Ultra-wide large plate and forging process method thereof

Abstract

The invention relates to an ultra-wide large plate and a forging process method thereof, and belongs to the technical field of forging processes. The forging process method for the ultra-wide large plate comprises the steps that jaw pressing is conducted on a riser of a steel ingot, then pre-drawing-out is conducted on an ingot body, an ingot tail is cut, a blank is manufactured, and the ratio of the length to the diameter of the blank is 1.5-2.5; the blank is subjected to upsetting and drawing-out, a jaw is cut off, a prefabricated blank is manufactured, the thickness of the prefabricated blank is H0, the length of the prefabricated blank is L0, and the width of the prefabricated blank is B0; a rotary table is placed on a movable platform, then a lower flat anvil is placed on the rotary table, then a prefabricated blank is placed on the lower flat anvil, and finally an upper flat anvil is pressed on the prefabricated blank; and a rotary table, an upper flat anvil and a lower flat anvil are combined, forging and pressing are conducted in the width direction and the length direction of the prefabricated blank, and the ultra-wide large plate with the thickness being H, the width being B and the length being L is manufactured. The ultra-wide and large plate forgings are successfully prepared through limited equipment, the structure is uniform, the performance is excellent, and the phenomena of coarse crystals and mixed crystals are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of forging processes, and in particular to an ultra-wide large plate and a forging process method thereof. Background Art

[0002] Ultra-wide large plate forgings refer to plate forgings whose width dimension B and length dimension L satisfy B < L < 1.4B, the thickness dimension H is much smaller than the width dimension B and the length dimension L, and the tonnage of the forgings is large, and the width dimension B is usually close to the inner opening limit of the forging press.

[0003] At present, there are two traditional forging and forming process methods for wide plate forgings: One is to press the ingot mouth, pre-draw the ingot body, cut off the ingot tail waste, upset, and use a wide flat anvil to draw and flatten the square until the width of the blank > 0.95B, and then draw the length of the blank to L, and obtain the finished forging after cutting off the ingot mouth. According to the empirical formula for the change of the drawn cross-section, to form a forging of this size, the steel ingot needs to be upset to a diameter D > (2B + H) / 2.5. However, the forming force is proportional to the diameter after upsetting. For ultra-wide large plates, when using this method for forging production, to meet the requirements of the diameter D size after upsetting, the forming force requirement is high, and it often exceeds the equipment pressure limit. In addition, the height of the blank after upsetting is small, and it is very easy to appear concave in the center after subsequent drawing and flattening. The other is to press the ingot mouth, pre-draw the ingot body, cut off the ingot tail waste, upset, draw to obtain a thick plate blank, cut off the ingot mouth, and use the upper flat anvil and the lower platform to repeatedly draw in two directions perpendicular to the thickness direction to the finished forging size. However, the upper flat anvil and the lower platform are of an asymmetric structure, and the blank deformation is also asymmetric. During the forming process, multiple rotations and turnovers are required, resulting in a decrease in the temperature of the blank. Therefore, multiple heating and forming are required, which is extremely easy to cause grain coarsening and mixed crystal phenomena, thereby having an adverse impact on the mechanical properties of the product.

[0004] Therefore, there is an urgent need for a forming method suitable for ultra-wide large plate forgings to successfully prepare ultra-wide large plate forgings with limited equipment. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide an ultra-wide large plate and a forging process method thereof, which can successfully prepare ultra-wide large plate forgings with limited equipment, and have uniform organization and excellent performance.

[0006] On the one hand, the present invention provides an ultra-wide large plate forging process method, including the following steps:

[0007] S1: Press the ingot riser to form an ingot mouth, then pre-draw the ingot body, cut the ingot tail, and obtain a blank, and the ratio of the length to the diameter of the blank is 1.5 - 2.5;

[0008] S2: upsetting and stretching the blank, cutting off the jaws, and obtaining a preform having a thickness of H0, a length of L0, and a width of B0;

[0009] S3: Place the turntable on the mobile platform, then place the lower anvil on the turntable, then place the preform on the lower anvil, and finally press the upper anvil on the preform; use the turntable, upper anvil and lower anvil combination to forge the preform in both width and length directions to obtain an ultra-wide large plate with a thickness of H, a width of B and a length of L.

