Integral rolling and metallurgical quality evaluation method for TC4 integral blade ring forgings

Abstract

The invention provides a forming and metallurgical quality evaluation method of a TC4 alloy integral blade ring forging, which can meet the requirements of an aero-engine on the integral blade ring forging. The method comprises the following steps: firstly, determining the shape and size of a forging according to a part drawing provided by design, calculating the blanking weight according to a volume invariant principle, and determining the specification and size of a bar; and then carrying out forming process design, determining a process route and process parameters, and carrying out process verification by utilizing finite element simulation. And after the scheme passes verification, trial-manufacturing of the forge piece is carried out, acceptance inspection is carried out according to the metallurgy quality evaluation method provided by the invention, and the matching performance of the standard technical index and the forming process is verified. The method has the advantages that the problem that the product lacks a special metallurgical quality evaluation method and a forming process matched with the method is solved, and the metallurgical quality control level of the TC4 alloy integral blade ring forging can be improved, so that the quality reliability of the forging is improved, and the flight safety of an aero-engine is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of manufacturing integral blade ring forgings for aircraft engines, and in particular to an integral rolling and metallurgical quality assessment method for TC4 integral blade ring forgings. Background Art

[0002] In order to further improve the thrust-to-weight ratio of aircraft engines, integral blade ring components with lightweight manufacturing as the goal have begun to be gradually applied to aircraft engines. For such new structural forgings, there is currently a lack of special acceptance standards for metallurgical quality assessment. Only ordinary titanium alloy ring standards can be used for metallurgical quality assessment, mainly testing room temperature hardness, room temperature tensile, high temperature tensile, high temperature endurance and high and low magnification structures. However, the above metallurgical quality assessment method has two drawbacks. First, in terms of test items, in addition to mechanical properties such as hardness, tensile, and endurance, room temperature impact performance is also an important mechanical property indicator for measuring blade quality. Second, in terms of sampling direction, ring forgings are mainly tested for physical and chemical tests along the chord direction, while for blades, mechanical properties are mainly tested along the blade body direction, which is equivalent to the radial direction of the ring forging. As we all know, due to the existence of rolling deformation streamlines, there may be differences in mechanical properties in different sampling directions. Therefore, the metallurgical quality assessment method currently used cannot fully achieve the control of the metallurgical quality of integral blade ring forgings.

[0003] In addition to metallurgical quality assessment issues, considering that the integral blade ring forging must take into account the organization and mechanical properties of the ring and blade at the same time, there are strict requirements for deformation and deformation temperature. However, the TC4 alloy integral blade ring is still a common ring rolling process, and the forging process parameters need to be optimized to match the organization and performance requirements of the blade ring forging. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problems. This patent proposes a TC4 alloy integral blade ring rolling forming and forging metallurgical quality assessment method, which is used to guide the rolling forming of TC4 alloy integral blade ring forgings and the metallurgical quality assessment of forgings, to achieve the improvement of the metallurgical quality control level of TC4 alloy integral blade ring forgings, thereby improving the quality reliability of forgings and ensuring the flight safety of aircraft engines. A TC4 integral blade ring forging overall rolling and metallurgical quality assessment method is specially provided.

[0005] The TC4 alloy integral blade ring forgings for aircraft engines need to take into account the microstructure and performance of the ring and blade at the same time. Currently, there is a lack of forming processes that match them, and the existing metallurgical quality assessment items and sampling directions cannot fully achieve the metallurgical quality control of forgings. The purpose of the present invention is to propose a TC4 alloy integral blade ring forging rolling forming and forging metallurgical quality assessment method, so as to improve the metallurgical quality control level of such forgings.

[0006] The present invention provides a method for integral rolling and metallurgical quality assessment of TC4 integral blade ring forgings, which is characterized by:

[0007] The present invention mainly provides a forming and metallurgical quality assessment method for TC4 alloy integral blade ring forgings, which can meet the needs of aircraft engines for the integral blade ring forgings. First, according to the part drawing provided by the design, the shape and size of the forging are determined, and the blanking weight is calculated according to the principle of constant volume, and the specifications and dimensions of the bar are determined. Then the forming process design is carried out, the process route and process parameters are determined, and the process verification is carried out using finite element simulation. After the scheme is verified, the forging is trial-produced, and acceptance is carried out according to the metallurgical quality assessment method proposed in the name of the invention, and the matching of the standard technical indicators and the forming process is verified.

