Preparation method of composite arc-shaped plate on rolling mill equipment

Abstract

The invention discloses a preparation method of a composite arc-shaped plate on rolling mill equipment. The preparation method comprises the following steps that S1, the whole working face of a single arc-shaped plate is cut according to a first cutting depth; s2, a bottom plate is fixed to the non-working end of the single arc-shaped plate; s3, the bottom plates on the two arc-shaped plates are combined, a base plate is arranged between the two bottom plates, opposite pressure is applied to the two ends of the two arc-shaped plates, and the maximum rolling reduction of the two ends of each arc-shaped plate is half of the thickness of the base plate; s4, after a connecting plate is matched with the side face of the arc-shaped plate, the connecting plate and the side face of the arc-shaped plate are welded to form an integral structural part; s5, the overall structural part is fed into a heating furnace to be subjected to stress removal; and S6, after the stress-removed integral structural part is taken out of the heating furnace, surfacing is conducted on the arc-shaped plate. The method can guarantee that the shape of the arc-shaped plate after surfacing is qualified.

Description

Technical Field

[0001] The invention relates to the technical field of rolling mill arc plate manufacturing, and in particular to a method for preparing a composite arc plate on rolling mill equipment. Background Art

[0002] The curved plate on the rolling mill equipment plays a guiding role in front of the coiler on the steel coil. The working surface of the curved plate is subjected to greater impact and friction. The curved plate in the rolling mill equipment is an integral carbon steel structure, which wears quickly and has a short service life. In order to increase the service life of the curved plate, the applicant plans to perform surfacing welding on the working surface of the curved plate to improve the wear resistance and impact resistance of the working surface.

[0003] However, the length of the arc plate's surfacing part is 2130mm, and the arc length is 484.4mm. The design thickness of the arc plate used is 40mm. After removing the surfacing layer, the actual thickness of the surfacing arc plate is more than 30 millimeters. Therefore, surfacing will face the following problems:

[0004] 1) The amount of surfacing is large, and the surfacing is done on one side of the parent material, which makes it extremely difficult to control deformation. If the control is not appropriate, the surfacing thickness of the finished product after processing may be seriously uneven, and the local thickness may not meet the design requirements.

[0005] 2) The length of the cladding layer of the parent material is long, which easily causes uneven thickness of the cladding layer and fluctuations in the hardness of the finished surface. Severe unevenness may cause the hardness of the finished surface to exceed the requirements.

[0006] Therefore, based on the above, it is necessary to design a reasonable surfacing process and take necessary measures to ensure that the process is implemented correctly. Summary of the invention

[0007] The invention provides a method for preparing a composite arc-shaped plate on rolling mill equipment. The invention can ensure that the shape of the arc-shaped plate after surfacing welding is qualified.

[0008] The technical solutions to the above technical problems are as follows:

[0009] The method for preparing a composite curved plate on a rolling mill equipment is characterized by comprising the following steps:

[0010] S1, cutting the entire working surface of a single curved plate at a first cutting depth;

[0011] S2, fixing the bottom plate at the non-working end of a single curved plate;

[0012] S3, combining the bottom plates on the two curved plates, and setting a pad in the middle of the two bottom plates, applying pressure to both ends of the two curved plates, so that the maximum pressure reduction at both ends of each curved plate is half of the thickness of the pad;

[0013] S4, after the connection plate and the side of the arc plate are matched, the connection plate and the side of the arc plate are welded to form an integral structural member;

[0014] S5, sending the whole structure into a heating furnace to remove stress;

[0015] S6, after the stress-relieved integral structural component is taken out from the heating furnace, surfacing welding is performed on the curved plate.

[0016] Furthermore, in S1, after cutting at the first cutting depth is completed, cutting processing is performed on the area from the first position on the arc plate to the two ends of the arc plate. In this area, the first position is the cutting high point, and a cutting low point is set on the end face of the arc plate. The cutting high point and the cutting low point have a height difference in the height direction, and the part located above the line connecting the cutting high point and the cutting low point is the cut-off part.

[0017] Furthermore, in S1, after cutting at the first cutting depth is completed, the highest point on one side of the arc surface of the arc plate is moved downward to the fitting point, and the first original point and the second original point are selected on the arc of the arc plate. The constructed arc is obtained according to the first original point, the second original point and the fitting point, and the part located above the constructed arc is the cut-off part.

