Apparatus and method for reducing heat treatment warpage of a flat sheet

Abstract

This invention provides a device for reducing heat treatment warpage of flat sheets for annular flat sheets. The device includes several equal-height blocks, which are adapted to be disposed between two adjacent coaxially arranged annular flat sheets. These equal-height blocks are arranged around the axis of the annular flat sheet and at its outer edge. This device, by using dispersed equal-height blocks, avoids deformation caused by surface quality issues of the annular flat sheet. Since the inner hole is thicker than the outer circle, it is less prone to deformation. By controlling the deformation of the outer circle, the flatness of the entire flat sheet can be guaranteed. Furthermore, the equal-height blocks can be machined from scrap materials, resulting in extremely low cost.

Description

Technical Field

[0001] This invention relates to the field of heat treatment technology, and specifically to a device and method for reducing warping during heat treatment of flat sheets. Background Technology

[0002] Flat products have significant differences in wall thickness and height, resulting in warping deformation after forging. In addition, the high-temperature heating during normalizing, quenching, and tempering heat treatment processes generate new thermal stress deformation and warping. Furthermore, the subsequent cooling process generates a compound superposition of structural stress and thermal stress, ultimately leading to severe warping deformation of the heat-treated product.

[0003] Currently, after heat treatment, warped products still need to be corrected and stress-relieved, which wastes energy, delays delivery, and in severe cases can even lead to scrap, causing significant losses to the manufacturer. In addition, in order to ensure that warped products can be processed, the allowance during forging must be increased, which increases the cost of forgings. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is that in the prior art, after the product is heat-treated, it is still necessary to correct and relieve the stress of the warped product, which wastes energy, delays the delivery time, and may even cause scrap, resulting in great losses to the manufacturer. At the same time, in order to ensure that the warped product can be processed, the allowance during forging must be increased, which increases the cost of forging.

[0005] Therefore, the present invention provides a device for reducing heat treatment warping of flat sheets for annular flat sheets, comprising a plurality of equal height blocks, wherein the plurality of equal height blocks are adapted to be disposed between two adjacent coaxially disposed annular flat sheets, and wherein the plurality of equal height blocks are disposed around the axis of the annular flat sheet, and wherein the plurality of equal height blocks are disposed at the outer edge of the annular flat sheet.

[0006] Optionally, along the direction from the center to the edge of the annular flat plate, one end of the leveling block is located at the outer edge of the annular flat plate, and the other end of the leveling block is located near the inner edge of the annular flat plate.

[0007] Optionally, the distance between the contour block and the inner edge of the annular flat plate is D, and the distance between the inner edge of the annular flat plate and the outer edge of the annular flat plate is T, where D>T / 2.

[0008] Optionally, several of the equal-height blocks are spaced apart.

[0009] Optionally, the height difference between the equal-height blocks on the same layer is ≤1mm.

[0010] Optionally, the distance between the centers of adjacent contour blocks is 800-900mm.

[0011] Optionally, the center deviation between the upper and lower layers of some of the equal-height blocks is ≤40mm.

[0012] A method for reducing heat treatment warpage of flat sheets, used in the aforementioned device for reducing heat treatment warpage of flat sheets, includes the following steps:

[0013] Place the equal-height blocks: Place the equal-height blocks at equal intervals on one side of the annular flat plate and arrange them around the center line of the annular flat plate;

[0014] Heating: The annular flat sheet is heated, and the heating rate is controlled to be ≤90℃ / h;

[0015] Quenching and tempering: Quenching the annular flat sheet, and then tempering it in the furnace after quenching;

[0016] Cooling: After the annular flat sheet is tempered and removed from the furnace, it must be cooled in still air.

[0017] Alternatively, methods for reducing heat treatment warpage of flat sheets also include:

[0018] Post-quenching inspection: After quenching the annular flat sheet, check whether the equal-height blocks are in their original positions. If they have shifted, they must be restored to their original positions before tempering. If any are missing, they must be replaced immediately before being put back into the furnace for tempering.

