A precision forming method and die for ultra-large complex turbine disk forgings

Abstract

The present invention provides a method for precision zoned die forging of ultra-large turbine disk forgings, comprising the following steps: Step 1, dividing the ultra-large turbine disk forging into two areas: a central hub and spoke area and an outer spoke rim area, wherein pre-forging mainly forms the central hub and spoke area, and final forging mainly forms the outer spoke rim area; Step 2, based on Step 1, designing a pre-forging cavity, including a precision-formed central hub, spoke area, and outer spoke and rim area; Step 3, designing a final forging cavity, including a central hub, spoke area, and outer spoke and rim area; Step 4, based on the above steps, adjusting the shape and size of the pre-forging die and the final forging die according to the filling and forming load conditions of the ultra-large turbine disk forging through simulation; Step 5, simulating and analyzing the forming process of the ultra-large turbine disk forging to ensure that the pre-forging and final forging forming loads are both less than 800MN. The present invention effectively solves the problems of high forming loads and large machining allowances in traditional forging of ultra-large turbine disk forgings.

Description

Technical Field

[0001] The invention relates to a precision forming method and a die for an ultra-large turbine disk forging, belonging to the technical field of metal forging. Background Art

[0002] Ultra-large turbine disks for heavy-duty gas turbines are primarily used in industrial production, the oil and gas industry, and power generation. However, these disks are subject to high forming loads and large machining allowances, making precision forming difficult. For example, a high-temperature alloy turbine disk produced by one company has a diameter of 2.3 meters and a billet weight of 13.5 tons. Precision forming is extremely challenging, and the machining allowance is very large, resulting in extremely low material utilization.

[0003] In response to the above-mentioned problems, those skilled in the art have conducted extensive research. For example, CN105750469 discloses a forging die and forging method for disc-type forgings. This method is based on dividing a circular ring blank into right and left parts, and sequentially forming the right and left parts of the circular ring blank. However, the method is not suitable for the precision forming of ultra-large and complex turbine disc structures. The reasons are: (1) The initial blank of the product involved in this method is a round cake, and the product is a solid structure rather than a circular ring structure. The die structure of the method is not suitable for solid structure products; (2) There are serious problems such as uneven deformation and uneven structure at the junction of the left and right sides that are formed sequentially.

[0004] Therefore, how to solve the problems of high forming load, large machining allowance and coarse mixed grains caused by severe uneven deformation when forging ultra-large and complex structure turbine disks required for heavy gas turbines is an urgent issue to be solved by technical personnel in this field. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for precision zoning forming of ultra-large turbine disks. This method proposes the idea of ​​zoning die forging to address the problems of large forming load, large machining allowance and extremely low material utilization of ultra-large turbine disk forgings.

[0006] Furthermore, the present invention also provides a die for precision partitioned forming (pre-forging and final forging) of an ultra-large turbine disk.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for precision zoned die forging of an ultra-large turbine disk forging comprises the following steps:

[0009] The first step is to divide the forming design of the ultra-large turbine disk forging into two areas: the center hub and spoke area and the outer spoke and rim area; the pre-forging mainly forms the center hub and spoke area, and the final forging mainly forms the outer spoke and rim area;

[0010] Step 2: Based on the first step, design the pre-forging cavity, including the precision-formed center hub, spoke area, outer spoke, and rim area:

[0011] 1) When designing the center hub area, the dimensions should match the final forging being designed;

[0012] 2) When designing the center spoke area, the height of the center spoke area should be 10~40mm lower than the height of the final forging, and the outer side should be 5~20mm lower than the inner side;

[0013] 3) When designing the outer web area, the height dimension at the top of the outer web is 10~120mm higher than the height dimension of the final forging. At the same time, the mold cavity is provided with a positioning boss with a height of 10~30mm;

[0014] 4) When designing the outer rim area, the height dimension at the top of the outer rim is 10~120mm higher than the height dimension of the final forging;

[0015] Step 3: Based on the second step, design the final forging cavity, including the center hub, spoke area, outer spoke, and rim area:

[0016] 1) When designing the center hub area, the final forging cavity height should be 40~80mm higher than the pre-forging cavity to avoid contact between the final forging die and the center hub area;

[0017] 2) When designing the center spoke area, the final forging cavity height should be 40-80mm higher than the pre-forging cavity to avoid contact between the final forging die and the center spoke area;

[0018] 3) When designing the outer web area, the dimensions of the outer web should match those of the final forging;

[0019] 4) When designing the outer rim area, the dimensions of the outer rim should match the final forging.

[0020] Furthermore, based on the above steps, through simulation, the cavity structure dimensions of the pre-forging die and final forging die are optimized according to the filling and forming load conditions of the ultra-large turbine disk forgings; and the forming process of the ultra-large turbine disk forgings is simulated and analyzed to ensure that the forging forming load is less than 800MN.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention relates to a precision partitioned die forging method and die for ultra-large complex turbine disk forgings. Combined with the analysis of numerical simulation results of the forging forming process, it effectively solves the problems of large forming load, large machining allowance and extremely low material utilization rate of ultra-large turbine disk forgings.

