Preparation method of high alloy hard-to-deform high temperature alloy GH4151 disc forging

Abstract

The invention discloses a method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging, comprising the following steps: preparing a homogeneous fine-grained bar by a hot extrusion molding process; performing a γ′ phase structure coarsening heat treatment on the bar; cutting the bar into bar blocks and finishing the processing; heating the bar blocks and placing them in a blanking die on a hydraulic press to prepare an intermediate blank; transferring the intermediate blank strip to a pre-heated resistance heating furnace for hot charging annealing; heating the intermediate blank and placing it in a forging die on a hydraulic press, and preparing a disc forging by a near-isothermal forging process; performing a homogenization heat treatment on the disc forging, and finally preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging. The invention makes the preparation method safer and more reliable through strict process parameter control and process coordination, improves the uniformity of the structure and consistency of mechanical properties of the disc forging, improves the qualified rate of the disc forging, reduces the production cost, and significantly improves the economic benefit.

Description

Technical Field

[0001] The invention belongs to the technical field of advanced manufacturing of high-temperature alloys, and in particular relates to a method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging. Background Art

[0002] As we all know, deformed high-temperature alloy disc forgings are widely used in the field of aviation power. They are indispensable blanks for manufacturing turbine discs, which are key hot end components of aircraft engines. With the improvement of thrust-to-weight ratio of advanced aircraft engines, turbine disc forgings are required to have excellent manufacturing quality, which is mainly reflected in: first, the forming effect of different parts of the disc forging (such as disc edge, disc core, and web) should be good; second, different parts of the disc forging should have uniform and fine grain structure; third, the consistency of mechanical properties of different parts of the disc forging should be high.

[0003] At present, the deformed high-temperature alloys (such as GH4151) used to prepare advanced aero-engine turbine disk forgings have a high degree of alloying. The total amount of solid solution strengthening elements (such as W, Mo, Co and Cr) in this type of alloy is relatively high, and the content of precipitation strengthening elements (such as Al, Ti, Nb and Ta) is also relatively high. The content of the main strengthening phase γ′ phase of this type of alloy is usually higher than 50%. Due to the chemical composition characteristics of high alloying and the characteristics of high γ′ phase content, this type of alloy has increased resistance to hot working deformation, poor process plasticity, difficulty in hot working deformation, poor mold filling effect, and imperfect dynamic recrystallization structure of hot deformation, which increases the difficulty of forming this type of alloy disk forgings during die forging, the difficulty of obtaining homogeneous fine-grained structure, and the difficulty of coordinated control of fine-grained structure and multi-scale γ′ phase structure of disk forgings.

[0004] In addition, the deformed high-temperature alloy bars used in the preparation of disc forgings are generally made by the method of upsetting and forging. However, the upsetting and forging process is a multi-fire deformation process with a complex deformation process. It is difficult to stabilize and accurately control the process parameters, which can easily cause uneven forging structure of the bars, which also makes it difficult to control the uniformity of the structure of the disc forgings. The traditional process of upsetting and forging bars + disc forging die forging is prone to problems such as uneven structure of deformed high-temperature alloys, especially high-alloyed difficult-to-deform high-temperature alloy disc forgings, poor forming effect, obvious dispersion of mechanical properties, poor safety and reliability, and high product scrap rate. Figure 1 The microstructure of the bar prepared by the upsetting and forging process is shown in Figure 2. Figure 1 It can be seen that the structure of the rod is coarse and uneven.

[0005] The invention patent with application publication number CN114645162A discloses a method for manufacturing fine-grained homogeneous disc forgings of difficult-to-deform high-temperature alloys, first obtaining a homogenized annealed ingot, then using a fast forging machine to perform multiple-fire successive cooling and upsetting forging on the ingot to obtain a fine-grained homogeneous bar, then cutting the bar according to the required specifications of the disc forging and isothermally upsetting the bar to obtain an intermediate billet, and finally subjecting the intermediate billet to die forging and subsequent heat treatment. This technical solution uses the traditional upsetting and blanking method to prepare the bar, but the upsetting and forging process is very likely to cause uneven organization of the bar. If the organization of the original bar is uneven, it is difficult to improve the organization uniformity of the subsequent intermediate billet and disc forging.

