Heat treatment charging anti-deformation method for large-span complex-molded-line herringbone support steel casting

Abstract

The invention relates to a heat treatment charging anti-deformation method for a large-span complex molded line herringbone bracket steel casting, belongs to the technical field of heat treatment deformation prevention, and solves the problems of large deformation and low percent of pass of a large-span complex molded line herringbone bracket after heat treatment. Comprising the following steps: constructing a heat treatment charging and padding supporting position of the large-span complex molded line herringbone bracket; three stainless steel pipes are transversely welded between two palm plates of the herringbone support, and three stainless steel pipes are vertically welded between every two transverse stainless steel pipes; the stainless steel pipe is charged after being welded, and a cushion piece is selected for supporting at the thermal treatment charging and cushion supporting position of the herringbone support; after the support is firm, the lower part of the lowermost stainless steel pipe between the two palm plates of the herringbone bracket is cushioned by a support for preventing the stainless steel pipe from bending without being cushioned firmly; and checking whether the pads of the herringbone bracket are firmly supported or not again, and filling the parts with gaps. The herringbone bracket treated by the heat treatment charging anti-deformation method disclosed by the invention is small in deformation and high in percent of pass.

Description

Technical Field

[0001] The invention relates to the technical field of heat treatment deformation prevention, in particular to a method for heat treatment furnace loading deformation prevention of a large-span complex-shaped herringbone bracket steel casting. Background Art

[0002] Large-span complex-shaped herringbone bracket steel castings are key components on ships, used to support and fix the propeller shaft components of ships; complex-shaped herringbone brackets on large ships are generally composed of a hub, two arms and two palm plates, and the structure is a herringbone. The cross-sections of the two arms are designed to be streamlined according to the principles of fluid mechanics to reduce the resistance of the ship during navigation. At the same time, the angle between the two arms, the distance between the two palm plates and the twisting angle of each arm also have specific requirements when designing the bracket structure.

[0003] The large-span complex-shaped herringbone bracket steel castings are huge in size and complex in structure. In the past, due to the limitation of the foundry's manufacturing capacity, split molding was mostly adopted, that is, the large-span complex-shaped herringbone bracket steel castings were disconnected at the arm during molding, and divided into two parts: the hub with arm and the palm plate with arm; after heat treatment, they were welded together into a whole. This method simplifies the structure of the large-span complex-shaped herringbone bracket steel castings, making them smaller in size, reducing the requirements for heat treatment furnace loading, and making the heat treatment deformation easier to control; but it increases the welding workload, and because it is a welding method, not an integral manufacturing method, the quality of the weld area directly affects the service life of the herringbone bracket steel castings.

[0004] With the development of the manufacturing industry, the manufacturing capacity of manufacturers has been continuously improved, and the size problem is no longer the main problem. In addition, the shipbuilding industry has continuously increased its requirements for ship quality. Large-span complex-shaped brackets have gradually abandoned split casting and adopted the method of integral casting. After integral casting, the outline size of the large-span complex-shaped herringbone bracket casting is huge, and the complex overall structure makes it very easy to deform during the heat treatment process.

[0005] In order to reduce deformation, some technicians proposed a method of welding the complex-shaped herringbone bracket steel castings on heat-treated pads. This method reduces the heat treatment deformation of the welding side of the lower end of the complex-shaped herringbone bracket steel castings, but the deformation of the upper end of the complex-shaped herringbone bracket steel castings increases, causing the palm plates of the two arms to deform from an "11" shape to an "eight" shape, or the arms cannot expand or shrink freely during heat treatment, resulting in bending deformation.

[0006] At the same time, some technicians have proposed a method of welding tie bars between the two palm plates of large-span complex-shaped herringbone bracket castings before heat treatment. The use of tie bars can reduce the opening or shrinkage deformation of the two palm plates during heat treatment to a certain extent. However, due to the long span of the tie bars, it is difficult to select the material or size of the tie bars reasonably. After heat treatment, the tie bars often fail due to bending deformation.

[0007] When the deformation of large-span complex-shaped herringbone bracket castings exceeds the dimensional deviation requirements, the product needs to be corrected. If the size still cannot meet the requirements after correction, a large amount of repair welding is required to ensure that the product size meets the use requirements; therefore, the relevant technologies for heat treatment of large-span complex-shaped herringbone bracket castings still need to be further optimized. Summary of the invention

[0008] In view of the above analysis, an embodiment of the present invention aims to provide a method for preventing deformation of large-span complex-shaped herringbone bracket castings during heat treatment and furnace loading, which is used to solve at least one of the following problems: 1. The existing heat treatment method of large-span complex-shaped herringbone bracket castings cannot completely solve the problem of heat treatment deformation of the herringbone bracket; 2. The large-span complex-shaped herringbone bracket castings are deformed after heat treatment, and the distance between the centers of the two palm plates does not meet the requirements, and openings or shrinkage occur, resulting in a low pass rate; 3. The existing treatment method will cause the palm plates of the two arms of the large-span complex-shaped herringbone bracket castings to be deformed from an "11" shape to an "eight" shape; or the arms cannot expand or shrink freely during heat treatment and are bent and deformed; or a large amount of repair welding is required after deformation to be qualified.

