Welding process for volute type products

Abstract

This invention provides a welding process for volute-type products, relating to the field of volute-type product welding technology. The welding process for volute-type products provided by this invention involves creating process holes that allow observation of one process hole from another at a certain angle. This allows adjacent process holes to be ground through one process hole to repair the other. After repairing one process hole, the repaired process hole can be ground through adjacent process holes, effectively reducing the height of the weld bead and thus controlling the weld bead height. This alleviates the technical problem of uncontrollable weld bead in traditional repair welding processes in the prior art.

Description

Technical Field

[0001] This invention relates to the field of volute product welding technology, and in particular to a welding process for volute products. Background Technology

[0002] As core components of fluid machinery, volute-type products (such as pump housings, turbine housings, and compressor volutes) directly affect the operating efficiency and service life of the equipment due to their manufacturing quality. In current industrial production, volutes are mainly produced using casting or welding processes, with welding technology widely applied in manufacturing, repair, and assembly. Because the volute structure has complex spatial curved surface features and operates under harsh conditions such as high pressure, high temperature, and corrosive media, its welding process must strictly meet multiple requirements, including material compatibility, structural integrity, sealing reliability, and fatigue resistance.

[0003] In the manufacturing process of the volute casing, the forming quality of the cavity structure is particularly critical. In existing technologies, the volute casing cavity is mostly assembled by segmented shell fabrication followed by welding. However, due to the elongated and curved geometric characteristics of the cavity, there are technical challenges such as poor visibility during the shell fabrication process and difficulty in detecting the internal forming quality. Therefore, conventional processes require multiple process observation holes / venting holes to be opened in non-critical parts of the cavity. These process holes need to be sealed and repaired by welding after shell fabrication is completed.

[0004] However, traditional repair welding processes are limited by the spatial constraints of the narrow and long cavity structure. Operators cannot directly observe the height of the weld bead formation, and it is even more difficult to effectively grind the weld inside the deep cavity. As a result, defects such as protrusions and lack of fusion are prone to occur in the repair welding area, which directly affects the smoothness of the inner wall of the cavity and the fluid flow performance. Summary of the Invention

[0005] The purpose of this invention is to provide a welding process for volute-type products to alleviate the technical problem that welding beads cannot be controlled in traditional repair welding processes in the prior art.

[0006] The welding process for volute-type products provided by this invention includes the following steps: Opening steps: Open process holes, and the opened process holes should allow one process hole to be viewed from another process hole, so that two adjacent process holes can be ground through one process hole to grind the other process hole. Repair welding steps: Repair welding process holes; Grinding steps: After welding one process hole, grind through the adjacent process hole; Repeat the welding and grinding steps until all process holes are welded and ground.

[0007] In an optional implementation, The hole-opening step includes the following steps: The cavity structure of the volute product was analyzed using 3D modeling software, and the number of process holes was determined based on the analysis results.

[0008] In an optional implementation, The hole-opening step also includes the following steps: After determining the number of process holes, arrange the positions of the process holes so that the process holes can be observed from one process hole at a certain angle, and two adjacent processes are configured to grind one process hole through another process hole.

[0009] In an optional implementation, The process holes that are opened so that one process hole can be observed from another process hole at a certain angle include the following steps: The visibility condition is met between two adjacent process holes; The visibility conditions include the ability to directly observe a portion or all of the opening area of ​​an adjacent process hole from the axial or inclined direction of the current process hole.

[0010] In an optional implementation, The configuration of two adjacent processes to grind one process hole through the other process hole includes the following steps: The two adjacent process holes meet the operable connection condition, which allows the location of the other process hole that has been repaired to be ground through one of the process holes.

[0011] In an optional implementation, The operable connectivity conditions include a spatial arrangement between adjacent process holes that allows an operating tool to pass through one process hole into the internal cavity to mechanically grind or reshape weld beads formed on the outside of another completed process hole.

[0012] In an optional implementation, The repair welding process includes the following steps: After the casting is cleaned and cut, the process holes in the casting are cleaned with alcohol and an air gun, and then the process holes are repaired by welding with a welding gun.

[0013] In an optional implementation, The polishing steps include: If the temperature of the welding process hole area of ​​the casting is below 300℃, digital X-ray is used to observe whether there are any defects in the welded area after welding. If there are no defects, the previous welding process hole position is ground through the next adjacent process hole.

[0014] In an optional implementation, If defects are found in the welded area after digital X-ray observation, the welded area is reworked and re-welded. After repair, the welded area is re-observed using digital X-ray until there are no defects.

[0015] In an optional implementation, The repeated welding and grinding steps, until all process holes are welded and ground, include the following steps: Following the order of hole opening, welding and grinding are carried out sequentially until all process holes are welded and ground.

[0016] The welding process for volute-type products provided by this invention involves creating process holes that allow observation of one process hole from another at a certain angle. This enables the grinding of one process hole into another adjacent process hole, allowing the process hole to be ground after the previous one has been repaired by welding. This effectively reduces the height of the weld bead and controls its height, thus alleviating the technical problem of uncontrollable weld bead in traditional repair welding processes. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a volute-like product provided in an embodiment of the present invention; Figure 2 This is a structural schematic diagram of a volute-like product from another perspective, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the internal cavity structure of a volute-type product provided in an embodiment of the present invention.

[0019] Icons: 100 - volute; 200 - cavity; 300 - process hole. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 this invention according to the specific circumstances.

