Electron beam welding method for repairing hole defects on surface of finish machining part and part

Abstract

The invention discloses an electron beam welding method for repairing a hole defect on the surface of a finish machining part and the part, and belongs to the technical field of electron beam welding.The method comprises the steps that a drill bit with the diameter capable of enveloping the size of the hole defect in the part to be repaired is selected, and a drill hole is machined in the position of the hole defect; controlling the diameter and depth of the drilled hole; a filling body with the diameter equal to that of the drill hole and the length larger than the depth of the drill hole is machined or cut out, and the filling body is stuffed into the drill hole; corresponding electron beam welding parameters are selected, so that the welding penetration depth reaches the drilling depth; a circular scanning beam is adopted, electron beam welding is conducted on the filling body, the beam value during welding is gradually increased to the preset maximum value from the zero value and then gradually decreased to the zero value, and an electron beam welding seam is formed; and processing to remove excess weld metal on the surface of the part and weld beading on the back surface. In the repair welding process, the heat input amount is small, the welding time is short, the deformation problem of parts caused by repair welding can be effectively reduced, it is guaranteed that the parts are delivered in a qualified mode, and good applicability is achieved.

Description

Technical Field

[0001] This invention belongs to the field of electron beam welding technology, specifically relating to an electron beam welding method and part for repairing surface hole defects in precision-machined parts. Background Technology

[0002] In the field of aerospace manufacturing, some structurally complex parts in aero-engines or gas turbines have poor weldability or castability due to limitations in their materials or structures. Defects such as porosity and voids are prone to occur in the welds or castings. However, due to structural limitations, effective non-destructive testing of the welds / castings after welding or casting is not possible, resulting in the inability to effectively detect internal defects generated during welding or casting. During subsequent machining, as the surface material is ground and removed, these internal defects from welding or casting become exposed, failing to meet technical requirements and thus rendering the parts unusable. At this point, because the part dimensions are close to or have reached their final dimensions, conventional repair welding methods such as argon arc welding are used. However, due to the large heat input and lack of precise control, improper handling can lead to part deformation, dimensional deviations, and even scrapping the part due to its inability to meet final usage requirements. Therefore, in summary, current methods for repairing surface defects such as voids in precision-machined parts are prone to problems due to the large heat input and lack of precise control; improper handling can lead to part deformation, dimensional deviations, and even scrapping the part due to its inability to meet final usage requirements. Summary of the Invention

[0003] This invention provides an electron beam welding method and part for repairing surface hole defects in precision-machined parts. The purpose is to solve the problem that current methods for repairing surface hole defects in precision-machined parts are prone to problems such as large heat input and inability to control it precisely. Improper handling may lead to part deformation, dimensional deviations, or even parts that fail to meet final use requirements and are scrapped.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides an electron beam welding method for repairing surface hole defects in precision-machined parts, comprising the following steps: S1. For the part to be repaired, select a drill bit whose diameter can completely cover the size of all the hole defects in the part to be repaired, and drill holes at each hole defect location in the part to be repaired; control the following when drilling: the diameter is not less than the radial dimension of the hole defect, and the depth is not less than the axial dimension of the hole defect. S2. Based on the diameter of the drill hole, process or cut a filler with the same diameter as the drill hole and a length greater than the drill hole depth, and then insert the filler into the drill hole so that the surface of the filler protrudes from the drill hole. S3. Based on the drilling depth, select the appropriate electron beam welding parameters to ensure that the welding penetration reaches the drilling depth. S4. A circular scanning beam with the same diameter as the filler is used to perform electron beam welding on the filler. The beam current value during welding increases from zero to a preset maximum value and then decreases back to zero, thereby forming an electron beam weld. S5. Remove excess weld height and back weld beads from the surface of the repaired part to complete the repair of holes and defects in the part.

[0005] In some implementations, in S1, depending on the radial dimension of the hole defect in the part to be repaired, a through hole is drilled to the bottom of the weld or a blind hole is drilled to the bottom of the hole defect.