[0010] Furthermore, in step S2, the obtained preform satisfies the thickness dimension H0=(1.6-2.5)H, and the ratio of the length dimension L0 to the width dimension B0 L0 / B0=(1-1.2)L / B.

[0011] Further, in step S3, the width direction of the preform is first formed, the upper flat anvil and the lower flat anvil are perpendicular to the preform, and the forming starts from the center of the preform, the manipulator clamps the preform and feeds along the width direction with the center of the preform as the starting point, and half of the forming is completed; the turntable rotates 180°, the manipulator clamps the preform and moves it so that the upper flat anvil and the lower flat anvil are located at the center of the preform, and feeds along the width direction with the center of the preform as the starting point to continue forming the other half of the preform, and the above operation is repeated until the width size of the preform is greater than 0.95B;

[0012] To reshape the preform in the length direction, the turntable assists the lower blank to rotate 90°, the upper and lower anvils start to form from the center of the preform, the manipulator clamps the preform and feeds along the length direction starting from the center of the preform to complete half of the forming; the turntable rotates 180°, the manipulator clamps the preform and moves it so that the upper and lower anvils are located at the center of the preform, and feeds along the length direction starting from the center of the preform to continue forming the other half of the preform.

[0013] Furthermore, the upper flat anvil and the lower flat anvil are symmetrical structures, and the ratio of the width W of the upper flat anvil and the lower flat anvil to the thickness H0 of the preform is W / H0=0.6-0.9.

[0014] Furthermore, the depression rate of each anvil of the upper flat anvil is 15% to 20%, and the feed amount is 90% to 100% of the width of the upper flat anvil.

[0015] Furthermore, during the forging process of the upper anvil and the lower anvil, the preform is clamped by a clamp for moving and feeding, and / or a support frame is placed on the turntable, and the support frame is located on the side of the lower anvil away from the clamp.

[0016] Furthermore, the upper plane of the support frame is 100 to 150 mm lower than the upper plane of the lower anvil.

[0017] Furthermore, the initial forging temperature is 1180-1250°C.

[0018] On the other hand, the present invention provides an ultra-wide large plate, which is produced by the ultra-wide large plate forging process method of the present invention.

[0019] Furthermore, the width dimension B and the length dimension L of the ultra-wide large plate satisfy B<L<1.4B.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0021] 1. The present invention adopts a combination of a rotary table, an upper flat anvil, and a lower flat anvil to forge the preform after upsetting and drawing to produce ultra-wide large plate forgings. Compared with the existing method, when preparing large plate forgings of the same specifications, the pressure requirement for the forging equipment is relatively small, and the maximum capacity of the equipment can be exerted. The ultra-wide large plate forgings produced have a high density, and defects such as pores, shrinkage cavities and shrinkage are effectively healed, the organization is uniform, and good comprehensive mechanical properties can be obtained.

[0022] 2. The present invention adopts a rotary table and an upper flat anvil and a lower flat anvil for forming. The upper flat anvil and the lower flat anvil have the same specifications and are symmetrically arranged on the upper and lower sides of the preform. During the forging process, the preform does not need to be turned over, and only needs to be rotated to achieve forging in the width and length directions of the preform, and does not need to be returned to the furnace for heating multiple times, which reduces the risk of grain coarsening. At the same time, the organization is uniform and the production efficiency is increased by more than 50%.

[0023] 3. Use the upper flat anvil and the lower flat anvil to forge the preform. First, the width direction of the preform is formed. The preform is clamped by a clamp and fed along the width direction. After forming one half, the turntable rotates 180° to continue to form the other half of the preform. Repeat the above operation until the preform width size is greater than 0.95B; the turntable assists the lower billet to rotate 90°, and then the length direction of the preform is formed. The preform is clamped by a clamp and fed along the width direction. After forming one half, the turntable rotates 180° to continue to form the other half of the preform. The above process method can effectively reduce the number of forging fires, reduce energy consumption, and prevent the coarse grain and mixed grain phenomenon of forgings caused by small deformation in the final forging fire and small forging ratio.