[0006] The invention patent with application publication number CN103341586A discloses a method for forming a GH4738 nickel-based high-temperature alloy turbine disk, including the following steps: wrapping a cylindrical rod blank with a hard sleeve and performing a heat treatment; performing two-stage heating, upsetting and die forging; and heat treating the disk forging under subsolid solution conditions. This technical solution is a forming method for a GH4738 nickel-based high-temperature alloy turbine disk. If a turbine disk with uniform structure, fine grains and good forming effect is to be obtained, then certain requirements must be placed on the structure and performance of the original rod. However, this technical solution does not make any requirements or improvements on the preparation process of the original rod, but directly uses the existing rod blank, so it is difficult to obtain a turbine disk with uniform structure and good forming effect. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging, which comprises the following steps in order:

[0008] Step 1: Place the high-alloyed hard-to-deform high-temperature alloy GH4151 ingot into a high-temperature electric furnace for heating. After heating, take the ingot out of the high-temperature electric furnace and transfer it to an extrusion die on a hot extruder. Then, use a hot extrusion process to prepare the ingot into a cylindrical bar of target specifications.

[0009] Step 2: placing the hot extruded bar into a resistance heating furnace for heat treatment to coarsen the γ′ phase structure;

[0010] Step 3: Use a wire cutting machine or a sawing machine to cut the roughened heat-treated bar into bar blocks, and machine the two ends of the bar blocks to make the two end faces of the bar blocks flat and parallel, and round the edges of the two end faces of the bar blocks;

[0011] Step 4: Put the machined and finished bar block into a high-temperature electric furnace for heating. After heating, take the bar block out of the high-temperature electric furnace and transfer it to a blanking mold on a hydraulic press. Then, press the bar block into an intermediate blank of target specifications.

[0012] Step 5: Heat transfer the pressed intermediate billet strip to a pre-heated resistance heating furnace for hot charging annealing;

[0013] Step 6: Place the intermediate billet after hot charging and annealing into a high-temperature electric furnace for heating. After heating, take the intermediate billet out of the high-temperature electric furnace and transfer it to the forging die on the hydraulic press. Then, perform near-isothermal forging of the intermediate billet into a disc forging of target specifications.

[0014] Step 7: The disc forging after isothermal forging is placed in a resistance heating furnace for homogenization heat treatment, and finally a high-alloyed difficult-to-deform high-temperature alloy GH4151 disc forging is obtained.

[0015] The present invention adopts a hot extrusion forming process to prepare a homogeneous fine-grained bar used for a high-alloyed difficult-to-deform high-temperature alloy disc forging; the bar is subjected to a coarsening heat treatment to reduce the alloy's thermal deformation resistance and ensure the billet forming effect; the intermediate billet is subjected to hot charging annealing to improve the process plasticity and improve the near-isothermal forging forming conditions; the disc forging is subjected to a homogenizing heat treatment to obtain a high-quality disc forging with very high uniformity of organization and consistency of mechanical properties.

[0016] Preferably, in step one, the heating process of the ingot in the high-temperature electric furnace is: placing the ingot in the high-temperature electric furnace, heating the temperature to 950-980°C at a heating rate of 70-90°C / h, keeping it warm for 2-6h, and then continuing to heat the temperature to 1100-1130°C at a heating rate of 70-90°C / h, and keeping it warm for 6-10h; the transfer time of the ingot does not exceed 1min.

[0017] In any of the above schemes, preferably, in step 1, the hot extrusion process of the ingot is: extrusion temperature 1150-1180°C, extrusion ratio 2-10:1, extrusion rate 10-50mm / s; the diameter of the rod is 100-300mm.

[0018] In any of the above schemes, preferably, in step 2, the roughening heat treatment process of the bar is: put the bar into a resistance heating furnace, heat it to 1090-1120°C at a heating rate of 80-100°C / h, keep it warm for 4-10h, then cool it to below 100°C at a cooling rate of 10-30°C / h, and take it out of the furnace. In the present invention, after the bar is roughened by the roughening heat treatment, the γ′ phase structure can be roughened from the original 0.3-0.8μm to 3-7μm. The roughening of the bar is conducive to the subsequent forming of the disc forging, can reduce the thermal deformation resistance of the disc forging, and improve the hot process plasticity of the disc forging.

[0019] In any of the above schemes, preferably, in step four, the heating process of the rod block in the high-temperature electric furnace is: placing the rod block in the high-temperature electric furnace, heating the temperature to 930-950°C at a heating rate of 70-90°C / h, keeping it warm for 1-2h, and then continuing to heat the temperature to 1100-1160°C at a heating rate of 70-90°C / h, and keeping it warm for 6-10h; the transfer time of the rod block does not exceed 1min.

[0020] In any of the above schemes, preferably, in step five, the heating temperature of the intermediate billet after pressing is 800-900°C, the preheating temperature of the resistance heating furnace is 800-980°C, and the transfer time of the intermediate billet does not exceed 3 minutes.