[0006] In some implementations, in S1, the hole defect is a welding defect exposed in the weld of the part to be repaired, or a localized porosity or hole defect exposed on the casting surface of the part to be repaired.

[0007] In some implementations, in S2, the filler includes a shaped plug or a cut welding wire; the length of the filler is controlled to be 0.5 mm to 0.7 mm greater than the drilling depth.

[0008] In some implementations, in S2, the welding parameters include a beam current value, which is set based on the depth to which the weld penetration reaches the borehole.

[0009] Furthermore, in S3, for hole defects that are not drilled to the full depth of the weld, the selected welding parameters make the weld width at the root of the hole defect reach or exceed the radius of the drill hole.

[0010] In some implementations, in S4, the diameter of the circular scanning beam is the same as the diameter of the filler.

[0011] In some implementations, in S4, the increase and decrease of the beam current value during welding is carried out in a linear or nonlinear manner.

[0012] In some implementations, in S5, machining is used to remove excess weld height and back weld beads from the surface of the repaired part.

[0013] The present invention also provides a part, which is obtained by electron beam welding to repair defects in the surface of a precision-machined part.

[0014] Compared with the prior art, the electron beam welding method and part for repairing surface hole defects in precision-machined parts of the present invention have the following beneficial effects: This invention discloses an electron beam welding method for repairing surface hole defects in precision-machined parts. Through defect pretreatment by drilling to envelop the defect, the diameter of the drill hole is controlled to be no less than the radial dimension of the hole defect, and the depth is no less than the axial dimension of the hole defect, ensuring complete removal of the defect. Precise filling with diameter matching and length allowance, and complete envelopment of the defect size by drilling in both radial and axial directions, can physically remove the defect material relatively thoroughly, avoiding internal residues caused by traditional surface repair. This invention combines customized parameters for matching penetration depth with drilling depth, zero-start / fall scanning beam gradient welding, and final removal of excess weld height and back weld beads from the surface of the repaired part. The filler body is designed to provide pre-reserved space for molten pool formation. Beam gradient control reduces thermal shock and suppresses cracks. The circular scanning beam diameter matches the filler body, achieving precise energy focusing. The electron beam welding used has high energy density, a small heat-affected zone, and significantly reduced heat input, minimizing deformation of the finished parts. The beam gradient design allows for slow heating or cooling, reducing the cooling rate and significantly suppressing cracks. Furthermore, this invention ensures high controllability of electron beam welding penetration depth, guaranteeing complete metallurgical bonding between the filler body and the substrate at the bottom and sidewalls of the hole. Compared to existing defect repair methods such as argon arc welding, this invention effectively reduces deformation caused by welding due to low heat input and short welding time during repair. It ensures both repair efficiency and improved final part quality, enabling qualified delivery and demonstrating significant practical value. Attached Figure Description

[0015] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0016] Figure 1 This is an electron beam welding method for repairing surface holes and defects in precision-machined parts, and a schematic diagram of the repair process for the part to be repaired.

[0017] In the figure, 1 is the defective part, 2 is the first hole defect on the surface of the part, 3 is the first drill hole along the depth direction of the defect, 4 is the first electron beam weld, 5 is the second hole defect on the surface of the part, 6 is the second drill hole along the depth direction of the defect, and 7 is the second electron beam weld. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is 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 orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0023] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0024] In the process of repairing surface defects such as holes in precision-machined parts, it is necessary to reduce heat input and perform precise control to minimize part deformation and dimensional deviations, so that the parts can meet the final use requirements.