[0009] The purpose of the present invention is mainly achieved through the following technical solutions:

[0010] The present invention provides a method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment and loading into a furnace, comprising the following steps:

[0011] S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting;

[0012] S2: Three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket casting as anti-deformation reinforcements, and three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for the anti-deformation reinforcements;

[0013] S3: After the stainless steel pipe is welded, according to the furnace loading sketch, the riser end of the herringbone bracket steel casting is loaded into the furnace downwards. Under the support position of the herringbone bracket steel casting for heat treatment loading and padding, according to the position relationship and height, a pad or pad of appropriate size is selected for support, and then a thin steel plate is used to fill the gap;

[0014] S4: After the herringbone bracket steel casting is firmly supported, use anti-bending support to pad the bottom of the stainless steel pipe between the two palm plates of the herringbone bracket steel casting, but do not pad it tightly, leaving a gap;

[0015] S5: Check again whether the spacers and steel plates, spacers and pads, and pads and herringbone bracket steel castings in step S3 are firmly supported. For gaps, fill them with thin steel plates. At this point, the loading of the herringbone bracket steel castings into the furnace is completed.

[0016] Furthermore, the step S1 comprises:

[0017] Flame cutting of all risers of large-span complex-shaped herringbone bracket castings;

[0018] After all the risers are cut, the remaining uneven roots of the risers are machined into smooth and flat surfaces. All planes must be parallel to each other and perpendicular to the normal direction of the product's center of gravity.

[0019] Furthermore, in step S2, the anti-deformation reinforcements are distributed at equal intervals.

[0020] Furthermore, the equidistant distribution means that when the height of two palm plates in the large-span complex-shaped herringbone bracket casting is H, anti-deformation reinforcement bars are welded at the palm plate heights H / 4, H / 2 and 3H / 4 respectively.

[0021] Furthermore, in step S2, the auxiliary reinforcement bars are distributed at equal intervals.

[0022] Furthermore, the equidistant distribution means that when the distance between the centers of the two palm plates in the large-span complex-shaped herringbone bracket casting is L, auxiliary tie bars are welded at L / 4, L / 2 and 3L / 4 respectively.

[0023] Furthermore, the anti-deformation reinforcement has a diameter of 100-120 mm and a wall thickness of 8-12 mm.

[0024] Furthermore, the auxiliary tensioning rod has a diameter of 80-100 mm and a wall thickness of 6-10 mm.

[0025] Furthermore, the anti-bending stainless steel pipe support is padded at two locations, the two padded locations are symmetrical, and the spacing is 1 / 3 of the distance between the centers of the two palm plates in the large-span complex-shaped herringbone bracket casting.

[0026] Furthermore, in step S4, the gap is 10-25 mm.

[0027] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0028] 1. The method for preventing deformation of large-span complex-shaped herringbone bracket cast steel parts during heat treatment and loading into a furnace of the present invention can effectively control the deformation of the complex-shaped herringbone bracket during heat treatment by welding three transverse stainless steel pipes at equal intervals between the two palm plates of the large-span complex-shaped herringbone bracket cast steel parts as anti-deformation reinforcements, and welding a stainless steel pipe in the vertical direction between every two stainless steel pipes as auxiliary reinforcements, thereby avoiding the opening or shrinkage of the two palm plates of the large-span complex-shaped herringbone bracket cast steel parts after heat treatment, and avoiding the problems of insufficient product size requiring welding or excessive size requiring finishing and grinding, thereby improving the production quality of castings and achieving a high pass rate.

[0029] 2. The method for preventing deformation during heat treatment loading of large-span complex-shaped herringbone bracket steel castings of the present invention processes the root of the casting riser of the large-span complex-shaped herringbone bracket steel castings, constructs mutually parallel supporting planes at the positions of the hub, support arm, palm plate, etc., and adopts various types of pads for support according to different heights, so that loading into the furnace is more stable and not easy to deform; and solves the problem that the herringbone bracket steel castings themselves are mostly curved or inclined surfaces, there are not enough suitable support parts for heat treatment loading, and the heat treatment loading is unstable and easy to deform.

[0030] 3. The method for preventing deformation of large-span complex-shaped herringbone bracket cast steel parts during heat treatment loading in the present invention aims at supporting the palm plate position by placing a thick steel plate of appropriate size at the lowest end under the two palm plates, and ensuring that the upper end surface of the steel plate and the lower end surface of the palm plate are in parallel contact; during the heat treatment process, the two arms are elongated by heat or shortened by cooling, and the palm plates can slide freely on the steel plates, thereby avoiding bending and deformation of the arms of the large-span complex-shaped herringbone bracket cast steel parts due to limitation during heat treatment.

[0031] 4. The heat treatment and furnace anti-deformation method of the large-span complex-shaped herringbone bracket cast steel piece of the present invention is achieved by welding a stainless steel pipe between the two palm plates of the large-span complex-shaped herringbone bracket cast steel piece as an anti-deformation tie rod, and at the same time, a refractory brick or other suitable support is used to padded a certain height below the bottom stainless steel pipe as a supporting point for the stainless steel pipe, which can reduce the bending deformation of the stainless steel pipe and make the anti-deformation effect of the anti-deformation tie rod truly effective.

