Refining method for blocky carbide of high-carbon-chromium stainless steel and air cooling equipment thereof

Abstract

The invention relates to a high-carbon chromium stainless steel blocky carbide refining method and air cooling equipment thereof, and the refining method comprises the following steps: S1, heating to 690 DEG C, and carrying out low-temperature decomposition on a bearing ring for 3 hours; s2, the bearing ring obtained in the step S1 is subjected to air cooling to the room temperature; s3, normalizing the bearing ring according to the following steps; and S4, the steps of low-temperature decomposition, air cooling to the room temperature and normalizing are repeated, and refining of carbides can be achieved through the steps. And the air cooling device can adjust the air cooling mode according to air cooling or air blowing cooling so as to improve the air cooling efficiency.

Description

Technical Field

[0001] The invention relates to a heat treatment method and equipment thereof, in particular to a high-carbon chromium stainless steel block carbide refinement method and air cooling equipment thereof. Background Art

[0002] Bearing rings are an important part of bearings and are usually made of high-carbon chromium stainless steel. Their performance directly affects the bearing's load capacity and service life. During the heat treatment process, controlling and refining massive carbides is a key step in improving the performance of the rings.

[0003] Failure to heat treat high-carbon chromium stainless steel in bearing rings, especially to refine the massive carbides, can lead to a number of negative consequences. Large carbides act as stress concentration points, reduce bearing fatigue life, increase wear rate, increase the risk of early failure, reduce load-bearing capacity, and affect thermal stability at high temperatures. In addition, untreated material may exhibit uneven wear during machining, increasing machining difficulty and cost, while reducing corrosion resistance and leading to increased noise and vibration during operation. Therefore, heat treatment to refine the massive carbides is essential to improving bearing performance and reliability.

[0004] At the same time, air cooling equipment is crucial in the heat treatment process of bearing rings. It ensures rapid and uniform cooling after quenching, which helps refine carbides and release stress, thereby improving the hardness and toughness of the material. The uniformity and controllability of air cooling equipment directly affect the final performance of bearing rings, including their wear resistance, fatigue resistance and dimensional stability. Therefore, air cooling equipment plays a decisive role in ensuring the quality of bearing rings and extending their service life.

[0005] In summary, the present application is proposed to refine the size of blocks during heat treatment and improve air cooling efficiency. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method for refining high carbon chromium stainless steel block carbides for reducing the size of blocks during heat treatment.

[0007] To achieve the above object, the technical solution of the present invention is as follows: A method for refining blocky carbides of high carbon chromium stainless steel is carried out according to the following steps: S1, heating to 690°C, and performing low-temperature decomposition of the bearing ring for 3 hours; S2, air cooling the bearing ring after step S1 to room temperature; S3, normalizing the bearing ring according to the following steps; S301, raising the temperature to 920°C and keeping the bearing rings warm for 2 hours; S302, raising the temperature to 1130°C and keeping the bearing rings warm for 1.5 hours; S303, cooling the bearing ring after step S302 to room temperature by blowing air; S4, repeat the low temperature decomposition (ie S1) - air cooling to room temperature (ie S2) - normalizing steps.

[0008] Furthermore, the low-temperature decomposition in step S1 is repeated three times, and the low-temperature decomposition in step S4 is performed only once.

[0009] Furthermore, in step S4, normalizing the bearing ring is performed according to the following steps: S401, raising the temperature to 920°C and keeping the bearing rings warm for 2 hours; S402, raising the temperature to 1100°C and keeping the bearing rings warm for 1 hour; S403, cooling the bearing ring after step S402 to room temperature by air blowing.

[0010] The beneficial effects of the high-carbon chromium stainless steel block carbide refinement method are: first, the components dissolved in the matrix can be more fully converted into granular carbides through low-temperature decomposition, and block carbides such as M7C can be completely dissolved in the matrix; the subsequent normalizing process can effectively dissolve the granular carbides in the matrix; and by repeating the above process, the block carbides in the material can be better refined.

[0011] Secondly, the carbides are dissolved in the matrix through high temperature in the first normalizing, and the temperature can be lowered in the second normalizing, which can not only reduce the energy consumption of the heat treatment equipment, but also ensure that the remaining carbides can be effectively dissolved in the matrix.

[0012] Finally, by refining the carbides, black stains generated by friction with blocky carbides can be effectively prevented from appearing on the retainer surface during bearing operation, thereby preventing the retainer surface from being excessively worn and keeping the retainer surface clean.

[0013] At the same time, in view of the deficiencies in the prior art, the present invention also provides an air cooling device that improves air cooling efficiency.