[0025] like Figure 1 As shown, the present invention provides an electron beam welding method for repairing surface hole defects in precision-machined parts, comprising the following steps: S1. For the part to be repaired, select a drill bit whose diameter can completely cover the size of all the hole defects in the part to be repaired, and drill holes at each hole defect location in the part to be repaired; control the following when drilling: the diameter is not less than the radial dimension of the hole defect, and the depth is not less than the axial dimension of the hole defect. S2. Based on the diameter of the drill hole, process or cut a filler with the same diameter as the drill hole and a length greater than the drill hole depth, and then insert the filler into the drill hole so that the surface of the filler protrudes from the drill hole. S3. Based on the drilling depth, select the appropriate electron beam welding parameters to ensure that the welding penetration reaches the drilling depth. S4. A circular scanning beam with the same diameter as the filler is used to perform electron beam welding on the filler. The beam current value during welding increases from zero to a preset maximum value and then decreases back to zero, thereby forming an electron beam weld. S5. Remove excess weld height and back weld beads from the surface of the repaired part to complete the repair of holes and defects in the part.

[0026] The electron beam welding method of the present invention for repairing surface hole defects of precision-machined parts can not only be used to repair surface hole-type welding defects exposed after precision machining of complex parts, but also to repair local porosity, holes and other defects exposed after precision machining of complex precision castings. This expands the application scenarios of the method, meets the needs of repairing defects of different types of parts, and improves the versatility of the method.

[0027] This invention presents an electron beam welding method for repairing surface defects such as holes in precision-machined parts. Electron beam welding offers advantages such as high energy density, concentrated heating, and a small heat-affected zone, effectively reducing part deformation and dimensional inconsistencies. Compared to traditional repair methods, it allows for more precise repair of defective areas, ensuring the quality of repaired parts, guaranteeing qualified delivery, and extending the service life of the parts. This invention provides a clear framework for the repair method, offering technical guidance for practical operation. From drilling and filler selection to electron beam welding parameter setting and the welding process, as well as subsequent processing, it enables operators to follow specifications, improving the repeatability and stability of the repair process.

[0028] In practical applications, the electron beam welding method of this invention for repairing surface hole defects in precision-machined parts involves selecting either a through-hole to the bottom of the weld or a blind hole to the bottom of the hole defect, based on the radial size of the hole defect in the part to be repaired. This invention precisely removes defects by selecting a drill bit with a diameter that completely encompasses the defect size, and selecting the drilling depth according to the diameter of the hole defect on the part surface (for small-diameter holes such as the second hole defect 5 on the part surface, drilling to the bottom of the defect; for large-diameter holes such as the first hole defect 2 on the part surface, drilling to the bottom of the weld). A second drill hole 6 is formed along the defect depth direction for the second hole defect 5 on the part surface, and a first drill hole 3 is formed along the defect depth direction for the first hole defect 2 on the part surface. This precisely removes the hole defects from the surface of the defective part 1, avoiding defect residue and laying a good foundation for subsequent repair work, ensuring thorough repair. Furthermore, this invention guarantees welding quality; the precise drilling operation ensures a more stable molten pool formation during welding, reducing welding quality problems caused by defect residue and improving the performance of the welded joint.

[0029] In practical applications, the electron beam welding method of this invention for repairing surface hole defects in precision-machined parts utilizes pre-formed plugs or cut welding wires as fillers. The length of the filler is controlled to be 0.5mm–0.7mm greater than the drilling depth, ensuring good filling performance. By machining or cutting plugs or welding wires with the same diameter as the drilling hole and inserting them into the hole, ensuring the surface of the plug or wire is slightly higher than the weld surface by 0.5mm–0.7mm, good filling of the hole is achieved. Appropriate filler size and extension length facilitate efficient energy transfer and molten pool formation during electron beam welding, ensuring a good bond between the welded area and the original part. This invention allows the use of readily available plugs or welding wires as fillers, eliminating the need for on-site fabrication of complex filler structures, simplifying the repair process, and improving repair efficiency. Furthermore, standardized filler dimensions help ensure consistent repair quality.

[0030] In some embodiments, the electron beam welding method of the present invention for repairing surface hole defects in precision-machined parts includes a beam current value, which is set based on the weld penetration depth reaching the drilling depth. The present invention selects appropriate electron beam welding parameters, particularly the beam current value, to ensure the weld penetration depth reaches the drilling depth, guaranteeing complete penetration of the filler and the base material around the drilled hole during welding, forming a good weld joint, effectively repairing defects, and avoiding weak welds caused by insufficient penetration depth.