[0032] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0034] Figure 1 It is a structural top view of a large-span complex-shaped herringbone bracket steel casting of the present invention;

[0035] Figure 2 It is a top view of the casting riser and transverse stainless steel pipe tie bars of the large-span complex-shaped herringbone bracket casting of the present invention;

[0036] Figure 3 It is a left view of the riser root after the hot-cut riser of the large-span complex-shaped herringbone bracket casting of the present invention;

[0037] Figure 4 It is a left view of the heat treatment furnace loading and pad loading position of the large-span complex-shaped herringbone bracket steel casting of the present invention created by processing;

[0038] Figure 5 It is a schematic diagram of the transverse stainless steel pipe reinforcement of the large-span complex-shaped herringbone bracket casting of the present invention;

[0039] Figure 6 It is a left view of the furnace loading of the large-span complex-shaped wire support of Example 1 of the present invention;

[0040] Figure 7 This is a top view of the furnace installation of the large-span complex-shaped wire support according to Example 1 of the present invention.

[0041] Reference numerals:

[0042] 1-hub; 2-first support arm; 3-second support arm; 4-first palm plate; 5-second palm plate; 6-No. 1 riser at the hub; 7-No. 2 riser at the first support arm; 8-No. 2 riser at the second support arm; 9-No. 3 riser at the first palm plate; 10-No. 3 riser at the second palm plate; 11-transverse stainless steel pipe lacing rod; 12-No. 1 riser root at the hub; 13-No. 2 riser root at the first or second support arm; 14-No. 3 riser root at the first or second palm plate; 15-hub pad support position; 16-first or second support arm pad support position; 17-first or second palm plate pad support position; 18-vertical stainless steel pipe lacing rod; 19-anti-bending support for stainless steel pipe; 20-horizontal thick steel plate; 21-support pad at the hub position; 22-support pad at the first or second support arm; 23-support pad at the first or second palm plate. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0044] The present invention provides a method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment and loading into a furnace, comprising the following steps:

[0045] S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting;

[0046] S2: Three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket casting as anti-deformation reinforcements, and three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for the anti-deformation reinforcements;

[0047] S3: After the stainless steel pipe is welded, according to the furnace loading sketch, the riser end of the herringbone bracket steel casting is loaded into the furnace downwards. Under the support position of the herringbone bracket steel casting for heat treatment loading and padding, according to the position relationship and height, a pad or pad of appropriate size is selected for support, and then a thin steel plate is used to fill the gap;

[0048] S4: After the herringbone bracket steel casting is firmly supported, use anti-bending support to pad the bottom of the stainless steel pipe between the two palm plates of the herringbone bracket steel casting, but do not pad it tightly, leaving a gap;

[0049] S5: Check again whether the spacers and steel plates, spacers and pads, and pads and herringbone bracket steel castings in step S3 are firmly supported. For gaps, fill them with thin steel plates. At this point, the loading of the herringbone bracket steel castings into the furnace is completed.

[0050] It should be noted that the large-span complex-shaped herringbone bracket casting described in the present invention includes a hub 1, a first support arm 2 and a second support arm 3 respectively connected to the hub 1, the center line extension lines of the first support arm 2 and the second support arm 3 are connected to form a V shape, the end of the first support arm 2 away from the hub 1 is provided with a first palm plate 4, and the end of the second support arm 3 away from the hub 1 is provided with a second palm plate 5; there is an angle between the first support arm 2 and the second support arm 3, there is an angle between the first support arm 2 and the first palm plate 4, and there is an angle between the second support arm 3 and the second palm plate 5.

[0051] There are a total of 5 risers arranged on the herringbone bracket casting. The first riser 6 is located at the junction of the hub 1 and the two support arms; the second riser 7 is located at the center of the first support arm 2; the third riser 8 is located at the center of the second support arm 3; the fourth riser 9 is located at the junction of the first support arm 2 and the first palm plate 4; the fifth riser 10 is located at the junction of the second support arm 3 and the second palm plate 5.

[0052] It should be noted that the herringbone bracket steel casting itself is mostly curved or inclined, and there are not enough and suitable heat treatment furnace loading support parts in the structure. If the heat treatment pad is not stable, the strength of the material support force-bearing part will be reduced at high temperature, which will cause product deformation. Therefore, in step S1, after all risers are flame cut, it is necessary to use machining means to process the remaining uneven roots of the risers into smooth and flat planes. All planes must be parallel to each other and perpendicular to the normal direction of the product's center of gravity, so as to facilitate the stable padding support of the large-span complex-shaped herringbone bracket steel casting; then use the riser root part left after the riser is cut on the herringbone bracket steel casting to construct the heat treatment furnace loading support part of the large-span complex-shaped herringbone bracket steel casting; use machining means to process the support planes of the hub position, the arm position and the palm plate position. All support planes must be parallel to each other and perpendicular to the normal direction of the product's center of gravity.