[0024] 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

[0025] 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.

[0026] Figure 1 This is a schematic diagram of forging an ultra-wide large plate in an embodiment;

[0027] Figure 2 This is a top view of the forging of an ultra-wide large plate in an embodiment;

[0028] Figure 3 The ultra-wide large plate prepared in Example 1;

[0029] In the figure, 1. upper anvil; 2. lower anvil; 3. preform; 4. support frame; 5. clamp; 6. turntable; 7. mobile platform; 8. press column. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention 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.

[0031] In recent years, with the rapid development of domestic petrochemical and nuclear power industries, the market demand for large plate forgings has increased day by day. They are important components of projects such as chemical containers and nuclear power pressure vessels. As the tendency of continuous large-scale equipment becomes increasingly obvious, large plate forging products are developing towards ultra-wide and ultra-large. Flat plate forgings need to be combined with forging equipment, such as hydraulic forging machines, in the preparation process. According to the two existing methods: one is to press the jaws of the steel ingot, pre-draw the ingot body, cut off the ingot tail discarded material, upset, and flatten the wide anvil to form the billet width>0.95B, and then stretch the billet length to L, and cut the jaws to obtain the finished forging. With the increase in the size of flat plate forgings, the pressure required in the process of upsetting and flattening often exceeds the pressure limit of the existing forging equipment, and it is necessary to replace the forging equipment with higher pressure for preparation, which also invisibly increases the production cost. The second is to press the jaws of the steel ingot, pre-draw the ingot body, cut off the ingot tail discarded material, upset, and draw to obtain a thick plate blank, cut the jaws, and use the upper flat anvil and the lower platform for forging. The size of the flat forgings produced by this method is limited by the size of the lower platform, and during the forging process, the billet needs to be rotated and turned over many times by a crane. During the rotation and turning process, the billet is severely cooled, so it needs to be heated many times. Therefore, this method has low production efficiency and is very likely to cause coarse grains and mixed crystals.

[0032] For example, for an ultra-wide large plate whose width dimension B and length dimension L satisfy B<L<1.4B and whose weight is above 100t, the present invention provides an ultra-wide large plate forging process method, which uses existing forging equipment without replacing forging equipment with higher pressure, successfully prepares ultra-wide large plates, and has high production efficiency. The obtained ultra-wide large plates are uniform, dense and have excellent performance.

[0033] The ultra-wide large plate forging process of the present invention comprises the following steps:

[0034] S1: The riser of the steel ingot is clamped, and then the ingot body is pre-lengthened and the ingot tail is cut to obtain a billet, wherein the ratio of the length to the diameter of the billet is 1.5-2.5;

[0035] S2: upsetting and stretching the blank, cutting off the jaws, and obtaining a preform having a thickness of H0, a length of L0, and a width of B0;

[0036] S3: Place the turntable on the mobile platform, then place the lower anvil on the turntable, then place the preform on the lower anvil, and finally press the upper anvil on the preform; use the turntable, upper anvil and lower anvil combination to forge the preform in both width and length directions to obtain an ultra-wide large plate with a thickness of H, a width of B and a length of L.

[0037] Compared with the prior art, the forming method provided by the present invention includes pressing the jaws, pre-drawing, upsetting, drawing and forging in two directions, and under the cooperation of these processes, the forming force of the entire preparation process is relatively small, so the pressure requirement for the forging equipment is relatively small, and ultra-wide large plates of larger specifications can be formed using equipment with relatively small pressure. The forging process in two directions is carried out under the cooperation of the turntable, the upper flat anvil and the lower flat anvil. The upper flat anvil and the lower flat anvil have the same specifications and are symmetrically arranged on the upper and lower sides of the preform. The preform does not need to be turned over, and does not need to be returned to the furnace for heating multiple times. It only needs to be rotated to achieve forging in the width and length directions of the preform to prevent grain coarsening and mixed crystals. The resulting ultra-wide large plate forgings have a high density, and defects such as pores, shrinkage cavities and shrinkage porosity have been effectively healed, and the comprehensive mechanical properties have been improved.