[0019] Optionally, avoid direct airflow onto the hot annular flat plate during the cooling process.

[0020] The present invention provides a device and method for reducing heat treatment warpage of flat sheets, which has the following advantages:

[0021] 1. The present invention provides a device for reducing heat treatment warping of flat sheets for annular flat sheets, comprising a plurality of equal-height blocks, wherein the plurality of equal-height blocks are adapted to be disposed between two adjacent coaxially arranged annular flat sheets, and the plurality of equal-height blocks are disposed around the axis of the annular flat sheet, and the plurality of equal-height blocks are disposed at the outer edge of the annular flat sheet.

[0022] This structure reduces warping during heat treatment of flat plates by placing several equal-height blocks between two adjacent coaxially arranged annular flat plates. These equal-height blocks are arranged around the axis of the annular flat plates and are located at the outer edge of the annular flat plates. By using dispersed equal-height blocks, deformation caused by surface quality issues of the annular flat plates can be avoided. Since the inner hole is thicker than the outer circle, it is less prone to deformation. As long as the deformation of the outer circle is controlled, the flatness of the entire flat plate can be guaranteed. Furthermore, the equal-height blocks can be processed from waste materials, resulting in extremely low cost.

[0023] 2. The present invention provides a device for reducing heat treatment warping of flat sheet. Along the center to the edge direction of the annular flat sheet, one end of the equalizing block is disposed at the outer edge of the annular flat sheet, and the other end of the equalizing block is disposed near the inner edge of the annular flat sheet. The distance between the equalizing block and the inner edge of the annular flat sheet is D, and the distance between the inner edge of the annular flat sheet and the outer edge of the annular flat sheet is T, wherein D>T / 2.

[0024] This structure reduces the warping of flat sheet during heat treatment. Because the flat sheet is thicker near the inner hole than the outer hole due to the wear of the tapered roller and the difference in the distribution and flow of the hot billet during actual forging and rolling, the inner hole is less likely to sag and deform during heating. In order to reduce the superposition of deformation caused by wall thickness, the equal height block is required to be placed at the position D>T / 2.

[0025] 3. The present invention provides a device for reducing warping of flat sheet during heat treatment, wherein the height difference of the equal-height blocks in the same layer is ≤1mm.

[0026] This structure reduces warpage during heat treatment of flat sheet. The height difference between the equal-height blocks in the same layer is ≤1mm. By controlling the vertical height difference between the centers of the equal-height blocks, the warpage of a Φ4000 diameter flat sheet after heat treatment can be controlled within ≤5mm, and the warpage of the heat-treated part after machining can be controlled within ≤3mm. This is beneficial for subsequent machining, ensures uniform surface hardness of the product, improves product quality, reduces forging allowance, further reduces the weight of forging blanks, saves energy and reduces weight, and improves economic efficiency.

[0027] 4. The present invention provides a device for reducing warping of flat sheet during heat treatment, wherein the distance between the centers of adjacent equal-height blocks is 800-900mm.

[0028] The structure of this device for reducing warping during heat treatment of flat sheets has a distance of 800-900mm between the centers of adjacent equal-height blocks. Excessive gaps can cause the stress caused by the weight of the workpiece to exceed its yield strength when heated to high temperatures, resulting in bending deformation of the flat sheets. Conversely, insufficient gaps would require more equal-height blocks, leading to a waste of energy and materials.

[0029] 5. The present invention provides a device for reducing warping of flat sheet during heat treatment, wherein the center deviation between the upper and lower layers of the plurality of equal-height blocks is ≤40mm.

[0030] This structure reduces the warping of the flat sheet during heat treatment. It ensures concentricity on the same vertical line, preventing the flat sheet from twisting and deforming due to pressure differences caused by deviations between upper and lower layers, thus ensuring the flatness of the final flat sheet.