[0053] Specifically, in step S2, three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket as anti-deformation reinforcements, and the three stainless steel pipes are evenly spaced, so that the deformation trends of the middle and lower positions of the two palm plates are close, and the anti-deformation effect is better played; it should be noted that the three stainless steel pipes are evenly spaced according to the height of the two palm plates, that is, when the height of the two palm plates is H, the stainless steel pipes are welded at the palm plate heights of about H / 4, H / 2 and 3H / 4, respectively, so that the deformation trends of the middle and lower positions of the two palm plates are close, and the anti-deformation effect is better played;

[0054] At the same time, three stainless steel pipes are vertically welded between every two transverse stainless steel pipes as auxiliary reinforcements for anti-deformation reinforcement. The three vertical stainless steel pipes are evenly spaced according to the distance between the centers of the two palm plates. That is, when the center distance of the two palm plates is L, the stainless steel pipes are welded at L / 4, L / 2 and 3L / 4 respectively to prevent the transverse stainless steel pipe from bending; the diameter of the transverse stainless steel pipe is 100-120mm, and the wall thickness is 8-12mm; the diameter of the vertical stainless steel pipe is 80-100mm, and the wall thickness is 6-10mm.

[0055] Specifically, in step S3, after the stainless steel pipe is welded, according to the furnace loading sketch ( Figure 7 As shown), place the riser end of the herringbone bracket steel casting into the furnace with the riser end facing downwards, and select pads of appropriate size for support according to the position relationship and height at the support position for the herringbone bracket steel casting for heat treatment loading into the furnace.

[0056] Among them, the pads under the hub and the two arms are shims and blocks. Shims and blocks of different heights are used according to the height design, and thin pads are used to fully pad and secure them. The pads selected for the support points under the palm plate are shims and thick steel plates. Shims of appropriate sizes and straight thick steel plates are used to pad and secure them.

[0057] The first palm plate and the second palm plate are supported by thick steel plates respectively to ensure that the lower ends of the two palm plates are horizontal and the upper surface of the steel plate is in parallel contact with the lower surface of the palm plate. During the heat treatment process, the two arms are extended by heat or shortened by cooling, and the palm plates can slide freely on the steel plates to avoid the bending deformation of the arms of the large-span complex-shaped herringbone bracket castings during heat treatment. The upper surface area of ​​the thick steel plate should be larger than the area of ​​the lower end of the palm plate. It should be noted that the two arms will elongate when heated or shorten when cooled, and their lengths will change. The hub connected to the two arms and the two palm plates must have one end sliding. Due to the small size and heavy weight of the hub, it is a fixed point in the complex linear herringbone bracket and will not slide during the heat treatment process. The palm plate is connected to the hub through the support arm, and the upper end surface of the rear steel plate is in contact with the lower end surface of the palm plate. The steel plate is a straight steel plate with a smooth contact surface and low friction. It is easy to slide after thermal expansion during the heat treatment process. The sliding is relatively slight, generally only a dozen millimeters or a few millimeters. Because the upper surface area of ​​the thick steel plate is larger than the area of ​​the lower end surface of the palm plate, enough sliding distance is left. Therefore, the palm plate will not fall off the steel plate and can slide freely on the steel plate.

[0058] It should be noted that the hub is small in size and heavy in weight. It is a fixed point in the complex linear herringbone bracket and will not slide during the heat treatment process. The palm plate is connected to the hub through the support arm and is easy to slide after thermal expansion during the heat treatment process. Therefore, the pads under the hub and the two support arms are selected as pads and blocks, while the pads under the palm plate are selected as pads and thick steel plates. The design dimensions of the complex linear herringbone bracket are different. After the herringbone bracket casting is loaded into the furnace with the riser end facing down, different support heights will appear. In theory, different support heights should be padded with pads of the right height. However, in actual production, it is difficult to achieve pads of various specifications and sizes that can completely match the support height after the herringbone bracket casting is loaded into the furnace with the riser end facing down. Therefore, various specifications of pads are generally used for padding on site first. The remaining height needs to be supplemented with pads, thin steel plates, or pads, thick steel plates of different specifications according to the different support positions to ensure that the gaps at the support positions that appear after loading are fully padded and firm.

[0059] Specifically, in step S4, after the herringbone bracket steel casting is firmly supported, the bottom of the lowest stainless steel pipe among the three stainless steel pipes between the two palm plates of the herringbone bracket steel casting is padded with anti-bending stainless steel pipe supports, without padding, leaving a gap of 10-25mm; the anti-bending stainless steel pipe supports are refractory bricks or other suitable supports; the refractory bricks or other suitable supports are padded at two locations, the two padded locations are symmetrical, and the spacing is about L / 3 (the center distance of the two palm plates). Using refractory bricks or other suitable supports to padded a certain height as the support point of the stainless steel pipe can reduce the bending deformation of the stainless steel pipe and make the anti-deformation effect of the anti-deformation reinforcement truly effective.

[0060] Specifically, in step S5, it is checked again whether the pads, blocks, steel plates and the herringbone bracket steel casting in step S3 are firmly supported, and where there are gaps, they are filled with thin steel plates. At this point, the loading of the herringbone bracket steel casting into the furnace is completed.