[0021] In any of the above schemes, preferably, in step 5, the hot charging annealing process of the intermediate billet is: heating the resistance heating furnace equipped with the intermediate billet from 800-980°C to 1100-1140°C at a heating rate of 70-100°C / h, keeping the temperature for 2-8h, and then cooling to room temperature with the furnace. In the present invention, hot charging annealing refers to the process of placing the intermediate billet with a certain amount of heat after being pressed into a resistance heating furnace for annealing treatment, and the heating temperature of the intermediate billet should be close to the preheating temperature of the resistance heating furnace.

[0022] In any of the above schemes, it is preferred that in step six, the heating process of the intermediate billet in the high-temperature electric furnace is: placing the intermediate billet in the high-temperature electric furnace, heating the temperature to 950-980°C at a heating rate of 70-90°C / h, keeping it warm for 2-6h, and then continuing to heat the temperature to 1100-1150°C at a heating rate of 70-90°C / h, and keeping it warm for 6-10h; the transfer time of the intermediate billet does not exceed 3min.

[0023] In any of the above schemes, it is preferred that in step six, the near-isothermal forging process of the intermediate billet is: controlled by a variable rate forming method, the height of the intermediate billet is forged to 2 / 3 of the original height at a rate of 3-5mm / s, the height of the intermediate billet is continued to be forged to 1 / 2 of the original height at a rate of 1-3mm / s, the height of the intermediate billet is continued to be forged to 1 / 3 of the original height at a rate of 0.5-1mm / s, and the intermediate billet is continued to be forged into a disc forging of target specifications at a rate of 0.1-0.5mm / s, the disc forging is taken out of the forging die, and covered with aluminosilicate fiber felt for cooling; the preheating temperature of the forging die is 900-1000℃; the diameter of the disc forging is 200-700mm.

[0024] In the present invention, a variable rate forming method is used for control, and the forming rate gradually changes from fast to slow. The forming rate in the early stage is fast, which can ensure the stability of the deformation temperature. If the forming temperature is reduced, the deformation resistance will increase, and defects such as cracks are likely to occur; the forming rate in the later stage is slow, which is conducive to achieving the superplastic effect.

[0025] In any of the above schemes, preferably, in step 7, the homogenization heat treatment process of the disc forging is: placing the disc forging in a resistance heating furnace, heating it to 1040-1080°C at a heating rate of 80-100°C / h, keeping it warm for 8-16h, and then air cooling. Before the disc forging is subjected to homogenization heat treatment, the aluminosilicate fiber felt covering it needs to be removed.

[0026] The method for preparing the high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging of the present invention has the following beneficial effects:

[0027] (1) The hot extrusion blanking process is used to prepare high-alloyed difficult-to-deform high-temperature alloy rods. The material undergoes plastic deformation under a triaxial compressive stress state, which improves the process plasticity and allowable deformation degree, and is conducive to single-pass large deformation processing, so that the extruded rod has high uniformity of structure, fine grains, and a grain size of about ASTM 11. In addition, the hot extrusion blanking deformation and rod forming are completed in one fire, the deformation time is short, and the process stability is high. The prior art uses a multi-fire upsetting forging process to blank, and the prepared rod has a coarse structure, poor uniformity of structure, and a long deformation time.

[0028] (2) By subjecting the extruded rod to a γ′ phase strengthening and coarsening heat treatment, the γ′ phase is maintained to have a cohesive, coarsened, and irregular morphological distribution. This morphologically characteristic γ′ phase no longer has a coherent relationship with the matrix γ, which eliminates the coherent strain strengthening during the hot working deformation process. The alloy’s resistance to hot deformation is greatly reduced, and the process plasticity is improved, thereby ensuring the subsequent billet forming effect and the control of the microstructure uniformity during the billet making process.

[0029] (3) By hot-charging and annealing the intermediate billet, on the one hand, hot work hardening is eliminated, and on the other hand, the grain size of the γ matrix and the distribution characteristics of the γ′ phase particles of the billet are simultaneously regulated to form an appropriate organization, improve process plasticity, reduce deformation resistance, and improve the deformation conditions of subsequent near-isothermal forging, which is beneficial to improving the filling and forming effect of the disc forging during the die forging process and to forming a fine grain organization with perfect dynamic recrystallization.

[0030] (4) By performing homogenization heat treatment on the disc forging, the deformation texture caused by die forging can be eliminated, the residual stress of the disc forging can be reduced, the distribution characteristics of the γ′ phase particle structure can be regulated, the uniformity of the γ solid solution can be improved, and more uniform and favorable recrystallization conditions can be created in the entire volume of the disc forging, ensuring that different parts of the disc forging obtain uniform fine-grained structure of ASTM grade 10 and highly consistent mechanical properties.

