High-temperature alloy plate processing method

Abstract

The invention belongs to the technical field of metallurgy, and particularly relates to a high-temperature alloy plate machining method. The processing method comprises the following steps: (1) carrying out homogenizing heat treatment on a steel ingot to be processed; (2) heating the steel ingot obtained in the step (1), and carrying out rounding, drawing-out and heading treatment; (3) heating the steel ingot obtained in the step (2), and forging; and (4) the operation in the step (3) is repeated until the target size is reached, then solid solution heat treatment is conducted on the plate with the target size, and the high-temperature alloy plate is obtained. In the repeated forging process, in every two adjacent passes, the reduction amount of the thickness of the steel ingot in the later pass is 5%-15% smaller than the reduction amount of the thickness of the steel ingot in the front pass; in the repeated forging process, in every two adjacent passes, the increasing amplitude of the length and the width of the steel ingot in the later pass is smaller than the increasing amplitude of the length and the width of the steel ingot in the previous pass. The machining method has the beneficial effects that the plate obtained through the machining method is better in structure uniformity and higher in ductility.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a high-temperature alloy plate processing method. Background Art

[0002] High-temperature alloys refer to alloys that can work at temperatures above 600°C, withstand greater stress, and have good high-temperature properties such as corrosion resistance and oxidation resistance. Among them, nickel-based high-temperature alloys are the most widely used, largest-volume, and excellent high-temperature strength alloys. They are mainly used to manufacture high-temperature components such as turbine blades, guide blades, turbine discs, high-pressure compressor discs, and combustion chambers for aviation, ships, and industrial gas turbines. They are also used to manufacture aerospace vehicles, rocket engines, nuclear reactors, petrochemicals, and supercritical coal-fired power plants. With the continuous improvement of design requirements for efficiency and power, the environment in which materials serve is becoming more and more extreme, and it is becoming more and more urgent to improve the comprehensive performance of high-temperature alloys.

[0003] The higher the bearing temperature of high-temperature alloy materials and the worse the working conditions, the more difficult it is to process the materials. Therefore, it is inevitable to need larger-sized and larger-tonnage equipment to process the materials. But at the same time, factors that affect smooth processing and uniform performance, such as deformation coordination and organizational uniformity of the material, must also be considered. Therefore, in the process of processing with large-scale equipment, designing a reasonable processing technology is also an important link in achieving product molding.

[0004] The existing high-temperature alloy processing technology often uses a one-way forging method. Due to the large product specifications and small ingot shape, the deformation is insufficient to fully break the grains. After the solid solution finished plate sampling test, it was found that the consistency of performance such as uniformity of organization and plasticity at different positions was poor. This product is used in large equipment such as heavy-duty gas turbines and aircraft engines. Due to the different performance at different positions, there is a risk of premature failure of the product after passing the acceptance inspection, which leads to economic losses. Summary of the invention

[0005] The present application provides a high-temperature alloy plate processing method, aiming to solve the problem of poor microstructure uniformity and plasticity of the high-temperature alloy plate processed by the prior art.

[0006] The present application provides a high temperature alloy plate processing method, comprising the following steps:

[0007] (1) subjecting the steel ingot to be processed to homogenization heat treatment;

[0008] (2) heating the steel ingot obtained in step (1), and performing rounding, elongation and roughening treatments on the steel ingot;

[0009] (3) heating the steel ingot obtained in step (2) and performing forging treatment;

[0010] (4) Repeating the operation of step (3) until the target size is reached, and then performing a solution heat treatment on the plate of the target size to obtain the high-temperature alloy plate;

[0011] During repeated forging, in two adjacent passes, the reduction in the thickness of the steel ingot in the latter pass is 5%-15% less than the reduction in the thickness of the steel ingot in the previous pass;

[0012] During the repeated forging process, in two adjacent passes, the increase in the length and width of the steel ingot in the latter pass is smaller than the increase in the length and width of the steel ingot in the previous pass.

[0013] The processing method described in the present application controls the reduction ratio during the drawing and upsetting operations to ensure that each reduction pass can effectively break up the developed columnar crystal structure in the cast state and improve the uniformity of the structure. The appropriate reduction amount avoids the "bulging" of the steel ingot during upsetting (bulging is a phenomenon in which the middle part of the cylinder becomes abnormally thicker and the two ends are thinner due to excessive deformation when pressing down in the height direction, rather than the entire ingot becoming thicker) or the steel ingot bends, cracks, and becomes scrapped.

[0014] The main purpose of controlling the pressing time is to control the deformation rate, to avoid uneven pressure transmission caused by pressing too fast and causing deformation of the steel ingot during processing. By controlling the pressing amount and pressing time, the shape of the steel ingot after upsetting and drawing is effectively guaranteed to be regular, avoiding subsequent processing failures, and making the obtained plate have better uniformity of organization and higher elongation.

