Production process of nickel-based alloy hanger forge piece for deep sea

Abstract

The invention discloses a production process of a nickel-based alloy hanger forge piece for deep sea, which comprises the following steps: S1, material selection: selecting proper raw materials according to an alloy formula, and pouring the raw materials into an electroslag ingot; s2, cogging is conducted, specifically, the prepared electroslag ingot is put into a heating furnace, then heating and heat preservation treatment is conducted, and tools such as an anvil block are preheated in advance; s3, primary forging is carried out, specifically, the heated blank is loaded into a mold, forging treatment can be carried out after the mold is started, a blank rod can be obtained after forging is finished, and the blank rod is inserted into reinforcing liquid and can be cooled; the production process is simple in step and convenient to operate, and it can be guaranteed that the Inconel 718 nickel base alloy hanger forge piece with the wall thickness larger than or equal to 360 mm has a uniform metallographic structure and excellent mechanical performance by controlling the temperature and deformation in the forging deformation process and the actual temperature and time of a product in the heat treatment process; and the forging production difficulty of the Inconel 718 nickel-based alloy hanger forge piece is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of corrosion-resistant high-temperature alloy forging materials for deep-sea use, and in particular to a production process for a nickel-based alloy hanger forging for deep-sea use. Background Art

[0002] High-temperature nickel-based alloy Inconel 718 has high strength, good plasticity and toughness, processing performance, long-term organizational stability, good fatigue resistance, oxidation resistance and corrosion resistance in the range of -60℃-650℃, and is widely used in aviation, aerospace, deep-sea petrochemical and other fields. Since my country's technical research on the application of this material in the oil industry is relatively late, many forgings rely on foreign imports, with high procurement costs and long production cycles, which greatly restricts the progress of my country's deep-sea oil development.

[0003] For example, the authorization announcement number is CN105734344B, and the authorization announcement date is 20180417, which provides a nickel-based alloy with excellent comprehensive high-temperature performance, and also involves its production process. The weight percentage of the components of the nickel-based alloy is: single-arm carbon nanotubes: 0.02%-0.048%; Cr: 19.8%-20.8%; Ni: 51.7%-52.7%; Co: 0.75%-0.88%; Mo: 2.9%-3.1%; Al: 0.47%-0.76%; Ti: 0.79%-1.05%; Nb: 5.0%-5.2%; B: 0.002%-0.0056% ; Mg: 0.005%-0.0077%; Mn: 0.2%-0.27%; Si: 0.2%-0.28%; Cu: 0.14%-0.23%; Fe: 15.18%-17.4%; and inevitable impurities; The mechanical properties of the nickel-based alloy of the present invention are about 1.2-1.5 times that of the traditional nickel-based Inconel718 alloy, and the high temperature and high pressure corrosion resistance and heat corrosion resistance are significantly improved.

[0004] The wall thickness of Inconel 718 nickel-based alloy hanger forgings is greater than 360mm. The temperature of this material drops very quickly during the forging production process, and it is difficult to stably ensure sufficient deformation within the forgeable temperature range, which often results in structural defects such as coarse grains and necklace crystals, and fails to meet performance requirements; in addition, the wall thickness of this product is uneven, and the deformation amount is different during the forging process. The thick wall parts are prone to low-temperature impact and unqualified cross-sectional shrinkage; and when the final forging temperature is too low, cracking is prone to occur in the thin wall parts. It can be seen from the above that the forging of Inconel718 nickel-based alloy is difficult. In order to solve the above problems, a production process of deep-sea nickel-based alloy hanger forgings is proposed to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a production process for a deep-sea nickel-based alloy hanger forging to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A production process for a deep-sea nickel-based alloy hanger forging comprises the following steps:

[0008] S1. Material selection: Select appropriate raw materials according to the alloy formula and cast the raw materials into electroslag ingots;

[0009] S2. Opening: The prepared electroslag ingot is placed in a heating furnace, and then heated and kept warm, and the anvil and other tooling are preheated in advance;

[0010] S3. Initial forging: The heated billet is loaded into the die, and the die is started to forge. After forging, a billet is obtained, and the billet is inserted into the strengthening liquid for cooling.