[0018] Further, in S6, before surfacing, a plurality of surfacing areas are divided on the cutting surface of each arc plate along the length direction of the arc plate, and the overall structural component is positioned in the original position. During surfacing, first, surfacing is performed on the first surfacing area on the first arc plate along the length direction of the arc plate, and then the overall structural component is rotated by a first angle, and surfacing is performed on the first surfacing area on the second arc plate along the length direction of the arc plate, and then the overall structural component is rotated by a second angle, and surfacing is performed on the second surfacing area on the first arc plate along the length direction of the arc plate, and then the overall structural component is rotated by the first angle, and surfacing is performed on the second surfacing area on the second arc plate along the length direction of the arc plate; the overall structural component is reset to its original position, and the remaining surfacing areas are surfacing according to the above process.

[0019] Furthermore, the first angle is 180°, and the second angle is 191°.

[0020] Furthermore, in S5, the temperature for stress relief of the overall structural component is 625±25°C, and the stress relief time is 6-8h.

[0021] Furthermore, in S6, the surfacing layer on the integral structural member is multi-layered, and after each surfacing layer is completed on the integral structural member, the integral structural member with the surfacing layer is sent into a heating furnace to remove stress from the surfacing layer.

[0022] Furthermore, the stress relief temperature of each weld overlay layer is 550-560°C, and the stress relief time is 6-8h.

[0023] The present invention is based on the following measures:

[0024] (1) Fix the bottom plate on the curved plate to increase the rigidity of the curved plate.

[0025] (2) The part located above the line connecting the high cutting point and the low cutting point is the cut-off part. This measure deepens the arc plate in the length direction, reducing the insufficient thickness of the surfacing caused by the upward warping of the two ends after welding.

[0026] (3) The part located above the constructed arc is cut off to prevent the arc plate from shrinking and deforming in the direction of the arc surface, resulting in insufficient surfacing thickness.

[0027] (4) A pad is set in the middle of the two bottom plates. This measure is to reserve anti-deformation. After the connecting plate is removed after welding, the reserved anti-deformation and welding deformation can offset each other.

[0028] (5) The connecting plate is welded to the side of the arc plate to form an integral structural member, and the rigidity of the arc plate is increased by the connecting plate to reduce deformation during welding.

[0029] (6) The two arc-shaped plates are divided into sections and symmetrically welded so that the stresses partially offset each other, thereby reducing welding deformation.

[0030] (7) Relieving stress of the integral structural part and sending the integral structural part with the cladding layer into the heating furnace to relieve stress of the cladding layer after each cladding layer is completed on the integral structural part are both to reduce the deformation of the cladding arc plate caused by stress.

[0031] It can be seen that the present invention reduces the deformation of the arc plate caused by the surfacing process through the above-mentioned multi-directional measures, so that the arc plate after surfacing becomes a qualified product. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of cutting at a first cutting depth on a curved plate.

[0033] Figure 2 It is a schematic diagram of the cutting area from the high point to the low point on the curved plate.

[0034] Figure 3 Schematic diagram of the constructed arc fitted on the curved plate.

[0035] Figure 4 A three-dimensional diagram of a curved plate.

[0036] Figure 5 The configuration diagram of two curved plates with a bottom plate.

[0037] Figure 6 For Figure 5Schematic diagram of the connecting plate welded on the basis.

[0038] Figure 7a This is a simplified diagram of the first surfacing area on the first curved plate after surfacing welding.

[0039] Figure 7b This is a simplified diagram of the first surfacing area on the second curved plate after surfacing welding.

[0040] Figure 7c This is a simplified diagram of the second surfacing area on the first curved plate after surfacing welding.

[0041] Figure 7d This is a simplified diagram of the second surfacing area on the second curved plate after surfacing welding.

[0042] Figure 7e This is a simplified diagram of the third surfacing area on the first curved plate after surfacing welding.

[0043] Figure 7f This is a simplified diagram of the third surfacing area on the second curved plate after surfacing welding.

[0044] Figure 7g This is a simplified diagram of the fourth surfacing area on the first curved plate after surfacing welding.

[0045] Figure 7h This is a simplified diagram of the fourth surfacing area on the first curved plate after surfacing welding. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0047] The method for preparing the composite curved plate on the rolling mill equipment of the present invention comprises the following steps:

[0048] S1, such as Figure 1 , the working surface of a single arc plate 1 is cut as a whole according to the first cutting depth. For example, the design thickness of the plate is 40mm. Considering the machining allowance after surfacing, the surfacing layer is set to 8-9mm. Therefore, the first cutting depth is preferably 6mm. Figure 1 The dotted line part is the cut-off part.