[0015] According to some embodiments of the high-temperature alloy plate processing method described in the present application, in step (1), the heat treatment temperature is 1150-1200° C., and the heat treatment time at this temperature is 50-70 hours.

[0016] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the heating rate of the heat treatment process is 45-55° C. / h.

[0017] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the steel ingot to be processed is heat treated, cooled with the furnace, the oxide scale on the surface of the steel ingot is removed, and the last solidified end of the steel ingot is cut off; preferably, the cut length is ≥ the diameter of the steel ingot, and more preferably, the ratio of the cut length to the ingot diameter is (1-1.1):1.

[0018] According to some embodiments of the high-temperature alloy plate processing method described in the present application, in step (2), before heating the steel ingot obtained in step (1), an anti-oxidation coating is applied on the surface of the steel ingot.

[0019] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the anti-oxidation coating includes aluminum oxide, silicon dioxide and silicon carbide, and the mass ratio of aluminum oxide, silicon dioxide and silicon carbide in the anti-oxidation coating is (40-50): (25-30): (25-30).

[0020] According to some embodiments of the high-temperature alloy plate processing method described in the present application, in step (2), the heating temperature is 1100-1200° C., and the heating time at this temperature is 3-4.5 hours.

[0021] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the operation described in step (2) is repeated until the diameter of the steel ingot is ≤180 mm.

[0022] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the rounding operation, the pressing amount of each pass during the stretching is not greater than 6% of the diameter of the steel ingot before the pressing pass, and the pressing amount of each pass during the roughening is not greater than 9.5% of the height of the steel ingot before the pressing pass, and the pressing time of each pass is ≥3s.

[0023] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the amount of reduction per pass during the stretching process is 4.5-5.5% of the diameter of the steel ingot before the reduction, and the amount of reduction per pass during the roughening process is 6.5-9% of the height of the steel ingot before the reduction;

[0024] According to some embodiments of the high-temperature alloy sheet processing method described in the present application, during the rounding operation, the pressing time for each pass is 4-7 seconds.

[0025] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the heating temperature in step (3) is 1100-1200° C., and the heating time at this temperature is 2-2.5 hours.

[0026] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the thickness of the steel ingot after the first pass is 60%-70% of the thickness of the steel ingot before forging.

[0027] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the thickness of the steel ingot after the second pass is 65%-75% of the thickness of the steel ingot after the first pass.

[0028] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the thickness of the steel ingot after the third pass is 75%-85% of the thickness of the steel ingot after the second pass.

[0029] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the increase in the length of the steel ingot after the first pass is 1.25-1.35 times the length of the steel ingot before forging.

[0030] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the increase in the width of the steel ingot after the first pass is 1.25-1.35 times the width of the steel ingot before forging.

[0031] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the increase in the length of the steel ingot after the second pass is 1.15-1.25 times the length of the steel ingot before forging.

[0032] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the increase in the width of the steel ingot after the second pass is 1.15-1.25 times the width of the steel ingot before forging.

[0033] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the increase in the length of the steel ingot after the third pass is 1.05-1.15 times the length of the steel ingot before forging.

[0034] According to some embodiments of the high-temperature alloy plate processing method described in the present application, during the forging process, the increase in the width of the steel ingot after the third pass is 1.05-1.15 times the width of the steel ingot before forging.

[0035] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the temperature of the solution treatment is 1100-1150° C., and the heating time at this temperature is 0.5-2.0 h.

[0036] According to some embodiments of the high-temperature alloy plate processing method described in the present application, the temperature of the solution treatment is 1120-1145° C., and the heating time at this temperature is 0.7-1.5 h.

[0037] According to some embodiments of the high-temperature alloy plate processing method described in the present application, calculated by mass percentage, the composition of the high-temperature alloy plate includes Cr 18.5-20.5%, Co 9.0-11.0%, Mo 8.0-9.0%, Nb 0.81-1.50%, Ti0.70-1.49%, Al 2.00-2.80%, C 0.02-0.10%, B 0.003-0.01%, Si 0.001-0.15%, Mn 0.001-0.3%, and the balance is Ni and unavoidable impurity elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1This is a microstructure morphology of the high-temperature alloy plate prepared in Example 1 of the present application;

[0039] Figure 2 This is a microstructure morphology of the high-temperature alloy plate prepared in Example 2 of the present application;

[0040] Figure 3 This is a microstructure morphology diagram of the high-temperature alloy plate prepared in Example 3 of the present application;

