Titanium alloy blade anticorrosion groove welding protection tooling

Abstract

The application relates to the field of steam turbine blades, in particular to the field of corrosion prevention of steam turbine blades, and specifically relates to a titanium alloy blade corrosion prevention groove welding protection tool which can effectively isolate the reaction of oxygen and nitrogen in air with welding wire, prevent the generation of unqualified welding porosity, cracks and the like, effectively improve the qualified rate of welding and product quality, and comprises a welding stop block, a flow guide groove seat body, a base and a cover plate. A flow guide groove matched with the shape of a blade crown lock is arranged on the flow guide groove seat body. One end of the flow guide groove seat body is connected with the base, and the other end is connected with the welding stop block. The surface of the welding stop block is attached to the blade profile. A sintering screen mounting groove one is arranged on the welding stop block and is mounted with a sintering screen one. A gas hole one is arranged at the bottom of the sintering screen mounting groove one. A sintering screen mounting groove two is arranged on the end surface of the base or one end of the flow guide groove seat body and is mounted with a sintering screen two. The base is provided with a gas channel connected with the flow guide groove.

Description

Technical Field

[0001] This invention relates to the field of steam turbine blades, and more particularly to the field of corrosion protection for steam turbine blades, specifically a welding protection tool for corrosion-resistant grooves on titanium alloy blades. Background Technology

[0002] Anti-corrosion protection of turbine blades is one of the key technologies to ensure the safe and efficient operation of the unit. Currently, relatively mature technologies include brazing Stellite alloy, titanium nitride coating, and laser hardening. Replacing the entire last-stage turbine blade with titanium alloy is an important attempt at corrosion protection for last-stage turbine blades. Currently, only Dongfang Electric Corporation in China has completed the design, manufacturing, and engineering application of complete titanium alloy blades. Titanium alloy itself is a difficult-to-machine material, and machining the large last-stage turbine blades with titanium alloy is even more expensive. To reduce the replacement cost of titanium alloy blades, β-Ti surfacing is performed for the first time at the blade crown interlocking joint of the titanium alloy last-stage blade to increase the hardness of this area and extend its service life. Figure 1 As shown in the figure, point A is the location of the leaf crown lock.

[0003] Titanium alloys are highly sensitive to oxygen and nitrogen during welding, easily forming nitrides and oxides, which can lead to weld cracking. Measures must be taken during welding to protect the weld from oxidation and improve the weld pass rate. Currently, there are no suitable tooling tools to achieve adequate weld protection, resulting in weld oxidation and reduced product quality. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a welding protection fixture for anti-corrosion grooves on titanium alloy blades. During the welding process, it effectively isolates oxygen and nitrogen in the air from reacting with the welding wire, preventing defects such as welding porosity and cracks, and effectively improving the welding pass rate and product quality.

[0005] The technical solution is as follows: a welding protection fixture for anti-corrosion grooves on titanium alloy blades, characterized in that it includes a welding block, a guide groove seat, a base, and a cover plate. The guide groove seat has a guide groove that matches the shape of the blade crown lock. One end of the guide groove seat is connected to the base, and the other end is connected to the welding block. The surface of the welding block is fitted to the blade profile. The welding block is provided with a sintered mesh mounting groove and a sintered mesh is installed thereon. The bottom of the sintered mesh mounting groove is provided with a vent hole. The base or the end face of one end of the guide groove seat is provided with a sintered mesh mounting groove and a sintered mesh is installed thereon. The base has a gas channel communicating with the guide groove.

[0006] A further feature is that extension blocks are respectively provided on both sides of the end of the guide channel seat that is connected to the welding block, and the outer side of the welding block is connected to the inner side of one of the extension blocks by a side screw.

[0007] A side guide plate is provided at one end of the sintering mesh mounting groove near the guide groove seat, and forms a channel with the inner side of the welding block.

[0008] The gas channel includes a countersunk hole on the side of the base and a second air hole on the bottom of the base. The countersunk hole is connected to the second air hole, and the shape of the countersunk hole matches the guide groove.

[0009] The cover plate has a long groove that exposes the flow guide groove and the welding point with the blade;

[0010] The outer end of the base is connected to a U-shaped support plate, and the outer side of the guide channel seat is provided with a slot for engaging with the U-shaped support plate.

[0011] By adopting this invention, a tooling is formed by using a welding block, a guide channel seat, a base, and a cover plate to allow protective gas to pass through the welding area. The blade profile fits the welding block, and the blade crown lock matches the guide channel. During the welding process, the protective gas can smoothly cover the welding position, preventing oxygen and nitrogen in the air from reacting with the welding wire, thus preventing defects such as welding porosity and cracks, and effectively improving the welding pass rate and product quality. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a titanium alloy blade.