[0011] S4. Cutting: After the cooling process is completed, the billet is wiped dry and then placed in a cutting device. When the cutting device is started, the billet is cut to a fixed length to obtain a blank block to be processed;

[0012] S5. Heating treatment: placing the blank block into a heating furnace, followed by heating and heat preservation treatment;

[0013] S6. Secondary forging: The heated and insulated blank is placed in the die. When the die is started, the forging process is carried out. After the forging is completed, the reinforcing liquid is placed in the blank for cooling. After the cooling is completed, the forging is obtained.

[0014] S7. Heat treatment: Place the forging into a quenching furnace for solution treatment. After the solution treatment is completed, place the forging into a quenching furnace for aging treatment. After the aging treatment is completed, take out the forging and place it into a strengthening liquid for cooling treatment.

[0015] S8. Machining: Dewater the forgings after cooling. After dewatering, put the forgings into machining equipment and perform polishing, drilling and other treatments according to the drawings;

[0016] S9. Acceptance processing: Perform non-destructive testing on the forgings after machining through testing equipment, take samples of the forgings, and then conduct tensile, impact, hardness metallographic structure and other tests.

[0017] Furthermore, the raw materials in step S1 are smelted using a smelting process of vacuum arc furnace smelting + vacuum consumable remelting, and the raw materials and their percentages are as follows:

[0018] Carbon (C) ≤ 0.045, Silicon (Si) ≤ 0.35, Manganese (Mn) ≤ 0.35, Phosphorus (P) ≤ 0.010, Sulfur (S) ≤ 0.010, Chromium (Cr): 17.00-21.00, Molybdenum (Mo): 2.80-3.30, Nickel (Ni): 50.00-55.00, Copper (Cu) ≤ 0.23, Bismuth (Bi) ≤ 0.00005, Iron (F e): Balance, titanium (Ti): 0.80-1.15, aluminum (Al): 0.40-0.60, cobalt (Co) ≤1.00, boron (B) ≤0.0060, lead (Pb) ≤0.0010, selenium (Se) ≤0.0005, calcium (Ca) ≤0.0030, magnesium (Mg) ≤0.0060, niobium (Nb) + tantalum (Ta): 4.87-5.20.

[0019] Furthermore, the weight of the electroslag ingot heated and kept warm in step S2 is 3-5 tons, and the heating and keeping warm process in step S2 is divided into three stages, which are specifically as follows:

[0020] (1) Initially heat to 300°C and keep warm for no less than 3 hours;

[0021] (2) Heating the temperature to 850°C for a second time and keeping the temperature for not less than 4 hours;

[0022] (3) Finally, raise the temperature to 1120℃±10℃ and keep it warm for no less than 8 hours.

[0023] Furthermore, the forging in step S3 is divided into two steps, and the two-step forging process is as follows:

[0024] (1) Upsetting, stretching, and reheating for not less than 3 hours;

[0025] (2) Upsetting, stretching, and subsequent placement into strengthening liquid for cooling treatment.

[0026] Furthermore, the heating process in step S5 is divided into three stages, as shown below:

[0027] (1) Initially heat to 300°C and keep warm for no less than 1 hour;

[0028] (2) Heating the temperature to 850°C for a second time and keeping the temperature for not less than 2 hours;

[0029] (3) Finally, raise the temperature to 1120℃±10℃ and keep it warm for no less than 4 hours.

[0030] Furthermore, the forging in step S6 is divided into three steps, and the three-step forging process is as follows:

[0031] (1) Upsetting, stretching, and reheating for not less than 3 hours;

[0032] (2) Make a round bar with a variable cross-section at the left end and return it to the furnace for insulation for no less than 2 hours;

[0033] (3) Make a round rod with a variable cross-section at the right end, and then put it into the reinforcing liquid for cooling treatment.

