Weak rigidity welding casing blade bending deformation control method

Abstract

The invention relates to the technical field of aero-engines, in particular to a weak-rigidity welding casing blade bending deformation control method which mainly comprises the following steps: firstly, setting the steps of performing electron beam welding on a blade, an inner casing and an outer casing: positioned welding, penetration welding and modification welding; then setting the electron beam welding sequence of strip welding seams between the blade and the inner casing as well as between the blade and the outer casing as the third welding seam, the fourth welding seam, the first welding seam and the second welding seam; and finally, the electron beam welding step in the first step is executed on the four welding seams according to the electron beam welding sequence determined in the second step. According to the mechanism of generation of welding buckling deformation, the welding buckling deformation of the blade is compensated by setting the steps of weak-rigidity cartridge receiver blade electron beam welding and setting the welding sequence, the straightness of the cartridge receiver blade is controlled, meanwhile, the influence on stress concentration parts such as a blade body anti-icing groove hole is reduced, the probability of fatigue cracks is reduced, and the service life of the cartridge receiver blade is prolonged. Therefore, the service life of the engine case is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengines, and in particular to a method for controlling bending deformation of weak-rigidity welded casing blades. Background Art

[0002] The titanium alloy welded casing is a widely used casing structure in aircraft engines, which is composed of an outer casing, an inner casing, and blades. It has both manufacturing cost and efficiency advantages. However, due to the thin casing wall thickness and the use of titanium alloy materials with low elastic modulus and large rebound, the casing has weak rigidity and is easy to deform. When the casing blades are welded to the inner and outer casings, the warping deformation caused by multiple welding passes is superimposed, resulting in bending deformation and increased residual stress in the blades as a whole, especially for blades without machining allowances, whose size cannot be guaranteed by reserving machining allowances.

[0003] At present, rigid clamping and limiting tooling is usually used to control the deformation of the blades when welding titanium alloy welding casing blades. Although the deformation can be reduced to a certain extent, due to the weak rigidity and large springback of titanium alloy blades and casings, once the clamping limit is released, the blades will still have a large bending deformation, and the blade straightness may easily exceed the standard. The risk of repair and manufacturing is relatively high, and large residual stress is generated in the blade body. Under vibration conditions, the risk of fatigue cracks in stress concentration areas such as blade body holes and grooves is aggravated. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for controlling the bending deformation of blades in a weakly rigid welded casing, which is used to solve the problem that due to the weak rigidity of the titanium alloy welded structure casing, the blade body bends and deforms after welding, which does not meet the design requirements for blade straightness and affects the working performance.

[0005] The technical solution adopted by the present invention is: a method for controlling bending deformation of weak rigidity welded casing blades, comprising the following steps:

[0006] Step 1: Set the steps of electron beam welding of blades with inner casing and outer casing as follows: positioning welding → penetration welding → finishing welding;

[0007] Step 2: Set the order of electron beam welding of the strip welds between the blade and the inner casing and the outer casing as follows:

[0008] The third weld → the fourth weld → the first weld → the second weld;

[0009] Step 3: Perform the electron beam welding steps in step 1 on the four welds in the order of electron beam welding determined in step 2.

[0010] The beneficial effects of the present invention are as follows: according to the mechanism of welding warping deformation, the present invention compensates for the welding warping deformation of the blades by setting the steps of electron beam welding of weak rigidity casing blades and setting the welding sequence, and realizes the control of the straightness of the casing blades. On the one hand, the design requirements for blade straightness control can be achieved. On the other hand, the improvement of blade straightness can reduce the residual stress of the blade body, reduce the impact on stress concentration parts such as the anti-icing slot holes of the blade body, reduce the probability of fatigue cracks, and thus increase the service life of the engine casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of a titanium alloy welded structure casing;

[0012] Figure 2 It is a schematic diagram of the partial structure of the titanium alloy welded structure casing;

[0013] Figure 3 is a schematic diagram of the blade structure;

[0014] Among them: 1. Blade; 2. Inner casing; 3. Outer casing; 4. Weld; 4.1. First weld; 4.2. Second weld; 4.3. Third weld; 4.4. Fourth weld. DETAILED DESCRIPTION

[0015] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative work belong to the scope of protection of the present invention.