[0031] (5) Through strict process parameter control and process coordination, the preparation method is made more reliable and safer, the uniformity of the disc forgings' organization and the consistency of mechanical properties are improved, the qualified rate of the disc forgings is improved, the production cost is reduced, and the economic benefits are significantly improved.

[0032] Special note: The technical solution of the present invention involves many parameters, and the synergistic effects between the various parameters need to be comprehensively considered to obtain the beneficial effects and significant progress of the present invention. Moreover, the value ranges of the various parameters in the technical solution are obtained after a large number of experiments. For each parameter and the combination of each parameter, the inventors have recorded a large amount of test data. Due to space limitations, the specific test data are not disclosed here. The various types of equipment used in the present invention (such as high-temperature electric furnaces, hot extruders, resistance heating furnaces and hydraulic presses, etc.) are commonly used equipment in this field, and there are no special requirements for specific models. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The microstructure of the bar prepared by the upsetting and forging blanking process in the prior art;

[0034] Figure 2 The microstructure of a rod prepared by a hot extrusion blanking process in a preferred embodiment of the method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to the present invention;

[0035] Figure 3 for Figure 2 The γ′ phase coarsened microstructure morphology obtained after the rod is subjected to a coarsening heat treatment in the embodiment shown;

[0036] Figure 4 for Figure 2 The microstructure of the disc edge after the disc forging is subjected to homogenization heat treatment in the embodiment shown;

[0037] Figure 5 for Figure 2 The microstructure of the disc core after the disc forging is subjected to homogenization heat treatment in the embodiment shown;

[0038] Figure 6 for Figure 2 The microstructure of the web portion of the disc forging after homogenization heat treatment in the illustrated embodiment. DETAILED DESCRIPTION

[0039] In order to further understand the content of the present invention, the present invention will be described in detail below in conjunction with specific embodiments.

[0040] Embodiment 1:

[0041] According to a preferred embodiment of the method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging of the present invention, the method comprises the following steps in chronological order:

[0042] Step 1: Place the high-alloyed hard-to-deform high-temperature alloy GH4151 ingot into a high-temperature electric furnace for heating. After heating, take the ingot out of the high-temperature electric furnace and transfer it to an extrusion die on a hot extruder. Then, use a hot extrusion process to prepare the ingot into a cylindrical bar of target specifications.

[0043] Step 2: placing the hot extruded bar into a resistance heating furnace for heat treatment to coarsen the γ′ phase structure;

[0044] Step 3: Use a wire cutting machine or a sawing machine to cut the roughened heat-treated bar into bar blocks, and machine the two ends of the bar blocks to make the two end faces of the bar blocks flat and parallel, and round the edges of the two end faces of the bar blocks;

[0045] Step 4: Put the machined and finished bar block into a high-temperature electric furnace for heating. After heating, take the bar block out of the high-temperature electric furnace and transfer it to a blanking mold on a hydraulic press. Then, press the bar block into an intermediate blank of target specifications.

[0046] Step 5: Heat transfer the pressed intermediate billet strip to a pre-heated resistance heating furnace for hot charging annealing;

[0047] Step 6: Place the intermediate billet after hot charging and annealing into a high-temperature electric furnace for heating. After heating, take the intermediate billet out of the high-temperature electric furnace and transfer it to the forging die on the hydraulic press. Then, perform near-isothermal forging of the intermediate billet into a disc forging of target specifications.

[0048] Step 7: The disc forging after isothermal forging is placed in a resistance heating furnace for homogenization heat treatment, and finally a high-alloyed difficult-to-deform high-temperature alloy GH4151 disc forging is obtained.

[0049] In step one, the heating process of the ingot in the high-temperature electric furnace is as follows: placing the ingot in the high-temperature electric furnace, heating it to 965°C at a heating rate of 80°C / h, keeping it warm for 4 hours, and then continuing to heat it to 1120°C at a heating rate of 80°C / h, keeping it warm for 8 hours; the transfer time of the ingot does not exceed 1 minute.

[0050] In step 1, the hot extrusion process of the ingot is: extrusion temperature 1165°C, extrusion ratio 6:1, extrusion rate 30mm / s; the diameter of the rod is 200mm. Figure 2 As shown in the figure, the rods prepared by hot extrusion blanking process have good uniformity of structure and fine grains, which is beneficial to improve the forming effect, uniformity of structure and consistency of mechanical properties of subsequent disc forgings.