[0049] like Figure 2 After the first cutting depth is cut, cutting is performed on the area from the first position on the arc plate 1 to the two ends of the arc plate 1. In this area, the first position is the cutting high point B, and a cutting low point C is set on the end surface of the arc plate 1. The cutting high point B and the cutting low point C have a height difference H1 in the height direction, and the part located above the line connecting the cutting high point B and the cutting low point C is the cut part.

[0050] The distance L1 between the cutting high point B and the end face of the arc plate 1 is preferably 665 mm, and the height difference H1 between the cutting high point B and the cutting low point C in the height direction is preferably 3 mm. The surface after cutting is in an inclined state. This can reduce the warping of the two ends after welding to a certain extent, resulting in insufficient surfacing thickness.

[0051] like Figure 3 After cutting at the first cutting depth, move downward to the fitting point D at the highest point on one side of the arc surface of the arc plate 1, select the first original point E and the second original point F on the arc of the arc plate 1, and since a circle can be drawn through three points, recalculate and obtain the constructed arc G based on the first original point E, the second original point F and the fitting point D, and the portion above the constructed arc G is the removed portion.

[0052] Based on the above, since the lower part of the arc plate 1 has a base 1a, after the arc plate 1 is fixed to one end of the bottom 1a, it is in a state where one side is higher than the other side. For example, the highest side on the right side is higher than the highest side on the left side, and the rigidity of the right side is lower than that of the left side. The deformation of the right side is large during the surfacing process, and the deformation shrinks toward the inside. Therefore, in order to reduce the welding deformation, the present invention obtains the constructed arc G through the above method, and cuts off the part located above the constructed arc G to prevent insufficient surfacing thickness on the right side. Therefore, it is deepened during processing, and the surfacing thickness of the side with poor rigidity (right side) is increased during subsequent surfacing.

[0053] S2, such as Figure 4 The bottom plate 2 is fixed to the non-working end of the single arc plate 1, that is, the other end of the base 1a is fixed to the bottom plate 2, and the fixing method is preferably welding. The bottom plate 2 helps to increase the overall rigidity of the arc plate 1.

[0054] S3, such as Figure 5 , the bottom plates 2 on the two arc-shaped plates 1 are combined so that the two arc-shaped plates 1 are arranged back to back, and a pad 3 is set in the middle of the two bottom plates 2, and a pressure P is applied to the two ends of the two arc-shaped plates 1 in opposite directions, so that the maximum pressing amount at the two ends of each arc-shaped plate 1 is half of the thickness of the pad 3;

[0055] like Figure 5 , due to the physical property of thermal expansion and contraction of the material, the arc plate 1 will shrink toward the side of the surfacing after welding. The overall deformation of the arc plate 1 after welding is shown as upward warping in the length direction and inward contraction on both sides of the arc. Based on this, during assembly, the present invention arranges a pad 3 between the base plates 2, and the thickness of the pad 3 is preferably 5mm. After applying a pressure P in opposite directions to the two ends of the two arc plates 1, the maximum amount of pressure reduction at both ends of each arc plate 1 is half of the thickness of the pad 3, that is, the amount of pressure reduction is 2.5mm.

[0056] S4, such as Figure 6As shown, after the connecting plate 4 is matched with the side of the arc plate 1, the connecting plate 4 and the side of the arc plate 1 are welded to form an integral structural member A; after the connecting plate 4 and the arc plate 1 are fixed, the rigidity of the integral structural member A can be increased and the deformation during the welding process can be reduced.

[0057] S5, since the connecting plate 4 and the curved plate 1 are fixed by welding, the curved plate 1 will expand thermally during the welding process. Although the deformation of the curved plate 1 caused by the thermal expansion is not large, it is still one of the factors causing the deformation. Therefore, the integral structural part A needs to be sent to the heating furnace for stress removal. In this step, the temperature for stress removal of the integral structural part A is 625±25℃, and the stress removal time is 6-8h.

[0058] In this embodiment, the temperature of the integral structural part A before entering the heating furnace is ≤200°C, the heating rate is ≤70°C / h, and when the temperature reaches 650°C, it is kept at this temperature for 7 hours. When the integral structural part A is taken out of the heating furnace, the cooling rate of the heating furnace is controlled to be ≤70°C / h, and the temperature of the integral structural part A before leaving the furnace is ≤200°C.

[0059] S6, after the stress-relieved integral structural member A is taken out from the heating furnace, surfacing welding is performed on the curved plate 1. Before surfacing welding, a preferred method is to divide a plurality of surfacing welding areas on the cutting surface of each curved plate 1 along the length direction of the curved plate 1, such as Figure 6 As shown by the dotted lines in FIG. 1 , three dotted lines divide the cutting surface of the arc-shaped plate 1 into four surfacing areas.

