Production process of iron-nickel-based alloy

Abstract

The invention relates to the technical field of alloy production, and discloses a production process of an iron-nickel-based alloy, which comprises the following steps of: 1, preparing the following raw materials in percentage by mass: 30 to 40 percent of nickel, 45 to 55 percent of iron, 10 to 15 percent of chromium, 3 to 5 percent of molybdenum, 1 to 3 percent of tungsten, 0.5 to 1.5 percent of aluminum, 0.2 to 0.8 percent of titanium, 0.1 to 0.5 percent of niobium, 0.05 to 0.15 percent of carbon, 0.1 to 0.5 percent of silicon, 0.2 to 0.8 percent of manganese, 0.01 to 0.03 percent of phosphorus, 0.01 to 0.03 percent of sulfur and the balance of inevitable impurities; 2, smelting, wherein the prepared raw materials are put into a vacuum induction smelting furnace to be smelted; the precision of mixed molten steel is ensured by smelting materials again after the materials are smelted, a mold used later is also heated, a formed alloy ingot is heated again to be subjected to multi-heating-number forging to prepare a forging stock only by waiting for solidification without waiting for continuous reduction of the temperature, and the alloy ingot is repeatedly lengthened and compressed; and the situation that grains cannot be kept uniform due to large temperature difference between the molten steel temperature and the mold is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of alloy production, in particular to a production process of an iron-nickel based alloy. Background Art

[0002] Iron-nickel-based alloys are mainly alloys composed of iron and nickel. This alloy is generally used in high-temperature and corrosion-resistant applications. For example, in aerospace and electronic equipment, iron-nickel-based alloys are widely used due to their good performance in harsh environments such as high temperatures.

[0003] In the current production of iron-nickel-based alloys, when the mixed steel liquid is cast into alloy ingots, the temperature difference causes the grains to be unable to remain uniform, and the forging blank will deform and crack during the subsequent heat treatment preparation. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a production process for an iron-nickel based alloy, which solves the problem that the grains cannot be kept uniform and the forging blanks may deform and crack.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: A production process of an iron-nickel based alloy comprises the following steps:

[0006] Step 1: Prepare raw materials according to mass percentage:

[0007] Nickel 30% to 40%, iron 45% to 55%, chromium 10% to 15%, molybdenum 3% to 5%, tungsten 1% to 3%, aluminum 0.5% to 1.5%, titanium 0.2% to 0.8%, niobium 0.1% to 0.5%, carbon 0.05% to 0.15%, silicon 0.1% to 0.5%, manganese 0.2% to 0.8%, phosphorus 0.01% to 0.03%, sulfur 0.01% to 0.03%, and the balance is unavoidable impurities;

[0008] Step 2: Melting:

[0009] Put the prepared raw materials into a vacuum induction melting furnace for melting at a temperature of 1500°C to 1600°C for 2 to 3 hours. After the raw materials are completely melted, they are refined at a temperature of 1600°C to 1700°C for 1 to 2 hours.

[0010] Step 3: Pouring:

[0011] The refined alloy liquid is poured into a mold preheated to 200°C to 300°C to obtain an alloy ingot;

[0012] Step 4: Hot forging:

[0013] The alloy ingot is further heated to 1100° C. to 1200° C. and subjected to multi-fire forging to prepare a forging blank;

[0014] Step 5: Heat treatment:

[0015] The hot-worked alloy is subjected to a solution treatment at a temperature of 1000°C to 1100°C for 1 to 2 hours, followed by water cooling, and then an aging treatment at a temperature of 600°C to 700°C for 4 to 6 hours, followed by air cooling;

[0016] In the step 4, preparing the forging blank by multi-fire forging includes the following specific steps:

[0017] Step 1: Preliminary upsetting and drawing:

[0018] Firstly, the billet is heated to 1160-1180°C and the alloy ingot is processed by upsetting process to reduce the height of the billet, increase the cross-sectional area, and the deformation degree is 20%-30%. After the temperature is maintained at 1160-1180°C, the billet is stretched by stretching process to increase the length and reduce the cross-sectional area, and the deformation degree is 25%-35%.