[0034] Furthermore, in the forging process of step S3 and step S6, the upsetting ratio is greater than 1.4, the drawing forging ratio is greater than 1.4, and the final forging temperature is greater than 900°C.

[0035] Furthermore, the strengthening liquid has two components, hot and cold. The cooling treatment first uses mineral oil added with antioxidants, rust inhibitors and stabilizers for the initial cooling treatment, and the cooling time is 5-10 minutes. Subsequently, a water bath quenching liquid containing copper ions, chromium ions and molybdenum ions is used to continue cooling until room temperature.

[0036] Furthermore, during the solution treatment in step S7, the solution temperature is 1030°C±5°C, and the holding time is 2 hours. During the aging treatment in step S7, the aging temperature is 785°C±5°C, and the holding time is 8 hours. During the solution and aging treatment in step S7, an external thermocouple is connected to the product surface to monitor the product temperature and holding time.

[0037] Furthermore, in the step S9, the detection equipment is an ultrasonic detection equipment and a penetrant detection equipment, and two types of non-destructive detection, ultrasonic detection and penetrant detection, are performed respectively.

[0038] In the above technical solution, the present invention provides a production process for a deep-sea nickel-based alloy hanger forging, which has the following beneficial effects:

[0039] (1) The production process designed by the present invention has simple steps and is easy to operate. It can ensure that the Inconel 718 nickel-based alloy hanger forgings with a wall thickness of ≥360 mm have uniform metallographic structure and excellent mechanical properties by controlling the temperature and deformation amount during the forging deformation process and the actual temperature and time of the product during the heat treatment process, thereby greatly reducing the difficulty of forging production of the Inconel 718 nickel-based alloy hanger forgings.

[0040] (2) The production process designed by the present invention can perform two cooling treatments on the blank bars, blank blocks and forgings after heat treatment by using the strengthening liquid. The mineral oil added with antioxidants, rust inhibitors and stabilizers in this process can improve the rust and corrosion resistance of the forgings, while the water bath quenching liquid containing copper ions, chromium ions and molybdenum ions can improve the strength and hardness of the forgings. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0042] Figure 1 A process flow diagram is provided for a production process embodiment of a nickel-based alloy hanger forging for deep sea use of the present invention.

[0043] Figure 2 A schematic diagram of a forging process is provided for a production process embodiment of a deep-sea nickel-based alloy hanger forging according to the present invention.

[0044] Figure 3 A schematic diagram of heat treatment is provided for a production process embodiment of a deep-sea nickel-based alloy hanger forging according to the present invention.

[0045] Figure 4 A schematic diagram of the metallographic structure at the thick part of the hanger wall is provided for a production process embodiment of a nickel-based alloy hanger forging for deep-sea use of the present invention. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0047] like Figure 1-4 As shown, a production process of a deep-sea nickel-based alloy hanger forging provided in an embodiment of the present invention comprises the following steps:

[0048] S1. Material selection: Select appropriate raw materials according to the alloy formula. The raw materials and their percentages are as follows:

[0049] Carbon (C) ≤ 0.045, Silicon (Si) ≤ 0.35, Manganese (Mn) ≤ 0.35, Phosphorus (P) ≤ 0.010, Sulfur (S) ≤ 0.010, Chromium (Cr): 17.00-21.00, Molybdenum (Mo): 2.80-3.30, Nickel (Ni): 50.00-55.00, Copper (Cu) ≤ 0.23, Bismuth (Bi) ≤ 0.00005, Iron (Fe): Balance, Titanium (Ti): 0.80 -1.15, aluminum (Al): 0.40-0.60, cobalt (Co) ≤1.00, boron (B) ≤0.0060, lead (Pb) ≤0.0010, selenium (Se) ≤0.0005, calcium (Ca) ≤0.0030, magnesium (Mg) ≤0.0060, niobium (Nb) + tantalum (Ta): 4.87-5.20; and the raw materials are cast into electroslag ingots through the smelting process of vacuum arc furnace smelting + vacuum consumable remelting;