[0023] (1) Under the existing 800MN press equipment conditions, the required billet and forging tonnage is reduced from the current 13.5 tons to 10 tons, saving 26% of materials, and saving about 1.5 million yuan in material costs per forging;

[0024] (2) Save a lot of subsequent machining hours and increase efficiency by more than 50%;

[0025] (3) Effectively increase the deformation of the difficult-to-deform area of ​​the forging and reduce the risk of producing coarse grains and mixed grains. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram (cross-sectional view) of the ultra-large turbine disk forging and part forming zones according to Example 1 of the present invention;

[0027] Figure 2 for Figure 1 Schematic diagram of the pre-forging and final forging cavities of the super-large turbine disk;

[0028] Figure 3 Schematic diagram of the forming area of ​​the ultra-large turbine disk pre-forging in Example 1, where 1 and 2 are the main forming areas of the pre-forging center hub and spoke plate;

[0029] Figure 4 Schematic diagram of the forming area of ​​the ultra-large turbine disk pre-forging in Example 1, wherein 3' is the final forging area mainly forming the outer web and rim;

[0030] Figure 5 Schematic diagram of the forming area of ​​the ultra-large turbine disk final forging in Example 1;

[0031] Figure 6 (a) Schematic diagram of the die shape during the final forging of the ultra-large turbine disk forging, (b) schematic diagram of the simulation results of the final forging, and (c) equivalent strain diagram of the final forging in Example 1;

[0032] Figure 7 Schematic diagram comparing the part drawing and the final forging in Example 1. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions of the present invention in conjunction with specific embodiments and drawings. Obviously, the embodiments are only representative of the embodiments of the present invention and are not limited to the described embodiments. Therefore, the following detailed description of the embodiments provided in the drawings is not intended to limit the scope of the invention claimed for protection. 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.

[0034] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. The terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the figures, or the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Example 1

[0036] In this embodiment 1, a pre-forging and final forging zoned die forging method is proposed to address the problems of existing ultra-large turbine disk forgings having a load far exceeding 800MN, large machining allowance, and extremely low material utilization during one-time die forging.

[0037] like Figure 1 As shown, the main body of the super-large turbine disk is in the shape of a disk, and the outer side of the central hub is sequentially composed of an annular central spoke plate area, a spoke plate, an outer spoke plate area and a rim.

[0038] See also Figure 2 , which is a schematic diagram of a specific mold cavity when the partitioned forging is adopted in Example 1 of the invention; wherein, line A is a machined part, line B is a pre-forging cavity, line C is a final forging cavity, and line D is a final forging.

[0039] The method for precision zoned die forging of ultra-large turbine disk forgings of the present invention includes pre-forging and final forging steps. The pre-forging mainly forms the center hub and the spoke area, and the final forging mainly forms the outer spoke and the rim area. The specific steps are as follows:

[0040] Step 1: Divide the forming design of the ultra-large turbine disk forging into two areas: the central hub and spoke area and the outer spoke and rim area;

[0041] Step 2: Based on the first step, design the pre-forging cavity (see Figure 2 The B line in the figure includes the precision-formed center hub, the web area, the outer web area, and the rim area:

[0042] 1) When designing the center hub area, the dimensions should match the final forging being designed;

[0043] 2) When designing the center spoke area, the height of the center spoke area should be 10~40mm lower than the height of the final forging, and the outer side should be 5~20mm lower than the inner side;

[0044] 3) When designing the outer web area, the height dimension at the top of the outer web is 10~120mm higher than the height dimension of the final forging. At the same time, the mold cavity is provided with a positioning boss with a height of 10~30mm;

[0045] 4) When designing the outer rim area, the height dimension at the top of the outer rim is 10~120mm higher than the height dimension of the final forging;

[0046] Step 3: Based on the second step, design the final forging cavity (see Figure 2 The C line in the figure includes the center hub, the spoke area, the outer spokes, and the rim area:

[0047] 1) When designing the center hub area, the final forging cavity height should be 40~80mm higher than the pre-forging cavity to avoid contact between the final forging die and the center hub area;

[0048] 2) When designing the center spoke area, the final forging cavity height should be 40-80mm higher than the pre-forging cavity to avoid contact between the final forging die and the center spoke area;

[0049] 3) When designing the outer web area, the dimensions of the outer web should match those of the final forging;

[0050] 4) When designing the outer rim area, the dimensions of the outer rim should match the final forging.