[0023] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] like Figures 1 to 3 As shown, the welding process for volute products provided by this invention first involves modeling and spatial path analysis of the cavity 200 structure of the volute 100 product using 3D modeling software. Based on the complexity of the internal flow channel and the accessibility assessment of the welding torch, it is determined that multiple process holes 300 can be opened without affecting the structural strength and aerodynamic performance of the product. The following description uses four process holes 300 as an example.

[0025] The optimal distribution positions of multiple process holes 300 are planned, and each process hole 300 is arranged sequentially along the circumference of the volute 100. Adjacent process holes 300 have visual connectivity, that is, from the axial or inclined direction of the current process hole 300, part or all of the opening area of ​​the next process hole 300 can be directly observed, ensuring that the line of sight is unobstructed and meeting the penetration angle requirements of digital X-ray inspection.

[0026] At the same time, the two adjacent process holes 300 also meet the operable connection conditions, so that the external grinding tool can pass through one of the process holes 300 and enter the inner cavity of the volute 100 to perform mechanical grinding on the weld area outside the process hole 300 that has been repaired by the previous welding.

[0027] After the casting has been cleaned and cut, use alcohol to wipe it and use a high-pressure air gun to blow it to thoroughly remove residual sand, oxide scale and oil around the process hole 300, so as to ensure that the welding interface is clean.

[0028] Subsequently, manual electric arc welding or argon arc welding is used to repair the process hole 300, filling it with metal material until the hole is completely sealed, forming the initial weld bead.

[0029] After the welded area has cooled naturally to below 300°C, digital radiography (DR) imaging technology is used to perform non-destructive testing on the welded area to determine whether there are internal defects such as lack of fusion, porosity, or slag inclusions. If defects are found, the weld is returned for re-welding until the DR image shows that the weld quality is qualified.

[0030] After confirming that there are no defects, the grinding tool is inserted into the volute 100 through the process hole 300. The angle and feed depth are adjusted to finely grind the weld beads on the outside of the process hole 300, so that its surface smoothly transitions to the outline of the base material, and the height is controlled within the design allowable range.

[0031] Following the same procedure, process holes 3002, 3003, and 3004 were sequentially repaired by welding. After each repair, the internal visual guidance and external reverse grinding of the welded hole were achieved through the subsequent adjacent process hole 300. For the last process hole 3004, since there was no usable observation channel behind it, the product outlet was used as an auxiliary channel for grinding to complete the final weld bead shaping.

[0032] Throughout the process, the visual pathways between the process holes 300 not only support real-time visual monitoring and DR inspection path construction, but also provide necessary guiding references for the grinding tools, thereby achieving controllable quality and repairable morphology of the welding area inside the closed cavity structure. This method effectively solves the problems of excessive weld beads and stress concentration caused by the inability to observe and contact in traditional welding processes, significantly improving the overall structural consistency and service reliability of the volute 100 type castings.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A welding process for volute-type products, characterized in that, Includes the following steps: Opening steps: Open process holes (300), and the opened process holes (300) allow one process hole (300) to be observed from another process hole (300), so that two adjacent process holes (300) can be polished through one process hole (300) to make the other process hole (300). Repair welding steps: Repair welding process holes (300); Grinding steps: After welding a process hole (300), grind through the adjacent process hole (300); Repeat the welding and grinding steps until all process holes (300) are welded and ground. The hole-opening step also includes the following steps: After determining the number of process holes (300), the positions of the process holes (300) are arranged so that the process holes (300) can be observed from one process hole (300) at a certain angle, and two adjacent processes are configured to grind one process hole (300) through one process hole (300). The process hole (300) is designed to allow observation of another process hole (300) from one process hole (300) at a certain angle, including the following steps: The visibility condition is met between two adjacent process holes (300); The visibility conditions include the ability to directly observe a portion or all of the opening area of ​​an adjacent process hole (300) from the axial or inclined direction of the current process hole (300); The configuration of two adjacent processes for grinding one process hole (300) through one process hole (300) includes the following steps: The two adjacent process holes (300) meet the operable connection conditions, so that the position of the other process hole (300) that has been repaired by welding can be ground through one of the process holes (300); The operable connectivity conditions include a spatial arrangement between adjacent process holes (300) that allows an operating tool to pass through one process hole (300) into the internal cavity to mechanically grind or reshape the weld bead formed on the outside of another completed process hole (300). The polishing steps include: If the temperature of the welding process hole (300) area of ​​the casting is below 300℃, use digital X-ray to observe whether there are any defects in the welded area after welding. If there are no defects, then grind the previous welding process hole (300) position through the next adjacent process hole (300).

2. The welding process for volute-type products according to claim 1, characterized in that, The hole-opening step includes the following steps: The cavity (200) structure of the volute (100) product was analyzed using 3D modeling software, and the number of process holes (300) was determined based on the results of the software analysis.

3. The welding process for volute-type products according to claim 1, characterized in that, The repair welding process includes the following steps: After the casting is cleaned and cut, the process hole (300) of the casting is cleaned with alcohol and air gun, and then the process hole (300) of the casting is repaired by welding gun.

4. The welding process for volute-type products according to claim 1, characterized in that, If defects are found in the welded area after digital X-ray observation, the welded area is reworked and re-welded. After repair, the welded area is re-observed using digital X-ray until there are no defects.

5. The welding process for volute-type products according to claim 1, characterized in that, The repeated welding and grinding steps, until all process holes (300) are welded and ground, include the following steps: Following the order of opening, welding and grinding are carried out sequentially until all process holes (300) are welded and ground.

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