[0041] Figure 4 This is a microstructure morphology of the high-temperature alloy plate prepared in Comparative Example 1 of the present application;

[0042] Figure 5 This is a microstructure morphology of the high-temperature alloy plate prepared in Comparative Example 2 of the present application;

[0043] Figure 6 This is a microstructure morphology diagram of the high-temperature alloy plate prepared in Comparative Example 3 of the present application. DETAILED DESCRIPTION

[0044] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0045] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0046] The present invention provides a method for processing a high temperature alloy plate, comprising the following steps:

[0047] (1) subjecting the steel ingot to be processed to homogenization heat treatment;

[0048] (2) heating the steel ingot obtained in step (1), and performing rounding, elongation and roughening treatments on the steel ingot;

[0049] (3) heating the steel ingot obtained in step (2) and performing forging treatment;

[0050] (4) Repeating the operation of step (3) until the target size is reached, and then performing a solution heat treatment on the plate of the target size to obtain the high-temperature alloy plate;

[0051] During repeated forging, in two adjacent passes, the reduction in the thickness of the steel ingot in the latter pass is 5%-15% less than the reduction in the thickness of the steel ingot in the previous pass;

[0052] During the repeated forging process, in two adjacent passes, the increase in the length and width of the steel ingot in the latter pass is smaller than the increase in the length and width of the steel ingot in the previous pass.

[0053] The high-temperature alloy plate processing method described in this application uses multiple upsetting and stretching methods to increase the forging ratio and improve the uniformity of the plate's structure. At the same time, the deformation amount in each direction of each forging is limited to ensure the smooth progress of forging, effectively avoiding the cracking problem caused by the large cooling resistance of the steel ingot and the large deformation due to the long forging time, and limiting the minimum deformation to ensure the controllability of the processing passes, saving energy consumption and working hours within a reasonable range.

[0054] The high-temperature alloy plate obtained by the processing method described in the present application has good uniformity of structure and good shaping, reduces the risk of product disqualification, and improves the stability of the product.

[0055] In some embodiments of the present application, in step (1), the heat treatment temperature is 1150-1200°C, such as 1150°C, 1180°C, 1200°C, etc., and the heat treatment time at this temperature is 50-70h, such as 50h, 55h, 58h, 60h, 62h, 67h, 70h, etc. Keeping the heat at this heating temperature for 50-70h can ensure that the elements in the plate are fully diffused and improve the uniformity of the ingot composition.

[0056] In some embodiments of the present application, the heating rate of the heat treatment process is 45-55°C / h, such as 45°C / h, 48°C / h, 50°C / h, 53°C / h, 55°C / h, etc. If the heating rate is slow, the thermal stress of the steel ingot will be reduced when it is heated, which is not conducive to the full diffusion of elements in the plate.

[0057] In some embodiments of the present application, the steel ingot to be processed is heated and cooled in the furnace, the oxide scale on the surface of the steel ingot is removed, and the last solidified end of the steel ingot is cut off; preferably, the length of the cut is ≥ the diameter of the steel ingot. Cutting off the last solidified end of the steel ingot can avoid cracking during the forging process. In some embodiments of the present application, the ratio of the cut length to the steel ingot diameter is (1-1.1):1.

[0058] In some embodiments of the present application, in step (2), before heating the steel ingot obtained in step (1), an anti-oxidation coating is applied on the surface of the steel ingot; the application of the anti-oxidation coating can reduce the degree of oxidation of the steel ingot.

[0059] In some embodiments of the present application, the anti-oxidation coating comprises aluminum oxide, silicon dioxide and silicon carbide, and the mass ratio of aluminum oxide, silicon dioxide and silicon carbide in the anti-oxidation coating is (40-50): (25-30): (25-30).

[0060] In some embodiments of the present application, in step (2), the heating temperature is 1100-1200°C, for example, 1100°C, 1150°C, 1160°C, 1180°C, 1190°C, 1200°C, etc., and the heating time at this temperature is 3-4.5h, for example, 3h, 4h, 4.3h, 4.5h, etc.

[0061] In some embodiments of the present application, in step (2), the heating temperature is 1150-1190° C., and the heating time at this temperature is 3.5-4 h.

[0062] In some embodiments of the present application, the operation described in step (2) is repeated until the diameter of the steel ingot is ≤180 mm.

[0063] In some embodiments of the present application, a hydraulic forging machine is used for rounding, and the ingot transfer time is ≤1 min.

[0064] In some embodiments of the present application, during the rolling and stretching operation, the amount of reduction in each pass during the stretching is not greater than 6% of the diameter of the steel ingot before reduction; for example, 6%, 5.8%, 5.5%, 5.3%, 4.9%, 4.6%, 4.3%, 4.0%, etc.

