Titanium alloy material spot welding method applied to dynamic characteristic test of steam turbine moving blade

Abstract

The application belongs to the field of thermal power steam turbine unit power generation, and discloses a titanium alloy material spot welding method applied to dynamic characteristic test of steam turbine moving blade, wherein, through polishing double-layer titanium alloy clips, adjusting working voltage and working current of a micro spot welding machine, and finally polishing and polishing spot welding positions of titanium alloy thin skins, spot welding is completed. The application can meet the requirements of titanium alloy steam turbine blade dynamic characteristic test and monitoring in the case of turbine blade test, and ensures the safety and stability of titanium alloy steam turbine blade, has important engineering application value for improving the safety and economy of steam turbine, and solves related technical problems such as titanium alloy material sensitivity to notches and unfirm welding of special-shaped materials. The process method has strong practicability, can shorten the process and period of steam turbine blade dynamic characteristic test and monitoring, and reduces the preparation time and cost of test.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of thermal power steam turbine unit power generation, and particularly relates to a titanium alloy material spot welding method applied in dynamic characteristic testing of turbine moving blades. BACKGROUND

[0002] With the continuous development of national economy and the continuous improvement of clean energy utilization, the low-pressure last-stage blade of a steam turbine bears a large unit load, and developing longer last-stage blades is one of important ways to greatly reduce the exhaust loss of the steam turbine and improve the efficiency of the steam turbine.

[0003] Meanwhile, the low-pressure last-stage blade faces many technical challenges such as blade material performance, safety design, blade manufacturing and the like, and is limited by a huge centrifugal stress of the blade and a high peripheral speed of the blade tip. In order to meet the safety requirement of the low-pressure last-stage blade root strength and break through the limitation of the blade material strength, titanium alloy, carbide or glass fiber and the like are adopted, and titanium alloy material becomes the first choice for the current last-stage super-long blade due to its high strength, excellent fatigue resistance and corrosion resistance and the like. The titanium alloy super-long low-pressure last-stage blade has problems of sensitivity of titanium alloy material to a notch and a complex lead fixing process due to a large centrifugal stress, so that the dynamic characteristic testing and monitoring of the titanium alloy super-long low-pressure last-stage blade have great technical difficulties and challenges.

[0004] The original spot welding process method and technology of the steel material turbine blade cannot adapt to the characteristics and requirements of the titanium alloy material turbine blade, can cause a slight damage to the titanium alloy material blade, and can bring uncertain risks for the later operation of the unit, so an urgent need exists for a titanium alloy material spot welding process method, so as to completely solve the adverse effects and hidden dangers of the original spot welding process on the titanium alloy material blade in the dynamic characteristic testing and monitoring of the titanium alloy material blade, and ensure the safe operation of the longer blade of the large unit steam turbine. SUMMARY

[0005] The application aims to overcome the above-mentioned deficiencies, and provides a titanium alloy material spot welding method applied in dynamic characteristic testing of turbine moving blades.

[0006] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0007] In a first aspect, the application provides a titanium alloy material spot welding method applied in dynamic characteristic testing of turbine moving blades, including the following steps:

[0008] S1, a titanium alloy thin skin suitable for the shape of the titanium alloy blade is made, and a double-layer titanium alloy clip for fixing a signal line is made;

[0009] S2, the double-layer titanium alloy clip is polished and cleaned.

[0010] S3, adjusting the working voltage and working current of the micro spot welder, when spot welding the double-layer titanium alloy clasp and the titanium alloy thin skin, the outer titanium alloy can be welded without damaging the surface of the titanium alloy blade;

[0011] S4, covering the titanium alloy thin skin on the double-layer titanium alloy clasp, and spot welding the titanium alloy thin skin on the surface of the titanium alloy blade by the micro spot welder;

[0012] S5, polishing the spot welding position of the titanium alloy thin skin to complete the spot welding.

[0013] The further improvement of the present application is that the thickness of the titanium alloy thin skin is 0.25mm.

[0014] The further improvement of the present application is that the specific method for manufacturing the double-layer titanium alloy clasp for fixing the signal line is as follows:

[0015] The titanium alloy thin skin is cut into the titanium alloy thin skin with the required size, and is folded and flattened along the middle part to manufacture the double-layer titanium alloy clasp for fixing the signal line.

[0016] The further improvement of the present application is that the double-layer titanium alloy clasp is cleaned by industrial alcohol, and the purity of the industrial alcohol is higher than 95%.

[0017] The further improvement of the present application is that after the titanium alloy thin skin is spot welded on the surface of the titanium alloy blade by the micro spot welder, the condition of the fixing position at both ends of the double-layer titanium alloy clasp after spot welding is checked to ensure that there is no abnormal situation.

[0018] The further improvement of the present application is that if there is a protruding position at the fixing position at both ends of the double-layer titanium alloy clasp after spot welding, the protruding position is polished.

[0019] The further improvement of the present application is that fine-grained sandpaper is used to polish the spot welding position of the titanium alloy thin skin.