[0031] 6. This invention provides a method for reducing warping of flat sheet during heat treatment. By setting the heating rate to ≤90℃ / h, the deformation caused by thermal stress during the heating process of the annular flat sheet can be reduced. The warping of the flat sheet workpiece with a diameter of Φ4000 after actual heat treatment can be further controlled within ≤3mm, and the warping of the heat-treated part after machining can be controlled within ≤1mm. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a device for reducing warping during heat treatment of flat sheets provided by the present invention;

[0034] Figure 2 A diagram showing the placement position of the annular flat sheet in a device for reducing flat sheet warping during heat treatment, provided by the present invention.

[0035] Figure 3 This is another structural schematic diagram of a device for reducing warping during heat treatment of flat sheets provided by the present invention;

[0036] Explanation of reference numerals in the attached figures:

[0037] 1- Ring-shaped flat plate;

[0038] 2-Contour blocks. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In addition, the technical features involved in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.

[0041] Example 1

[0042] This embodiment provides a device for reducing heat treatment warpage of flat sheets, comprising several equal-height blocks 2. This device is used to reduce warpage during heat treatment of flat sheets. Figure 1 The annular flat sheet 1 shown is subjected to a warpage reduction treatment during production, such as... Figure 2 As shown, multiple annular flat plates 1 are coaxially arranged inside the heat treatment furnace, and equal-height blocks 2 are placed between two adjacent annular flat plates 1.

[0043] In this embodiment, ten equal-height blocks 2 are arranged between two adjacent annular flat plates 1. The ten equal-height blocks 2 are placed around the axis of the annular flat plate 1, and a gap is set between two adjacent equal-height blocks 2.

[0044] In other embodiments of this example, the number of contour blocks 2 can also be set to other quantities, which can be determined according to the size of the annular flat plate 1. It can be understood that the larger the size of the annular flat plate 1, the more contour blocks 2 are used.

[0045] In this embodiment, the height equalization block 2 has dimensions of 80×80×120mm. In use, 120mm refers to the height direction, meaning the height interval between two adjacent annular flat pieces 1 is 120mm. The height deviation of the height equalization block 2 is ±0.5mm.

[0046] In some other embodiments, such as Figure 3 As shown, the size of the equal height block 2 can also be set as a long equal height block 2 of 40×500×120mm. The equal height block 2 of this size is placed obliquely along the outer circle, which is suitable for thinner annular flat plates 1. Using a long equal height block 2 can reduce the suspension distance between the equal height blocks 2 on the outer circle of the flat plate, and further reduce the warping deformation of the flat plate during the heat treatment process. In order to ensure that it is placed close to the T / 2 range of the outer circle, it must be placed obliquely.

[0047] In this embodiment, as Figure 1As shown, the equalizing block 2 is placed along the center of the annular flat plate 1 towards the edge. That is, one end of the equalizing block 2 is located at the outer edge of the annular flat plate 1, and the other end of the equalizing block 2 is located near the inner edge of the annular flat plate 1. The distance between the equalizing block 2 and the inner edge of the annular flat plate 1 is set as D, and the distance from the inner edge of the annular flat plate 1 to the outer edge of the annular flat plate 1 is set as T. In use, it is necessary to ensure that D>T / 2. This is because during the actual forging and rolling of the flat plate, due to the wear of the tapered roller and the difference in the distribution and flow of the hot billet, the thickness of the part near the inner hole is thicker than that of the outer circle. The inner hole is not easy to sag and deform during heating. In order to reduce the superposition of deformation caused by the wall thickness factor, it is required that the equalizing block 2 be placed at the position of D>T / 2.