[0060] The integral structural member A is positioned at an original position, which may be any position, but the preferred position is that the line connecting the centers of the two arc-shaped plates 1 is parallel to the Y direction (the Y direction is the vertical direction of the integral structural member A).

[0061] During surfacing welding, surfacing welding is first performed on the first surfacing welding area on the first arc-shaped plate 1 along the length direction of the arc-shaped plate (the first surfacing welding area is as follows: Figure 7a Area ①), the cladding method is climbing welding (such as Figure 7a ), the first surfacing area is located in the middle of the curved plate 1.

[0062] Then the overall structural member A is rotated by a first angle, that is, Figure 7a The first angle is preferably 180°. Figure 7b As shown, the first surfacing area on the second arc-shaped plate 1 is surfacing-welded along the length direction of the arc-shaped plate (the first surfacing area is as shown in FIG. Figure 7b The first surfacing area is located in the middle of the curved plate 1.

[0063] Then the overall structural member A is rotated to a second angle, that is, Figure 7bThe second angle is rotated based on the first angle, and the second angle is preferably 191°. Figure 7c As shown, the second surfacing area on the first arc-shaped plate 1 is surfacing-welded along the length direction of the arc-shaped plate (the second surfacing area is as shown in FIG. Figure 7c The area in ③).

[0064] Then the overall structural member A is rotated by a first angle, that is, Figure 7c Based on the first angle, the rotation is as follows Figure 7d As shown, the second surfacing area on the second arc-shaped plate 1 is surfacing-welded along the length direction of the arc-shaped plate (the third surfacing area is as shown in FIG. Figure 7b Area in ④).

[0065] Reset the overall structural member A to its original position, that is, Figure 7a Same position, see after reset Figure 7e , the third surfacing area on the first arc-shaped plate 1 is surfacing-welded along the length direction of the arc-shaped plate (the third surfacing area is as follows Figure 7e The third surfacing area is located in the middle of the curved plate 1.

[0066] Then the overall structural member A is rotated by a first angle, that is, Figure 7e Based on the first angle, the rotation is as follows Figure 7f As shown, the third surfacing area on the second curved plate 1 is surfacing-welded along the length direction of the curved plate (the third surfacing area is as shown in FIG. Figure 7f The third surfacing area is located in the middle of the curved plate 1.

[0067] Then the overall structural member A is rotated to a second angle, that is, Figure 7f Based on the second angle, the rotation is as follows Figure 7g As shown, the fourth surfacing area on the first arc-shaped plate 1 is surfacing-welded along the length direction of the arc-shaped plate (the fourth surfacing area is as shown in FIG. Figure 7g The area in ⑦).

[0068] Then the overall structural member A is rotated by a first angle, that is, Figure 7g Based on the first angle, the rotation is as follows Figure 7h As shown, the fourth surfacing area on the second arc-shaped plate 1 is surfacing-welded along the length direction of the arc-shaped plate (the fourth surfacing area is as shown in FIG. Figure 7h The area in ⑧).

[0069] In S6, the surfacing layer on the integral structural part A is multi-layer. After each surfacing layer is completed on the integral structural part A, the integral structural part A with the surfacing layer is sent to a heating furnace to remove stress from the surfacing layer. That is, after the first layer is stacked in the order of the above-mentioned area ① to area ⑧, the integral structural part A with the first layer of surfacing layer is sent to a heating furnace to remove stress from the surfacing layer. After the stress removal is completed, the integral structural part A is taken out, and then after the second layer is stacked in the order of the above-mentioned area ① to area ⑧, the integral structural part A with two layers of surfacing layers is sent to a heating furnace to remove stress from the surfacing layer, and this is repeated. In this embodiment, the number of layers of the surfacing layer is preferably three layers.

[0070] During the surfacing process, the parent material (arc plate 1) is deformed by thermal expansion. Due to the long length of the parent material and the large amount of surfacing, the surfacing causes a large deformation of the parent material. Stress relief is taken after each layer is surfacing to reduce the deformation of the parent material. The stress relief temperature of each surfacing layer is 550-560°C, and the stress relief time is 6-8h. In this embodiment, the temperature of the integral structural part A before entering the heating furnace is ≤200°C, the heating rate is ≤70°C / h, and when the temperature is raised to 650°C, it is kept warm for 7h. When the integral structural part A is taken out of the heating furnace, the cooling rate of the heating furnace is controlled to be ≤70°C / h, and the temperature of the integral structural part A before it comes out of the furnace is ≤200°C.

