Large-specification GH4169 high-temperature alloy plate blank free forging method

Abstract

The invention discloses a large-specification GH4169 high-temperature alloy plate blank free forging method which comprises the following steps: 1) preserving heat in a temperature interval of 1060-1140 DEG C, setting the heat preservation time for 2-12 hours according to the temperature when materials are fed into a furnace, performing at least one heating number of upsetting and drawing deformation on a cast ingot on a 8000T fast forging machine, controlling the upsetting deformation to be 20-50%, controlling the drawing deformation to be 18-35%, and controlling the drawing deformation to be 18-35%; the deformation of each pass is 10%-20%; (2) the blank is heated and subjected to heat preservation for 60 min to 210 min in the temperature interval of 1010 DEG C to 1060 DEG C, upsetting and drawing deformation of at least two heating numbers is conducted on a 8000 T fast forging machine, the deformation amount of drawing of each heating number ranges from 30% to 60%, the width of the blank ranges from 900 mm to 1800 mm after radial drawing is completed, drawing is continuous remelting, and the deformation amount of each pass ranges from 10% to 20%; according to the method, the problems that in the prior art, the plate blank size is small, forging temperature drop is fast, and the forging window interval is narrow can be solved, the plate blank small in thickness and large in specification can be obtained through free forging, and the material surface structure is improved.

Description

Technical Field

[0001] The invention belongs to the field of hot processing of metal materials, and in particular relates to a method for preparing a large-size GH4169 high-temperature alloy free forging slab. Background Art

[0002] GH4169 alloy is a precipitation-strengthened nickel-based superalloy with the highest yield strength among deformable superalloys in the temperature range of -253 to 650°C. It exhibits excellent fatigue, radiation, and corrosion resistance, making it the most widely used deformable superalloy both domestically and internationally. Annual production exceeds 20,000 tons, accounting for over 50% of the total output of deformable superalloys. GH4169 alloy exhibits excellent deformation properties, but the slabs currently produced are relatively small in size, limiting their practical application and resulting in high costs. Furthermore, the rapid temperature drop during forging of large slabs creates a narrow forging window, which can easily lead to deterioration of the surface structure.

[0003] The present invention provides a free forging method for large-size GH4169 high-temperature alloy slabs, which solves the problems existing in the prior art such as small slab size, rapid forging temperature drop, and narrow forging window range. Summary of the Invention

[0004] The object of the present invention is to provide a free forging method for large-sized GH4169 high-temperature alloy slabs to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for free forging a large-sized GH4169 high-temperature alloy slab, comprising the following steps:

[0006] 1) Keep the temperature within the range of 1060℃~1140℃, set the holding time for 2h~12h according to the temperature of the material when entering the furnace, and perform at least one fire of upsetting and drawing deformation on an 8000T fast forging machine. The deformation of upsetting is 20%~50%, the deformation of drawing is 18%~35%, and the deformation of each pass is 10%~20%;

[0007] 2) The blank is heated and kept warm in the temperature range of 1010℃~1060℃ for 60min~210min, and subjected to at least 2 fires of upsetting and drawing deformation on an 8000T fast forging machine, with the deformation of each fire being 30%~60%. After the radial drawing is completed, the width of the blank is (900~1800)mm, and the drawing is continuously returned to the furnace, with the deformation of each pass being 10%~20%;

[0008] 3) The blank is heated and kept at a temperature of 990°C to 1040°C for 60min to 180min, and radially stretched for 2 to 3 times on an 8000T fast forging machine, with a deformation of 25% to 50% in each time. After the radial stretching is completed, the blank width is (800 to 1500) mm, and the stretching is continuously returned to the furnace, with a deformation of 10% to 20% in each time.

[0009] 4) The blank is heated and kept warm in the temperature range of 990℃~1040℃ for 30min~150min, and the material is shaped and straightened in one fire on an 8000T fast forging machine without preset deformation. The material is air-cooled after forging.