[0008] The specific steps include:

[0009] (1) Forging structure design. According to the part design drawing provided by the design unit, the integral leaf ring forging drawing is determined. Considering that the integral leaf ring is a new structure forging, in order to ensure that the forging can meet the subsequent machining requirements, the cross-sectional shape is selected as a rectangular ring, and the single-side margin can be controlled at 5 to 10 mm, thereby obtaining the integral leaf ring forging dimensions, including the outer diameter D, inner diameter d, and height h.

[0010] (2) Calculate the weight of the bar material. According to the principle of constant volume, the volume V of the raw material bar can be approximately equal to the volume of the ring forging plus the volume of the punching core material, that is, The weight of the rod is m=ρV, where ρ is the density of the titanium alloy. The specification and height of the rod are determined according to the weight.

[0011] (3) Forging process design. The process route of the integral leaf ring forging is upsetting → punching → hole expansion → rolling. In order to ensure that the integral leaf ring forging can take into account the performance of the ring part and the blade part, the deformation amount of the last process is controlled within 14% to 20%. The deformation amount distribution of the previous processes is determined in sequence according to the final deformation amount.

[0012] (4) Process simulation verification. Determine the material thermophysical parameters according to the type of titanium alloy, build a finite element model, and use finite element software to simulate the rolling process of the integral blade ring forging to predict whether the final deformation and final rolling temperature can meet the process requirements.

[0013] (5) Trial production of forgings. The bar is heated to Tβ-(20℃-50℃) with a heating coefficient of 0.4mm / min, then upsetting and punching are performed, and the ring is returned to the furnace and reheated to the rolling temperature with a heating coefficient of 0.6mm / min. The ring is expanded and rolled to the size specified in the forging drawing, and air-cooled to room temperature. The forging is then heat treated.

[0014] (6) Metallurgical quality assessment of forgings. Samples were taken from the dissected parts and tested for hardness, room temperature tensile, high temperature tensile, high temperature endurance, room temperature impact, and high and low magnification structures. Figure 2 The specific detection is shown in Table 1.

[0015] Table 1 TC4 integral blade ring metallurgical quality assessment plan

[0016]

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The overall rolling and metallurgical quality assessment method of TC4 integral blade ring forgings described in the present invention solves the problem that this type of product lacks a dedicated metallurgical quality assessment method and a forming process that matches it, and can achieve an improvement in the metallurgical quality control level of TC4 alloy integral blade ring forgings, thereby improving the quality reliability of forgings and ensuring the flight safety of aircraft engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 Design a schematic diagram of the technical implementation plan for the simulated test piece;

[0021] Figure 2 Schematic diagram of sampling of physical and chemical properties of integral blade ring forgings. DETAILED DESCRIPTION

[0022] The present invention will be further explained below in conjunction with specific implementation plans, but the present invention is not limited thereto. The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the restrictive conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0023] The present invention mainly provides a forming and metallurgical quality assessment method for TC4 alloy integral blade ring forgings, which can meet the requirements of forming and acceptance of TC4 alloy integral blade ring forgings for aircraft engines. To this end, the main technical solution of the present invention includes the following steps:

[0024] (1) Forging structure design. According to the part design drawing provided by the design unit, the integral leaf ring forging drawing is determined. Considering that the integral leaf ring is a new structure forging, in order to ensure that the forging can meet the subsequent machining requirements, the cross-sectional shape is selected as a rectangular ring, and the single-side margin can be controlled at 5 to 10 mm, thereby obtaining the integral leaf ring forging dimensions, including the outer diameter D, inner diameter d, and height h.

[0025] (2) Calculate the weight of the bar. According to the principle of constant volume, the volume V of the raw material bar can be approximately equal to the volume of the ring forging plus the volume of the punching core material, that is, V = V0 + π1 / 4h (D2-d2). The weight of the bar is m = ρV, where ρ is the density of the titanium alloy.

[0026] (3) Forging process design. The process route of the integral leaf ring forging is upsetting → punching → hole expansion → rolling. In order to ensure that the integral leaf ring forging can take into account the performance of the ring part and the blade part, the deformation amount of the last process is controlled within 14% to 20%. The deformation amount distribution of the previous processes is determined in sequence according to the final deformation amount.

[0027] (4) Process simulation verification. Determine the material thermophysical parameters according to the type of titanium alloy, build a finite element model, and use finite element software to simulate the rolling process of the integral blade ring forging to predict whether the final deformation and final rolling temperature can meet the process requirements.