[0051] In step 2, the roughening heat treatment process of the rod is as follows: put the rod into a resistance heating furnace, heat it to 1110°C at a heating rate of 90°C / h, keep it at that temperature for 7 hours, then cool it to below 100°C at a cooling rate of 20°C / h, and take it out of the furnace. In this embodiment, after the roughening heat treatment of the rod, the γ′ phase structure can be roughened from the original 0.3-0.8μm to 3-7μm. Figure 3 As shown in the figure, the γ′ phase coarsening structure obtained after the rod is subjected to coarsening heat treatment presents condensed, coarsened and irregular morphological distribution characteristics, which makes the coherent strain strengthening in the hot working deformation process disappear, greatly reduces the alloy's hot deformation resistance, and improves the process plasticity.

[0052] In step 4, the heating process of the rod block in the high-temperature electric furnace is as follows: place the rod block in the high-temperature electric furnace, heat it to 940°C at a heating rate of 80°C / h, keep it warm for 1.5 hours, and then continue to heat it to 1130°C at a heating rate of 80°C / h, and keep it warm for 8 hours; the transfer time of the rod block does not exceed 1 minute.

[0053] In step five, the heating temperature of the intermediate billet after pressing is 850° C., the preheating temperature of the resistance heating furnace is 900° C., and the transfer time of the intermediate billet does not exceed 3 minutes.

[0054] In step 5, the hot charging annealing process of the intermediate billet is as follows: the resistance heating furnace equipped with the intermediate billet is heated from 900°C to 1120°C at a heating rate of 85°C / h, kept at this temperature for 5 hours, and then cooled to room temperature with the furnace. In this embodiment, hot charging annealing refers to the process of placing the intermediate billet with a certain amount of heat after being pressed into the resistance heating furnace for annealing, and the heating temperature of the intermediate billet should be close to the preheating temperature of the resistance heating furnace.

[0055] In step six, the heating process of the intermediate billet in the high-temperature electric furnace is as follows: place the intermediate billet in the high-temperature electric furnace, heat it to 965°C at a heating rate of 80°C / h, keep it warm for 4 hours, then continue to heat it to 1125°C at a heating rate of 80°C / h, and keep it warm for 8 hours; the transfer time of the intermediate billet does not exceed 3 minutes.

[0056] In step 6, the near-isothermal forging process of the intermediate billet is as follows: the intermediate billet is forged to 2 / 3 of the original height at a rate of 4 mm / s, the intermediate billet is forged to 1 / 2 of the original height at a rate of 2 mm / s, the intermediate billet is forged to 1 / 3 of the original height at a rate of 0.8 mm / s, the intermediate billet is forged to a disc forging of target specifications at a rate of 0.3 mm / s, the disc forging is taken out of the forging die, and covered with aluminosilicate fiber felt for cooling; the preheating temperature of the forging die is 950°C; the diameter of the disc forging is 500 mm. In this embodiment, the variable rate forming method is used for control, and the forming rate gradually decreases from fast to slow.

[0057] In step 7, the homogenization heat treatment process of the disc forging is as follows: put the disc forging into a resistance heating furnace, heat it to 1060°C at a heating rate of 90°C / h, keep it at that temperature for 12 hours, and then air cool it. Before the disc forging is subjected to homogenization heat treatment, the aluminosilicate fiber felt covering it needs to be removed. Figure 4-6 As shown, after the disc forging is subjected to homogenization heat treatment, the structures of the disc edge, disc core and web of the disc forging are very uniform, the grains are fine, and the grain sizes of the three parts are very consistent.

[0058] The method for preparing the high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging of this embodiment has the following beneficial effects:

[0059] (1) The hot extrusion blanking process is used to prepare the rods. The material undergoes plastic deformation under the triaxial compressive stress state, which improves the process plasticity and allowable deformation degree, and is conducive to single-pass large deformation processing, so that the extruded rods have high uniformity of organization, refined grains, and grain size of about ASTM 11. In addition, the hot extrusion blanking deformation and rod forming are completed in one fire, the deformation time is short, and the process stability is high. (2) By subjecting the extruded rods to a γ′ phase strengthening phase coarsening heat treatment, the γ′ phase is maintained to be condensed, coarsened, and irregular in shape and distribution. The γ′ phase with this morphological characteristic no longer has a coherent relationship with the matrix γ, so that the coherent strain strengthening in the hot working deformation process disappears, the alloy's hot deformation resistance is greatly reduced, and the process plasticity is improved, ensuring the subsequent blanking forming effect and the control of microstructure uniformity during the blanking process. (3) By hot-charging and annealing the intermediate billet, the hot work hardening is eliminated, the grain size of the γ matrix and the distribution characteristics of the γ′ phase particles of the billet are regulated at the same time, and an appropriate organization is formed, which improves the process plasticity, reduces the deformation resistance, improves the deformation conditions of the subsequent near-isothermal forging, and is conducive to improving the filling and forming effect of the disc forging during the die forging process, and is conducive to forming a fine grain organization with perfect dynamic recrystallization. (4) By homogenizing the disc forging, the deformation texture caused by die forging deformation can be eliminated, the residual stress of the disc forging can be reduced, the distribution characteristics of the γ′ phase particle organization can be regulated, the uniformity of the γ solid solution can be improved, and a more uniform and more favorable recrystallization condition can be created in the entire volume of the disc forging, ensuring that different parts of the disc forging obtain ASTM10 grade uniform fine grain organization and highly consistent mechanical properties. (5) Through strict process parameter control and process coordination, the organization uniformity and mechanical property consistency of the disc forging are improved, the qualified rate of the disc forging is improved, the production cost is reduced, and the economic benefits are significantly improved.