[0050] S2. Opening: Put the prepared electroslag ingot into a heating furnace, and then heat and keep it warm. The weight of the electroslag ingot to be heated and kept warm is 3-5 tons. The heating and keeping warm process in step S2 is divided into three stages, and the anvil and other tooling are preheated in advance, and the specific steps are as follows:

[0051] (1) Initially heat to 300°C and keep warm for no less than 3 hours;

[0052] (2) Heating the temperature to 850°C for a second time and keeping the temperature for not less than 4 hours;

[0053] (3) Finally, heat to 1120℃±10℃ and keep warm for no less than 8 hours;

[0054] S3. Initial forging: The heated billet is loaded into the die, and the die is started to forge. The forging process is divided into two steps, and the two-step forging process is as follows:

[0055] (1) Upsetting, stretching, and reheating for not less than 3 hours;

[0056] (2) Upsetting, stretching, and subsequent cooling in a strengthening liquid;

[0057] After forging, a billet will be obtained, and the billet will be inserted into the strengthening liquid for cooling;

[0058] S4. Cutting: After the cooling process is completed, the billet is wiped dry and then placed in a cutting device. When the cutting device is started, the billet is cut to a fixed length to obtain a blank block to be processed;

[0059] S5. Heating treatment: The blank block is placed in a heating furnace and then heated and kept warm. The heating process is divided into three stages, as shown below:

[0060] (1) Initially heat to 300°C and keep warm for no less than 1 hour;

[0061] (2) Heating the temperature to 850°C for a second time and keeping the temperature for not less than 2 hours;

[0062] (3) Finally, heat to 1120℃±10℃ and keep warm for no less than 4 hours;

[0063] S6. Secondary forging: The heated and insulated blank is placed in the die, and the die is started to forge. The forging process is divided into three steps, and the three-step forging process is as follows:

[0064] (1) Upsetting, stretching, and reheating for not less than 3 hours;

[0065] (2) Make a round bar with a variable cross-section at the left end and return it to the furnace for insulation for no less than 2 hours;

[0066] (3) Beat the right end of the variable cross-section round rod, and then put it into the strengthening liquid for cooling treatment;

[0067] After forging, the reinforcing liquid is put into the forging for cooling. After cooling, the forging will be obtained.

[0068] S7. Heat treatment: Place the forgings in a quenching furnace for solution treatment. During solution treatment, the solution temperature is 1030℃±5℃ and the holding time is 2 hours. After solution treatment, place the forgings in a quenching furnace for aging treatment. During aging treatment, the aging temperature is 785℃±5℃ and the holding time is 8 hours. After aging, take out the forgings and place them in strengthening liquid for cooling treatment. During solution and aging treatment, connect an external thermocouple to the product surface to monitor the product temperature and holding time.

[0069] S8. Machining: Dewater the forgings after cooling. After dewatering, put the forgings into machining equipment and perform polishing, drilling and other treatments according to the drawings;

[0070] S9. Acceptance processing: The forgings after machining are subjected to non-destructive testing by means of testing equipment, such as ultrasonic testing equipment and penetrant testing equipment. Ultrasonic testing and penetrant testing are used for non-destructive testing respectively. Samples are taken from the forgings for tensile, impact, hardness, metallographic structure and other tests.

[0071] The present invention provides a production process for a nickel-based alloy hanger forging for deep sea use. The production process steps are simple and the operation is convenient. The Inconel 718 nickel-based alloy hanger forging with a wall thickness of ≥360 mm can be ensured to have a uniform metallographic structure and excellent mechanical properties by controlling the temperature and deformation amount during the forging deformation process and the actual temperature and time of the product during the heat treatment process, thereby greatly reducing the difficulty of forging production of the Inconel 718 nickel-based alloy hanger forging.