[0031] Furthermore, the electron beam welding method for repairing surface hole defects in precision-machined parts according to the present invention, for hole defects that have not been drilled to the full depth of the weld, selects welding parameters such that the weld width at the root of the hole defect reaches or exceeds the radius of the drilled hole. By selecting appropriate welding parameters based on the drilling depth, this method can adapt to repairing hole defects of different depths and sizes, improving its flexibility and adaptability. This ensures complete fusion of the bottom surface. For defects with small diameters and opening depths that do not reach the full weld depth, the selected welding parameters should ensure that the weld width at the defect root reaches or exceeds the radius of the opening. This ensures that during the welding process, the electron beam can fully act on the defect root, resulting in complete fusion of the bottom surface and avoiding defects such as incomplete fusion and porosity caused by insufficient weld width, thus improving the quality of the weld joint. This limitation also improves repair reliability. By refining the welding parameters, especially for small-diameter, shallow opening defects, the welding process can be controlled more precisely, improving repair reliability. This ensures effective repair even for such difficult-to-repair defects, reducing the risk of repair failure.

[0032] In this invention, an electron beam welding method for repairing surface hole defects in precision-machined parts utilizes a circular scanning beam with a diameter identical to that of the plug or welding wire. The beam current value is controlled to gradually increase from 0 to a selected maximum value and then slowly decrease back to 0 during welding. This beam current variation method makes the welding process more stable, reducing welding defects. Simultaneously, the circular scanning beam ensures a more uniform energy distribution, improving welding quality. The stable welding process and uniform energy distribution contribute to forming a high-quality weld joint, improving its strength and other properties, and ensuring that the repaired part meets usage requirements. Furthermore, the beam current increase and decrease process during welding employs linear or non-linear gradual changes, making it applicable to different working conditions and part processing, thus broadening the method's applicability.

[0033] Furthermore, the electron beam welding method of this invention for repairing surface defects such as holes in precision-machined parts can, in actual working conditions, remove excess weld bead and back weld beads from the surface of the part to be repaired through machining. This results in a smooth surface on the repaired part, restoring its original geometric shape and dimensional accuracy, thus meeting the requirements of precision machining. Simultaneously, removing weld beads also improves the performance and lifespan of the part.

[0034] This invention also provides a part obtained by electron beam welding to repair surface defects such as holes in a precision-machined part. The part repaired using this invention has a certain quality and can meet usage and delivery requirements.

[0035] The following detailed description of the electron beam welding method and parts for repairing surface hole defects in precision-machined parts, through specific embodiments, provides further details of the present invention.

[0036] The purpose of this invention is to provide a method for repairing surface porosity defects exposed after finishing of welds in complex parts. This method can also be used to repair localized porosity, holes, and other defects exposed on the surface of complex precision castings after finishing. Specifically, the operation steps of this method are as follows: 1) Select a drill bit with a diameter that can completely cover the defect size and drill a hole at the hole defect of the defective part 1. For the first hole defect 2 on the surface of the part with a larger diameter, drill to the bottom of the weld to form the first drill hole 3 (through hole) along the defect depth direction; for the second hole defect 5 on the surface of the part with a smaller diameter, drill to the bottom of the defect to form the second drill hole 6 (blind hole) along the defect depth direction. The drilling must ensure that the welding defect is completely removed. 2) Machining a plug with the same diameter as the borehole or cutting a piece of welding wire with the same diameter as the borehole and inserting it into the borehole. The length of the plug or welding wire is slightly longer than the borehole depth, so that the surface of the plug or welding wire is slightly higher than the weld surface (0.5mm to 0.7mm higher than the weld surface). That is, the height of the machined plug or the length of the cut welding wire is slightly greater than the borehole depth. 3) Select appropriate electron beam welding parameters. The welding beam current value should be able to make the welding penetration reach the depth of the drill hole. For defects with small diameter and opening depth that do not reach the full weld depth, the selected welding parameters should be able to make the weld width at the root of the defect reach or exceed the radius of the opening to ensure that the bottom surface can be completely fused during electron beam scanning welding. 4) A circular scanning beam with the same diameter as the plug / welding wire is used to perform electron beam welding on the plug or welding wire to form the first electron beam weld 4 and the second electron beam weld 7. During welding, the beam current value is gradually increased from 0 to the selected maximum value and then slowly decreased to 0. 5) Use machining to remove excess weld bead and weld nugget from the surface of the repaired part. This completes the repair of defective part 1.