[0060] Embodiment 2:

[0061] According to another preferred embodiment of the method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging of the present invention, the preparation process, equipment, principle and beneficial effects used are basically the same as those of the first embodiment, except that:

[0062] In step one, the heating process of the ingot in the high-temperature electric furnace is as follows: placing the ingot in the high-temperature electric furnace, heating the temperature to 950°C at a heating rate of 70°C / h, keeping the temperature for 6 hours, and then continuing to heat the temperature to 1100°C at a heating rate of 70°C / h, and keeping the temperature for 10 hours; the transfer time of the ingot does not exceed 1 minute.

[0063] In step 1, the hot extrusion process of the ingot is: extrusion temperature 1150° C., extrusion ratio 2:1, extrusion rate 50 mm / s; the diameter of the rod is 100 mm.

[0064] In step 2, the roughening heat treatment process of the rod is as follows: the rod is placed in a resistance heating furnace, heated to 1090°C at a heating rate of 80°C / h, kept at this temperature for 10 hours, then cooled to below 100°C at a cooling rate of 10°C / h, and taken out of the furnace. In this embodiment, after the roughening heat treatment of the rod, the γ′ phase structure can be roughened from the original 0.3-0.8μm to 3-7μm.

[0065] In step 4, the heating process of the rod block in the high-temperature electric furnace is as follows: place the rod block in the high-temperature electric furnace, heat it to 930°C at a heating rate of 70°C / h, keep it warm for 2 hours, and then continue to heat it to 1100°C at a heating rate of 70°C / h, and keep it warm for 10 hours; the transfer time of the rod block does not exceed 1 minute.

[0066] In step five, the heating temperature of the intermediate billet after pressing is 800° C., the preheating temperature of the resistance heating furnace is 800° C., and the transfer time of the intermediate billet does not exceed 3 minutes.

[0067] In step five, the hot charging annealing process of the intermediate billet is as follows: heating the resistance heating furnace equipped with the intermediate billet from 800° C. to 1100° C. at a heating rate of 70° C. / h, keeping the temperature for 8 hours, and then cooling to room temperature along with the furnace.

[0068] In step six, the heating process of the intermediate billet in the high-temperature electric furnace is as follows: place the intermediate billet in the high-temperature electric furnace, heat it to 950°C at a heating rate of 70°C / h, keep it warm for 6 hours, then continue to heat it to 1100°C at a heating rate of 70°C / h, and keep it warm for 10 hours; the transfer time of the intermediate billet does not exceed 3 minutes.

[0069] In step six, the near-isothermal forging process of the intermediate billet is as follows: a variable rate forming method is used for control, the height of the intermediate billet is forged to 2 / 3 of the original height at a rate of 3 mm / s, the height of the intermediate billet is continued to be forged to 1 / 2 of the original height at a rate of 1 mm / s, the height of the intermediate billet is continued to be forged to 1 / 3 of the original height at a rate of 0.5 mm / s, and the intermediate billet is continued to be forged into a disc forging of target specifications at a rate of 0.1 mm / s, the disc forging is taken out of the forging die, and covered with aluminosilicate fiber felt for cooling; the preheating temperature of the forging die is 900°C; the diameter of the disc forging is 200 mm.

[0070] In step 7, the homogenization heat treatment process of the disc forging is as follows: the disc forging is placed in a resistance heating furnace, heated to 1040°C at a heating rate of 80°C / h, kept at this temperature for 8h, and then air-cooled. Before the disc forging is subjected to homogenization heat treatment, the aluminosilicate fiber felt covering it needs to be removed.

