Forging forming process for high-temperature alloy material

Abstract

The invention discloses a forging forming process of a small ring forging made of a high-temperature alloy material (GH4169), and aims to solve the problem that the internal quality is unstable due to the fact that the forging deformation of the small ring forging (the outer diameter is smaller than phi 180) is difficult to control by a manual ring throwing method in the prior art. According to the process, a traditional forging process is optimized into three-fire forging, and the forging temperature, the forging ratio and the time parameter of each heating number are adjusted, so that the internal structure of the forge piece is improved, and the mechanical property is improved. The method specifically comprises the following steps: in the first fire, drawing-out and upsetting are carried out at the temperature of 1120 DEG C (the forging ratio is 1.7); in the second fire, drilling, chambering and spheroidizing are carried out at the temperature of 1,120 DEG C (the forging ratio is 1.3); and shaping at 1040 + / -5 DEG C (the forging ratio is 1.4, the forging time is less than or equal to 10 seconds, and the finish forging temperature is greater than or equal to 930 DEG C) in the third fire. After the method is applied, the average grain size of the forge piece is improved from grade 4 to grade 5 or above, the method is suitable for high-temperature alloys of other brands, and the consistency and stability of the internal quality of the forge piece can be guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of forging technology for high-temperature alloy materials, and specifically relates to the forging process of GH4169 high-temperature alloy small ring forgings (outer diameter less than Φ180). Background Technology

[0002] GH4169 high-temperature alloy, due to its excellent comprehensive properties (such as high yield strength, fatigue resistance, and corrosion resistance) within the temperature range of -253 to 700℃, is widely used in the manufacture of small ring forgings in fields such as aero-engines and nuclear energy. Currently, large and medium-sized ring forgings with a diameter greater than 150mm are generally forged using ring rolling mills, a mature process; however, small ring forgings with an outer diameter less than Φ180mm still rely on traditional manual ring polishing methods, which have significant drawbacks. Deformation control is difficult: manual ring polishing makes it difficult to accurately control the forging deformation, resulting in uneven internal structure of the forging and grain size reaching only level 4 (lower than the design requirement of level 5). Poor quality stability: Existing methods are prone to problems such as mixed crystals and intergranular cracking, resulting in large fluctuations in mechanical properties (such as tensile strength and hardness); Process limitations: The traditional one-fire forging process of punching, polishing, and shaping after two forgings is prone to cracking when punching in the range of 980~1010℃, and the high final forging temperature (≥1100℃) can easily lead to grain coarsening.

[0003] Although some studies have improved performance through medium-temperature deformation heat treatment (such as billet opening at 1130~1160℃ + rolling at 980~1020℃) or improved the uniformity of large forgings by using irregular integral rolling, none of them have solved the problem of controlling the deformation of small ring forgings by artificial ring polishing. Summary of the Invention

[0004] The present invention aims to solve the problems of difficulty in controlling the forging deformation and unstable internal quality when using the manual ring polishing method for GH4169 high temperature alloy small ring forgings (outer diameter less than Φ180) in the prior art. By optimizing the process scheme, the internal structure of the forging is improved, the mechanical properties are enhanced, and the consistency of product quality is guaranteed.

[0005] This solution describes a forging process for a high-temperature alloy material, specifically a GH4169 small ring forging. The process steps are as follows: Material cutting: Determine the blank specifications based on the product dimensions; First stage of forging: The billet is heated to 1120°C and then drawn and uptaked. The forging ratio is 1.7. Drilling: Drill a Φ50 hole in the upsetting billet to ensure that the mandrel can pass through; Second forging: The billet is reheated to 1120°C, and then expanded and polished. The forging ratio is 1.3. Third stage of forging: The billet is heated to 1040±5°C and forged. The forging ratio is 1.4 and the forging time is controlled within 10 seconds to ensure that the final forging temperature is not less than 930°C.