[0014] To achieve the above-mentioned purpose, the technical solution of the present invention is as follows: it includes a square inner shell, an outer shell and an equipment layer located therebetween, the outer shell is provided with a moving mechanism that can move along the four sides of the outer shell and an exhaust fan that is provided on the moving mechanism and moves with the moving mechanism, an exhaust window is provided on the inner shell at the position corresponding to the moving mechanism, and the equipment layer is provided with blowing fans at the intersections of the four sides thereof.

[0015] The beneficial effect of the air cooling device is: in order to cooperate with the carbide refinement method in this application, the above-mentioned air cooling device must include a control module, and how to control the moving mechanism, exhaust fan, blowing fan and other equipment through the control module belongs to the existing technology and will not be elaborated here. Only its specific working method and the effect produced are explained.

[0016] First, when air cooling is required, the moving mechanism drives the exhaust fan to move to the center of each side of the outer shell, and starts low-speed exhaust as needed, so as to promptly remove the heat emitted by the internal bearing ring to achieve the effect of quickly cooling to room temperature. At this time, air cooling can be achieved by connecting the inner shell to the outside, that is, setting an openable door, and the air blowing fan can be started synchronously so that the bearing ring is located in the center of the inner shell to achieve the effect of air cooling.

[0017] Secondly, when air cooling is required, the moving mechanism drives the exhaust fan to move to the intersection of the outer shell, that is, the four corners of the square outer shell cooperate with the air blowing fans set near the intersection of the equipment layer to form air inlet-outlet air ducts at the four sides of the inner shell. At this time, a device can be set inside the inner shell to drive the bearing ring to move back and forth at the four air ducts to quickly cool the bearing ring.

[0018] In summary, the above scheme can accelerate the cooling rate of air cooling and the cooling rate of blowing cooling. At the same time, when the bearing ring enters from one air duct to another during blowing cooling, the blowing fan and the exhaust fan can cooperate to discharge the hot air in the air duct where the bearing ring has just left to the outside. At the same time, since the bearing ring needs to pass through three air ducts before it can re-enter the air duct, the above setting can reduce the heat retention in the air duct and accelerate the cooling rate of the bearing ring.

[0019] In addition, the rolling wheels arranged around the equipment layer can not only support the rolling chain at the bending part of the rolling chain, but also tension the rolling chain to prevent it from loosening and affecting the moving efficiency.

[0020] Furthermore, the moving mechanism includes a rolling wheel arranged at the intersection of the equipment layer and a rolling chain matched therewith, and the outer peripheral surface of the rolling wheel is circumferentially provided with a plurality of semicircular snap-in grooves, and the rolling chain includes a plurality of connecting plates and a hinge shaft for hingedly connecting adjacent connecting plates, and the hinge shaft can be matched with the snap-in groove to form positioning.

[0021] The above arrangement can form a stable transmission connection between the rolling wheel and the rolling chain, and can also make full use of the hinge shafts between the rolling chains, thereby effectively optimizing the space design.

[0022] Furthermore, the equipment layer is provided with a placement layer whose shell is made of heat-insulating material and is used to place the air blowing fan, and a starting door is movably connected to the placement layer, and the starting door is controlled to be opened or closed according to the different rotation directions of the rolling wheel.

[0023] In the specific working steps, when the moving mechanism drives the exhaust fan to move to the center of the outer shell, the rolling wheel rotates and drives the start door to close to prevent the hot air from affecting the air fan; when the moving mechanism drives the exhaust fan to move to the edge of the outer shell, the rolling wheel rotates and drives the start door to open to allow the air fan to work. The above arrangement can effectively protect the air fan closer to the heat source and prevent the air fan from malfunctioning. As a preferred method, cooling pipes can also be arranged in a serpentine shape on the outside of the placement layer to further prevent the hot air from affecting the air fan and increase the service life of the air fan.

[0024] Furthermore, a connecting rod is provided between the starting door and the rolling wheel, one end of the connecting rod is hinged to an eccentric position of the rolling wheel, and the other end is hinged to one end of the starting door.

[0025] The above arrangement can realize the linkage between the rolling wheel and the start door. In addition, a slot for the connecting rod and the start door hinge to move can be provided on the start door to limit the connecting rod from driving the start door to move in other directions, so that the torque transmitted by the connecting rod can more smoothly drive the start door to close or open.

[0026] Furthermore, a rotating ring is arranged in the inner shell body, and a clamping ring is arranged on the rotating ring for forming a clamping relationship with the bearing ring.