[0019] Step 2: Secondary upsetting and drawing:

[0020] The billet heating temperature is adjusted to 1130-1150°C, and the upsetting operation is performed again, with a deformation degree of 15%-25%. Then, the heating temperature is set at 1090-1120°C, and the drawing process is continued to further elongate the billet, with a deformation degree of 20%-30%.

[0021] Step 3: Three times upsetting and drawing:

[0022] Finally, the billet heating temperature is controlled at 1060-1090°C, and upsetting treatment is performed with a deformation degree of 10%-20%. The billet is compressed again, and finally the billet is heated to 1030-1060°C and stretched to a size and shape close to the final forging billet with a deformation degree of 15%-25%.

[0023] Preferably, the smelting temperature is 1550°C, the smelting time is 2.5 hours, the refining temperature is 1650°C, and the refining time is 1.5 hours.

[0024] Preferably, during the hot working forging process, after each forging is completed, the forging blank needs to be returned to the furnace for heat preservation, and the heat preservation temperature is 800° C. to 900° C., and the heat preservation time is 0.5 to 1 hour.

[0025] Preferably, the alloy is subjected to an intermediate annealing treatment between the solution treatment and the aging treatment, with the annealing temperature being 800°C to 900°C and the holding time being 1 to 2 hours, followed by furnace cooling to below 500°C and air cooling.

[0026] Preferably, in step five, the water temperature during solution treatment is not higher than 40°C, and the cooling rate during air cooling during aging treatment is not lower than 10°C / min.

[0027] Preferably, during the hot working forging process in step 4, the surface of the forging blank should be cleaned before each forging to remove oxide scale and impurities.

[0028] Preferably, in the solid solution treatment of step 5, the alloy should be completely immersed in cooling water, and proper stirring should be maintained during the water cooling process.

[0029] Preferably, in step five, during the aging treatment, the alloy is placed in a well-ventilated environment, and during the aging treatment, the alloy is turned over every 20 to 30 minutes to ensure the uniformity of the aging treatment.

[0030] Preferably, the mold comprises a lower mold and an upper mold, the lower mold and the upper mold are both provided with corresponding molding grooves, the top of the upper mold is provided with a material injection groove, and the lower mold and the upper mold are provided with a rapid cooling mechanism;

[0031] The rapid cooling mechanism includes a cooling pipe, a connecting pipe, a water pump, a heat conduction plate and a heat conduction member. A liquid storage tank is provided inside the lower mold. The water pump is fixedly installed inside the lower mold. The input end of the water pump is connected to the liquid storage tank. The cooling pipe is spirally installed inside the lower mold and the upper mold. A connecting pipe is fixedly installed inside the cooling pipe inside the upper mold. The output end of the water pump is connected to one end of the cooling pipe, and the other end of the cooling pipe is connected to the liquid storage tank. The cooling pipes inside the lower mold and the upper mold are connected by a connecting pipe. The heat conduction plate is fixedly installed at one end of the heat conduction member. The other end is located at one side of the forming groove; a filling pipe is fixedly installed inside the lower mold, the filling pipe is connected with the liquid storage tank, a drainage groove is provided at one end of the liquid storage tank, and a plugging piece is fixedly connected inside the drainage groove; a guide rail is fixedly installed on the top of the lower mold, the upper mold is slidably connected to the side wall of the guide rail, and a hydraulic rod is fixedly installed on the top of the upper mold; a heat dissipation groove is provided on one side of the lower mold, and a heat dissipation fin is fixedly installed inside the heat dissipation groove, one end of the heat dissipation fin is located inside the liquid storage tank, and a plurality of flow holes are provided inside the heat dissipation fin; a material delivery hole connected to the forming groove is provided inside the injection groove

[0032] The present invention provides a production process of an iron-nickel based alloy. It has the following beneficial effects:

[0033] 1. The present invention ensures the accuracy of the mixed molten steel by melting the material again after melting it. The mold used is then heated up. It only needs to wait for solidification without waiting for the temperature to continue to drop. The formed alloy ingot is heated again to perform multi-fire forging to prepare a forging blank, so that the alloy ingot is repeatedly stretched and compressed to avoid the inability to maintain uniform grains due to the large temperature difference between the molten steel and the mold.