[0071] Embodiment three:

[0072] According to another preferred embodiment of the method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging of the present invention, the preparation process, equipment, principle and beneficial effects used are basically the same as those of the first embodiment, except that:

[0073] In step one, the heating process of the ingot in the high-temperature electric furnace is as follows: placing the ingot in the high-temperature electric furnace, heating it to 980°C at a heating rate of 90°C / h, keeping it warm for 2 hours, and then continuing to heat it to 1130°C at a heating rate of 90°C / h, keeping it warm for 6 hours; the transfer time of the ingot does not exceed 1 minute.

[0074] In step 1, the hot extrusion process of the ingot is: extrusion temperature 1180° C., extrusion ratio 10:1, extrusion rate 10 mm / s; the diameter of the rod is 300 mm.

[0075] In step 2, the roughening heat treatment process of the rod is as follows: the rod is placed in a resistance heating furnace, heated to 1120°C at a heating rate of 100°C / h, kept at this temperature for 4 hours, then cooled to below 100°C at a cooling rate of 30°C / h, and taken out of the furnace. In this embodiment, after the roughening heat treatment of the rod, the γ′ phase structure can be roughened from the original 0.3-0.8μm to 3-7μm.

[0076] In step 4, the heating process of the rod block in the high-temperature electric furnace is as follows: place the rod block in the high-temperature electric furnace, heat it to 950°C at a heating rate of 90°C / h, keep it warm for 1 hour, and then continue to heat it to 1160°C at a heating rate of 90°C / h, and keep it warm for 6 hours; the transfer time of the rod block does not exceed 1 minute.

[0077] In step five, the heating temperature of the intermediate billet after pressing is 900° C., the preheating temperature of the resistance heating furnace is 980° C., and the transfer time of the intermediate billet does not exceed 3 minutes.

[0078] In step five, the hot charging annealing process of the intermediate billet is as follows: the resistance heating furnace equipped with the intermediate billet is heated from 980° C. to 1140° C. at a heating rate of 100° C. / h, kept at this temperature for 2 hours, and then cooled to room temperature along with the furnace.

[0079] In step six, the heating process of the intermediate billet in the high-temperature electric furnace is as follows: place the intermediate billet in the high-temperature electric furnace, heat it to 980°C at a heating rate of 90°C / h, keep it warm for 2 hours, and then continue to heat it to 1150°C at a heating rate of 90°C / h, and keep it warm for 6 hours; the transfer time of the intermediate billet does not exceed 3 minutes.

[0080] In step six, the near-isothermal forging process of the intermediate billet is as follows: a variable rate forming method is used for control, the height of the intermediate billet is forged to 2 / 3 of the original height at a rate of 5 mm / s, the height of the intermediate billet is continued to be forged to 1 / 2 of the original height at a rate of 3 mm / s, the height of the intermediate billet is continued to be forged to 1 / 3 of the original height at a rate of 1 mm / s, and the intermediate billet is continued to be forged into a disc forging of target specifications at a rate of 0.5 mm / s, the disc forging is taken out of the forging die, and covered with aluminosilicate fiber felt for cooling; the preheating temperature of the forging die is 1000°C; the diameter of the disc forging is 700 mm.

[0081] In step 7, the homogenization heat treatment process of the disc forging is as follows: the disc forging is placed in a resistance heating furnace, heated to 1080°C at a heating rate of 100°C / h, kept at this temperature for 16 hours, and then air-cooled. Before the disc forging is subjected to homogenization heat treatment, the aluminosilicate fiber felt covering it needs to be removed.

[0082] The mechanical properties of the above three groups of embodiments were tested using the same testing equipment and testing environment, and the test results are shown in Table 1 and Table 2. From the test data in Table 1 and Table 2, it can be seen that the mechanical properties of different parts of the same disc forging are highly consistent.

[0083] Table 1 Tensile properties of different parts of high alloyed hard-to-deform high temperature alloy GH4151 disc forging (at room temperature)

[0084]

[0085] Table 2 Tensile properties of different parts of high alloyed hard-to-deform high temperature alloy GH4151 disc forgings (750℃)

[0086]