[0071] In S6, the arc plate 1 has a surfacing thickness of no less than 6mm. The surfacing material is preferably alloy steel with a hardness of Hv300-360, and the surfacing surface is qualified by flaw detection. The finished product length of the surfacing part is 2130mm, and the arc length is 484.4mm. According to the design requirements, the welding material consumption is calculated to be about 88kg / piece. Through robot surfacing three layers, the surfacing thickness is 8-9mm, and the processing thickness is guaranteed to be 6mm.

[0072] After the cladding is completed, the weld hardness is found to be beyond the required hardness range. Therefore, the hardness must be adjusted to the required range through heat treatment. The following table shows the heat treatment test of the cut test plate.

[0073]

[0074] According to the results of the test plate heat treatment test, when the tempering temperature is lower than 560℃, the hardness does not change much and still does not meet the required range. When the tempering temperature is 650℃, the hardness is reduced to <280HV; when the tempering temperature is 580℃, the hardness is within the required range.

Claims

1. A method for preparing a composite curved plate on a rolling mill, characterized in that: The following steps are involved: S1, cutting the entire working surface of a single arc-shaped plate (1) at a first cutting depth; S2, fixing the bottom plate (2) at the non-working end of the single curved plate; S3, combining the bottom plates (2) on the two arc-shaped plates (1), and arranging a pad (3) in the middle of the two bottom plates (2), applying pressure to the two ends of the two arc-shaped plates (1) in opposite directions, so that the maximum amount of pressure at the two ends of each arc-shaped plate (1) is half the thickness of the pad (3); S4, after the connecting plate (4) and the side surface of the arc-shaped plate (1) are matched, the connecting plate (4) and the side surface of the arc-shaped plate (1) are welded to form an integral structural member (A); S5, sending the integral structural member (A) into a heating furnace to remove stress; S6, after taking out the stress-relieved integral structural member (A) from the heating furnace, surfacing welding is performed on the curved plate (1).

2. The method for preparing a composite curved plate on a rolling mill according to claim 1, characterized in that: In S1, after cutting at the first cutting depth is completed, cutting processing is performed in the area from the first position on the arc plate (1) to the two ends of the arc plate (1). In this area, the first position is the cutting high point (B), and a cutting low point (C) is set on the end surface of the arc plate (1). The cutting high point (B) and the cutting low point (C) have a height difference in the height direction, and the part located above the line connecting the cutting high point (B) and the cutting low point (C) is the cut part.

3. The method for preparing a composite curved plate on a rolling mill according to claim 1, characterized in that: In S1, after cutting is completed at the first cutting depth, the highest point on one side of the arc surface of the arc plate (1) is moved downward to the fitting point (D), and a first original point (E) and a second original point (F) are selected on the arc of the arc plate (1). A constructed arc (G) is obtained based on the first original point (E), the second original point (F) and the fitting point (D), and the portion located above the constructed arc (G) is the removed portion.

4. The method for preparing a composite curved plate on a rolling mill according to claim 1, characterized in that: In S6, before surfacing, a plurality of surfacing areas are divided on the cutting surface of each arc plate (1) along the length direction of the arc plate (1), and the integral structural member (A) is positioned at the original position. During surfacing, firstly, surfacing is performed on the first surfacing area on the first arc plate (1) along the length direction of the arc plate, and then the integral structural member (A) is rotated by a first angle, and surfacing is performed on the first surfacing area on the second arc plate (1) along the length direction of the arc plate, and then the integral structural member (A) is rotated by a second angle, and surfacing is performed on the second surfacing area on the first arc plate (1) along the length direction of the arc plate, and then the integral structural member (A) is rotated by the first angle, and surfacing is performed on the second surfacing area on the second arc plate (1) along the length direction of the arc plate; the integral structural member (A) is reset to the original position, and the remaining surfacing areas are surfacing according to the above process.

5. The method for preparing a composite curved plate on a rolling mill according to claim 4, characterized in that: The first angle is 180°, and the second angle is 191°.

6. The method for preparing a composite curved plate on a rolling mill according to claim 1, characterized in that: In S5, the temperature for stress relief of the integral structural member (A) is 625±25°C, and the stress relief time is 6-8h.

7. The method for preparing a composite curved plate on a rolling mill according to claim 1, characterized in that: In S6, the cladding layer on the integral structural member (A) is multi-layered. After each cladding layer is completed on the integral structural member (A), the integral structural member (A) with the cladding layer is sent into a heating furnace to remove stress from the cladding layer.

8. The method for preparing a composite curved plate on a rolling mill according to claim 7, characterized in that: The stress relief temperature of each weld overlay layer is 550-560℃ and the stress relief time is 6-8h.

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