treatment; 2. See Figure 2 , for the machine jumping due to the large vibration of the front and rear bearings during movement, the shaft diameter was found to be worn during maintenance, and the surfacing welding scheme was used to repair the shaft parts. The material of the shaft parts is 30Cr2Ni4MoV. Heating the surfacing welding parts of the shaft parts within the reasonable temperature range of 550℃-605℃ can achieve local stress relief treatment; 3. See Figure 3 For shaft parts with large processing volume and large processing stress due to large forging blank allowance, in order to prevent deformation after subsequent fine processing, it is necessary to add a stress relief process after the rough processing process. Among them, the material of the shaft parts is 30Cr2Ni4MoV. The stress relief process can be achieved by heating the parts of the shaft parts that require subsequent fine processing within a reasonable temperature range of 550℃-605℃.

[0055] The stress relief annealing method of the present invention can realize the local heat treatment production of horizontally placed shaft parts of various specifications through the above-mentioned local stress relief annealing device, realize mechanized operation, and is easy to operate. At the same time, the rotation heating of the shaft parts is realized through the roller rack to prevent the bending deformation of the shaft parts. Especially for large shaft parts, the cost is low and the dependence on the use of large-scale shaft-type heat treatment furnace equipment is reduced.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A local stress relief annealing device, characterized in that: The invention comprises a heat treatment cylinder (1), an electric control cabinet and a placement bracket (2); one axial end of the heat treatment cylinder (1) is open, and a plurality of temperature sensors (3) are arranged at intervals inside the heat treatment cylinder (1); the heat treatment cylinder (1) and the plurality of temperature sensors (3) are all connected to the electric control cabinet signal; the heat treatment cylinder (1) is horizontally arranged on the placement bracket (2).

2. The local stress relief annealing device according to claim 1, characterized in that: The heat treatment cylinder (1) comprises a heat-insulating cylinder (11) and a heating cylinder (12); the outer wall of the heating cylinder (12) is in contact with the inner wall of the heat-insulating cylinder (11), and the heating cylinder (12) is signal-connected to the electric control cabinet.

3. The local stress relief annealing device according to claim 1, characterized in that: The heat treatment cylinder (1) consists of two parts, an upper cylinder and a lower cylinder, which are split along the axial direction. The upper cylinder and the lower cylinder are detachably connected.

4. The local stress relief annealing device according to claim 3, characterized in that: The outer wall of the upper cylinder and the outer wall of the lower cylinder are both installed with lifting ears (5), and the upper cylinder and the lower cylinder are fastened and fixed by the lifting ears (5).

5. The local stress relief annealing device according to claim 1, characterized in that: The temperature sensor (3) is arranged on the inner wall of the heat treatment cylinder (1) outside the open end.

6. A stress relief annealing method, characterized in that: The local stress relief annealing device according to claim 3 or 4 is used, and The following steps are involved: S1: arranging the axial placement positions of the roller frame (4) and the heat treatment cylinder (1) according to the size of the shaft parts; S2: hoisting the shaft parts onto the roller frame (4), and adjusting the height of the roller frame (4) so ​​that the gap between the shaft parts and the heat treatment cylinder (1) in the circumferential direction is uniform; S3: After the part of the shaft part to be treated enters the heat treatment cylinder (1), a heat-insulating material is used to seal the gap between the shaft part and the opening of the heat treatment cylinder (1); S4: starting the roller frame (4) to drive the shaft parts to rotate, and causing the heat treatment cylinder (1) to execute a preset heating program; S5: After the heating program is completed, the heat-insulating material blocking the opening of the heat treatment cylinder (1) is removed, the upper cylinder part of the heat treatment cylinder (1) is lifted off, and then the shaft parts are vertically moved out of the heat treatment cylinder (1) and the shaft parts are lifted off.

7. The stress relief annealing method according to claim 6, characterized in that: In step S4, the heat treatment cylinder (1) heats the to-be-treated portion of the shaft-type component at a heating and cooling rate within 40°C / h.

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