GH2132 high-temperature alloy forged bar billet and preparation method thereof

Abstract

The invention discloses a GH2132 high-temperature alloy forged bar billet and a preparation method thereof, and belongs to the technical field of non-ferrous metal processing. The method comprises the following steps: (1) a GH2132 high-temperature alloy ingot smelted by a duplex smelting process of vacuum induction melting and vacuum consumable remelting comprises the following chemical components in percentage by mass: less than or equal to 0.08% of C, less than or equal to 1% of Si, 0.003-0.010% of B, less than 0.01% of Cu, less than or equal to 2% of Mn, 13.50-16% of Cr, 0.10-0.50% of V, 1-1.50% of Mo, less than or equal to 0.35% of Al and less than or equal to 1% of Co; ti: 1.90% to 2.35%; ni: 24%-27%; p: less than or equal to 0.025%; s: less than or equal to 0.025%; (2) homogenizing heat treatment; (3) forging is carried out in a 80MN fast forging machine, seven-heating-number drawing-out forging is carried out, the forging temperature is 1080-1100 DEG C, continuous remelting is carried out, and the deformation amount of each heating number is 20%-45%; (4) before fourth fire forging, the forging temperature of the bar starts to be reduced to 1080 DEG C; after forging, the surface of the material has no crack, the structure is uniform, and the grain size is 4-5 level; according to the method, the GH2132 alloy forged bar billet is prepared through the free forging technology, the process stability is good, and the prepared GH2132 alloy bar billet is uniform in structure and excellent in performance.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal processing, and in particular relates to a GH2132 high-temperature alloy forging rod blank and a preparation method thereof. Background Art

[0002] GH2132 alloy is a Fe-25Ni-15Cr-based high-temperature alloy, which is comprehensively strengthened by adding molybdenum, titanium, aluminum, vanadium and trace boron. It is mainly used as a high-temperature load-bearing part of aircraft engines below 650℃; it has high yield strength and long-lasting and creep strength below 650℃, and is an indispensable material for my country's new aircraft engines. The alloy has excellent mechanical properties, good processability and weldability, making it highly favored by aircraft engine designers. The main supply varieties include plates, wires, pipes, bars, forgings and rings.

[0003] GH2132 alloy achieves excellent performance among high-temperature alloys through its unique chemical composition design. The main strengthening phase is γ' phase. The strengthening phase is continuously dissolved and precipitated during the heating and hot working process of the alloy, affecting the recrystallization process of the alloy, thereby affecting the grain structure and performance. With the continuous improvement of the performance requirements of modern aircraft engines and the continuous increase in thrust-to-weight ratio, some ordinary forming processes can no longer fully meet the requirements of the development of the aviation industry. Forging can enable metals to obtain comprehensive mechanical properties that cannot be surpassed by other metal processing processes, and can make the bars have a uniform grain size of 4 to 5. Ordinary hot working methods are difficult to meet this demanding requirement. Therefore, the GH2132 alloy billet produced by the 80MN free forging process provides a new method for improving the performance of GH2132. Summary of the invention

[0004] The object of the present invention is to provide a GH2132 high temperature alloy forging rod blank and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: In view of the development of the existing GH2132 alloy bar blank preparation technology, the present invention provides a GH2132 high-temperature alloy forging bar blank and a preparation method thereof, and adopts a dual smelting process of vacuum induction melting + vacuum consumable remelting to smelt the GH2132 high-temperature alloy ingot. Through high-temperature homogenization and forging process design, a bar blank with a specification of Φ160mm is prepared, a flaw detection level of not less than Φ0.8-8dB, a uniform structure from the center to the edge, a grain size of 4 to 5, and various performance indicators of the GH2132 alloy forging bar blank are qualified.

[0006] Its specific implementation includes the following steps:

[0007] (1) GH2132 high temperature alloy ingot smelted by vacuum induction melting + vacuum consumable remelting double smelting process, the ingot diameter is Φ390mm~Φ500mm;

[0008] (2) The ingot is subjected to high temperature homogenization heat treatment in a natural gas furnace;

[0009] (3) The ingot after homogenization heat treatment is subjected to 7 rounds of upsetting and drawing forging in an 80MN fast forging machine at a forging temperature of 1080°C to 1100°C, and is continuously melted down with a deformation of 15% to 40% in each round.

[0010] Preferably, the step (2) is as follows: heating the ingot to 650°C with a thermal insulation coefficient of 0.6 min / mm, then heating it to 1140°C-1160°C at a heating rate of 2°C-6°C / min, with a thermal insulation time of ≥24h, then heating it to 1180°C-1200°C at a heating rate of 2°C-6°C / min, with a thermal insulation time of ≥48h, and after the thermal insulation is completed, furnace cooling to 650°C, followed by air cooling.

