A high-efficiency deformation correction method for blade castings based on local groove welding

Abstract

The application provides a kind of high-efficiency deformation correction method for blade casting based on local groove welding, comprising the following steps: step one, determining the maximum deformation area, the junction line of deformation area and undeformed area; step two, groove treatment: groove welding slot on the junction line of deformation area and undeformed area; step three, reference measurement point selection and arrangement; step four, welding correction: welding operation in the groove welding slot; step five, real-time feedback and parameter adjustment: dynamically adjust the welding parameters according to the size change of the reference measurement point; step six, complete the correction. The application does not require tooling, reduces the dependence on tooling and operation difficulty, and the correction process can be monitored in real time. High-precision control can be achieved by adjusting the welding parameters through the feedback of the reference measurement point, thereby improving the correction qualification rate. The single-piece correction time is short, the efficiency is significantly improved, and the energy consumption and cost are saved; the first-time qualification rate is high, and the engineering applicability is good.

Description

Technical Field

[0001] This invention relates to the field of blade casting deformation correction technology, and in particular to an efficient deformation correction method for blade castings based on local slot welding. Background Technology

[0002] During the blade casting process, local deformation of the blade casting often occurs due to factors such as casting stress and uneven cooling shrinkage, which affects the geometric dimensions and aerodynamic performance of the blade casting. At present, conventional correction methods mainly rely on graphite tooling positioning + heating correction or mechanical pressure correction. However, these methods have the following problems: (1) High correction difficulty: the graphite tooling for blade casting is complex to manufacture, the positioning accuracy requirement is high, and the operation is difficult; (2) Low efficiency: the correction process is time-consuming, and the correction time for a single piece can reach more than 1 hour; (3) High cost: the tooling cost is high; (4) Low pass rate: dimensional deviations still exist after correction, and the pass rate is difficult to guarantee. Summary of the Invention

[0003] In view of this, the present invention aims to propose an efficient deformation correction method for blade castings based on local slot welding, so as to solve the problems of existing technologies that require tooling, have long correction time, and low pass rate when performing correction.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] A highly efficient deformation correction method for blade castings based on local slot welding includes the following steps:

[0006] Step 1: Determine the area of ​​maximum deformation and the boundary between the deformed and undeformed areas;

[0007] Step 2, Groove treatment: Groove a weld groove on the boundary line between the deformed area and the undeformed area;

[0008] Step 3: Selection and arrangement of benchmark measurement points;

[0009] Step 4, Welding Correction: Perform welding operations in the weld groove;

[0010] Step 5: Real-time feedback and parameter adjustment: Dynamically adjust welding parameters based on the dimensional changes of the reference measurement points;

[0011] Step 6: Complete the calibration.

[0012] Furthermore, in step one, the boundary line between the maximum deformation area and the deformation area and the undeformed area is determined by three-dimensional scanning or size detection.

[0013] Furthermore, in step two, a weld groove with a depth of 1 / 3 of the wall thickness of the blade casting is excavated along the wall thickness direction of the blade casting on the boundary line.

[0014] Furthermore, in step three, 2 to 3 reference measurement points are set on the surface of the blade casting.

[0015] Furthermore, in step three, the reference measurement point is set in the maximum deformation area and selected at a location that facilitates measurement.

[0016] Furthermore, in step three, the reference measurement point is marked using any one of the following methods: laser marking, micro-grinding, or micro-indentation.

[0017] Furthermore, in step four, manual argon arc welding is used for welding, and the welding parameters are as follows: initial welding current 200~220A, welding speed 100~150mm / min, pure argon gas is introduced as a protective gas, the flow rate of pure argon gas is 12~18L / min, welding wire diameter is 1~3mm, welding wire material is matched with the base material, and the number of welding layers is 3~5.

[0018] Furthermore, in step five, during the welding process, the dimensional change of the reference measurement point is measured once after each layer is welded, the data is recorded and fed back to the operator for dynamic adjustment of welding parameters; when the dimensional deviation of the reference measurement point reaches the lower limit of tolerance, the welding current is reduced to 90~150A, the welding speed is reduced to 80~120mm / min, and other welding parameters remain unchanged.