[0038] In step S1, the steel ingot is divided into a riser, an ingot body and an ingot bottom from top to bottom. The riser is clamped to facilitate clamping and subsequent operations; the ingot body is pre-lengthened to remove the edges and corners of the steel ingot, and the height-to-diameter ratio of the ingot is adjusted to a range of 1.5-2.5 to prepare for the next upsetting; the ingot tail is removed by gas cutting to prevent defects in the ingot tail from entering the ingot body, thereby ensuring the internal quality of the final ultra-wide large plate.

[0039] In step S2, the blank is upset and stretched, wherein the purpose of upsetting is to break the coarse original structure of the steel ingot, increase the cross-sectional area of ​​the blank, and increase the forging ratio of the subsequent stretching; the purpose of stretching is to press the internal shrinkage cavities and shrinkage, break the coarse grains, and improve segregation. The obtained preform is a rectangular thick plate, satisfying the thickness dimension H0 = (1.6 ~ 2.5) H, and the ratio of the length dimension L0 to the width dimension B0 L0 / B0 = (1 ~ 1.2) L / B.

[0040] After upsetting by the existing method, a wide flat anvil is used for subsequent drawing and forming, and the size and performance of the ultra-wide large plate are guaranteed to meet the technical requirements. The diameter of the billet after upsetting needs to meet the requirement of D>(2B+H) / 2.5. At this time, the diameter of the billet is much larger than the diameter of the billet after upsetting of the present invention. When upsetting by the existing method, the limit of the equipment is often exceeded, so it is necessary to replace the forging equipment with higher pressure for operation. In the upsetting stage of the present invention, the diameter of the billet after upsetting is relatively small, and the required forming force is relatively small. Combined with the subsequent drawing and forging in two directions, during forging, the rotary table, the upper flat anvil and the lower flat anvil cooperate with each other to ensure the efficient forging of the ultra-wide large plate and obtain a uniform and dense structure and excellent performance.

[0041] In step S3, the width direction of the preform is first formed, the upper flat anvil and the lower flat anvil are perpendicular to the preform, and the forming starts from the center of the preform. The manipulator clamps the preform and feeds it along the width direction starting from the center of the preform to complete half of the forming; the turntable rotates 180°, the manipulator clamps the preform and moves it so that the upper flat anvil and the lower flat anvil are located at the center of the preform, and feeds it along the width direction starting from the center of the preform to continue forming the other half of the preform, and the above operation is repeated until the width size of the preform is greater than 0.95B;

[0042] To reshape the preform in the length direction, the turntable assists the lower blank to rotate 90°, the upper and lower anvils start to form from the center of the preform, the manipulator clamps the preform and feeds along the length direction starting from the center of the preform to complete half of the forming; the turntable rotates 180°, the manipulator clamps the preform and moves it so that the upper and lower anvils are located at the center of the preform, and feeds along the length direction starting from the center of the preform to continue forming the other half of the preform.

[0043] The upper and lower flat anvils are symmetrical structures, and their length is much larger than the width and length of the preform. The preform is symmetrical in shape from top to bottom. There is no need to turn the preform over during the forging process in both width and length directions. The turntable can rotate the preform efficiently, which can solve the problem of time-consuming billet rotation operation in conventional methods and save more than 50% of working hours.

[0044] In the present invention, the forming in step S3 is completed in one fire, which effectively reduces the number of forging fires, reduces energy consumption, and prevents the coarse grain and mixed grain phenomenon of forgings caused by small deformation in the final forging fire and small forging ratio.

[0045] Specifically, the upper flat anvil and the lower flat anvil are symmetrical structures, and the ratio of the width of the upper flat anvil and the lower flat anvil to the thickness of the preform is W / H0=0.6-0.9.

[0046] During the forging process, it is necessary to ensure that the anvil width ratio of the upper flat anvil and the lower flat anvil is in the range of 0.6-0.9, so that the internal stress and strain distribution of the preform is relatively uniform during the forming process, and the internal defects of the forging are further forged while improving the production efficiency, ensuring the performance of the ultra-wide large plate. When the anvil width ratio is less than 0.6, the deformation of the core of the preform is small, and tensile stress is prone to occur, resulting in an increase in the crack growth rate of the ultra-wide large plate; when the anvil width ratio is greater than 0.9, it is easy to cause internal sliding tearing of the preform, and the drawing efficiency is also low.