[0016] First, if Figure 1 and Figure 2 It can be seen from the structural schematic diagram of the titanium alloy welded structure casing and the blade structural schematic diagram shown in that the titanium alloy welded structure casing includes a blade 1, an inner casing 2, and an outer casing 3;

[0017] The blade 1 is fixed between the inner casing 2 and the outer casing 3 by welding, that is, welding seams 4 are provided between the blade 1 and the inner casing 2 and the outer casing 3 .

[0018] like Figure 3 It can be seen from the schematic diagram of the blade structure that the blade 1 is a hollow structure, and when it is welded with the inner casing 2 and the outer casing 3, it has four welds 4, namely: a first weld 4.1 and a second weld 4.2 formed by welding with the inner casing 2, and a third weld 4.3 and a fourth weld 4.4 formed by welding with the outer casing 3;

[0019] Each weld 4 will produce warping deformation during welding. Since the cantilever of the blade 1 relative to the inner casing 2 and the outer casing 3 is long and the rigidity is weak, the deformation caused by welding is mainly manifested on the blade 1, resulting in a low straightness of the blade 1. The present invention uses the welding warping deformation law to provide a method for controlling the bending deformation of a blade of a weak rigidity welding casing, comprising the following steps:

[0020] Step 1: The steps of electron beam welding of blade 1, inner casing 2 and outer casing 3 are set as follows: tack welding → penetration welding → finishing welding, wherein the specific welding process parameters of tack welding, penetration welding and finishing welding are shown in Table 1:

[0021] Table 1 Blade electron beam welding parameters

[0022]

[0023] In this embodiment, the welding of the blade 1 adopts an electron beam welding method with high energy density, low heat input, small deformation and stable process, which can greatly improve the stability of the control of the welding bending deformation of the blade 1;

[0024] Step 2: Set the order of electron beam welding of the four welds 4 between the blade 1 and the inner casing 2 and the outer casing 3 as follows:

[0025] Third weld 4.3→fourth weld 4.4→first weld 4.1→second weld 4.2;

[0026] Step 3: Perform the electron beam welding steps in step 1 on the four welds 4 according to the electron beam welding sequence determined in step 2.

[0027] The above method completes the welding of blade 1 to inner casing 2 and outer casing 3. After inspection, the weld quality of the welder welded by the above method meets the standard requirements. The straightness of blade 1 after welding does not exceed 0.5mm, which meets the straightness control requirements of casing blades after welding.

Claims

1. A method for controlling bending deformation of weak rigidity welded casing blades, characterized in that: The following steps are involved: Step 1: The steps of setting the blade (1) and the inner casing (2) and the outer casing (3) to be electron beam welded are as follows: Positioning welding → penetration welding → finishing welding; Step 2: The order of electron beam welding of the four welds (4) between the blade (1) and the inner casing (2) and the outer casing (3) is set as follows: The third weld (4.3) → the fourth weld (4.4) → the first weld (4.1) → the second weld (4.2); Step 3: Perform the electron beam welding steps in step 1 on the four welds (4) in the order of electron beam welding determined in step 2.

2. The method for controlling bending deformation of weak rigidity welded casing blades according to claim 1, characterized in that: In step 1, the welding process parameters of the positioning welding are: acceleration voltage: 150KV; focusing current: 1888mA; speed: 20mm / s; Welding current: 2mA~4mA; The welding process parameters of penetration welding are: acceleration voltage: 150KV; Focusing current: 1888mA; speed: 20mm / s; Welding current: 9mA~13mA; The welding process parameters of the modified welding are: acceleration voltage: 150KV; Focusing current: 1988mA; speed: 20mm / s; Welding current: 6mA~8mA.

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