[0019] Furthermore, after welding is completed, a coordinate measuring machine is used to re-measure the corrected blade casting to confirm whether the deformation has been eliminated and whether the dimensions have been restored to the design tolerance range. If it is confirmed that the deformation has been eliminated and the dimensions have been restored to the design tolerance range, X-ray flaw detection is performed on the weld area to ensure that the welding quality meets the relevant standard requirements.

[0020] Compared with existing technologies, the efficient deformation correction method for blade castings based on local slot welding described in this invention has the following advantages:

[0021] (1) By accurately locating the deformation area, setting benchmark measurement points, using multi-layer welding for local heating correction, and combining real-time size feedback and dynamic adjustment of welding parameters, rapid, controllable, and high-quality deformation repair can be achieved, significantly shortening the correction time and reducing the risk of deformation in the heat-affected zone.

[0022] (2) The present invention does not require tooling, reducing the dependence on tooling and the difficulty of operation. Moreover, the calibration process can be monitored in real time, and the welding parameters can be adjusted through the feedback of the reference measurement point to achieve high-precision control, thereby improving the calibration qualification rate.

[0023] (3) The single-piece calibration time is short, the efficiency is significantly improved, and energy consumption and cost are saved; the first-pass yield is high, and it has good engineering applicability.

[0024] (4) This invention is applicable to the efficient repair of deformation of high-precision blade castings such as aero-engines, steam turbines, and compressors. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments. First, it should be noted that the data in the following experimental examples were obtained by the inventors through numerous experiments. Due to space limitations, only a portion of these data is shown in the specification, and those skilled in the art can understand and implement the present invention based on this data. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art can make various modifications or alterations to the invention, and these modifications or alterations also fall within the scope of protection of this application.

[0026] The present invention provides a method for efficient deformation correction of blade castings based on local slot welding, comprising the following steps:

[0027] Step 1: Determine the area of ​​maximum deformation and the boundary between the deformed and undeformed areas;

[0028] Step 2, Groove treatment: Groove a weld groove on the boundary line between the deformed area and the undeformed area;

[0029] Step 3: Selection and arrangement of benchmark measurement points;

[0030] Step 4, Welding Correction: Perform welding operations in the weld groove;

[0031] Step 5: Real-time feedback and parameter adjustment: Dynamically adjust welding parameters based on the dimensional changes of the reference measurement points;

[0032] Step 6: Complete the calibration.

[0033] This invention requires no tooling, reducing reliance on tooling and operational complexity. Furthermore, the calibration process can be monitored in real time, and high-precision control can be achieved by adjusting welding parameters based on feedback from the reference measurement points, thereby improving the calibration pass rate. The calibration time per piece is short, significantly improving efficiency and saving energy and costs. It also boasts a high first-pass yield and good engineering applicability. Therefore, this invention is suitable for the efficient repair of deformation in high-precision blade castings for aero-engines, steam turbines, compressors, and other similar applications.

[0034] Specifically, in step one, the boundary between the maximum deformation area and the undeformed area is determined through 3D scanning or dimensional inspection. A 3D scanner or a coordinate measuring machine is used for scanning to identify the areas of deformation and warping in the blade casting to be corrected compared to a standard blade casting. The area of ​​maximum deformation and warping is defined as the maximum deformation area.

[0035] Specifically, in step two, a weld groove with a depth of 1 / 3 of the blade casting wall thickness is excavated along the boundary line and along the wall thickness direction of the blade casting to provide space for subsequent welding operations and control heat input. A grinding head can be used to excavate the weld groove on the blade casting.

[0036] The distance between the opening of the weld groove and the boundary line between the deformed area and the undeformed area should not exceed 2mm, taking the boundary line as the boundary. This ensures that the opening width of the weld groove is not too large, so as to avoid unnecessary damage to the blade casting and increase the amount of welding work.

[0037] Specifically, in step three, 2 to 3 reference measurement points are set on the surface of the blade casting, and the reference measurement points are preferably set in the maximum deformation area and selected in a position that is convenient for measurement to ensure the operability and accuracy of the measurement.