[0087] It is not difficult for those skilled in the art to understand that the method for preparing the high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging of the present invention includes any combination of the invention content and specific implementation methods of the above-mentioned invention specification and the various parts shown in the drawings. Due to the limited space and to make the specification concise, the various schemes composed of these combinations are not described one by one. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging, comprising the following steps in order: Step 1: Place the high-alloyed hard-to-deform high-temperature alloy GH4151 ingot into a high-temperature electric furnace for heating. After heating, take the ingot out of the high-temperature electric furnace and transfer it to an extrusion die on a hot extruder. Then, use a hot extrusion process to prepare the ingot into a cylindrical bar of target specifications. Step 2: placing the hot extruded bar into a resistance heating furnace for heat treatment to coarsen the γ′ phase structure; Step 3: Use a wire cutting machine or a sawing machine to cut the roughened heat-treated bar into bar blocks, and machine the two ends of the bar blocks to make the two end faces of the bar blocks flat and parallel, and round the edges of the two end faces of the bar blocks; Step 4: Put the machined and finished bar block into a high-temperature electric furnace for heating. After heating, take the bar block out of the high-temperature electric furnace and transfer it to a blanking mold on a hydraulic press. Then, press the bar block into an intermediate blank of target specifications. Step 5: Heat transfer the pressed intermediate billet strip to a pre-heated resistance heating furnace for hot charging annealing; Step 6: Place the intermediate billet after hot charging and annealing into a high-temperature electric furnace for heating. After heating, take the intermediate billet out of the high-temperature electric furnace and transfer it to the forging die on the hydraulic press. Then, perform near-isothermal forging of the intermediate billet into a disc forging of target specifications. Step 7: The disc forging after isothermal forging is placed in a resistance heating furnace for homogenization heat treatment, and finally a high-alloyed difficult-to-deform high-temperature alloy GH4151 disc forging is obtained.

2. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 1, characterized in that: In step one, the heating process of the ingot in the high-temperature electric furnace is to place the ingot in the high-temperature electric furnace, heat it to 950-980°C at a heating rate of 70-90°C / h, keep it warm for 2-6h, and then continue to heat it to 1100-1130°C at a heating rate of 70-90°C / h, and keep it warm for 6-10h; the transfer time of the ingot does not exceed 1min.

3. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 2, characterized in that: In step 1, the hot extrusion process of the ingot is as follows: extrusion temperature 1150-1180°C, extrusion ratio 2-10:1, extrusion rate 10-50mm / s; the diameter of the rod is 100-300mm.

4. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 1, characterized in that: In step 2, the roughening heat treatment process of the rod is to put the rod into a resistance heating furnace, heat it to 1090-1120°C at a heating rate of 80-100°C / h, keep it warm for 4-10h, then cool it to below 100°C at a cooling rate of 10-30°C / h, and take it out of the furnace.

5. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 1, characterized in that: In step 4, the heating process of the rod block in the high-temperature electric furnace is to place the rod block in the high-temperature electric furnace, heat it to 930-950°C at a heating rate of 70-90°C / h, keep it warm for 1-2h, and then continue to heat it to 1100-1160°C at a heating rate of 70-90°C / h, and keep it warm for 6-10h; the transfer time of the rod block does not exceed 1min.

6. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 1, characterized in that: In step five, the heating temperature of the intermediate billet after pressing is 800-900° C., the preheating temperature of the resistance heating furnace is 800-980° C., and the transfer time of the intermediate billet does not exceed 3 minutes.

7. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 6, characterized in that: In step five, the hot charging annealing process of the intermediate billet is to heat the resistance heating furnace equipped with the intermediate billet from 800-980°C to 1100-1140°C at a heating rate of 70-100°C / h, keep the temperature for 2-8h, and then cool it to room temperature with the furnace.

8. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 1, characterized in that: In step six, the heating process of the intermediate billet in the high-temperature electric furnace is to place the intermediate billet in the high-temperature electric furnace, heat it to 950-980°C at a heating rate of 70-90°C / h, keep it warm for 2-6h, and then continue to heat it to 1100-1150°C at a heating rate of 70-90°C / h, and keep it warm for 6-10h; the transfer time of the intermediate billet does not exceed 3min.

9. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 8, characterized in that: In step six, the near-isothermal forging process of the intermediate billet is controlled by a variable rate forming method, the height of the intermediate billet is forged to 2 / 3 of the original height at a rate of 3-5mm / s, the height of the intermediate billet is continued to be forged to 1 / 2 of the original height at a rate of 1-3mm / s, the height of the intermediate billet is continued to be forged to 1 / 3 of the original height at a rate of 0.5-1mm / s, and the intermediate billet is continued to be forged into a disc forging of target specifications at a rate of 0.1-0.5mm / s, the disc forging is taken out of the forging die, and covered with aluminosilicate fiber felt for cooling; the preheating temperature of the forging die is 900-1000℃; the diameter of the disc forging is 200-700mm.

10. The method for preparing a high-alloyed hard-to-deform high-temperature alloy GH4151 disc forging according to claim 1, characterized in that: In step seven, the homogenization heat treatment process of the disc forging is to place the disc forging in a resistance heating furnace, heat it to 1040-1080° C. at a heating rate of 80-100° C. / h, keep it at that temperature for 8-16 hours, and then air cool it.

Images