[0072] In another embodiment provided by the present invention, during the forging process of step S3 and step S6, the upsetting ratio is greater than 1.4, the drawing forging ratio is greater than 1.4, and the final forging temperature is greater than 900°C.

[0073] In another embodiment provided by the present invention, the enhancing liquid has two components, hot and cold. The cooling treatment first uses mineral oil added with antioxidants, rust inhibitors and stabilizers for the initial cooling treatment, and the cooling time is 5-10 minutes. Subsequently, a water bath quenching liquid containing copper ions, chromium ions and molybdenum ions is used to continue cooling until room temperature.

[0074] It can be seen from step S9 that the performance test of the Inconel 718 nickel-based alloy hanger forging for deep sea use with a wall thickness greater than 360 mm at the maximum wall thickness is as follows:

[0075]

[0076]

[0077] Comparing this embodiment with the prior art, it can be seen that the forgings produced by this embodiment have the best quality.

[0078] Working principle: Select appropriate raw materials according to the alloy formula, and cast the raw materials into electroslag ingots; put the prepared electroslag ingots into the heating furnace, and then heat and keep them warm, and preheat the anvil and other tooling in advance; put the heated billet into the mold, and the mold will start forging. After forging, a billet will be obtained, and the billet will be inserted into the strengthening liquid for cooling; wipe the billet dry after cooling, and then put it into the cutting equipment. The cutting equipment will start to cut the billet to a fixed length to obtain the blank block to be processed; put the blank block into the heating furnace, and then heat and keep it warm; heat The insulated blank block is placed in the mold, and the mold will be forged when it is started. After forging, it is placed in strengthening liquid for cooling. After cooling, a forging is obtained; the forging is placed in a quenching furnace for solid solution treatment first, and then the forging is placed in a quenching furnace for aging treatment. After the aging is completed, the forging is taken out and placed in strengthening liquid for cooling; the forging treated with cooling is dehydrated, and after the dehydration is completed, the forging is placed in machining equipment and polished, drilled and other treatments are performed according to the drawings; the forgings after machining are subjected to non-destructive inspection by testing equipment, and the forgings are sampled for tensile, impact, hardness, metallographic structure and other inspections.

[0079] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A production process for deep-sea nickel-based alloy hanger forgings, characterized in that: The following steps are involved: S1. Material selection: Select appropriate raw materials according to the alloy formula and cast the raw materials into electroslag ingots; S2. Opening: The prepared electroslag ingot is placed in a heating furnace, and then heated and kept warm, and the anvil and other tooling are preheated in advance; S3. Initial forging: The heated billet is loaded into the die, and the die is started to forge. After forging, a billet is obtained, and the billet is inserted into the strengthening liquid for cooling. S4. Cutting: After the cooling process is completed, the billet is wiped dry and then placed in a cutting device. When the cutting device is started, the billet is cut to a fixed length to obtain a blank block to be processed; S5. Heating treatment: placing the blank block into a heating furnace, followed by heating and heat preservation treatment; S6. Secondary forging: The heated and insulated blank is placed in the die. When the die is started, the forging process is carried out. After the forging is completed, the reinforcing liquid is placed in the blank for cooling. After the cooling is completed, the forging is obtained. S7. Heat treatment: Place the forging into a quenching furnace for solution treatment. After the solution treatment is completed, place the forging into a quenching furnace for aging treatment. After the aging treatment is completed, take out the forging and place it into a strengthening liquid for cooling treatment. S8. Machining: Dewater the forgings after cooling. After dewatering, put the forgings into machining equipment and perform polishing, drilling and other treatments according to the drawings; S9. Acceptance processing: Perform non-destructive testing on the forgings after machining through testing equipment, take samples of the forgings, and then conduct tensile, impact, hardness metallographic structure and other tests.