[0038] This invention corrects existing warping by welding at the weld groove, utilizing the localized heat input generated during welding to cause the blade casting to shrink, thus reversing the deformation. The area of ​​maximum deformation is the most sensitive deformation area. During welding, reference measurement points located in this area can capture the dimensional changes caused by welding correction, promptly and clearly reflecting the correction effect of each layer of welding heat input. This information serves as a basis for adjusting welding parameters, making the entire correction process controllable. If the reference measurement points are located in areas with insignificant deformation, the dimensional changes will be delayed or insignificant as welding progresses, making it difficult for operators to accurately judge the correction progress. This hinders the adjustment of welding parameters and may result in under-correction or over-correction.

[0039] The reference measurement points can be marked by laser marking, micro-grinding, or micro-indentation, and the markings should be clear, not easily worn, and easy to measure multiple times.

[0040] Specifically, in step four, manual argon arc welding is used for welding, and the welding parameters are as follows: initial welding current 200~220A, welding speed 100~150mm / min, pure argon gas is introduced as a protective gas, the flow rate of pure argon gas is 12~18L / min, welding wire diameter is 1~3mm, welding wire material is matched with the base material, and the number of welding layers is 3~5.

[0041] Specifically, in step five, during the welding process, the dimensional change of the reference measurement point is measured once after each layer is welded, the data is recorded and fed back to the operator for dynamic adjustment of welding parameters. When the dimensional deviation of the reference measurement point reaches the lower limit of the tolerance, the welding current is reduced to 90~150A, the welding speed is reduced to 80~120mm / min, and other welding parameters remain unchanged.

[0042] The dimensional deviation refers to the difference between the actual size of the deformed area where the reference measurement point is located and the target size of the standard part. When the dimensional deviation of the reference measurement point reaches the lower limit of the tolerance, it indicates that the size of the deformed area has gradually decreased and is about to be corrected to the edge of the acceptable range. Therefore, it is necessary to slow down the welding current and welding speed, and switch from the fast correction mode to the fine adjustment mode to avoid over-correction.

[0043] After each layer is welded, the dimensional change at the reference measurement point is measured. If the dimensional deviation at the reference measurement point does not reach the lower tolerance limit, the initial welding parameters remain unchanged. When the dimensional deviation at the reference measurement point is detected to have reached the lower tolerance limit, the welding current and welding speed are reduced in the next layer of welding. This usually eliminates deformation and completes the welding. Generally, 3 to 5 layers need to be welded.

[0044] Specifically, after welding, a coordinate measuring machine is used to re-measure the corrected blade casting to confirm whether the deformation has been eliminated and whether the dimensions have returned to the design tolerance range. If it is confirmed that the deformation has been eliminated and the dimensions have returned to the design tolerance range, X-ray flaw detection is performed on the weld area to ensure that the welding quality meets the relevant standards and requirements for aerospace parts.

[0045] This invention presents a highly efficient deformation correction method for blade castings based on localized seam welding. By precisely locating the deformation area, setting benchmark measurement points, employing multi-layer welding for localized heating correction, and combining real-time dimensional feedback with dynamic adjustment of welding parameters, it achieves rapid, controllable, and high-quality deformation repair, significantly shortening the correction time and reducing the risk of deformation in the heat-affected zone. The entire correction process can be controlled within 30 minutes, making it suitable for rapid repair and quality control of batch blade castings.

[0046] Example 1

[0047] The calibration target is a titanium alloy compressor blade with a wall thickness of 9 mm.

[0048] Step 1: Use a coordinate measuring machine to scan the titanium alloy compressor blades. It was found that the blades were warped and deformed, with a maximum deformation of about 3 mm. The maximum deformation area and the boundary between the deformed area and the undeformed area were determined.

[0049] Step 2: On the boundary line between the deformed area and the undeformed area, dig a weld groove along the wall thickness direction of the titanium alloy compressor blade, and the depth of the weld groove is 3mm, and the distance between the opening of the weld groove and the boundary line does not exceed 2mm.

[0050] Step 3: Set two laser marking reference points at the location of maximum deformation of the titanium alloy compressor blade;

[0051] Step 4: Manual TIG welding is performed in the weld groove. The initial welding current is 210A, the welding speed is 120mm / min, pure argon gas is introduced as the shielding gas, the flow rate of pure argon gas is 12L / min, the diameter of the welding wire is 1mm, and the material of the welding wire is matched with the base material.