[0048] In this embodiment, the height difference of blocks 2 of the same layer is ≤1mm, that is, as shown below. Figure 1 As shown, the height difference between the centers of two equal-height blocks 2 symmetrically arranged along line a in the vertical direction should be ≤1mm. By controlling the height difference between the centers of equal-height blocks 2 in the vertical direction, the warpage of the flat workpiece with a diameter of Φ4000 after heat treatment can be controlled within ≤5mm, and the warpage of the heat-treated part after machining can be controlled within ≤3mm. This is beneficial for subsequent machining, ensures the uniformity of the surface hardness of the product, improves product quality, reduces forging allowance, further reduces the weight of forging blanks, saves energy and reduces weight, and improves economic efficiency.

[0049] In this embodiment, the center deviation between the upper and lower layers of the contour block 2 is ≤40mm, i.e. Figure 1 As shown, two equal-height blocks 2 are symmetrically arranged along line b, for example... Figure 1 The center deviation of contour blocks A and B in the middle is ≤40mm in the horizontal direction. They are on the same vertical line to ensure concentricity. This can prevent the flat sheet from being twisted and deformed due to the pressure difference caused by the deviation between the upper and lower layers, and ensure the flatness of the final flat sheet.

[0050] In this embodiment, as Figure 1 As shown, the distance L between the centers of adjacent contour blocks 2 is

[0051] A gap of 800-900mm is too large. When the workpiece is heated to a high temperature, the stress caused by its own weight will exceed the yield strength of the workpiece, causing the flat sheet to bend and deform. On the other hand, a gap that is too small will require more equal-height blocks, resulting in a waste of energy and materials.

[0052] Due to the significant differences in wall thickness and height of large flat products, warping deformation occurs immediately after forging. In addition, the high-temperature austenitizing heating during normalizing, quenching, and tempering heat treatment generates new thermal stress deformation and warping. Furthermore, the subsequent cooling process generates a composite deformation of structural stress and thermal stress, ultimately resulting in severe warping deformation (>10mm) of the heat-treated product.

[0053] The device for reducing warping during heat treatment of flat sheets provided in this embodiment only requires placing ten equal-height blocks 2 between two adjacent annular flat sheets 1. The equal-height blocks 2 are processed from scrap materials, resulting in extremely low cost. Using dispersed equal-height blocks 2 can avoid deformation caused by surface quality issues of the flat sheets. Since the inner hole is thicker than the outer circle, it is not easily deformed. As long as the deformation of the outer circle is controlled, the flatness of the entire flat sheet can be guaranteed. If equal-height blocks 2 are also used on the inner side, the deformation of the upper workpiece will increase due to the superposition of thicknesses.

[0054] Furthermore, due to equipment limitations, the height of the portion near the inner hole of large flat products after forging is higher than that near the outer circle. If simply leveling is used, the deformation will only increase when multiple layers are stacked. The higher the flat, the more severe the deformation due to the cumulative effect of the height difference between the inner and outer parts, seriously affecting the output and quality of heat treatment. The device for reducing warping of flat heat treatment provided in this embodiment corrects the warping deformation at different heights of the inner and outer circles of the forged (rolled) annular flat 1, preventing the cumulative deformation of the thickness in the inner hole area. Moreover, by controlling the warping deformation on the outer side of the annular flat 1, the deformation on the inner side of the flat is constrained to the greatest extent.

[0055] Meanwhile, the device for reducing warping of flat pieces during heat treatment provided in this embodiment can increase the furnace loading height (loading amount) for heat treatment. The higher the stacked loading, the better the effect, because the more forgings are stacked, the heavier the weight on the same stack, and the more significant the correction effect on the lower flat pieces. More flat pieces become flatter due to the large pressure. In addition, since the annular flat pieces 1 are separated by equal-height blocks 2, the heating and holding time is reduced, and the heat treatment cost is lowered.

[0056] Example 2

[0057] This embodiment provides a method for reducing heat treatment warpage of flat sheets, used in the device for reducing heat treatment warpage of flat sheets in Embodiment 1. The method includes the following steps:

[0058] Place the equal height blocks 2: Place the equal height blocks 2 at equal intervals on one side of the annular flat plate 1 and set them around the center line of the annular flat plate 1;

[0059] Heating: The annular flat plate 1 is heated, and the heating rate is controlled to be ≤90℃ / h;

[0060] Quenching and tempering: Quenching the annular flat piece 1, and then tempering it in the furnace after quenching;

[0061] Cooling: After the annular flat sheet 1 is tempered and removed from the furnace, it should be cooled in still air.