[0051] Furthermore, based on the above steps, through simulation, the cavity structure dimensions of the pre-forging die and the final forging die are optimized according to the filling and forming load conditions of the ultra-large turbine disk forgings, and the forming process of the ultra-large turbine disk forgings is simulated and analyzed to ensure that the forging forming load is less than 800MN.

[0052] See also Figure 3 Figure 1 shows the forming area of ​​the preforged ultra-large turbine disk of Example 1. The disk has a diameter of 2.3 meters and a billet weight of 13.5 tons. The preforged cavity's central hub area 1 matches the dimensions of the designed final forging. The central spoke area 2 is 10-40 mm lower than the final forging, and the outer side is 5-20 mm lower than the inner side. The outer spoke's top 3 is 10-120 mm higher than the final forging. The mold cavity is equipped with a positioning boss 5 with a height of 10-30 mm. The outer rim's top 4 is 10-120 mm higher than the final forging.

[0053] Figure 4 (a) is a schematic diagram of the die shape during the pre-forging of the ultra-large turbine disk forging of the invention. The pre-forging process is numerically simulated, and the pre-forged part after forming is as follows Figure 4 (b)

[0054] Figure 5This is a schematic diagram of the forming area of ​​the final forging of the ultra-large turbine disk, the subject of the invention. The center hub area 1' of the final forging cavity is 40-80mm higher than the pre-forging cavity, preventing contact between the final forging die and the center hub area. The center spoke area 2' of the final forging cavity is 40-80mm higher than the pre-forging cavity, preventing contact between the final forging die and the center spoke area. The dimensions of the outer spoke area and rim 3' match those of the final forging.

[0055] Figure 6 (a) is a schematic diagram of the die shape during the final forging of the ultra-large turbine disk forging of the invention. The final forging process is numerically simulated, and the final forging after forming is as follows Figure 6 (b) As shown. Figure 6 (c) The equivalent strain diagram of the final forging shows that the deformation uniformity of the forging is effectively improved.

[0056] like Figure 7 The final forging and component drawings of the ultra-large turbine disk, the subject of the invention, are shown. As can be seen, the method of the present invention can produce parts that meet dimensional requirements within the equipment's capabilities. Verification has shown that, using existing 800MN press equipment, the required billet and forging tonnage can be reduced from the current 13.5 tons to 10 tons, saving 26% of material and approximately 1.5 million yuan in material costs per forging. This significantly reduces subsequent machining time and improves efficiency by over 50%.

[0057] In summary, the present invention designs a partitioned forging process to address the problems of high forming load and large machining allowance during traditional forging of ultra-large turbine disk forgings. The method of the present invention can process parts that meet size requirements within the equipment capacity.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for precision zoned die forging of ultra-large turbine disk forgings, characterized in that: The following steps are involved: Step 1: Divide the forming design of the ultra-large turbine disk forging into two areas: the central hub spoke area and the outer spoke rim area. Pre-forging is mainly used to form the central hub spoke area, while final forging is mainly used to form the outer spoke rim area. Step 2: Based on the first step, design the pre-forging cavity, including the precision-formed center hub, spoke area, outer spoke, and rim area: 1) When designing the center hub area, the dimensions should match the final forging being designed; 2) When designing the center spoke area, the height of the center spoke area should be 10~40mm lower than the height of the final forging, and the outer side should be 5~20mm lower than the inner side; 3) When designing the outer web area, the height dimension at the top of the outer web is 10~120mm higher than the height dimension of the final forging. At the same time, the mold cavity is provided with a positioning boss with a height of 10~30mm; 4) When designing the outer rim area, the height dimension at the top of the outer rim is 10~120mm higher than the height dimension of the final forging; Step 3: Based on the second step, design the final forging cavity, including the center hub, spoke area, outer spoke, and rim area: 1) When designing the center hub area, the final forging cavity height should be 40~80mm higher than the pre-forging cavity to avoid contact between the final forging die and the center hub area; 2) When designing the center spoke area, the final forging cavity height should be 40-80mm higher than the pre-forging cavity to avoid contact between the final forging die and the center spoke area; 3) When designing the outer web area, the dimensions of the outer web should match those of the final forging; 4) When designing the outer rim area, the dimensions of the outer rim should match the final forging.

2. The method for precision zoning forming of ultra-large turbine disk forgings according to claim 1 is characterized in that it also includes simulation to adjust the shape and size of the pre-forging die and the final forging die according to the filling and forming load conditions of the ultra-large turbine disk forgings.

3. The method for precision zoning forming of ultra-large turbine disk forgings according to claim 1 is characterized in that the forming process of the ultra-large turbine disk forgings is simulated and analyzed to ensure that the forging forming load is less than 800MN.

4. The method for precision zoning forming of ultra-large turbine disk forgings according to any one of claims 1 to 3, characterized in that: The ultra-large turbine disc forging is an ultra-large turbine disc with a diameter greater than 1.9 meters and a blank weight of 10 tons.

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