[0047] Specifically, the depression rate of each anvil of the upper flat anvil is 15% to 20%, and the feed amount is 90% to 100% of the width of the upper flat anvil.

[0048] The preform is further compacted under the forging action of the upper and lower flat anvils, and the compressive strain at the center of the thickness of the billet at each anvil deformation is greater than 0.5, which can achieve the effect of forging through compaction and improve the quality of forgings. When the pressing rate of each anvil of the upper flat anvil is less than 15%, the deformation and strain at the center of the thickness of the preform are small, and the forming efficiency is also low; when the pressing rate of each anvil of the upper flat anvil is greater than 20%, the preform is prone to surface folding or cracks.

[0049] Specifically, during the forging process of the upper flat anvil and the lower flat anvil, it is necessary to use a clamp to clamp the preform for feeding.

[0050] During the forging process, the preform is placed on the lower anvil, and the lower anvil and the upper anvil are symmetrically arranged and located at the center of the preform at the beginning of forging. The upper anvil is connected to the forging equipment. At the beginning of forging, the forging equipment drives the upper anvil to press the preform, and the pressing rate is 15% to 20%; after pressing, the upper anvil is separated from the preform, at this time, the clamp clamps the preform for feeding, and the feeding amount is 90%-100% of the width of the upper anvil. The forging equipment drives the upper anvil to press the preform again. After pressing, the upper anvil is separated from the preform, and the clamp clamps the preform again for feeding. Repeat the above steps until the length and width of the preform are forged.

[0051] Specifically, during the forging process of the upper anvil and the lower anvil, the preform is clamped by a clamp for moving and feeding, and / or a support frame is placed on the turntable, and the support frame is located on the side of the lower anvil away from the clamp.

[0052] During the forging process, the width direction needs to be formed first, and then the length direction needs to be formed. The preform needs to be rotated 90° or 180° using a turntable. During the rotation process, the clamp hinders the rotation of the preform and needs to be withdrawn. However, after the clamp is withdrawn, the preform cannot be supported by the lower anvil alone, so a support frame needs to be placed on the side away from the clamp. The function of the support frame is to assist the rotation of the billet. When the billet needs to be rotated, the preform is placed on the lower anvil and the support frame, the clamp is withdrawn, and the turntable drives the billet to rotate.

[0053] Preferably, the upper plane of the support frame is 100 to 150 mm lower than the upper plane of the lower anvil.

[0054] Specifically, the material of the extra-wide large plate is carbon steel or alloy steel.

[0055] Specifically, when the material of the ultra-wide large plate is carbon steel, the forging start temperature can be 1180-1250°C; when the material of the ultra-wide large plate is medium-low alloy steel, the forging start temperature can be 1180-1250°C. When the material of the ultra-wide large plate is high alloy steel, the forging start temperature can be 1180-1220°C.

[0056] By using the forming method provided by the present invention, an ultra-wide large plate is obtained, the width dimension B and the length dimension L of the ultra-wide large plate satisfy B<L<1.4B, and the weight of the ultra-wide large plate is above 100t.

[0057] In order to more clearly describe the present invention, the following examples and comparative examples are further described.

[0058] The embodiment of the present invention and the comparative example prepare ultra-wide large plates with a size of 5400mm×7300mm×450mm, made of medium carbon low alloy steel, the grade of alloy steel is 30CrNi3MoV. The model of the forging equipment used is a 150MN forging hydraulic press, and the pressure limit is 150MN.