[0062] By setting the heating rate to ≤90℃ / h, the deformation caused by thermal stress during the heating process of the annular flat sheet 1 can be reduced. The warpage of the flat sheet workpiece with a diameter of Φ4000 after actual heat treatment can be further controlled within ≤3mm, and the warpage of the heat-treated part after machining can be controlled within ≤1mm.

[0063] In this embodiment, the method for reducing warping of flat sheet during heat treatment also includes post-quenching inspection. Post-quenching inspection involves checking whether the equal-height block 2 is in its original position after the annular flat sheet 1 is quenched. If it is displaced, it must be restored to its original position before tempering. If it is missing, it must be replenished immediately before being put into the furnace for tempering.

[0064] In this embodiment, during the cooling process, direct airflow onto the hot annular flat plate 1 is avoided. If airflow directly onto the hot workpiece, the cooling rate will be different due to the different airflow forces on different parts of the flat plate, resulting in different thermal stress and structural stress. This will inevitably cause warping and deformation of the flat plate, affecting the final flatness.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A device for reducing the warping of a hot treated flat sheet (1) for a toroidal flat sheet, characterized in that, It includes several equal height blocks (2), which are adapted to be arranged between two adjacent coaxially arranged annular flat plates (1), and the several equal height blocks (2) are arranged around the axis of the annular flat plate (1), and the several equal height blocks (2) are arranged at the outer edge of the annular flat plate (1); Along the direction from the center to the edge of the annular flat plate (1), one end of the equal height block (2) is located at the outer edge of the annular flat plate (1), and the other end of the equal height block (2) is located near the inner edge of the annular flat plate (1); Several of the aforementioned equal-height blocks (2) are spaced apart.

2. The apparatus of claim 1, wherein, The distance between the contour block (2) and the inner edge of the annular flat piece (1) is D, and the distance between the inner edge of the annular flat piece (1) and the outer edge of the annular flat piece (1) is T, where D>T / 2.

3. The apparatus of claim 1, wherein the apparatus further comprises a plurality of rollers positioned between the first and second heating stations and configured to reduce the warpage of the flat sheet. 3 The height difference of the equal-height blocks (2) in the same layer is ≤1mm.

4. The apparatus of claim 3, wherein, The distance between the centers of adjacent contour blocks (2) is 800-900mm.

5. The apparatus of claim 4, wherein, The center deviation between the upper and lower layers of the aforementioned equal-height blocks (2) is ≤40mm.

6. A method for reducing heat treatment warpage of a flat sheet using the apparatus for reducing heat treatment warpage of a flat sheet according to any one of claims 1 to 5, characterized by, Includes the following steps: Place the equal height blocks (2): Place the equal height blocks (2) at equal intervals on one side of the annular flat plate (1) and set them around the center line of the annular flat plate (1); Heating: The annular flat plate (1) is heated, and the heating rate is controlled to be ≤90℃ / h; Quenching and tempering: Quenching of the annular flat piece (1) and tempering after quenching in the furnace; Cooling: After the annular flat sheet (1) is tempered and taken out of the furnace, it should be cooled in still air.

7. The method for reducing heat treatment warpage of flat sheets according to claim 6, characterized in that, Also includes: Inspection after quenching: After quenching the ring flat piece (1), check whether the height block (2) is in its original position. If it is displaced, it must be restored to its original position before tempering. If it is missing, it must be replenished immediately before being put into the furnace for tempering.

8. The method for reducing heat treatment warpage of flat sheets according to claim 6, characterized in that, During the cooling process, avoid direct airflow onto the hot annular flat plate (1).

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