[0052] Step 5: After each layer is welded, use a portable micrometer to measure the dimensional change of the reference measurement point. If the dimensional deviation of the reference measurement point does not reach the lower tolerance limit, the welding parameters of Step 4 are maintained. After the welding of the 3rd layer is completed, the measured size reaches the lower tolerance limit. Therefore, when welding the 4th layer, the welding current is adjusted to 130A and the welding speed is reduced to 100mm / min.

[0053] Step 6: After completing 4 layers of welding, the alignment is finished.

[0054] After welding, a coordinate measuring machine was used to re-measure the calibrated titanium alloy compressor blades to confirm that the deformation had been eliminated and the dimensions had returned to the design tolerance range. Simultaneously, X-ray flaw detection was performed on the weld area to ensure that the welding quality met the relevant aerospace component standards.

[0055] In Example 1, three titanium alloy compressor blades were calibrated, and all three were calibrated successfully on the first attempt, with each blade taking 28-30 minutes. In contrast, traditional calibration methods require 60-90 minutes.

[0056] Comparative Example 1

[0057] The correction object and method in Comparative Example 1 are basically the same as in Example 1, except that the depth of the weld groove in step two of Comparative Example 1 is 2mm. The correction effect was unsatisfactory after correction. The reason was that the groove depth was too shallow, resulting in a small volume of weld metal used for filling, and the resulting shrinkage force was insufficient to overcome the original deformation stress of the blade, leading to insufficient correction. Simultaneously, due to the shallow groove depth, the heat generated during welding was rapidly conducted to the entire blade casting, failing to concentrate better in the weld area, causing unnecessary thermal deformation in areas of the blade casting that were originally undeformed.

[0058] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A highly efficient deformation correction method for blade castings based on local slot welding, characterized in that, Includes the following steps: Step 1: Determine the area of ​​maximum deformation and the boundary between the deformed and undeformed areas; Step 2, Groove treatment: Groove a weld groove on the boundary line between the deformed area and the undeformed area; Step 3: Selection and arrangement of benchmark measurement points; Step 4, Welding Correction: Perform welding operations in the weld groove; Step 5: Real-time feedback and parameter adjustment: Dynamically adjust welding parameters based on the dimensional changes of the reference measurement points; Step 6: Complete the calibration.

2. The correction method according to claim 1, characterized in that, In step one, the boundary between the maximum deformation area and the deformation area and the undeformed area is determined by three-dimensional scanning or size detection.

3. The correction method according to claim 1, characterized in that, In step two, a weld groove with a depth of 1 / 3 of the wall thickness of the blade casting is excavated along the boundary line.

4. The correction method according to claim 1, characterized in that, In step three, 2 to 3 reference measurement points are set on the surface of the blade casting.

5. The correction method according to claim 1, characterized in that, In step three, the reference measurement point is set in the maximum deformation area and selected at a location that facilitates measurement.

6. The correction method according to claim 1, characterized in that, In step three, the reference measurement points are marked using any one of the following methods: laser marking, micro-grinding, or micro-indentation.

7. The correction method according to claim 1, characterized in that, In step four, manual argon arc welding is used for welding. The welding parameters are as follows: initial welding current 200~220A, welding speed 100~150mm / min, pure argon gas is introduced as a protective gas with a flow rate of 12~18L / min, welding wire diameter 1~3mm, welding wire material matching the base material, and 3~5 welding layers.

8. The correction method according to claim 1, characterized in that, In step five, during the welding process, the dimensional change of the reference measurement point is measured once after each layer is welded, the data is recorded and fed back to the operator for dynamic adjustment of welding parameters; when the dimensional deviation of the reference measurement point reaches the lower limit of tolerance, the welding current is reduced to 90~150A, the welding speed is reduced to 80~120mm / min, and other welding parameters remain unchanged.

9. The correction method according to claim 1, characterized in that, After welding, the corrected blade casting is re-measured using a coordinate measuring machine to confirm whether the deformation has been eliminated and whether the dimensions have returned to the design tolerance range. If the deformation has been eliminated and the dimensions have returned to the design tolerance range, X-ray flaw detection is performed on the weld area to ensure that the welding quality meets the relevant standard requirements.