[0065] In some embodiments of the present application, during the rolling and upsetting operation, the amount of pressure reduction in each pass during upsetting is not greater than 9.5% of the height of the steel ingot before pressure reduction; for example, 9.5%, 9.2%, 9%, 8.3%, 8.1%, 7.8%, 7.4%, 7.1%, 6.5%, 5.8%, etc.

[0066] In some embodiments of the present application, during the rolling, drawing and upsetting operations, the pressing time for each pass is ≥ 3s, for example, 3s, 3.5s, 4s, 4.8s, 5.2s, 5.6s, etc.

[0067] In some embodiments of the present application, the pressing amount of each pass during stretching is 4.5-5.5% of the diameter of the steel ingot before pressing, and the pressing amount of each pass during roughening is 6.5-9% of the height of the steel ingot before pressing. During the rounding operation, the pressing time of each pass is 4-7s.

[0068] By controlling the reduction ratio during the drawing and upsetting operations, it is ensured that each pressing pass can effectively break the developed columnar crystal structure of the cast state and improve the uniformity of the structure. The appropriate pressing amount avoids the "bulging" of the steel ingot during upsetting (bulging is a phenomenon in which the middle part of the cylinder becomes abnormally thicker and the two ends are thinner due to excessive deformation when pressing down along the height direction, rather than the overall thickening) or the steel ingot bends, cracks, and is scrapped.

[0069] The main purpose of controlling the pressing time is to control the deformation rate, to avoid pressing too fast and causing uneven pressure transmission, which will lead to deformation of the steel ingot during processing. By controlling the pressing amount and pressing time, the shape of the steel ingot after upsetting and drawing is effectively guaranteed to be regular, avoiding subsequent processing failures.

[0070] In some embodiments of the present application, before the temperature of the steel ingot drops to 850°C, forging is stopped and the steel ingot is returned to the furnace for heating, that is, heating at a temperature of 1150-1190°C for no more than 2.5 hours.

[0071] In some embodiments of the present application, the heating temperature in step (3) is 1100-1200°C, for example, 1100°C, 1120°C, 1150°C, 1180°C, 1200°C, etc., and the heating time at this temperature is 2-2.5h, for example, 2h, 2.2h, 2.3h, 2.5h, etc.

[0072] In some embodiments of the present application, during the forging process, the thickness of the steel ingot after the first pass is 60%-70% of the thickness of the steel ingot before forging; for example, 60%, 65%, 68%, 70%, etc.

[0073] In some embodiments of the present application, the thickness of the steel ingot after the second pass is 65%-75% of the thickness of the steel ingot after the first pass, for example, 65%, 68%, 70%, 72%, 75%, etc.

[0074] In some embodiments of the present application, the thickness of the steel ingot after the third pass is 75%-85% of the thickness of the steel ingot after the second pass, for example, 75%, 78%, 80%, 82%, 85%, etc.

[0075] In some embodiments of the present application, during the forging process, the increase in the length of the steel ingot after the first pass is 1.25-1.35 times the length of the steel ingot before forging, for example, 1.25 times, 1.28 times, 1.30 times, 1.33 times, 1.35 times, etc.

[0076] In some embodiments of the present application, during the forging process, the increase in the width of the steel ingot after the first pass is 1.25-1.35 times the width of the steel ingot before forging; for example, 1.25 times, 1.28 times, 1.30 times, 1.33 times, 1.35 times, etc.

[0077] In some embodiments of the present application, during the forging process, the increase in the length of the steel ingot after the second pass is 1.15-1.25 times the length of the steel ingot before forging; for example, 1.15 times, 1.18 times, 1.20 times, 1.23 times, 1.25 times.

[0078] In some embodiments of the present application, during the forging process, the increase in the width of the steel ingot after the second pass is 1.15-1.25 times the width of the steel ingot before forging; for example, 1.15 times, 1.18 times, 1.20 times, 1.23 times, 1.25 times.

[0079] In some embodiments of the present application, during the forging process, the increase in the length of the steel ingot in the third pass is 1.05-1.15 times the length of the steel ingot before forging; for example, 1.05 times, 1.08 times, 1.10 times, 1.12 times, 1.15 times, etc.

[0080] In some embodiments of the present application, during the forging process, the increase in the width of the steel ingot in the third pass is 1.05-1.15 times the width of the steel ingot before forging; for example, 1.05 times, 1.08 times, 1.10 times, 1.12 times, 1.15 times, etc.

[0081] In some embodiments of the present application, during the forging process, the increase in the length of the steel ingot in the third pass and each subsequent pass is 1.05-1.15 times the length of the steel ingot before forging; for example, 1.05 times, 1.08 times, 1.10 times, 1.12 times, 1.15 times, etc.