[0034] 2. The present invention adopts multi-fire forging to prepare the forging blank. After the uneven grains are dispersed, the ingot is stretched and compressed during hammering, and the temperature, deformation amount and deformation rate during the forging process are accurately controlled, thereby reducing the cracking tendency and no obvious cracking occurs during the preparation process.

[0035] 3. The corrosion rate of the present invention in 5% NaCl solution is 0.05 mm / a, the corrosion rate in 5% NaCl solution is 0.06 mm / a, and the corrosion rate in 5% NaCl solution is 0.04 mm / a. These specific corrosion rate data indicate that the iron-nickel-based alloy has a low corrosion rate, thereby reflecting high corrosion resistance.

[0036] 4. The alloy casting mold of the present invention adopts a rapid cooling mechanism. By setting a filling trough, it can be used for filling. By setting a feeding hole, the material inside the filling trough can flow into the molding trough. By setting a water pump, the liquid inside the liquid storage tank can be transported to the cooling pipe. When the liquid circulates inside the cooling pipe, the alloy rod inside the molding trough can be quickly cooled and formed through the heat conduction plate and the heat conduction part, thereby greatly increasing the production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention is a flow chart of a production process of an iron-nickel based alloy.

[0038] Figure 2 It is a schematic diagram of the mold structure of the present invention.

[0039] Figure 3 It is a schematic diagram of the cross-sectional structure of the mold of the present invention.

[0040] Figure 4 It is a schematic diagram of the partial cross-sectional structure of the connection between the upper mold and the lower mold of the mold of the present invention.

[0041] Figure 5 It is a schematic diagram of the structure of the heat dissipation slot of the mold of the present invention. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example:

[0044] Please see attached Figure 1 The embodiment of the present invention provides a production process of an iron-nickel-based alloy, comprising the following steps:

[0045] Step 1: Prepare raw materials according to mass percentage:

[0046] Nickel 30% to 40%, iron 45% to 55%, chromium 10% to 15%, molybdenum 3% to 5%, tungsten 1% to 3%, aluminum 0.5% to 1.5%, titanium 0.2% to 0.8%, niobium 0.1% to 0.5%, carbon 0.05% to 0.15%, silicon 0.1% to 0.5%, manganese 0.2% to 0.8%, phosphorus 0.01% to 0.03%, sulfur 0.01% to 0.03%, and the balance is unavoidable impurities;

[0047] Step 2: Melting:

[0048] Put the prepared raw materials into a vacuum induction melting furnace for melting at a temperature of 1500°C to 1600°C for 2 to 3 hours. After the raw materials are completely melted, they are refined at a temperature of 1600°C to 1700°C for 1 to 2 hours.

[0049] Step 3: Pouring:

[0050] The refined alloy liquid is poured into a mold preheated to 200°C to 300°C to obtain an alloy ingot;

[0051] Step 4: Hot forging:

[0052] The alloy ingot is further heated to 1100° C. to 1200° C. and subjected to multi-fire forging to prepare a forging blank;

[0053] Step 5: Heat treatment:

[0054] The hot-worked alloy is solution treated at a temperature of 1000°C to 1100°C for 1 to 2 hours, then water cooled, and then aging treated at a temperature of 600°C to 700°C for 4 to 6 hours, followed by air cooling.

[0055] The melting temperature is 1550°C, the melting time is 2.5 hours, the refining temperature is 1650°C, and the refining time is 1.5 hours.

[0056] During the hot forging process, after each forging is completed, the forging billet needs to be returned to the furnace for insulation at a temperature of 800°C to 900°C for a time of 0.5 to 1 hour.

[0057] The alloy is also subjected to an intermediate annealing treatment between the solution treatment and the aging treatment. The annealing temperature is 800℃~900℃, the holding time is 1~2 hours, and then the alloy is furnace cooled to below 500℃ and air cooled.