[0061] The method for preventing deformation of a large-span complex-shaped herringbone bracket cast steel piece during heat treatment and loading into a furnace can effectively control the deformation of the complex-shaped herringbone bracket during heat treatment by welding three horizontal stainless steel pipes at equal intervals between two palm plates of the large-span complex-shaped herringbone bracket cast steel piece as anti-deformation reinforcement, and welding a stainless steel pipe in the vertical direction between every two stainless steel pipes as auxiliary reinforcement, thereby avoiding the occurrence of opening or shrinkage in the two palm plates of the large-span complex-shaped herringbone bracket cast steel piece after heat treatment, and avoiding the occurrence of problems such as insufficient product size requiring repair welding or excessive size requiring finishing and grinding, thereby improving the production quality of castings and achieving a high pass rate.

[0062] Example 1

[0063] This embodiment provides a method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment and loading into a furnace, comprising the following steps:

[0064] S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting;

[0065] The overall dimensions of the large-span complex-shaped herringbone bracket casting in this embodiment are approximately 5.1×4.3×3.5m, wherein the center distance between the two palm plates is 4m and the palm plate height is 3.5m;

[0066] The large-span complex-shaped herringbone bracket casting includes a hub 1, a first support arm 2 and a second support arm 3 respectively connected to the hub 1, the center line extension lines of the first support arm 2 and the second support arm 3 are connected to form a V shape, the end of the first support arm 2 away from the hub 1 is provided with a first palm plate 4, and the end of the second support arm 3 away from the hub 1 is provided with a second palm plate 5; there is an angle between the first support arm 2 and the second support arm 3, there is an angle between the first support arm 2 and the first palm plate 4, and there is an angle between the second support arm 3 and the second palm plate 5.

[0067] A total of 5 risers are cut on the herringbone bracket casting, the first riser 6 is located at the junction of the hub 1 and the two support arms; the second riser 7 is located at the center of the first support arm 2; the third riser 8 is located at the center of the second support arm 3; the fourth riser 9 is located at the junction of the first support arm 2 and the first palm plate 4; the fifth riser 10 is located at the junction of the second support arm 3 and the second palm plate 5.

[0068] After the herringbone bracket is cast, mark the horizontal line at the height of 5 risers at a height of 100-200mm from the body of the herringbone bracket casting. After the casting is heated, cut off the risers and meat by flame cutting along the marked position, and then use machining to process the remaining uneven roots of the risers into smooth and flush planes. The 5 processing planes at the hub position, the two arm positions and the two palm plate positions should be parallel to each other and perpendicular to the normal direction of the product's center of gravity, so as to facilitate the stable padding and support of the large-span complex-shaped herringbone bracket casting.

[0069] S2: Three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket casting as anti-deformation reinforcements, and three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for the anti-deformation reinforcements;

[0070] The height of the first palm plate 4 and the second palm plate 5 are both 3500mm, and stainless steel pipes are welded at the palm plate heights of 875mm, 1750mm, and 2625mm as anti-deformation reinforcements; the diameter of the three transverse stainless steel pipes is 100mm, and the wall thickness is 8mm;

[0071] Three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for anti-deformation reinforcement (i.e. a total of 6 pipes). For the welding positions of the 6 vertical stainless steel pipes, since the center distance between the two palm plates is 4000mm, the distance between the 6 vertically welded stainless steel pipes is 1000mm. The diameter of the 6 vertical stainless steel pipes is 80mm and the wall thickness is 6mm.

[0072] S3: After the stainless steel pipe is welded, according to the furnace loading sketch ( Figure 7 ), load the herringbone bracket steel casting into the furnace with the riser end facing downwards, and under the support position of the herringbone bracket steel casting for heat treatment loading and padding, select the appropriate size of pads or blocks for support according to the position relationship and height, and then use thin steel plates to fill the gaps.

[0073] Among them, the herringbone bracket casting is loaded into the furnace with the riser end facing downward. The support point height under the hub 1 is about 1700mm, and it is padded with double-layer 800mm high shims assisted by pads; the support point height under the first support arm 2 and the second support arm 3 is about 1900mm, and 1000mm high and 800mm high shims are selected, and then padded with pads. The support points under the first palm plate 4 and the second palm plate 5 are padded with 500mm high shims and straight thick steel plates, and the size of the steel plates is 1800×1000×100mm.

[0074] When placing supporting materials such as shims, blocks and thick steel plates in a heat treatment furnace, all kinds of pads should be placed away from the burners to ensure smooth furnace gas flow.

[0075] S4: After the herringbone bracket casting is firmly supported, use refractory bricks to pad the bottom of the lowest layer of the three stainless steel pipes between the two palm plates of the herringbone bracket casting. Do not pad it tightly, and leave a 10mm gap. The refractory bricks are placed at two locations, 1300mm apart.

[0076] S5: Check again whether the pads, blocks, steel plates and the herringbone bracket steel casting in step S3 are firmly supported. For any gaps, fill them with thin steel plates. At this point, the herringbone bracket steel casting is loaded into the furnace.

[0077] Example 2

[0078] This embodiment provides a method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment and loading into a furnace, comprising the following steps:

[0079] S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting;

[0080] The overall dimensions of the large-span complex-shaped herringbone bracket casting in this embodiment are approximately 7.3×6.2×4.2m, wherein the center distance between the two palm plates is 5.5m and the palm plate height is 3.6m;

[0081] The large-span complex-shaped herringbone bracket casting includes a hub 1, a first support arm 2 and a second support arm 3 respectively connected to the hub 1, the center line extension lines of the first support arm 2 and the second support arm 3 are connected to form a V shape, the end of the first support arm 2 away from the hub 1 is provided with a first palm plate 4, and the end of the second support arm 3 away from the hub 1 is provided with a second palm plate 5; there is an angle between the first support arm 2 and the second support arm 3, there is an angle between the first support arm 2 and the first palm plate 4, and there is an angle between the second support arm 3 and the second palm plate 5.