[0010] Preferably, the step 1 uses GH4169 alloy, the ingot of which is cast by a triple melting process of vacuum induction melting, protective atmosphere electroslag remelting, and vacuum consumable melting, the ingot diameter is 420 mm to 550 mm, and the chemical composition is as follows: carbon ≤ 0.06%, chromium 17.00% to 21.00%, nickel 50.00% to 55.00%, cobalt ≤ 1.0%, molybdenum 2.80% to 3.30%, aluminum 0.30% to 0.70%, titanium 0.75% to 1.15%, niobium 4.75% to 5.50%, boron ≤ 0.006%, magnesium ≤ 0.01%, manganese ≤ 0.35%, silicon ≤ 0.35%, sulfur ≤ 0.015%, phosphorus ≤ 0.015%, copper ≤ 0.30%, tantalum ≤ 0.10%, and the remainder is iron.

[0011] Preferably, the forging process of step 3 and step 4 requires that the forging clamps and the tooling be fully preheated to above 350°C, and asbestos be covered at the clamp contact position on the material surface. After the finished slab is stretched, the size of the blank (thickness × width × length) is (45~130)×(800~1500)×L.

[0012] Preferably, in the forging process described in steps 3 and 4, after each pressing in the thickness direction, a shaping and widening pass is required in the width direction to ensure that the material has no side protruding areas, reduce the subsequent material machining amount, and improve the yield rate.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the present invention can solve the problems existing in the prior art such as small slab size, rapid forging temperature drop, and narrow forging window range, and can obtain slabs with smaller thickness and larger specifications through free forging, and improve the surface structure of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The high-magnification structure of the 90mm thick slab material: a) core, b) edge. DETAILED DESCRIPTION

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0016] See also Figure 1 The present invention provides a technical solution: a method for free forging a large-size GH4169 high-temperature alloy slab, which specifically includes the following steps:

[0017] Step 1: Keep the temperature within the range of 1060°C to 1140°C, set the holding time to 2h to 12h according to the temperature of the material when it enters the furnace, and perform at least one fire of upsetting and drawing deformation on an 8000T fast forging machine, with the deformation amount of upsetting being 20% to 50%, the deformation amount of drawing being 18% to 35%, and the deformation amount of each pass being 10% to 20%;

[0018] Step 2: heating and holding the blank in a temperature range of 1010° C. to 1060° C. for 60 to 210 minutes, performing at least two upsetting and drawing cycles on an 8000T high-speed forging machine, wherein the deformation amount of each drawing cycle is 30% to 60%, and the width of the blank after radial drawing is (900 to 1800) mm. The drawing cycle is continuously reheated, and the deformation amount of each pass is 10% to 20%;

[0019] Step 3, heating and holding the blank in a temperature range of 990° C. to 1040° C. for 60 min to 180 min, and performing radial drawing on an 8000T fast forging machine for 2 to 3 passes, with a deformation of 25% to 50% in each pass. After the radial drawing is completed, the blank width is (800 to 1500) mm, and the drawing is continuously re-melted, with a deformation of 10% to 20% in each pass.

[0020] Step 4: Heat and hold the blank in a temperature range of 990° C. to 1040° C. for 30 to 150 minutes, perform one-fire material shaping and straightening on an 8000T high-speed forging machine without presetting the deformation amount, and air-cool the material after forging.

[0021] Example 1

[0022] A method for free forging a large-size GH4169 high-temperature alloy slab comprises the following steps:

[0023] Step 1, forging the GH4169 alloy ingot at 1110° C., keeping the temperature for 11 hours, and performing upsetting deformation for one time with a deformation amount of 20%;

[0024] Step 2: keep the blank at 1090℃ for 120min, and perform upsetting deformation for 2 times with a deformation of 30%;

[0025] Step 3, the blank is subjected to 2-fire axial drawing forging at 1050°C with a deformation of 45%;

[0026] Step 4: The intermediate billet is subjected to first heat shaping and straightening at 1040°C without preset deformation, and then air-cooled in the factory to obtain the finished alloy slab.