[0058] In step 4, the preparation of the forging blank by multi-fire forging includes the following specific steps:

[0059] Step 1: Preliminary upsetting and drawing:

[0060] Firstly, the billet is heated to 1160-1180°C and the alloy ingot is processed by upsetting process to reduce the height of the billet, increase the cross-sectional area, and the deformation degree is 20%-30%. After the temperature is maintained at 1160-1180°C, the billet is stretched by stretching process to increase the length and reduce the cross-sectional area, and the deformation degree is 25%-35%.

[0061] Step 2: Secondary upsetting and drawing:

[0062] The billet heating temperature is adjusted to 1130-1150°C, and the upsetting operation is performed again, with a deformation degree of 15%-25%. Then, the heating temperature is set at 1090-1120°C, and the drawing process is continued to further elongate the billet, with a deformation degree of 20%-30%.

[0063] Step 3: Three times upsetting and drawing:

[0064] Finally, the billet heating temperature is controlled at 1060-1090°C, and upsetting treatment is performed with a deformation degree of 10%-20%. The billet is compressed again, and finally the billet is heated to 1030-1060°C and stretched to a size and shape close to the final forging billet with a deformation degree of 15%-25%.

[0065] In step 5, the water temperature during solution treatment is not higher than 40°C, and the cooling rate during air cooling during aging treatment is not lower than 10°C / min.

[0066] Step 4: During the hot forging process, the surface of the forging blank should be cleaned before each forging to remove oxide scale and impurities.

[0067] In step 5, during the solution treatment, the alloy should be completely immersed in cooling water, and proper stirring should be maintained during the water cooling process.

[0068] In step five, during the aging treatment, the alloy is placed in a well-ventilated environment, and during the aging treatment, the alloy is turned over every 20 to 30 minutes to ensure the uniformity of the aging treatment.

[0069] like Figure 2-5 As shown, the mold in the pouring step includes a lower mold 1 and an upper mold 2, the lower mold 1 and the upper mold 2 are both provided with corresponding molding grooves 12, the upper mold 2 is provided with a material injection groove 5 on the top, and the material injection groove 5 is provided with a material feeding hole 6 connected to the molding groove 12, the lower mold 1 is fixedly installed with a guide rail 3 on the top, the upper mold 2 is slidably connected to the side wall of the guide rail 3, the upper mold 2 is fixedly installed with a hydraulic rod 4 on the top, and the lower mold 1 and the upper mold 2 are provided with a rapid cooling mechanism;

[0070] The rapid cooling mechanism includes a cooling pipe 11, a connecting pipe 16, a water pump 10, a heat conducting plate 17 and a heat conducting member 18. A liquid storage tank 9 is opened inside the lower mold 1, and the water pump 10 is fixedly installed inside the lower mold 1. The input end of the water pump 10 is connected to the liquid storage tank 9. The cooling pipe 11 is spirally installed inside the lower mold 1 and the upper mold 2. A connecting pipe 16 is fixedly installed inside the cooling pipe 11 inside the upper mold 2. The output end of the water pump 10 is connected to one end of the cooling pipe 11, and the other end of the cooling pipe 11 is connected to the liquid storage tank 9.

[0071] It should be noted that by setting the guide rail 3, the moving direction of the upper mold 2 can be limited to prevent the upper mold 2 from tilting. By setting the hydraulic rod 4, the upper mold 2 can be driven to move so that the upper mold 2 and the lower mold 1 can be closed. By setting the injection groove 5, it can be used for injection. By setting the feed hole 6, the material inside the injection groove 5 can flow into the molding groove 12. By setting the water pump 10, the liquid inside the liquid storage tank 9 can be transported to the cooling pipe 11. When the liquid circulates inside the cooling pipe 11, the alloy rod inside the molding groove 12 can be quickly cooled and formed through the heat conduction plate 17 and the heat conduction member 18, thereby greatly increasing the production efficiency.

[0072] In some embodiments, Figure 3 As shown, the cooling tubes 11 inside the lower mold 1 and the upper mold 2 are connected by a connecting tube 16, the heat conductor 18 is fixedly installed on the inner wall of the cooling tube 11, the heat conducting plate 17 is fixedly installed at one end of the heat conducting member 18, and the other end of the heat conducting plate 17 is located on one side of the molding groove 12.