[0013] Figure 2 This is a first-view schematic diagram of the tooling structure of the present invention;

[0014] Figure 3 This is a second-view schematic diagram of the tooling structure of the present invention (with the cover plate omitted);

[0015] Figure 4 This is a first-view schematic diagram of the welding stop structure;

[0016] Figure 5 This is a second-view schematic diagram of the welding stop structure;

[0017] Figure 6 This is a schematic diagram of the guide channel base structure;

[0018] Figure 7 This is a first-person view diagram of the base structure;

[0019] Figure 8 This is a second-view schematic diagram of the base structure;

[0020] Figure 9 This is a schematic diagram of the cover plate structure;

[0021] Figure 10 This is a schematic diagram of a sintered mesh structure;

[0022] Figure 11 This is a schematic diagram of the sintered mesh structure II;

[0023] Figure 12 Schematic diagram of the blade crown interlocking welding status Figure 1 ;

[0024] Figure 13 Schematic diagram of the blade crown interlocking welding status Figure 2 . Detailed Implementation

[0025] See Figures 2-11 As shown, a welding protection fixture for anti-corrosion grooves on titanium alloy blades includes a welding stop block 1, a guide channel seat 2, a base 3, and a cover plate 4. The guide channel seat 2 has a guide channel 2-1 that matches the shape of the blade crown lock. The guide channel 2-1 is designed to extend outward by 2mm on one side according to the shape of the welding groove on the blade. This design ensures that the protective gas can pass through the welding groove while controlling the welding length range. One end of the guide channel seat 2 is connected to the base 3, and the other end is connected to the welding stop block 1. Specifically, extension blocks 2-2 and 2-3 are respectively provided on both sides of the end of the guide channel seat 2 connected to the welding stop block 1. The outer side of the welding stop block 1 is connected to the inner side of one of the extension blocks 2-2 by a side screw 2-4. In order to better position the blade, a contour block 2-5 that fits the blade is provided on the inner side of the extension block 2-2.

[0026] The surface of the welding block 1 is fitted to the blade profile. The welding block 1 is provided with a sintered mesh mounting groove 1-1 and a sintered mesh 9 is installed. The bottom of the sintered mesh mounting groove 1-1 is provided with a vent hole 1-2. The end of the sintered mesh mounting groove 1-1 near the guide groove seat 2 is provided with a side guide plate 1-3 and forms a channel with the inner side of the welding block 1. The outer side of the side guide plate 1-3 can fit with the blade.

[0027] The end face of one end of the guide channel base 2 is provided with a sintered mesh mounting groove 2-6 and a sintered mesh 10 is installed thereon. The base 3 has a gas channel that connects to the guide channel 2-1. The gas channel includes a countersunk hole 3-1 opened on the side of the base 3 and a gas hole 3-2 opened at the bottom of the base 3. The countersunk hole 3-1 is connected to the gas hole 3-2. The shape of the countersunk hole 3-1 matches the guide channel 2-1.

[0028] Sintered mesh 19 and sintered mesh 20 are made of stainless steel sintered mesh, which can ensure the stability of the airflow when the protective gas is introduced and prevent the occurrence of turbulence.

[0029] The cover plate 4 is connected to the top of the guide channel seat 2 by the top screw 4-1 to prevent the protective gas from overflowing. The cover plate 4 has a long groove 4-2 that exposes the guide channel 2-1 and the welding groove on the blade, which facilitates the movement of the welding wire by the welding worker and ensures the field of vision during welding.

[0030] The outer end of the base 3 is connected to the U-shaped support plate 11 by the end screw 3-3. The outer sides of the guide channel seat 2 and the base 3 are provided with slots 2-7 and 3-4 for engaging with the U-shaped support plate 11. The welding block 1, the guide channel seat 2, and the base 3 can be tightened and fixed as a whole, and the entire welding protection device can be fixed on the blade to prevent the movement of the welding protection device during the welding process, which would lead to leakage of protective gas.

[0031] Welding condition as follows Figure 12 and 13 As shown, to facilitate viewing the welding position of blade 12, cover plate 4 is concealed. Protective gas is connected to vent holes 1-2 and 3-2 below welding block 1 and base 3. During welding, continuous gas injection ensures adequate air isolation, effectively protecting the anti-corrosion grooves of titanium alloy blades. Compared to previous protective fixtures, the first-pass yield rate is increased by 30%. The protective fixture can be installed and removed using only a few screws, with installation time not exceeding 3 minutes. It is convenient, quick, simple in structure, and low in cost.

Claims

1. A welding protection fixture for corrosion-resistant grooves on titanium alloy blades, characterized in that, It includes a welding block, a guide channel seat, a base, and a cover plate. The cover plate is connected to the top of the guide channel seat by a top screw. The guide channel seat has a guide channel that matches the shape of the blade crown lock. One end of the guide channel seat is connected to the base, and the other end is connected to the welding block. The surface of the welding block conforms to the blade profile. The welding block has a sintered mesh mounting groove and a sintered mesh is installed thereon. The bottom of the sintered mesh mounting groove has a vent hole. The end face of one end of the guide channel seat has a second sintered mesh mounting groove and a second sintered mesh is installed thereon. The base has a gas channel communicating with the guide channel. Extension blocks are respectively provided on both sides of the end of the guide channel seat connected to the welding block. The inner side of the extension block is provided with a conforming block that fits the blade. The outer side of the welding block is connected to the inner side of one of the extension blocks by a side screw. A side guide plate is provided at one end of the sintering mesh mounting groove near the guide groove seat, and the side guide plate forms a channel with the inner side of the welding block. The gas channel includes a countersunk hole on the side of the base and a second air hole on the bottom of the base. The countersunk hole communicates with the second air hole, and the shape of the countersunk hole matches the guide groove. The cover plate has an elongated groove that exposes the guide groove and the welding groove on the blade. A U-shaped support plate is connected to the outer end of the base. The outer sides of the guide groove seat and the base have slots for engaging with the U-shaped support plate.

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