[0027] Example 2

[0028] A method for free forging a large-size GH4169 high-temperature alloy slab comprises the following steps:

[0029] Step 1: Forging the GH4169 alloy ingot at 1105° C., keeping the temperature for 12 hours, and performing upsetting deformation for one time with a deformation amount of 23%;

[0030] Step 2: keep the blank at 1100°C for 120 minutes and perform upsetting deformation for 2 times with a deformation amount of 30%;

[0031] Step 3, the blank is subjected to 2-fire axial drawing forging at 1050°C with a deformation of 40%;

[0032] Step 4: The intermediate billet is subjected to first heat shaping and straightening at 1040°C without preset deformation, and then air-cooled in the factory to obtain the finished alloy slab.

[0033] Example 3

[0034] A method for free forging a large-size GH4169 high-temperature alloy slab comprises the following steps:

[0035] Step 1: Forging the GH4169 alloy ingot at 1100° C., keeping the temperature for 12 hours, and performing upsetting deformation for one time with a deformation amount of 25%;

[0036] Step 2: keep the blank at 1090℃ for 120min, and perform upsetting deformation for 2 times with a deformation of 30%;

[0037] Step 3, the blank is subjected to 2-fire axial drawing forging at 1040°C with a deformation of 40%;

[0038] Step 4: The intermediate billet is subjected to first heat shaping and straightening at 1040°C without preset deformation, and then air-cooled in the factory to obtain the finished alloy slab.

[0039] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for free forging large-size GH4169 high-temperature alloy slabs, characterized in that: The following steps are involved: Step 1, keeping the temperature within the range of 1060°C to 1140°C, setting the holding time for 2h to 12h according to the temperature of the material when entering the furnace, and performing at least one fire of upsetting and drawing deformation on an 8000T fast forging machine, with the deformation amount of upsetting being 20% to 50%, the deformation amount of drawing being 18% to 35%, and the deformation amount of each pass being 10% to 20%; Step 2, heating and holding the blank in a temperature range of 1010° C. to 1060° C. for 60 min to 210 min, performing at least two upsetting and drawing cycles on an 8000T high-speed forging machine, wherein the deformation amount of each drawing cycle is 30% to 60%, and the width of the blank after radial drawing is (900 to 1800) mm, and the drawing cycle is continuously reheated, and the deformation amount of each pass is 10% to 20%; Step 3, heating and holding the blank in a temperature range of 990° C. to 1040° C. for 60 min to 180 min, and radially stretching the blank for 2 to 3 times on an 8000T fast forging machine, with a deformation of 25% to 50% in each time. After the radial stretching is completed, the blank width is (800 to 1500) mm, and the stretching is continuously re-melted, with a deformation of 10% to 20% in each time. Step 4: Heat and hold the blank in a temperature range of 990° C. to 1040° C. for 30 to 150 minutes, perform one-fire material shaping and straightening on an 8000T high-speed forging machine without presetting the deformation amount, and air-cool the material after forging.

2. The method for free forging a large-sized GH4169 high-temperature alloy slab according to claim 1, characterized in that: In the step 1, GH4169 alloy is selected, and its chemical composition is as follows: carbon ≤ 0.06%, chromium 17.00% to 21.00%, nickel 50.00% to 55.00%, cobalt ≤ 1.0%, molybdenum 2.80% to 3.30%, aluminum 0.30% to 0.70%, titanium 0.75% to 1.15%, niobium 4.75% to 5.50%, boron ≤ 0.006%, magnesium ≤ 0.01%, manganese ≤ 0.35%, silicon ≤ 0.35%, sulfur ≤ 0.015%, phosphorus ≤ 0.015%, copper ≤ 0.30%, tantalum ≤ 0.10%, and the remainder is iron.

3. The method for free forging large-sized GH4169 high-temperature alloy slabs according to claim 2, characterized in that: In step 1, the GH4169 alloy ingot is cast by a triple melting process of vacuum induction melting, protective atmosphere electroslag remelting, and vacuum consumable melting.

4. The method for free forging large-sized GH4169 high-temperature alloy slabs according to claim 1, characterized in that: The forging process of step 3 and step 4 requires that the forging clamps and the tooling be fully preheated to above 350°C, and asbestos be covered at the clamp contact position on the material surface. After each pass of pressing in the thickness direction, a pass of shaping and widening is required in the width direction to ensure that the material has no side protruding areas, reduce the subsequent material machining amount, and improve the yield rate.

Images