[0027] A placement table for the bearing ring is also provided at the center of the rotating ring, so that the bearing ring can be placed when air cooling is required. In addition, when air cooling is required, the bearing ring is fixed by a clamping ring and driven to move in four air ducts, thereby completing the rapid cooling of the bearing ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow chart of an embodiment of the present invention; Figure 2 The metallographic diagram of the bearing ring before the implementation of the embodiment of the present invention; Figure 3 This is a metallographic diagram of a bearing ring after low-temperature decomposition according to an embodiment of the present invention; Figure 4 The metallographic diagram of the bearing ring after the implementation of the embodiment of the present invention; Figure 5 is an axonometric diagram of an embodiment of the present invention; Figure 6 is an internal view of an embodiment of the present invention; Figure 7An axonometric diagram of a scroll wheel and a placement layer according to an embodiment of the present invention; Figure 8 FIG. 4 is an internal view of the inner shell of an embodiment of the present invention. DETAILED DESCRIPTION

[0029] A method for refining high carbon chromium stainless steel block carbides according to an embodiment of the present invention is as follows Figure 1-4 As shown: It is carried out according to the following steps: S1, heating to 690℃, and performing low-temperature decomposition of the bearing ring for 3 hours; S2, air cooling the bearing ring after step S1 to room temperature; S3, normalizing the bearing ring according to the following steps; S301, raising the temperature to 920°C and keeping the bearing rings warm for 2 hours; S302, raising the temperature to 1130°C and keeping the bearing rings warm for 1.5 hours; S303, cooling the bearing ring after step S302 to room temperature by blowing air; S4, repeating the low temperature decomposition - air cooling to room temperature - normalizing steps according to the following steps; S401, raising the temperature to 920°C and keeping the bearing rings warm for 2 hours; S402, raising the temperature to 1100°C and keeping the bearing rings warm for 1 hour; S403, cooling the bearing ring after step S402 to room temperature by air blowing.

[0030] In step S1, low temperature decomposition is repeated three times, and in step S4, low temperature decomposition is performed only once.

[0031] An air cooling device according to an embodiment of the present invention is Figure 5-8As shown: it includes a square outer shell 1, an inner shell 2 and a device layer 3 located between the two. A moving mechanism 4 is arranged on the outer surface of the outer shell 1. The moving mechanism 4 includes a rolling chain 41 and a rolling wheel 42 for driving the rolling chain 41 to rotate. The rolling chain 41 is composed of a plurality of connecting pieces 411, and a hinge-shaped articulated shaft 412 is formed between adjacent connecting pieces 411. The articulated shaft 412 is cylindrical and arranged toward the rolling wheel 42. A plurality of clamping grooves 421 are arranged on the outer circumference of the rolling wheel 42 corresponding to the shape of the articulated shaft 412. The above-mentioned clamping grooves 421 are used to limit the articulated shaft 412 when the rolling wheel 42 rotates and drive the rolling chain 41 to move. An exhaust fan 43 is arranged on the connecting piece 411 of the rolling chain 41. The exhaust fan 43 can be used as one of the connecting pieces 411 in the rolling chain 41 and connected to other connecting pieces 411 through the hinge shaft 412; or it can be fixed on the connecting piece 411 and an air window is provided on the connecting piece 411 connected thereto. The exhaust fan 43 is arranged on each of the four sides of the square outer shell 1 and can be located at the center or edge of each face through the moving mechanism 4.

[0032] In the equipment layer 3, four placement layers 31 made of heat-insulating materials are arranged near the intersection of the four sides of the equipment layer 3, and air blowing fans (not shown in the figure) are arranged in the placement layers 31. Near the placement layers 31, there are rolling wheels 42, and the rolling wheels 42 are just located at the intersection of the four sides of the equipment layer 3. The placement layer 31 includes a starting door 311 and a fixed door 314 for accommodating the expansion and contraction of the starting door 311. The fixed door 314 is provided with an expansion slot 315 for accommodating the starting door 311; the fixed door 314 is also provided with a slot 312, and the starting door 311 is provided with a hinge 313 protruding from the slot 312. A connecting rod 6 is also provided between the rolling wheel 42 and the starting door 311 to form the linkage between the two. One end of the connecting rod 6 is hinged at the hinge 313 of the starting door 311, and the other end is hinged at the eccentric part of the rolling wheel 42. When the rolling wheel 42 drives the exhaust fan 43 to move toward the center of each surface of the outer shell 1, the starting door 311 is driven to close. When the rolling wheel 42 drives the exhaust fan 43 toward the edge of each surface of the outer shell 1 and forms a relative position relationship with the blowing fan (not shown in the figure) in the corresponding placement layer 31, the starting door 311 is driven to open.

[0033] An exhaust window 21 is provided on the inner shell 2 at the position corresponding to the moving mechanism 4. The exhaust window 21 is wrapped around the inner shell 2. A rotating ring 5 is provided inside the inner shell 2. A placement table 51 for placing the bearing ring is provided at the center of the rotating ring 5, and a clamping ring 52 for clamping the bearing ring is provided on the outer circumference of the rotating ring 5. A transmission mechanism for driving the rotating ring 5 to rotate can be as follows: the rotating ring 5 can be provided with a transmission tooth (not shown in the figure) on its side, and a transmission mechanism (not shown in the figure) with a bevel gear in front is provided in the equipment layer 3 corresponding to the transmission tooth (not shown in the figure), and a transmission window (not shown in the figure) in which the above two mesh is opened on the inner shell 2. Since the transmission mechanism of the rotating ring 5 is provided on its side, it can effectively stagger with the position of the exhaust window 21 to prevent it from affecting the exhaust and blowing effect when rotating.