[0011] Preferably, the step (3) is as follows: heating the cold forging billet to 850°C with a thermal insulation coefficient of 0.6 min / mm, then heating to 1080°C to 1100°C at a heating rate of 5°C to 8°C / min with a thermal insulation coefficient of 0.6 min / mm; continuously returning the hot material to a thermal insulation coefficient of 0.4 min / mm; and air cooling after forging is completed.

[0012] A GH2132 high-temperature alloy forging bar blank, wherein the room temperature tensile strength of the GH2132 alloy bar blank is 1000MPa-1100MPa, the room temperature tensile yield strength is 750MPa-780MPa, the room temperature tensile elongation is 20%-25%, and the room temperature tensile cross-sectional shrinkage is 50%-55%; the 650°C high-temperature tensile strength is 750MPa-800MPa, the 650°C high-temperature tensile elongation is 15%-20%, and the 650°C high-temperature cross-sectional shrinkage is 14%-17%.

[0013] Compared with the prior art, the characteristics and effects of the present invention are:

[0014] (1) The GH2132 high-temperature alloy ingot is smelted by a dual smelting process of vacuum induction melting + vacuum consumable remelting. After high-temperature homogenization, the segregation of the ingot is reduced, providing a good ingot and laying the foundation for subsequent forging;

[0015] (2) By controlling the forging process, the billet is deformed multiple times at high temperature, and during the deformation process, the billet is rapidly deformed to a large extent, so that the grain size of the Φ160mm bar billet is controlled at level 4 to 5, and the grain distribution is uniform, thereby improving the uniformity of the structure of the large bar billet.

[0016] (3) The performance of GH2132 alloy is stable, with room temperature tensile strength of 1000MPa~1100MPa, room temperature tensile yield strength of 750MPa~780MPa, room temperature tensile elongation of 20%~25%, and room temperature tensile cross-sectional shrinkage of 50%~55%; 650℃ high temperature tensile strength of 750MPa~800MPa, 650℃ high temperature tensile yield strength of 440MPa~460MPa, 650℃ high temperature tensile elongation of 15%~20%, and 650℃ high temperature cross-sectional shrinkage of 14%~17%. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The macrostructure of the Φ160mm rod blank in the embodiment:

[0018] (a) Center 100×; (b) R / 2 100×; (c) Edge 100×

[0019] Figure 2 Comparative Example Φ160mm rod billet high magnification structure:

[0020] (a) Center 100×; (b) R / 2 100×; (c) Edge 100×. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments 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.

[0022] See also Figure 1-2 In the embodiment of the present invention, the room temperature tensile test is carried out at room temperature using ASTM E 8 / E 8M standard.

[0023] In the embodiments of the present invention, the high temperature tensile test is carried out at 650° C. and then kept at this temperature for 30 minutes according to the ASTM E 21 national standard.

[0024] In the embodiment of the invention, the grain size rating adopts the ASTM E 112 standard, and samples are taken from the center, R / 2, and edge of the rod blank respectively, and then the structure is observed under a metallographic microscope after corrosion.

[0025] Example

[0026] The diameter of the GH2132 alloy ingot smelted by vacuum induction melting + vacuum consumable remelting process is Φ390mm. The ingot homogenization process is as follows: heating to 650℃, keeping warm for 300min, then heating to 1150℃ at a heating rate of 6℃ / min, keeping warm for 24h, then heating to 1195℃ at a heating rate of 6℃ / min, keeping warm for 48h, furnace cooling to 650℃ after the end of keeping warm, and then air cooling;

[0027] The ingot was kept at 1130℃ and then forged. There were 7 forgings in total. The deformation settings were as follows:

[0028] First fire: Ф390×(685)→[pull] 340×(850) in all directions;

[0029] Second fire: Bafang 340×(850)→[Upset] Bafang (380)×680→[Pull] Bafang 330×(905);

[0030] The third fire: Bafang 330×(905)→[Upset] Bafang (390)×650→[Pull] Bafang 330×(905);

[0031] Fourth Fire: Eight Directions 330×(905) → [Pull] Eight Directions 260×(1460);

[0032] Fifth Fire: Eight directions 260×(1460) → [Pull] Eight directions 205×(2345);

[0033] The sixth fire: Bafang 205×(2345)→[Pull] Bafang 165×(3620)→[Inverted]◇165(+3,-2)×(3825);

[0034] The seventh fire: ◇165×(3825)→[round]Ф165(+3,0)×(3825).