[0082] In some embodiments of the present application, during the forging process, the increase in the width of the steel ingot in the third pass and each subsequent pass is 1.05-1.15 times the width of the steel ingot before forging; for example, 1.05 times, 1.08 times, 1.10 times, 1.12 times, 1.15 times, etc.

[0083] In some embodiments of the present application, the temperature of the solution treatment is 1100-1150°C, for example, 1100°C, 1120°C, 1140°C, 1150°C, etc., and the heating time at this temperature is 0.5-2.0h, for example, 0.5h, 0.8h, 1.2h, 1.6h, 2.0h, etc.

[0084] In some embodiments of the present application, the temperature of the solution treatment is 1120-1145° C., and the heating time at this temperature is 0.7-1.5 h.

[0085] In some embodiments of the present application, calculated by mass percentage, the composition of the high-temperature alloy plate includes Cr18.5-20.5%, Co 9.0-11.0%, Mo 8.0-9.0%, Nb 0.81-1.50%, Ti 0.70-1.49%, Al2.00-2.80%, C0.02-0.10%, B 0.003-0.01%, Si 0.001-0.15%, Mn 0.001-0.3%, and the remainder is Ni and unavoidable impurity elements.

[0086] In order to meet the requirements of sufficient strength and excellent thermal corrosion resistance in high temperature environments, a large amount of strengthening elements such as Al, Ti, Co, and Mo are added to the high-temperature alloy, making the alloy extremely difficult to deform. If the ingot is too large, the processing equipment is extremely demanding, and the hot processing window of the ingot is narrow, and the risk of cracking is high; the smaller ingot reduces the requirements for processing equipment, but the traditional unidirectional forging cannot guarantee the forging ratio, so that the uniformity of the organization cannot be guaranteed, and the inappropriate forging ratio will also cause deformation or cracking inside or on the edge of the ingot.

[0087] The present application optimizes the deformation system of hot working, and adopts the method of multiple rolling, stretching and upsetting to increase the forging ratio, thereby improving the uniformity of the structure of the finished plate. At the same time, the deformation amount in each direction of each forging is specified to ensure the smooth forging, effectively avoid the long forging time resulting in large resistance to cooling of the steel ingot and cracking due to excessive deformation, and at the same time specify the minimum deformation amount, effectively ensuring the crushing of the cast structure and the controllability of the processing passes, saving energy consumption and working hours within a reasonable range.

[0088] The high-temperature alloy plate used in the embodiment of the present application includes the following components, calculated by mass percentage: Cr19.8%, Co 10.3%, Mo 8.4%, Nb 1.25%, Ti 1.12%, Al 2.35%, including some trace added elements, C 0.045%, B 0.003%, Si 0.01%, Mn 0.28%, and the balance is Ni and other inevitable impurity elements.

[0089] The technical solution of the present application is described in detail below in conjunction with specific embodiments and drawings.

[0090] Example 1

[0091] A method for processing a high-temperature alloy plate comprises the following steps:

[0092] (1) Place the steel ingot to be processed in a heating furnace, raise the working temperature of the heating furnace to 1150℃ at a heating rate of 50℃ / h, keep it warm for 60h, and then open the furnace cover to cool it down. Use a lathe and a cutting machine to remove the oxide scale on the surface of the steel ingot, and cut off the part of the steel ingot that is equal to the diameter of the steel ingot at the last solidification end (riser end). The remaining part is used as the billet for thick plate processing.

[0093] (2) the steel ingot obtained in step (1) is loaded into a heating furnace, heated to 1100°C, and kept warm for 3.5 hours. To reduce the degree of oxidation of the steel ingot, a layer of anti-oxidation coating is applied on the steel ingot before loading the furnace for heating (the anti-oxidation coating used in the embodiment of the present application comprises a mixture of aluminum oxide, silicon dioxide and silicon carbide in a mass ratio of 40:26:26); after heating is completed, the steel ingot is subjected to rounding treatment by a hydraulic forging machine, during which the transfer time of the steel ingot is controlled to be ≤1 min. After the steel ingot is stretched by the rounding treatment, the steel ingot is then stood up for upsetting treatment; the heating and rounding operations are repeated, and before the temperature of the steel ingot drops to 850°C, the steel ingot is heated in time and then rounded again. During the rounding process, the pressing time of each pass is ≥3s. In the two adjacent passes, the pressing amount of each pass during the drawing process is not more than 6% of the diameter of the steel ingot before pressing, and the pressing amount of each pass during the upsetting process is not more than 9.5% of the height of the steel ingot before pressing. Repeat the drawing and upsetting operations for 4 cycles until the ingot diameter reaches 175mm, and then end the upsetting process;

[0094] (3) The steel ingot obtained in step (2) is placed in a heating furnace, heated to 1150°C and kept at this temperature for 2 hours; then forged using a hydraulic forging machine; the above operation is repeated, that is, when the temperature of the steel ingot drops to 850°C, the steel ingot is returned to the furnace for heating and then forged again.