2. The production process of a deep-sea nickel-based alloy hanger forging according to claim 1 is characterized in that: In step S1, the raw materials are smelted by vacuum arc furnace smelting + vacuum consumable remelting, and the raw materials and their percentages are as follows: Carbon (C) ≤ 0.045, Silicon (Si) ≤ 0.35, Manganese (Mn) ≤ 0.35, Phosphorus (P) ≤ 0.010, Sulfur (S) ≤ 0.010, Chromium (Cr): 17.00-21.00, Molybdenum (Mo): 2.80-3.30, Nickel (Ni): 50.00-55.00, Copper (Cu) ≤ 0.23, Bismuth (Bi) ≤ 0.00005, Iron (F e): Balance, titanium (Ti): 0.80-1.15, aluminum (Al): 0.40-0.60, cobalt (Co) ≤1.00, boron (B) ≤0.0060, lead (Pb) ≤0.0010, selenium (Se) ≤0.0005, calcium (Ca) ≤0.0030, magnesium (Mg) ≤0.0060, niobium (Nb) + tantalum (Ta): 4.87-5.

20.

3. The production process of a deep-sea nickel-based alloy hanger forging according to claim 1, characterized in that: The weight of the electroslag ingot heated and kept warm in step S2 is 3-5 tons. The heating and keeping warm process in step S2 is divided into three stages, which are specifically as follows: (1) Initially heat to 300°C and keep warm for no less than 3 hours; (2) Heating the temperature to 850°C for a second time and keeping the temperature for not less than 4 hours; (3) Finally, raise the temperature to 1120℃±10℃ and keep it warm for no less than 8 hours.

4. The production process of a deep-sea nickel-based alloy hanger forging according to claim 1 is characterized in that: The forging in step S3 is divided into two steps, and the two-step forging process is as follows: (1) Upsetting, stretching, and reheating for not less than 3 hours; (2) Upsetting, stretching, and subsequent placement into strengthening liquid for cooling treatment.

5. The production process of a deep-sea nickel-based alloy hanger forging according to claim 1, characterized in that: The heating process in step S5 is divided into three stages, as shown below: (1) Initially heat to 300°C and keep warm for no less than 1 hour; (2) Heating the temperature to 850°C for a second time and keeping the temperature for not less than 2 hours; (3) Finally, raise the temperature to 1120℃±10℃ and keep it warm for no less than 4 hours.

6. The production process of a deep-sea nickel-based alloy hanger forging according to claim 4, characterized in that: The forging in step S6 is divided into three steps, and the three-step forging process is as follows: (1) Upsetting, stretching, and reheating for not less than 3 hours; (2) Make a round bar with a variable cross-section at the left end and return it to the furnace for insulation for no less than 2 hours; (3) Make a round rod with a variable cross-section at the right end, and then put it into the reinforcing liquid for cooling treatment.

7. The production process of a deep-sea nickel-based alloy hanger forging according to claim 6, characterized in that: In the forging process of step S3 and step S6, the upsetting ratio is greater than 1.4, the drawing forging ratio is greater than 1.4, and the final forging temperature is greater than 900°C.

8. The production process of a deep-sea nickel-based alloy hanger forging according to claim 6, characterized in that: The strengthening liquid has two components, hot and cold. The cooling treatment first uses mineral oil added with antioxidants, rust inhibitors and stabilizers for the initial cooling treatment, and the cooling time is 5-10 minutes. Subsequently, a water bath quenching liquid containing copper ions, chromium ions and molybdenum ions is used to continue cooling until room temperature.

9. The production process of a deep-sea nickel-based alloy hanger forging according to claim 1, characterized in that: During the solution treatment in step S7, the solution temperature is 1030°C±5°C, and the holding time is 2 hours. During the aging treatment in step S7, the aging temperature is 785°C±5°C, and the holding time is 8 hours. During the solution treatment and aging treatment in step S7, an external thermocouple is connected to the product surface to monitor the product temperature and holding time.

10. The production process of a deep-sea nickel-based alloy hanger forging according to claim 1, characterized in that: In the step S9, the detection equipment is an ultrasonic detection equipment and a penetrant detection equipment, and two types of non-destructive detection, ultrasonic detection and penetrant detection, are performed respectively.

Images