[0082] A total of 5 risers are cut on the herringbone bracket casting, the first riser 6 is located at the junction of the hub 1 and the two support arms; the second riser 7 is located at the center of the first support arm 2; the third riser 8 is located at the center of the second support arm 3; the fourth riser 9 is located at the junction of the first support arm 2 and the first palm plate 4; the fifth riser 10 is located at the junction of the second support arm 3 and the second palm plate 5.

[0083] After the herringbone bracket is cast, mark the horizontal line at the height of 5 risers at a height of 100-200mm from the body of the herringbone bracket casting. After the casting is heated, cut off the risers and meat by flame cutting along the marked position, and then use machining to process the remaining uneven roots of the risers into smooth and flush planes. The 5 processing planes at the hub position, the two arm positions and the two palm plate positions should be parallel to each other and perpendicular to the normal direction of the product's center of gravity, so as to facilitate the stable padding and support of the large-span complex-shaped herringbone bracket casting.

[0084] S2: Three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket casting as anti-deformation reinforcements, and three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for the anti-deformation reinforcements;

[0085] Among them, the height of the first palm plate 4 and the second palm plate 5 are both 3600mm, and stainless steel pipes are welded at the palm plate heights of 900mm, 1800mm, and 2700mm respectively as anti-deformation reinforcements; the diameter of the three transverse stainless steel pipes is 120mm, and the wall thickness is 12mm;

[0086] Three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for anti-deformation reinforcement (i.e. a total of 6 pipes). For the welding positions of the 6 vertical stainless steel pipes, since the center distance between the two palm plates is 5500mm, the distance between the 6 vertically welded stainless steel pipes is 1375mm. The diameter of the 6 vertical stainless steel pipes is 100mm and the wall thickness is 10mm.

[0087] S3: After the stainless steel pipe is welded, according to the furnace loading sketch ( Figure 7 ), load the herringbone bracket steel casting into the furnace with the riser end facing downwards, and under the support position of the herringbone bracket steel casting for heat treatment loading and padding, select the appropriate size of pads or blocks for support according to the position relationship and height, and then use thin steel plates to fill the gaps.

[0088] Among them, the herringbone bracket casting is loaded into the furnace with the riser end facing downward. The support point height under the hub 1 is about 1400mm, and 800mm high and 500mm high shims are selected and supported by pads; the support point height under the first support arm 2 and the second support arm 3 is about 1550mm, and 1000mm high and 500mm high shims are selected and supported by pads. The support points under the first palm plate 4 and the second palm plate 5 are supported by 500mm high shims and straight thick steel plates, and the size of the steel plates is 1800×1000×100mm.

[0089] When placing supporting materials such as shims, blocks and thick steel plates in a heat treatment furnace, all kinds of pads should be placed away from the burners to ensure smooth furnace gas flow.

[0090] S4: After the herringbone bracket casting is firmly supported, use refractory bricks to pad the bottom of the lowest stainless steel pipe between the two palm plates of the herringbone bracket casting. Do not pad it tightly, and leave a 25mm gap; the refractory bricks are placed in two places, with a distance of 1700mm between them.

[0091] S5: Check again whether the pads, blocks, steel plates and the herringbone bracket steel casting in step S3 are firmly supported. For any gaps, fill them with thin steel plates. At this point, the herringbone bracket steel casting is loaded into the furnace.

[0092] Comparative Example 1

[0093] This comparative example provides a method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting by heat treatment loading, comprising the following steps:

[0094] S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting;

[0095] The overall dimensions of the large-span complex-shaped herringbone bracket casting of this comparative example are about 5.1×4.3×3.5m, wherein the center distance between the two palm plates is 4m, and the palm plate height is 3.5m; the same as Example 1;

[0096] The large-span complex-shaped herringbone bracket casting includes a hub 1, a first support arm 2 and a second support arm 3 respectively connected to the hub 1, the center line extension lines of the first support arm 2 and the second support arm 3 are connected to form a V shape, the end of the first support arm 2 away from the hub 1 is provided with a first palm plate 4, and the end of the second support arm 3 away from the hub 1 is provided with a second palm plate 5; there is an angle between the first support arm 2 and the second support arm 3, there is an angle between the first support arm 2 and the first palm plate 4, and there is an angle between the second support arm 3 and the second palm plate 5.

[0097] A total of 5 risers are cut on the herringbone bracket casting, the first riser 6 is located at the junction of the hub 1 and the two support arms; the second riser 7 is located at the center of the first support arm 2; the third riser 8 is located at the center of the second support arm 3; the fourth riser 9 is located at the junction of the first support arm 2 and the first palm plate 4; the fifth riser 10 is located at the junction of the second support arm 3 and the second palm plate 5.