[0035] The deformation amount of each fire is: 19%, 25%, 28%, 28%, 38%, 38%, 5% respectively. After forging, the billet is air-cooled and peeled to Φ160×L.

[0036] The grain size of the finished bar billet is graded according to ASTM E 112, with the center and R / 2 being graded as 4 and the edge being graded as 4.5. Figure 1 The specific performance parameters are shown in Table 1.

[0037] Comparative Example

[0038] The diameter of the GH2132 alloy ingot smelted by vacuum induction melting + vacuum consumable remelting process is Φ390mm. The ingot is not homogenized and is directly heated forged. The forging temperature is 1120℃ and a total of 5 fires are completed. The deformation settings are as follows:

[0039] First fire: Ф390×(850)→[pull] 340×(1055) in all directions;

[0040] Second fire: 340×(1055) in all directions → [pull] 300×(1360) in all directions;

[0041] The third fire: 300×(1360) in all directions → [pulling] 260×(1805) in all directions;

[0042] Fourth Fire: Eight directions 260×(1805) → [Pull] Eight directions 200×(3055);

[0043] Fifth fire: 200×(3055) in all directions → 165×(4490) in diameter;

[0044] The deformation amount of each fire is: 20%, 22%, 25%, 40%, 32% respectively. After forging, the billet is air-cooled and peeled to Φ160×L.

[0045] The grain size of the finished bar billet is rated according to ASTM E 112, with the center and R / 2 being grade 2 and the edge being grade 3. Figure 2 The specific performance parameters are shown in Table 1.

[0046] Table 1

[0047]

[0048] In summary, it can be found from the embodiments and comparative examples that the organization and performance results of the GH2132 alloy Φ160mm bar blank prepared by the implementation method of the patent design are significantly better than the previous preparation method (comparative example). The present invention provides a new method for preparing GH2132 alloy Φ160mm bar blanks, which improves the performance indicators of the product and refines the grain size of the bar blanks.

[0049] 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 method for preparing a GH2132 high temperature alloy forging bar billet, which is required to be carried out according to the following steps: (1) GH2132 high temperature alloy ingot smelted by vacuum induction melting + vacuum consumable remelting double smelting process, the ingot diameter is Φ390mm~Φ600mm; (2) The ingot is subjected to high temperature homogenization heat treatment in a natural gas furnace; (3) The ingot after homogenization heat treatment is subjected to 7-fire drawing forging in an 80MN fast forging machine at a forging temperature of 1080°C to 1100°C, and is continuously remelted with a deformation of 20% to 45% per fire. After forging, the diameter of the billet is Φ160 mm.

2. The method for preparing a GH2132 high temperature alloy forging bar according to claim 1, characterized in that: In the step (2), the ingot is heated to 650°C with a thermal insulation coefficient of 0.6 min / mm, and then the temperature is increased to 1140°C to 1160°C at a heating rate of 2°C to 6°C / min, and the thermal insulation time is ≥24h, and then the temperature is increased to 1180°C to 1200°C at a heating rate of 2°C to 6°C / min, and the thermal insulation time is ≥48h. After the thermal insulation is completed, the ingot is furnace cooled to 650°C and then air cooled.

3. The method for preparing a GH2132 high temperature alloy forging bar according to claim 1, characterized in that: In the step (3), the cold forging blank is heated to 850°C with a thermal insulation coefficient of 0.6 min / mm, and then heated to 1080°C to 1100°C at a heating rate of 5°C to 8°C / min with a thermal insulation coefficient of 0.6 min / mm; the thermal insulation coefficient of the hot material continuously returned to the furnace is 0.4 min / mm; and air cooling is performed after forging is completed.

4. The method for preparing a GH2132 high temperature alloy forging bar according to claim 1, characterized in that: After the forging is completed, the room temperature tensile strength of the rod blank is 1000MPa-1100MPa, the room temperature tensile yield strength is 750MPa-780MPa, the room temperature tensile elongation is 20%-25%, and the room temperature tensile section shrinkage is 50%-55%; the 650℃ high temperature tensile strength is 750MPa-800MPa, the 650℃ high temperature tensile yield strength is 440MPa-460MPa, the 650℃ high temperature tensile elongation is 15%-20%, and the 650℃ high temperature section shrinkage is 14%-17%.

5. A GH2132 high temperature alloy forging bar blank prepared by the preparation method according to claim 1, characterized in that: The specification is Φ160mm, the flaw detection level is not less than Φ0.8-8dB, and the grain size is level 4 to 5.

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