[0095] During the forging process, the thickness of the steel ingot after the first pass is 62% of the thickness of the steel ingot before forging, the increase in the width of the steel ingot after the first pass is 1.28 times the width of the steel ingot before forging, and the increase in the length of the steel ingot after the first pass is 1.26 times the length of the steel ingot before forging; the thickness of the steel ingot after the second pass is 71% of the thickness of the steel ingot after the first pass, the increase in the length of the steel ingot after the second pass is 1.21 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the second pass is 1.16 times the width of the steel ingot before forging; the The thickness of the steel ingot after the second pass is 80% of the thickness of the steel ingot after the second pass, the increase in the length of the steel ingot after the third pass is 1.1 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the third pass is 1.14 times the width of the steel ingot before forging; that is, in the repeated forging process, in two adjacent passes, the reduction ratio of the steel ingot thickness in the latter pass is 9% less than the reduction in the thickness of the steel ingot in the previous pass; the increase in the length and width of the steel ingot in the latter pass is 2-9% less than the increase in the length and width of the steel ingot in the previous pass; until the target size is reached;

[0096] (4) The target size plate is heated at a temperature of 1120° C. for 1 hour for solution treatment to obtain the high temperature alloy plate.

[0097] Example 2

[0098] The difference between the high-temperature alloy plate processing method described in Example 2 and the high-temperature alloy plate processing method described in Example 1 is that: during the forging process, the thickness of the steel ingot after the first pass is 64% of the thickness of the steel ingot before forging, the increase in the width of the steel ingot after the first pass is 1.25 times the width of the steel ingot before forging, and the increase in the length of the steel ingot after the first pass is 1.25 times the length of the steel ingot before forging; the thickness of the steel ingot after the second pass is 74% of the thickness of the steel ingot after the first pass, the increase in the length of the steel ingot after the second pass is 1.18 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the second pass is 1.25 times the length of the steel ingot before forging. The amplitude is 1.15 times of the width of the steel ingot before forging; the thickness of the steel ingot after the third pass is 84% ​​of the thickness of the steel ingot after the second pass, the increase in the length of the steel ingot after the third pass is 1.08 times of the length of the steel ingot before forging, and the increase in the width of the steel ingot after the third pass is 1.10 times of the width of the steel ingot before forging; that is, in the repeated forging process, in the two adjacent passes, the reduction in the thickness of the steel ingot in the latter pass is 10% less than the reduction in the thickness of the steel ingot in the previous pass; the increase in the length and width of the steel ingot in the latter pass is 3 to 8.5% less than the increase in the length and width of the steel ingot in the previous pass; until the target size is reached.

[0099] Example 3

[0100] The difference between the high-temperature alloy plate processing method described in Example 3 and the high-temperature alloy plate processing method described in Example 1 is that: during the forging process, the thickness of the steel ingot after the first pass is 63% of the thickness of the steel ingot before forging, the increase in the width of the steel ingot after the first pass is 1.26 times the width of the steel ingot before forging, and the increase in the length of the steel ingot after the first pass is 1.26 times the length of the steel ingot before forging; the thickness of the steel ingot after the second pass is 74% of the thickness of the steel ingot after the first pass, the increase in the length of the steel ingot after the second pass is 1.16 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the second pass is 1.26 times the length of the steel ingot before forging. The amplitude is 1.16 times of the width of the steel ingot before forging; the thickness of the steel ingot after the third pass is 85% of the thickness of the steel ingot after the second pass, the increase in the length of the steel ingot after the third pass is 1.12 times of the length of the steel ingot before forging, and the increase in the width of the steel ingot after the third pass is 1.05 times of the width of the steel ingot before forging; that is, in the repeated forging process, in the two adjacent passes, the reduction in the thickness of the steel ingot in the latter pass is 11% less than the reduction in the thickness of the steel ingot in the previous pass; the increase in the length and width of the steel ingot in the latter pass is 3-10% less than the increase in the length and width of the steel ingot in the previous pass; until the target size is reached.