[0059] Example 1

[0060] The ultra-wide large plate forging process includes the following steps:

[0061] S1: Pressing the riser jaws, pre-pulling and cutting off the waste material at the ingot tail: The steel ingot is heated to 1250℃ and kept warm until it is evenly heated through, then taken out of the furnace, the riser jaws are pressed, the ingot body is pre-pulled and the waste material at the ingot tail is cut off to obtain the billet;

[0062] The specification of the steel ingot is 217t, and the ingot body specification after pre-drawing and cutting off the waste material at the ingot tail is φ2440mm×4200mm;

[0063] S2: Upsetting, drawing and compacting to obtain thick plate forging billet: The obtained billet is heated to 1250°C and kept warm until it is evenly heated through, then taken out of the furnace, upset to φ3500mm×2000mm and then drawn, and the billet is drawn to a size of 5300mm×3900mm×900mm (length L0×width B0×thickness H0) by WHF drawing and compacting method, and the jaws are cut off by gas cutting to obtain a preform;

[0064] S3: Reference Figure 1 and Figure 2 , the obtained preform 3 is heated to 1250°C and kept warm until it is evenly heated through. After it is taken out of the furnace, the clamp 5 clamps the preform 3 and places it on the lower flat anvil 2 of the turntable 6. Driven by the mobile platform 7, the preform 3 and the turntable 6 are moved between the columns 8 of the forging hydraulic press. The upper flat anvil 1 is connected to the forging hydraulic press, and the upper flat anvil 1 and the lower flat anvil 2 are symmetrically arranged. The obtained preform 3 is stretched in both width and length directions to the finished size of the forging;

[0065] The clamp 5 on the operating machine clamps the preform 3 and moves it for feeding. The upper flat anvil 1 starts to press down along the width direction of the preform 3 from the middle part. The width of the upper flat anvil 1 and the lower flat anvil 2 is 600mm, the pressing amount is 150mm, and the feeding amount is 550mm. Then the preform 3 is placed on the lower flat anvil 2 and the support frame 4, the clamp 5 is withdrawn, the turntable 6 drives the billet to rotate 180°, and the clamp 5 clamps the billet to forge the other half of the billet to complete the first pass. Repeat the above operation and press down the second pass with a pressing amount of 130mm. If the width of the preform 3 is <5150mm, repeat the above steps and press down until the width is >5150mm.

[0066] The turntable 6 drives the blank to rotate 90°, and the upper flat anvil 1 and the lower flat anvil 2 are used to press down along the length direction of the preform 3 in the same way. The first and second pressing amounts in this direction are 120mm and 100mm respectively. If the length dimension of the preform 3 is less than 7300mm, repeat the above steps and press down to form the final forging size of 5400mm×7300mm×450mm to obtain an ultra-wide large plate. The width of the obtained ultra-wide large plate is close to the opening size of the press, that is, the gap size between the columns. Figure 3 shown.

[0067] In this embodiment, the maximum forming force occurs during the upsetting process to φ3500mm×2000mm in step S2. The forming force during the upsetting process is determined by the empirical formula P=σb×F×K;

[0068] Where: P—pressure (MN);

[0069] σb—the ultimate strength of the material at this temperature (MPa);

[0070] F—cross-sectional area of ​​the blank after upsetting (M2);

[0071] K—coefficient of influence of multiple factors such as friction, temperature, and material, which is taken as 0.5 for this embodiment;

[0072] In this embodiment, the maximum forming force P = 2×0.5×(3.14 / 4)×35002×10-5=96.2 (MN) does not exceed the equipment limit of 150MN.

[0073] Example 2

[0074] The preparation process of Example 2 is substantially the same as that of Example 1, except that in step S3 of Example 2, the upper flat anvil and the lower flat anvil are pressed down sequentially along the width direction of the preform, and the pressing amount of the first pass is 160 mm; and the pressing amount of the second pass is 120 mm.

[0075] The upper flat anvil and the lower flat anvil are pressed down along the length direction of the preform, and the first and second pressing amounts in this direction are 110mm and 110mm respectively.

[0076] Example 3

[0077] The preparation process of Example 3 is substantially the same as that of Example 1, except that in step S2 of Example 3, the size of the preform is 5440 mm×3800 mm×900 mm.

[0078] Example 4

[0079] The preparation process of Example 4 is substantially the same as that of Example 1, except that in step S2 of Example 4, the size of the preform is 5300 mm×3700 mm×950 mm.