[0006] Furthermore, the outer diameter of the small ring forging is less than Φ180.

[0007] This invention breaks down the traditional forging process into a three-stage forging process, adjusting the heating temperature, forging ratio, and time parameters at each stage to achieve precise control over the deformation amount, and has the following beneficial technical effects: 1. Improved internal structure: By precisely controlling the deformation amount and temperature of each forging, the average grain size of the forgings is improved from level 4 in the traditional process to level 5 or above, and the uniformity of the structure is significantly improved. 2. Enhanced quality stability: Three-stage forging optimizes deformation distribution, improves internal microstructure uniformity, reduces mixed grains and intergranular cracking, and improves the consistency of mechanical properties (such as tensile strength and hardness). 3. Improved mechanical properties: A stable deformation process reduces fluctuations in the mechanical properties (such as strength and toughness) of forgings, resulting in improved overall performance; 4. Wide applicability: In addition to GH4169, this process can be extended to the forging of small ring forgings of other grades of high-temperature alloys, and has universal application value; 5. Stable quality: By controlling the deformation amount step by step, the defects of the manual ring polishing method are compensated for, and the consistency and stability of the internal quality of the forgings are greatly improved.

[0008] 6. Efficiency and cost optimization: Final forging time ≤ 10 seconds to avoid grain coarsening and reduce subsequent heat treatment costs. Detailed Implementation

[0009] The process of the present invention will be described in detail below with reference to specific steps: 1. Blanking: Based on the size requirements of the small ring forging (outer diameter Φ160), select GH4169 billet with Φ80×120mm.

[0010] II. First Fire Forging: Place the billet into a heating furnace, heat it to 1120°C, and hold it at that temperature for 1.5 hours; After removing the billet, it is drawn on a forging hammer to increase the length from 120mm to 200mm, and then upsetting to Φ100×100mm to ensure a forging ratio of 1.7.

[0011] 3. Drilling: Use a drilling machine to drill a Φ50 through hole in the center of the billet after upsetting, ensuring that the hole wall is smooth so that the mandrel (Φ48mm) can pass through smoothly.

[0012] IV. Second Fire Forging: The drilled billet is reheated to 1120°C and held for 1 hour; After inserting the mandrel, the hole is enlarged and polished to increase the outer diameter from Φ100mm to Φ140mm, while the thickness is controlled at 40mm, and the forging ratio is 1.3.

[0013] V. Third Fire Forging: Heat the billet to 1040°C (±5°C) and hold for 40 minutes; After removal, it is quickly shaped and forged to control the outer diameter to Φ160mm, the thickness to 25mm, and the forging ratio to 1.4; The forging process was strictly timed to ensure that the total time was ≤10 seconds, and the final forging temperature was measured to be 950°C (≥930°C).

[0014] Testing revealed that the average grain size of the ring forgings produced in this embodiment was grade 5.5, a significant improvement over the traditional process (grade 4). Furthermore, the mechanical properties such as hardness and tensile strength of the same batch of products showed a deviation of ≤3%, indicating a substantial improvement in quality stability.

Claims

1. A forging process for high-temperature alloy materials, characterized in that: The high-temperature alloy material is GH4169 small ring forging, and the process steps are as follows: Material cutting: Determine the blank specifications based on the product dimensions; First stage of forging: The billet is heated to 1120°C and then drawn and uptaked. The forging ratio is 1.

7. Drilling: Drill a Φ50 hole in the upsetting billet to ensure that the mandrel can pass through; Second forging: The billet is reheated to 1120°C, and then expanded and polished. The forging ratio is 1.

3. Third stage of forging: The billet is heated to 1040±5°C and forged. The forging ratio is 1.4 and the forging time is controlled within 10 seconds to ensure that the final forging temperature is not less than 930°C.

2. The forging process for high-temperature alloy materials according to claim 1, characterized in that: The outer diameter of the small ring forging is less than Φ180.