[0073] It should be noted that by providing a connecting pipe 16, the cooling pipe 11 in the upper mold 2 and the lower mold 1 can be connected through the connecting pipe 16 after the upper mold 2 and the lower mold 1 are closed, and by providing a heat conducting plate 17 and a heat conducting member 18, the heat inside the molding groove 12 can be introduced into the cooling pipe 11.

[0074] In some embodiments, Figure 2 As shown, a filling pipe 13 is fixedly installed inside the lower mold 1, and the filling pipe 13 is connected to the liquid storage tank 9. A drainage groove 14 is opened at one end of the liquid storage tank 9, and a sealing member 15 is fixedly clamped inside the drainage groove 14.

[0075] It should be noted that by providing a filling pipe 13, coolant or cooling water can be added to the liquid storage tank 9, by providing a drain tank 14, the liquid inside the liquid storage tank 9 can be easily replaced, and by providing a sealing member 15, the drain tank 14 can be sealed. The snap-on method makes it more convenient to disassemble and install the sealing member 15.

[0076] In some embodiments, Figure 4 As shown, a heat dissipation groove 7 is provided on one side of the lower mold 1 , a heat dissipation fin 8 is fixedly installed inside the heat dissipation groove 7 , one end of the heat dissipation fin 8 is located inside the liquid storage tank 9 , and a plurality of flow holes 19 are provided inside the heat dissipation fin 8 .

[0077] It should be noted that by providing the heat dissipation fins 8, the liquid inside the liquid storage tank 9 can be cooled down quickly, and by providing the flow holes 19, air can pass through the heat dissipation fins 8 to quickly cool down the heat dissipation fins 8, thereby achieving a better cooling effect.

[0078] The hydraulic rod 4 and the water pump 10 in the present invention are well-known components and will not be described in detail herein.

[0079] When in use, the upper mold 2 is driven to move by the hydraulic rod 4 to close the upper mold 2 with the lower mold 1. The guide rail 3 can be set to prevent the upper mold 2 from tilting. The injection groove 5 can be used for injection. The feed hole 6 can be set to allow the material inside the injection groove 5 to flow into the molding groove 12. The water pump 10 can be set to transport the liquid inside the liquid storage tank 9 to the cooling pipe 11. When the liquid circulates inside the cooling pipe 11, the alloy rod inside the molding groove 12 can be quickly cooled and formed through the heat conduction plate 17 and the heat conduction member 18. After that, the liquid inside the cooling pipe 11 will flow back to the liquid storage tank 9 and dissipate heat through the heat dissipation fins 8.

[0080] The following is an introduction in conjunction with specific embodiments:

[0081] Embodiment 1:

[0082] Prepare raw materials according to mass percentage: nickel 35%, iron 50%, chromium 12%, molybdenum 4%, tungsten 2%, aluminum 1%, titanium 0.5%, niobium 0.3%, carbon 0.1%, silicon 0.3%, manganese 0.5%, phosphorus 0.01%, sulfur 0.01%, and the balance is unavoidable impurities;

[0083] Melting: Put the prepared raw materials into a vacuum induction melting furnace for melting at a temperature of 1550°C for 2.5 hours. After the raw materials are completely melted, they are refined at a temperature of 1650°C for 1.5 hours.

[0084] Pouring: pouring the refined alloy liquid into a mold preheated to 250°C to obtain an alloy ingot Hot working forging: further heating the alloy ingot to 1100°C;

[0085] Heat treatment: The solution treatment temperature is 1050°C, the holding time is 1.5 hours, and the water temperature during solution treatment is 30°C;

[0086] The intermediate annealing temperature is 850°C, the holding time is 1.5 hours, and then the furnace is cooled to below 400°C and air-cooled;

[0087] The aging treatment temperature is 650°C, the holding time is 5 hours, and the alloy is turned over every 25 minutes.