[0080] Example 5

[0081] The preparation steps of Example 4 are substantially the same as those of Example 1, except that in step S3 of Example 4, the heating temperature is 1180°C.

[0082] Comparative Example 1

[0083] In comparative example 1, the preparation step S1 of the blank is the same as that of embodiment 1, except that steps S2 and S3 are:

[0084] The forging blank with a width of 5400 mm is obtained by upsetting, flattening with a wide flat anvil, and the finished forging is obtained by lengthening the length direction.

[0085] In order to flatten the steel ingot to obtain a forging billet with a width of 5400 mm, the diameter of the steel ingot after upsetting must satisfy D>(2B+H) / 2.5, that is, greater than (2×5400+450) / 2.5=4500 mm. For this comparative example, the billet is upset to a diameter of D>φ4550 mm.

[0086] According to the empirical formula of the maximum forming force during the upsetting process in the above embodiment 1, P = 2 × 0.5 × (3.14 / 4) × 4550 2 ×10 -5 =162.50 (MN), which exceeds the equipment limit (150MN).

[0087] Comparative Example 2

[0088] The preparation steps S1 and S2 of the preform in Comparative Example 2 are the same as those in Example 1, except for step S3:

[0089] Lengthen along the width direction to the final forging width size: Heat the obtained forging billet to 1250℃ and keep it warm until it is evenly heated through. After it comes out of the furnace, clamp the billet with tongs and place it on the lower platform. The length direction is placed along the length direction of the flat anvil. The upper flat anvil is pressed down from one end of the billet in sequence along the width direction of the billet. The upper flat anvil is 600mm wide, the pressing amount is 150mm, and the feed amount is 550mm. Then turn the billet over, and place it along the length direction of the flat anvil. The upper flat anvil is pressed down from one end of the billet in sequence along the width direction of the billet. The pressing amount is 130mm and the feed amount is 550mm. If the billet width size is <5150mm, repeat the above steps and press it down with a small pressing amount until the width size is >5150mm. Return to the furnace for heating.

[0090] S4: Lengthen along the length direction to the final forging size: Heat the obtained forging billet to 1250℃ and keep it warm until it is evenly heated. After it comes out of the furnace, clamp the billet with tongs and place it on the lower platform. The width direction is placed along the length direction of the flat anvil. The upper flat anvil is pressed down from one end of the billet in sequence along the length direction of the billet. The upper flat anvil is 600mm wide, the pressing amount is 120mm, and the feed amount is 550mm. Then turn the billet over, and place it along the length direction of the flat anvil in the width direction. The upper flat anvil is pressed down from one end of the billet in sequence along the length direction of the billet. The pressing amount is 100mm and the feed amount is 550mm. If the billet length is <7300mm, it is pressed down with a small amount to form the final forging size of 5400mm×7300mm×450mm.

[0091] The lower platform must meet the requirements of width greater than 5400mm and length greater than 7300mm.

[0092] Comparative Example 3

[0093] The preparation steps of Comparative Example 3 are substantially the same as those of Comparative Example 2, except that, in steps S1-S4 of Comparative Example 3, the heating temperature is 1300°C.

[0094] Performance Testing

[0095] The ultra-wide large plates obtained in the above-mentioned Examples 1-5 and Comparative Examples 1-3 were subjected to mechanical property and grain size tests, mainly including tensile strength, yield strength and impact energy.

[0096] Table 1 Performance test results

[0097]

[0098] It can be seen from Examples 1-5 and Comparative Examples 1-3 and Table 1 that when ultra-wide large plates are prepared using the forging method provided by Examples 1-5 of the present invention, the maximum forming force in the preparation process does not exceed the limit of the forging equipment, and the obtained ultra-wide large plates have a tensile strength of more than 1300 MPa, a yield strength of more than 1100 MPa, and an impact energy of more than 47 J. In addition, the forging times are relatively small, the structure is uniform, and the grain size is all level 5.