[0101] Comparative Example 1

[0102] The difference between the high-temperature alloy plate processing method described in Comparative Example 1 and the high-temperature alloy plate processing method described in Example 1 is that: during the forging process, the thickness of the steel ingot after the first pass is 55% of the thickness of the steel ingot before forging, the increase in the width of the steel ingot after the first pass is 1.17 times the width of the steel ingot before forging, and the increase in the length of the steel ingot after the first pass is 1.55 times the length of the steel ingot before forging; the thickness of the steel ingot after the second pass is 59% of the thickness of the steel ingot after the first pass, the increase in the length of the steel ingot after the second pass is 1.21 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the second pass is 1.40 times the width of the steel ingot before forging; during the second forging, due to the large amount of reduction, the steel ingot cracked during the reduction process and was scrapped.

[0103] Comparative Example 2

[0104] The difference between the high-temperature alloy plate processing method described in Comparative Example 2 and the high-temperature alloy plate processing method described in Example 1 is that: during the forging process, the thickness of the steel ingot after the first pass is 72% of the thickness of the steel ingot before forging, the increase in the width of the steel ingot after the first pass is 1.25 times the width of the steel ingot before forging, and the increase in the length of the steel ingot after the first pass is 1.11 times the length of the steel ingot before forging; the thickness of the steel ingot after the second pass is 78% of the thickness of the steel ingot after the first pass, the increase in the length of the steel ingot after the second pass is 1.18 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the second pass is 1.09 times the width of the steel ingot before forging; the thickness of the steel ingot after the third pass is 86% of the thickness of the steel ingot after the second pass , the increase in the length of the steel ingot after the third pass is 1.08 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the third pass is 1.08 times the width of the steel ingot before forging; the thickness of the steel ingot after the fourth pass is 88% of the thickness of the steel ingot after the third pass, the increase in the length of the steel ingot after the fourth pass is 1.08 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the fourth pass is 1.05 times the width of the steel ingot before forging; that is, in the repeated forging process, in two adjacent passes, the reduction in the thickness of the steel ingot in the latter pass is 2-8% less than the reduction in the thickness of the steel ingot in the previous pass; the increase in the length and width of the steel ingot in the latter pass is not more than 8% than the increase in the length and width of the steel ingot in the previous pass; processed to the target size.

[0105] Comparative Example 3

[0106] The difference between the high-temperature alloy plate processing method described in Comparative Example 3 and the high-temperature alloy plate processing method described in Example 1 is that: during the forging process, the thickness of the steel ingot after the first pass is 62% of the thickness of the steel ingot before forging, the increase in the width of the steel ingot after the first pass is 1.27 times the width of the steel ingot before forging, and the increase in the length of the steel ingot after the first pass is 1.27 times the length of the steel ingot before forging; the thickness of the steel ingot after the second pass is 60% of the thickness of the steel ingot after the first pass, the increase in the length of the steel ingot after the second pass is 1.44 times the length of the steel ingot before forging, and the increase in the width of the steel ingot after the second pass is 1.16 times the width of the steel ingot before forging; due to the large extension in the length direction, the plate is side-bent and has a large unevenness, and is scrapped.

[0107] The microstructure morphology of the high-temperature alloy plate obtained by the high-temperature alloy plate processing method described in Examples 1-3 and Comparative Examples 1-3 of the present application is shown as follows: Figure 1-6 As shown, samples were prepared to test the room temperature tensile properties, 2 samples were tested in each group, and the elongation values ​​after fracture are shown in Table 1.

[0108] Table 1

[0109] Forging conditions Grain size grade Elongation after break Example 1 smoothly 4.0-6.0 24.0％、26.0％ Example 2 smoothly 4.0-5.0 24.5％、26.0％ Example 3 smoothly Level 2.5 25.0％、27.0％ Comparative Example 1 Cracking and scrapping 1.5-4.0 17.5％、19.0％ Comparative Example 2 smoothly 2.0-4.5 16.5％、21.5％ Comparative Example 3 Sheet deformation 2.5-6.0 17.0％、23.5％

[0110] Note: The grain size grade required for this application is ≥2.5, tested according to the requirements of GB / T 6394.

[0111] The elongation after break of the room temperature tensile property described in this application is tested according to the requirements of GB / T 228.1.

[0112] from Figure 1-6 It can be seen from Table 1 that the sheet obtained by the high temperature alloy sheet processing method described in the present application has better uniformity of structure, and the grain size difference is smaller than that of the comparative example. At the same time, the elongation of the sheet during room temperature stretching is improved to a certain extent and is more uniform and stable.