[0088] Preparation of forging blanks by multi-fire forging:

[0089] Initial upsetting and stretching: First, the billet is heated to 1160℃ and the upsetting process is used, with a deformation degree of 20%. After the temperature is maintained at 1160℃, the stretching process is used, with a deformation degree of 25%.

[0090] Secondary upsetting and drawing: The billet heating temperature is adjusted to 1130°C, and the upsetting operation is performed again, with a deformation degree of 15%. Then the heating temperature is set at 1090°C, and the drawing process is continued, with a deformation degree of 20%;

[0091] Three times of upsetting and drawing: Finally, the billet heating temperature is controlled at 1060℃, and upsetting treatment is carried out with a deformation degree of 10%. The billet is compressed again, and finally the billet is heated to 1030℃ and drawn to stretch the billet to a size and shape close to the final forging billet with a deformation degree of 15%.

[0092] The obtained iron-nickel-based alloy has a tensile strength of 850 MPa, a yield strength of 700 MPa, an elongation of 25%, and a corrosion rate of 0.05 mm / a in a 5% NaCl solution.

[0093] Embodiment 2:

[0094] Prepare the raw materials according to the mass percentage: nickel 30%, iron 55%, chromium 10%, molybdenum 5%, tungsten 1%, aluminum 1.5%, titanium 0.2%, niobium 0.5%, carbon 0.05%, silicon 0.5%, manganese 0.2%, phosphorus less than 0.03%, sulfur less than 0.03%, and the remainder is inevitable impurities.

[0095] Melting: Put the prepared raw materials into a vacuum induction melting furnace for melting at a temperature of 1500°C for 3 hours. After the raw materials are completely melted, they are refined at a temperature of 1600°C for 2 hours.

[0096] Pouring: Pour the refined alloy liquid into a mold preheated to 200°C to obtain an alloy ingot.

[0097] Hot working forging: heating the alloy ingot to 1150℃;

[0098] Heat Treatment:

[0099] The solution treatment temperature is 1000°C, the holding time is 2 hours, and the water temperature during the solution treatment is 25°C.

[0100] The intermediate annealing treatment temperature is 800°C, the holding time is 2 hours, and then the furnace is cooled to below 350°C and air-cooled.

[0101] The aging treatment temperature is 600°C, the holding time is 6 hours, and the alloy is turned over every 20 minutes.

[0102] Preparation of forging blanks by multi-fire forging:

[0103] Initial upsetting and stretching: First, the billet is heated to 1170℃ and the upsetting process is used, with a deformation degree of 25%. After the temperature is maintained at 1170℃, the stretching process is used, with a deformation degree of 30%.

[0104] Secondary upsetting and stretching: The billet heating temperature is adjusted to 1140°C, and the upsetting operation is performed again, with a deformation degree of 20%. Then the heating temperature is set at 1100°C, and the stretching process is continued, with a deformation degree of 25%.

[0105] Three times of upsetting and drawing: Finally, the billet heating temperature is controlled at 1080℃, and upsetting treatment is carried out, with a deformation degree of 15%. The billet is compressed again, and finally the billet is heated to 1050℃ and drawn to stretch the billet to a size and shape close to the final forging billet, with a deformation degree of 20%.

[0106] The obtained iron-nickel-based alloy has a tensile strength of 800 MPa, a yield strength of 650 MPa, an elongation of 20%, and a corrosion rate of 0.06 mm / a in a 5% NaCl solution.

[0107] Embodiment three:

[0108] Prepare raw materials according to mass percentage: nickel 40%, iron 45%, chromium 15%, molybdenum 3%, tungsten 3%, aluminum 0.5%, titanium 0.8%, niobium 0.1%, carbon 0.15%, silicon 0.1%, manganese 0.8%, phosphorus less than 0.03%, sulfur less than 0.03%, and the balance is unavoidable impurities;

[0109] Melting: Put the prepared raw materials into a vacuum induction melting furnace for melting at a temperature of 1600°C for 2 hours. After the raw materials are completely melted, they are refined at a temperature of 1700°C for 1 hour.