[0028] (5) Trial production of forgings. The bar is heated to Tβ-(20℃-50℃) with a heating coefficient of 0.4mm / min, then upsetting and punching are performed, and the ring is returned to the furnace and reheated to the rolling temperature with a heating coefficient of 0.6mm / min. The ring is expanded and rolled to the size specified in the forging drawing, and air-cooled to room temperature. The forging is then heat treated.

[0029] (6) Metallurgical quality assessment of forgings. In addition to tangential specimens, radial specimen testing is required to conduct hardness, room temperature tensile, high temperature tensile, high temperature endurance, room temperature impact, and high and low magnification microstructure testing. Specifically:

[0030] The technical index requirements of the room temperature tensile mechanical properties of TC4 alloy integral blade ring forgings are: tensile strength σb = 950 ~ 1080MPa, yield strength σ0.2 ≥ 825MPa, elongation after fracture δ5 ≥ 12%, and section shrinkage ψ ≥ 15%;

[0031] The technical index requirements of the tensile mechanical properties of TC4 alloy integral blade ring forgings at 400℃ are: tensile strength σb≥615MPa, elongation after fracture δ5≥12%, and section shrinkage ψ≥40%;

[0032] The technical index requirements for the endurance mechanical properties of TC4 alloy integral blade ring forgings at 400℃ and 570MPa loading stress are: the duration of high temperature endurance specimen fracture τ≥100h;

[0033] The technical index requirements for the impact mechanical properties of TC4 alloy integral blade ring forgings at room temperature are: impact energy Aku2 ≥ 32J;

[0034] The technical index requirements for macrostructure of TC4 integral blade ring forgings are: cut a transverse (cross-section in the diameter direction) sample from the forging or test ring in the supply state to check the macrostructure, and cracks, shrinkage holes, pores, inclusions, segregation and other metallurgical defects are not allowed. The macrostructure should comply with GJB 2220-1994 Figure 1 Requirements for level 1 to 4 images.

[0035] The technical index requirements for the macrostructure of TC4 integral blade ring forgings are: the specimens are cut from the forgings or test rings in the supply state, and the macrostructure should comply with GJB 2220-1994 Figure 2 Requirements for pictures of levels 2 to 6.

[0036] Matters not covered by the present invention are known technologies.

[0037] 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 integral rolling and metallurgical quality assessment of TC4 integral blade ring forgings, characterized in that: First, the shape and size of the forging are determined according to the part drawing provided by the design. The blanking weight is calculated according to the principle of constant volume, and the specifications and size of the bar are determined. Then the forming process is designed, the process route and process parameters are determined, and the process is verified using finite element simulation. After the scheme is verified, the forgings are trial-produced and accepted according to the metallurgical quality evaluation method proposed in the name of the invention, and the matching of the standard technical indicators and the forming process is verified.

2. The method for integral rolling and metallurgical quality assessment of TC4 integral blade ring forgings according to claim 1, characterized in that: The specific steps include: (1) Forging structure design: According to the part design drawing provided by the design unit, the integral leaf ring forging drawing is determined, the cross-sectional shape is selected as a rectangular ring, and the single-side margin is controlled at 5 to 10 mm, thereby obtaining the integral leaf ring forging dimensions, including the outer diameter D, inner diameter d and height h; (2) Calculate the weight of the bar material; according to the principle of constant volume, the volume V of the raw material bar can be approximately equal to the volume of the ring forging plus the volume of the punching core material, that is, The weight of the rod is m=ρV, where ρ is the density of the titanium alloy; the specification and height of the rod are determined according to the weight; (3) Forging forming process design; the process route of the integral blade ring forging is upsetting → punching → hole expansion → rolling. In order to ensure that the integral blade ring forging can take into account the performance of the ring part and the blade part, the deformation amount of the last process is controlled within 14% to 20%; the deformation amount distribution of the previous processes is determined in sequence according to the final deformation amount; (4) Process simulation verification: Determine the material thermophysical parameters according to the type of titanium alloy, build a finite element model, use finite element software to simulate the rolling process of the integral blade ring forging, and predict whether the final deformation and final rolling temperature can meet the process requirements; (5) Trial production of forgings: The bar is heated to Tβ-(20℃-50℃) with a heating coefficient of 0.4mm / min, then upsetting and punching are performed, the ring is returned to the furnace and reheated to the rolling temperature with a heating coefficient of 0.6mm / min, the ring is expanded and rolled to the size specified in the forging drawing, and air-cooled to room temperature; then the forging is heat treated; (6) Metallurgical quality assessment of forgings: Samples are taken from dissected parts and tested for hardness, room temperature tensile strength, high temperature tensile strength, high temperature endurance, room temperature impact, and high and low magnification microstructures.

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