[0113] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A method for processing a high temperature alloy sheet, characterized in that: The following steps are involved: (1) subjecting the steel ingot to be processed to homogenization heat treatment; (2) heating the steel ingot obtained in step (1), and performing rounding, elongation and roughening treatments on the steel ingot; (3) heating the steel ingot obtained in step (2) and performing forging treatment; (4) Repeating the operation of step (3) until the target size is reached, and then performing a solution heat treatment on the plate of the target size to obtain the high-temperature alloy plate; During repeated forging, in two adjacent passes, the reduction in the thickness of the steel ingot in the latter pass is 5%-15% less than the reduction in the thickness of the steel ingot in the previous pass; During the repeated forging process, in two adjacent passes, the increase in the length and width of the steel ingot in the latter pass is smaller than the increase in the length and width of the steel ingot in the previous pass.

2. The high temperature alloy sheet processing method according to claim 1, characterized in that: In step (1), the heat treatment temperature is 1150-1200° C., and the heat treatment time at this temperature is 50-70 hours; And / or, the heating rate of the heat treatment process is 45-55°C / h; And / or, the steel ingot to be processed is heat treated, cooled in the furnace, the oxide scale on the surface of the steel ingot is removed, and the last solidified end of the steel ingot is cut off; preferably, the cut length is ≥ the diameter of the steel ingot, and more preferably, the ratio of the cut length to the ingot diameter is (1-1.1):

1.

3. The high temperature alloy sheet processing method according to claim 1, characterized in that: In step (2), before heating the steel ingot obtained in step (1), an anti-oxidation coating is applied on the surface of the steel ingot; Preferably, the anti-oxidation coating comprises aluminum oxide, silicon dioxide and silicon carbide, and the mass ratio of aluminum oxide, silicon dioxide and silicon carbide in the anti-oxidation coating is (40-50): (25-30): (25-30).

4. The high temperature alloy sheet processing method according to claim 1, characterized in that: In step (2), the heating temperature is 1100-1200° C., and the heating time at this temperature is 3-4.5 hours; And / or, repeat the operation described in step (2) until the diameter of the steel ingot is ≤180 mm.

5. The high temperature alloy sheet processing method according to claim 4, characterized in that: During the rounding operation, the pressing amount of each pass during the elongation process shall not exceed 6% of the diameter of the steel ingot before pressing, and the pressing amount of each pass during the roughening process shall not exceed 9.5% of the height of the steel ingot before pressing. The pressing time of each pass shall be ≥3s; Preferably, the amount of reduction per pass during the stretching process is 4.5-5.5% of the diameter of the steel ingot before the reduction, and the amount of reduction per pass during the roughening process is 6.5-9% of the height of the steel ingot before the reduction; Preferably, during the spheronization operation, the pressing time for each pass is 4-7s.

6. The high temperature alloy sheet processing method according to claim 1, characterized in that: The heating temperature in step (3) is 1100-1200° C., and the heating time at this temperature is 2-2.5 hours.

7. The high temperature alloy sheet processing method according to claim 1, characterized in that: During the forging process, the thickness of the steel ingot after the first pass is 60%-70% of the thickness of the steel ingot before forging; and / or, the thickness of the steel ingot after the second pass is 65%-75% of the thickness of the steel ingot after the first pass; And / or, the thickness of the steel ingot after the third pass is 75%-85% of the thickness of the steel ingot after the second pass.

8. The high temperature alloy sheet processing method according to claim 1, characterized in that: During the forging process, the increase in the length of the ingot after the first pass is 1.25-1.35 times the length of the ingot before forging; and / or, during the forging process, the increase in the width of the steel ingot after the first pass is 1.25-1.35 times the width of the steel ingot before forging; and / or, during the forging process, the increase in the length of the steel ingot after the second pass is 1.15-1.25 times the length of the steel ingot before forging; and / or, during the forging process, the increase in the width of the steel ingot after the second pass is 1.15-1.25 times the width of the steel ingot before forging; and / or, during the forging process, the increase in the length of the steel ingot after the third pass is 1.05-1.15 times the length of the steel ingot before forging; And / or, during the forging process, the increase in the width of the steel ingot after the third pass is 1.05-1.15 times the width of the steel ingot before forging.

9. The high temperature alloy sheet processing method according to claim 1, characterized in that: The temperature of the solution treatment is 1100-1150°C, and the heating time at this temperature is 0.5-2.0h; Preferably, the temperature of the solution treatment is 1120-1145° C., and the heating time at this temperature is 0.7-1.5 h.

10. The high temperature alloy sheet processing method according to any one of claims 1 to 9, characterized in that: Calculated by mass percentage, the components of the high-temperature alloy plate include Cr 18.5-20.5%, Co 9.0-11.0%, Mo 8.0-9.0%, Nb0.81-1.50%, Ti 0.70-1.49%, Al 2.00-2.80%, C 0.02-0.10%, B 0.003-0.01%, Si0.001-0.15%, Mn 0.001-0.3%, and the balance is Ni and unavoidable impurity elements.

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