[0037] In summary, this invention provides an electron beam welding method and part for repairing surface hole defects in precision-machined parts. Utilizing electron beam welding technology, it precisely repairs surface hole defects in precision-machined parts. By accurately controlling multiple steps, including drilling, filler installation, welding parameter selection, and the welding process, the accuracy and reliability of the repair are ensured. This invention expands the application scope of electron beam welding, making it suitable not only for repairing weld defects but also for repairing surface defects in castings, thus improving its applicability. Due to the advantages of electron beam welding, such as high energy density, concentrated heating, and a small heat-affected zone, it can effectively reduce part deformation and dimensional deviations, ensuring the quality of the repaired part. This invention proposes precise control of drilling diameter and depth, optimization of filler size and extension length, and refinement of welding parameters, especially for small-diameter, shallow opening defects, ensuring the thoroughness and reliability of the repair and providing technical support for repairing surface hole defects in precision-machined parts.

[0038] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Anyone skilled in the art can readily implement the present invention according to the description and above. Any modifications, alterations, or variations made based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An electron beam welding method for repairing surface hole defects in precision-machined parts, characterized in that, Includes the following steps: S1. For the part to be repaired, select a drill bit with a diameter that can cover the size of all the hole defects in the part to be repaired, and drill holes at each hole defect location in the part to be repaired; control the following for drilling: the diameter is not less than the radial dimension of the hole defect, and the depth is not less than the axial dimension of the hole defect. S2. Based on the diameter of the drill hole, process or cut a filler with the same diameter as the drill hole and a length greater than the drill hole depth, and then insert the filler into the drill hole so that the surface of the filler protrudes from the drill hole. S3. Based on the drilling depth, select the appropriate electron beam welding parameters to ensure that the welding penetration reaches the drilling depth. S4. A circular scanning beam with the same diameter as the filler is used to perform electron beam welding on the filler. The beam current value during welding increases from zero to a preset maximum value and then decreases back to zero, thereby forming an electron beam weld. S5. Remove excess weld height and back weld beads from the surface of the repaired part to complete the repair of holes and defects in the part.

2. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In S1, depending on the radial size of the hole defect in the part to be repaired, either a through hole is drilled to the bottom of the weld or a blind hole is drilled to the bottom of the hole defect.

3. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In S1, the hole defect is a welding defect exposed in the weld of the part to be repaired, or a localized looseness or hole defect exposed on the casting surface of the part to be repaired.

4. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In S2, the filler includes a shaped plug or a cut welding wire; the length of the filler is controlled to be 0.5 mm to 0.7 mm greater than the drilling depth.

5. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In S2, the welding parameters include the beam current value, which is set based on the depth at which the weld penetration reaches the borehole depth.

6. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 5, characterized in that, In S3, for hole defects that are not drilled to the full depth of the weld, the selected welding parameters make the weld width at the root of the hole defect reach or exceed the radius of the drill hole.

7. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In S4, the diameter of the circular scanning beam is the same as the diameter of the filler.

8. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In S4, the increase and decrease of the beam current value during welding are carried out in a linear or nonlinear gradual manner.

9. The electron beam welding method for repairing surface hole defects in precision-machined parts according to claim 1, characterized in that, In step S5, machining is used to remove excess weld height and back weld beads from the surface of the repaired part.

10. A component, characterized in that, The part is repaired by the electron beam welding method according to any one of claims 1-9 for repairing surface hole defects in precision-machined parts.

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