[0098] After the herringbone bracket is cast, horizontal lines are marked at the height of the five risers at a height of 100-200mm from the main body of the herringbone bracket casting. After the casting is heated, the risers and fillets are cut off by flame cutting along the marked positions, and then the remaining uneven roots of the risers are carbon planed by manual carbon planing. After carbon planing, the five processing planes at the hub position, the two arm positions and the two palm plate positions are not parallel to each other.

[0099] S2: Three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket casting as anti-deformation reinforcement;

[0100] The height of the first palm plate 4 and the second palm plate 5 are both 3500mm, and stainless steel pipes are welded at the palm plate heights of 875mm, 1750mm, and 2625mm as anti-deformation reinforcements; the diameter of the three transverse stainless steel pipes is 100mm, and the wall thickness is 8mm;

[0101] S3: After the stainless steel pipe is welded, according to the furnace loading sketch ( Figure 7), load the herringbone bracket steel casting into the furnace with the riser end facing downwards, and under the support position of the herringbone bracket steel casting for heat treatment loading and padding, select the appropriate size of pads or blocks for support according to the position relationship and height, and then use thin steel plates to fill the gaps.

[0102] Among them, the herringbone bracket casting is loaded into the furnace with the riser end facing downward. The support point height under the hub 1 is about 1600mm, which is padded with double-layer 800mm high shims; the support point height under the first support arm 2 and the second support arm 3 is about 1800mm, and 1000mm high and 800mm high shims are selected. The support points under the first palm plate 4 and the second palm plate 5 are padded with 500mm high shims supplemented by straight thick steel plates. The size of the steel plates is 1800×1000×100mm.

[0103] When placing supporting materials such as shims, blocks and thick steel plates in a heat treatment furnace, all kinds of pads should be placed away from the burners to ensure smooth furnace gas flow.

[0104] S4: Check again whether the pads, blocks, steel plates and the herringbone bracket steel castings in step S3 are firmly supported. For any gaps, fill them with thin steel plates. At this point, the herringbone bracket steel castings are loaded into the furnace.

[0105] Comparative Example 2

[0106] This comparative example provides a method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting by heat treatment loading, comprising the following steps:

[0107] S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting;

[0108] The overall dimensions of the large-span complex-shaped herringbone bracket casting of this comparative example are about 5.1×4.3×3.5m, wherein the center distance between the two palm plates is 4m, and the palm plate height is 3.5m; the same as Example 1;

[0109] The large-span complex-shaped herringbone bracket casting includes a hub 1, a first support arm 2 and a second support arm 3 respectively connected to the hub 1, the center line extension lines of the first support arm 2 and the second support arm 3 are connected to form a V shape, the end of the first support arm 2 away from the hub 1 is provided with a first palm plate 4, and the end of the second support arm 3 away from the hub 1 is provided with a second palm plate 5; there is an angle between the first support arm 2 and the second support arm 3, there is an angle between the first support arm 2 and the first palm plate 4, and there is an angle between the second support arm 3 and the second palm plate 5.

[0110] A total of 5 risers are cut on the herringbone bracket casting, the first riser 6 is located at the junction of the hub 1 and the two support arms; the second riser 7 is located at the center of the first support arm 2; the third riser 8 is located at the center of the second support arm 3; the fourth riser 9 is located at the junction of the first support arm 2 and the first palm plate 4; the fifth riser 10 is located at the junction of the second support arm 3 and the second palm plate 5.

[0111] After the herringbone bracket is cast, horizontal lines are marked at the height of the five risers at a height of 100-200mm from the main body of the herringbone bracket casting. After the casting is heated, the risers and fillets are cut off by flame cutting along the marked positions, and then the remaining uneven roots of the risers are carbon planed by manual carbon planing. After carbon planing, the five processing planes at the hub position, the two arm positions and the two palm plate positions are not parallel to each other.

[0112] S2: According to the furnace loading sketch ( Figure 7 ), load the herringbone bracket steel casting into the furnace with the riser end facing downwards, and under the support position of the herringbone bracket steel casting for heat treatment loading and padding, select the appropriate size of pads or blocks for support according to the position relationship and height, and then use thin steel plates to fill the gaps.

[0113] Among them, the herringbone bracket casting is loaded into the furnace with the riser end facing downward. The support point height under the hub 1 is about 1600mm, which is padded with double-layer 800mm high shims; the support point height under the first support arm 2 and the second support arm 3 is about 1800mm, and 1000mm high and 800mm high shims are selected. The support points under the first palm plate 4 and the second palm plate 5 are padded with 500mm high shims supplemented by straight thick steel plates. The size of the steel plates is 1800×1000×100mm.

[0114] When placing supporting materials such as shims, blocks and thick steel plates in a heat treatment furnace, all kinds of pads should be placed away from the burners to ensure smooth furnace gas flow.

[0115] S3: Spot weld the lower end of the herringbone bracket steel casting and the contact parts such as the washer iron together to ensure that the herringbone bracket steel casting and the washer iron and other cushions are relatively fixed. At this point, the herringbone bracket steel casting is loaded into the furnace.

[0116] The herringbone bracket steel castings of the embodiment and the comparative example were scribed after the heat treatment, and the center distances between the first palm plate and the second palm plate of the herringbone bracket steel castings were measured at three positions, namely, upper, middle and lower.