[0099] It can be seen from Example 1 and Comparative Example 1 and Table 1 that when ultra-wide large plates of the same specifications are prepared using Example 1 and Comparative Example 1, a forging hydraulic press of the same specifications is used. The maximum forming force of Example 1 (90-110 MPa) is less than the pressure limit of the forging hydraulic press (150 MPa), so there is no need to replace the forging hydraulic press with a higher pressure to prepare the ultra-wide large plates.

[0100] It can be seen from Example 1 and Comparative Example 2 and Table 1 that when the method provided in Example 1 is used to prepare ultra-wide large plates, during the forging stage along two directions, the preform does not need to be turned over through the cooperation of the turntable, the upper anvil and the lower anvil, and only needs to be heated and forged once. The obtained ultra-wide large plates have uniform structure, no mixed crystals appear, and the heating time is saved, thereby improving production efficiency.

[0101] 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 forging an ultra-wide large plate, characterized in that: The following steps are involved: S1: Press the riser of the steel ingot into a jaw, then pre-lengthen the ingot body and cut the ingot tail to obtain the billet. ， The ratio of the length to the diameter of the blank is 1.5-2.5; S2: The blank is subjected to upsetting and elongation, and the jaws are cut off to obtain a preform. ， Its thickness is H0, length is L0, and width is B0; S3: Place the turntable on the mobile platform, then place the lower anvil on the turntable, then place the preform on the lower anvil, and finally press the upper anvil on the preform; use the turntable, upper anvil and lower anvil combination to forge the preform in both width and length directions to obtain an ultra-wide large plate with a thickness of H, a width of B and a length of L.

2. The ultra-wide large plate forging process according to claim 1, characterized in that: In step S2, the obtained preform satisfies the thickness dimension H0=(1.6-2.5)H, and the ratio of the length dimension L0 to the width dimension B0 L0 / B0=(1-1.2)L / B.

3. The ultra-wide large plate forging process according to claim 1 is characterized in that: In step S3, the width direction of the preform is first formed, the upper flat anvil and the lower flat anvil are perpendicular to the preform, and the forming starts from the center of the preform. The manipulator clamps the preform and feeds it along the width direction starting from the center of the preform to complete half of the forming; the turntable rotates 180°, the manipulator clamps the preform and moves it so that the upper flat anvil and the lower flat anvil are located at the center of the preform, and feeds it along the width direction starting from the center of the preform to continue forming the other half of the preform, and the above operation is repeated until the width size of the preform is greater than 0.95B; Re-forming the preform in the length direction, the turntable assists the lower blank to rotate 90°, the upper and lower flat anvils start to shape from the center of the preform, the manipulator clamps the preform and feeds along the length direction starting from the center of the preform to complete half of the shaping; The turntable rotates 180°, and the manipulator clamps the preform and moves it so that the upper anvil and the lower anvil are located at the center of the preform. Starting from the center of the preform, the preform is fed along the length direction to continue forming the other half of the preform.

4. The ultra-wide large plate forging process according to claim 3 is characterized in that: The upper flat anvil and the lower flat anvil are of symmetrical structure, and the ratio of the width W of the upper flat anvil and the lower flat anvil to the thickness H0 of the preform is W / H0=0.6-0.

9.

5. The ultra-wide large plate forging process according to claim 3 is characterized in that: The upper flat anvil has a pressing rate of 15% to 20% per anvil, and a feeding amount of 90% to 100% of the width of the upper flat anvil.

6. The ultra-wide large plate forging process according to claim 3 is characterized in that: During the forging process of the upper anvil and the lower anvil, the preform is clamped by a clamp for moving and feeding, and / or a support frame is placed on the turntable, and the support frame is located on the side of the lower anvil away from the clamp.

7. The ultra-wide large plate forging process according to claim 6 is characterized in that: The upper plane of the support frame is 100 to 150 mm lower than the upper plane of the lower anvil.

8. The ultra-wide large plate forging process according to claim 1, characterized in that: The initial forging temperature is 1180-1250℃.

9. An ultra-wide large plate, characterized in that: It is produced by the ultra-wide large plate forging process described in any one of claims 1-8.

10. The ultra-wide large plate according to claim 9, characterized in that: The width dimension B and length dimension L of the ultra-wide large plate satisfy B<L<1.4B.

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