[0034] The use process of this embodiment, i.e., the air cooling device, is as follows: when air cooling is required, the bearing ring is placed on the placement table 51. Before this, if the placement table 51 is not in a horizontal state, the placement table 51 can be made horizontal by rotating the rotating ring 5. Of course, the horizontal state can also be achieved by setting a sensor in the inner shell 2 to cooperate with the control system. The exhaust fan 43 is located at the center of each surface of the outer shell 1. While the inner shell 2 is connected to the outside, the exhaust fan 43 is kept in a low-power operation state to enhance the air cooling efficiency.

[0035] When air blowing cooling is required, the bearing ring is clamped on the clamping ring 52, and the exhaust fan 43 is moved to the edge of each surface of the outer shell 1 and corresponds to the position of the air blowing fan (not shown in the figure) to form four air ducts at the four edges of the inner shell 2. At the same time, when the rolling wheel 42 rotates, it will drive the start door 311 to open through the connecting rod 6. When the air blowing fans (not shown in the figure) and the exhaust fan 43 of the four air ducts are started, the rotating ring 5 drives the bearing ring to rotate inside the inner shell 2 to cool in the four air ducts respectively. When the bearing ring enters other air ducts, since there is still gas circulation in the air duct, the hot air in the air duct can be discharged when the bearing ring enters the air duct again, so that the bearing ring can be effectively cooled.

[0036] The above embodiment is only one of the preferred specific embodiments of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included in the protection scope of the present invention.

Claims

1. A method for refining blocky carbides of high carbon chromium stainless steel, comprising the following steps: S1, heating to 690°C, and performing low temperature decomposition of the bearing ring for 3 hours; S2, air cooling the bearing ring after step S1 to room temperature; S3, normalizing the bearing ring according to the following steps; S301, raising the temperature to 920°C and keeping the bearing rings warm for 2 hours; S302, raising the temperature to 1130°C and keeping the bearing rings warm for 1.5 hours; S303, cooling the bearing ring after step S302 to room temperature by blowing air; S4, repeat the low temperature decomposition - air cooling to room temperature - normalizing steps.

2. The method for refining high carbon chromium stainless steel block carbides according to claim 1, characterized in that: The low temperature decomposition in step S1 is repeated three times, and the low temperature decomposition in step S4 is performed only once.

3. The method for refining high carbon chromium stainless steel block carbides according to claim 1, characterized in that: In the step S4, the normalizing of the bearing ring is performed according to the following steps: S401, heating to 920° C. and keeping the bearing ring warm for 2 hours; S402, raising the temperature to 1100°C and keeping the bearing rings warm for 1 hour; S403, cooling the bearing ring after step S402 to room temperature by air blowing.

4. An air cooling device for the high carbon chromium stainless steel block carbide refinement method according to any one of claims 1 to 3, characterized in that: It includes a square inner shell, an outer shell and an equipment layer located between the two. The outer shell is provided with a moving mechanism that can move along the outer shell and an exhaust fan that is arranged on the moving mechanism and moves with the moving mechanism. The inner shell is provided with an exhaust window at the position corresponding to the moving mechanism, and the equipment layer is provided with air blowing fans at the intersections of the four sides thereof.

5. The air cooling device according to claim 4, characterized in that: The moving mechanism includes a rolling wheel arranged at the intersection of the equipment layer and a rolling chain matched therewith. The outer peripheral surface of the rolling wheel is circumferentially provided with a plurality of semicircular clamping grooves. The rolling chain includes a plurality of connecting plates and a hinge shaft for hingedly connecting adjacent connecting plates. The hinge shaft can be matched with the clamping groove to form positioning.

6. The air cooling device according to claim 5, characterized in that: The equipment layer is provided with a placement layer whose shell is made of heat-insulating material and is used to place the air blowing fan. The placement layer is movably connected with a starting door, and the starting door is controlled to be opened or closed according to different rotation directions of the rolling wheel.

7. The air cooling device according to claim 6, characterized in that: A connecting rod is arranged between the starting door and the rolling wheel, one end of the connecting rod is hinged at an eccentric position of the rolling wheel, and the other end is hinged at one end of the starting door.

8. The air cooling device according to claim 4, characterized in that: A rotating ring is arranged in the inner shell body, and a clamping ring is arranged on the rotating ring for forming a clamping relationship with the bearing ring.

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