[0117] Table 1 Deformation of the center distance between the first and second palm plates of the herringbone bracket casting

[0118]

[0119]

[0120] The heat treatment furnace anti-deformation method for a large-span complex-shaped herringbone bracket steel casting provided by the present invention is adopted. In Example 1, the deformation of the herringbone bracket steel casting is shrinkage, and the deformation of the center distance dimension of the two palm plates before and after the heat treatment is -6mm to -5mm, which is within the deviation of 20mm and is qualified; in Example 2, the deformation of the herringbone bracket steel casting is opening, and the deformation of the center distance dimension of the two palm plates before and after the heat treatment is +13mm to +14mm, which is within the deviation of 20mm and is qualified; in Comparative Example 1, the deformation of the herringbone bracket steel casting is shrinkage, and the deformation of the center distance dimension of the two palm plates before and after the heat treatment is -24mm to -25mm, which exceeds the deviation requirement and is unqualified; in Comparative Example 2, the two palm plates of the herringbone bracket steel casting are changed from the original "11" shape to "eight" shape, and the upper end opening size exceeds the deviation requirement and is unqualified. That is to say, the qualified rate of large-span complex-shaped herringbone bracket castings processed by the method of the present invention is high, while the qualified rate of large-span complex-shaped herringbone bracket castings processed by the existing method is low, and the subsequent workload of corrective welding needs to be increased to make them qualified.

[0121] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preventing deformation of large-span complex-shaped herringbone bracket castings during heat treatment and furnace loading. It is characterized in that The following steps are involved: S1: Construct the heat treatment furnace loading and padding support position of the large-span complex-shaped herringbone bracket steel casting; S2: Three stainless steel pipes are horizontally welded between the two palm plates of the herringbone bracket casting as anti-deformation reinforcements, and three stainless steel pipes are vertically welded between every two horizontal stainless steel pipes as auxiliary reinforcements for the anti-deformation reinforcements; S3: After the stainless steel pipe is welded, according to the furnace loading sketch, the riser end of the herringbone bracket steel casting is loaded into the furnace downwards. Under the support position of the herringbone bracket steel casting for heat treatment loading and padding, according to the position relationship and height, a pad or pad of appropriate size is selected for support, and then a thin steel plate is used to fill the gap; S4: After the herringbone bracket steel casting is firmly supported, use anti-bending support to pad the bottom of the stainless steel pipe between the two palm plates of the herringbone bracket steel casting, but do not pad it tightly, leaving a gap; S5: Check again whether the spacers and steel plates, spacers and pads, and pads and herringbone bracket steel castings in step S3 are firmly supported. For gaps, fill them with thin steel plates. At this point, the loading of the herringbone bracket steel castings into the furnace is completed.

2. The method for preventing deformation of large-span complex-shaped herringbone bracket castings during heat treatment and loading into a furnace according to claim 1, It is characterized in that The step S1 comprises: Flame cutting of all risers of large-span complex-shaped herringbone bracket castings; After all the risers are cut, the remaining uneven roots of the risers are machined into smooth and flat surfaces. All planes must be parallel to each other and perpendicular to the normal direction of the product's center of gravity.

3. The method for preventing deformation of large-span complex-shaped herringbone bracket steel castings during heat treatment and loading into a furnace according to claim 2, It is characterized in that In step S2, the anti-deformation reinforcements are distributed at equal intervals.

4. The method for preventing deformation of large-span complex-shaped herringbone bracket castings during heat treatment and loading into a furnace according to claim 3, It is characterized in that The equidistant distribution means that when the height of the two palm plates in the large-span complex-shaped herringbone bracket casting is H, anti-deformation reinforcement bars are welded at the palm plate heights H / 4, H / 2 and 3H / 4 respectively.

5. The method for preventing deformation of large-span complex-shaped herringbone bracket castings during heat treatment and furnace loading according to claim 4, It is characterized in that In step S2, the auxiliary reinforcement bars are distributed at equal intervals.

6. The method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment during loading into a furnace according to claim 5, It is characterized in that The equidistant distribution means that when the distance between the centers of the two palm plates in the large-span complex-shaped herringbone bracket casting is L, auxiliary tie bars are welded at L / 4, L / 2 and 3L / 4 respectively.

7. The method for preventing deformation of large-span complex-shaped herringbone bracket steel castings during heat treatment and loading into a furnace according to claim 2, It is characterized in that The anti-deformation reinforcement has a diameter of 100-120 mm and a wall thickness of 8-12 mm.

8. The method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment and loading into a furnace according to claim 2, It is characterized in that The auxiliary reinforcement has a diameter of 80-100 mm and a wall thickness of 6-10 mm.

9. The method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment during loading into a furnace according to claim 6, It is characterized in that In step S4, the anti-bending stainless steel pipe support is padded at two locations, the two padded locations are symmetrical, and the spacing is 1 / 3 of the distance between the centers of the two palm plates in the large-span complex-shaped herringbone bracket casting.

10. The method for preventing deformation of a large-span complex-shaped herringbone bracket steel casting during heat treatment and loading into a furnace according to claim 1, It is characterized in that In step S4, the gap is 10-25 mm.

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