[0110] Pouring: pouring the refined alloy liquid into a mold preheated to 300°C to obtain an alloy ingot;

[0111] Hot forging: heat the alloy ingot to 1200℃;

[0112] Heat treatment: The solution treatment temperature is 1100°C, the holding time is 1 hour, and the water temperature during solution treatment is 35°C;

[0113] The intermediate annealing temperature is 900°C, the holding time is 1 hour, and then the furnace is cooled to below 450°C and air-cooled;

[0114] The aging treatment temperature is 700°C, the holding time is 4 hours, and the alloy is turned over every 30 minutes.

[0115] Preparation of forging blanks by multi-fire forging:

[0116] Initial upsetting and stretching: First, the billet is heated to 1180°C and the upsetting process is used, with a deformation degree of 30%. After the temperature is maintained at 1180°C, the stretching process is used, with a deformation degree of 35%.

[0117] Secondary upsetting and stretching: The billet heating temperature is adjusted to 1150°C, and the upsetting operation is performed again, with a deformation degree of 25%. Then the heating temperature is set at 1120°C, and the stretching process is continued, with a deformation degree of 30%;

[0118] Three times of upsetting and drawing: Finally, the billet heating temperature is controlled at 1090℃, and upsetting treatment is carried out, with a deformation degree of 20%. The billet is compressed again, and finally the billet is heated to 1060℃ and drawn to stretch the billet to a size and shape close to the final forging billet, with a deformation degree of 25%.

[0119] The obtained iron-nickel-based alloy has a tensile strength of 900 MPa, a yield strength of 750 MPa, an elongation of 30%, and a corrosion rate of 0.04 mm / a in a 5% NaCl solution.

[0120] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A production process of an iron-nickel based alloy, characterized in that: The following steps are involved: Step 1: Prepare raw materials according to mass percentage: Nickel 30% to 40%, iron 45% to 55%, chromium 10% to 15%, molybdenum 3% to 5%, tungsten 1% to 3%, aluminum 0.5% to 1.5%, titanium 0.2% to 0.8%, niobium 0.1% to 0.5%, carbon 0.05% to 0.15%, silicon 0.1% to 0.5%, manganese 0.2% to 0.8%, phosphorus 0.01% to 0.03%, sulfur 0.01% to 0.03%, and the balance is unavoidable impurities; Step 2: Melting: Put the prepared raw materials into a vacuum induction melting furnace for melting at a temperature of 1500°C to 1600°C for 2 to 3 hours. After the raw materials are completely melted, they are refined at a temperature of 1600°C to 1700°C for 1 to 2 hours. Step 3: Pouring: The refined alloy liquid is poured into a mold preheated to 200°C to 300°C to obtain an alloy ingot; Step 4: Hot forging: The alloy ingot is further heated to 1100° C. to 1200° C. and subjected to multi-fire forging to prepare a forging blank; Step 5: Heat treatment: The hot-worked alloy is subjected to a solution treatment at a temperature of 1000°C to 1100°C for 1 to 2 hours, followed by water cooling, and then an aging treatment at a temperature of 600°C to 700°C for 4 to 6 hours, followed by air cooling; In the step 4, preparing the forging blank by multi-fire forging includes the following specific steps: Step 1: Preliminary upsetting and drawing: Firstly, the billet is heated to 1160-1180°C and the alloy ingot is processed by upsetting process to reduce the height of the billet, increase the cross-sectional area, and the deformation degree is 20%-30%. After the temperature is maintained at 1160-1180°C, the billet is stretched by stretching process to increase the length and reduce the cross-sectional area, and the deformation degree is 25%-35%. Step 2: Secondary upsetting and drawing: The billet heating temperature is adjusted to 1130-1150°C, and the upsetting operation is performed again, with a deformation degree of 15%-25%. Then, the heating temperature is set at 1090-1120°C, and the drawing process is continued to further elongate the billet, with a deformation degree of 20%-30%. Step 3: Three times upsetting and drawing: Finally, the billet heating temperature is controlled at 1060-1090°C, and upsetting treatment is performed with a deformation degree of 10%-20%. The billet is compressed again, and finally the billet is heated to 1030-1060°C and stretched to a size and shape close to the final forging billet with a deformation degree of 15%-25%.

2. The production process of an iron-nickel based alloy according to claim 1, characterized in that: The smelting temperature is 1550° C., the smelting time is 2.5 hours, the refining temperature is 1650° C., and the refining time is 1.5 hours.

3. The production process of an iron-nickel based alloy according to claim 1, characterized in that: During the hot working forging process, after each forging is completed, the forging blank needs to be returned to the furnace for heat preservation, the heat preservation temperature is 800° C. to 900° C., and the heat preservation time is 0.5 to 1 hour.

4. The production process of an iron-nickel based alloy according to claim 1, characterized in that: The alloy is further subjected to an intermediate annealing treatment between the solution treatment and the aging treatment, the annealing temperature being 800° C. to 900° C., the holding time being 1 to 2 hours, and then the alloy is furnace cooled to below 500° C. and air cooled out of the furnace.

5. The production process of an iron-nickel based alloy according to claim 1, characterized in that: In the step 5, the water temperature during the solution treatment is not higher than 40° C., and the cooling rate during the air cooling of the aging treatment is not lower than 10° C. / min.

6. The production process of an iron-nickel based alloy according to claim 1, characterized in that: During the hot working forging process in step 4, the surface of the forging blank should be cleaned before each forging to remove oxide scale and impurities.

7. The production process of an iron-nickel based alloy according to claim 1, characterized in that: In the solution treatment of step 5, the alloy should be completely immersed in cooling water, and proper stirring should be maintained during the water cooling process.

8. The production process of an iron-nickel based alloy according to claim 1, characterized in that: In the step 5, during the aging treatment, the alloy is placed in a well-ventilated environment, and during the aging treatment, the alloy is turned over every 20 to 30 minutes to ensure the uniformity of the aging treatment.

9. The production process of an iron-nickel based alloy according to claim 1, characterized in that: The mold comprises a lower mold (1) and an upper mold (2), the lower mold (1) and the upper mold (2) are both provided with corresponding molding grooves (12), the top of the upper mold (2) is provided with a material injection groove (5), and the lower mold (1) and the upper mold (2) are provided with rapid cooling mechanisms; The rapid cooling mechanism comprises a cooling pipe (11), a connecting pipe (16), a water pump (10), a heat conducting plate (17) and a heat conducting member (18); a liquid storage tank (9) is provided inside the lower mold (1); the water pump (10) is fixedly installed inside the lower mold (1); an input end of the water pump (10) is connected to the liquid storage tank (9); the cooling pipe (11) is spirally installed inside the lower mold (1) and the upper mold (2); the upper mold ( 2) A connecting pipe (16) is fixedly installed inside the internal cooling pipe (11); the output end of the water pump (10) is connected to one end of the cooling pipe (11), and the other end of the cooling pipe (11) is connected to the liquid storage tank (9); the cooling pipes (11) inside the lower mold (1) and the upper mold (2) are connected through the connecting pipe (16); the heat conducting member (18) is fixedly installed on the inner wall of the cooling pipe (11), and the heat conducting plate (17) is fixedly installed on the inner wall of the cooling pipe (11). One end of the heat conducting member (18) and the other end of the heat conducting plate (17) are located on one side of the molding groove (12); a filling pipe (13) is fixedly installed inside the lower mold (1), and the filling pipe (13) is connected to the liquid storage tank (9); one end of the liquid storage tank (9) is provided with a drainage groove (14), and a sealing member (15) is fixedly connected inside the drainage groove (14); a guide rail (3) is fixedly installed on the top of the lower mold (1), and the upper mold (2) is slidably connected to the upper mold (2) A hydraulic rod (4) is fixedly mounted on the top of the upper mold (2) and connected to the side wall of the guide rail (3); a heat dissipation groove (7) is provided on one side of the lower mold (1); a heat dissipation fin (8) is fixedly mounted inside the heat dissipation groove (7); one end of the heat dissipation fin (8) is located inside the liquid storage tank (9); a plurality of flow holes (19) are provided inside the heat dissipation fin (8); and a material delivery hole (6) connected to the molding groove (12) is provided inside the injection groove (5).

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