[0020] The further improvement of the present application is that after the spot welding position of the titanium alloy thin skin is polished, the spot welding position is checked again to ensure smooth spot welding.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The application polishes the double-layer titanium alloy clamps, adjusts the working voltage and working current of the micro spot welding machine, polishes and finishes the spot welding position of the titanium alloy thin skin, and completes the spot welding, so that the application can meet the requirements of the titanium alloy turbine blade dynamic characteristic test and monitoring under the turbine blade test condition, guarantees the safety and stability of the titanium alloy turbine blade, has important engineering application value for improving the safety and economy of the turbine, solves the related technical problems such as the notch sensitivity of the titanium alloy material and the insecure welding of the special-shaped material, and has strong practicality. The process method can shorten the process and period of the turbine blade dynamic characteristic test and monitoring, reduces the preparation time and cost of the test, can greatly improve the safety and usability of the titanium alloy turbine blade, avoids the damage of the titanium alloy material matrix caused by the conventional process, and has important engineering significance for the safety guarantee of the normal deep peak regulation operation of the large thermal power unit under the current situation. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flowchart of the application. DETAILED DESCRIPTION

[0024] In order to further understand the content of the application, the application is described in detail below in combination with the drawings and specific embodiments. It should be understood that the embodiments are only used to explain the application but not to limit the application.

[0025] Reference Figure 1 A titanium alloy material spot welding method applied to the dynamic characteristic test of turbine moving blade, comprising the following steps:

[0026] S1, a titanium alloy thin skin suitable for the shape of the titanium alloy blade is made, and a double-layer titanium alloy clamp for fixing the signal line is made;

[0027] S2, the double-layer titanium alloy clamp is polished and cleaned;

[0028] S3, the working voltage and working current of the micro spot welding machine are adjusted, so that the external titanium alloy can be welded without damaging the surface of the titanium alloy blade when the double-layer titanium alloy clamp and the titanium alloy thin skin are spot welded;

[0029] S4, the titanium alloy thin skin is covered on the double-layer titanium alloy clamp, and the titanium alloy thin skin is spot welded on the surface of the titanium alloy blade by the micro spot welding machine;

[0030] S5, the spot welding position of the titanium alloy thin skin is polished and finished, and the spot welding is completed.

[0031] Embodiment:

[0032] The application comprises the following steps:

[0033] Step 101, test the required equipment and items, including titanium alloy thin skin, titanium alloy blade, fine-grained sandpaper, industrial alcohol, cotton ball, micro spot welding machine and other corresponding tools;

[0034] Step 102, the thickness of the titanium alloy thin skin is 0.5mm;

[0035] Step 103, the purity of industrial alcohol is required to be more than 95%.

[0036] Step 201, use titanium alloy thin skin and tools to make titanium alloy thin skin suitable for the shape of titanium alloy blade;

[0037] Step 202, cut a certain size of titanium alloy thin skin, fold and flatten along the middle part to make double-layer titanium alloy clip for fixing signal line;

[0038] Step 203, require double-layer titanium alloy clip to have no sharp edge to prevent scratching the signal line.

[0039] Step 301, use sandpaper to polish the double-layer titanium alloy clip;

[0040] Step 302, use medical degreasing cotton ball and alcohol to clean the titanium alloy blade and double-layer titanium alloy clip, remove the surface processing impurities, oil stains, etc., and confirm that the titanium alloy surface is clean and free of impurities.

[0041] Step 401, turn on the micro spot welding machine power supply and check the status of the spot welding machine;

[0042] Step 402, adjust the working voltage and current of the micro spot welding machine to appropriate values to ensure that the double-layer titanium alloy clip and titanium alloy thin skin are spot welded and the outer titanium alloy is melted without damaging the surface of the titanium alloy blade.

[0043] Step 501, place the double-layer titanium alloy clip on the surface of the titanium alloy blade and use the micro spot welding machine to spot weld and fix it at both ends of the double-layer titanium alloy clip;

[0044] Step 502, spot weld multiple double-layer titanium alloy clips in the direction of the signal line according to the above method.

[0045] Step 601, check the fixing condition of the double-layer titanium alloy clip after spot welding and ensure that there is no abnormal situation, if there is a protruding part, it should be polished;

[0046] Step 602, cover the titanium alloy thin skin on the double-layer titanium alloy clip that has been spot welded and fixed, and use the micro spot welding machine to spot weld the titanium alloy thin skin on the surface of the titanium alloy blade.

[0047] Step 701, use fine-grained sandpaper to polish the spot-welded position of the titanium alloy thin skin;

[0048] Step 702, check all spot welding sites again to ensure smooth spot welding.

[0049] The original spot welding process of turbine alloy steel blade can only be used on alloy steel blade, and cannot adapt to the characteristics and requirements of titanium alloy turbine blade, which may cause slight damage to the titanium alloy blade and bring uncertain risks to the future operation of the unit. The original spot welding process has seriously hindered the development and design of large turbine last-stage blades, and increased the process and research and development cost of turbine long blade design and development. Therefore, a titanium alloy material spot welding process is urgently needed to completely solve the adverse effects and hidden dangers of the original spot welding process on the titanium alloy blade in the dynamic characteristic test and monitoring of the titanium alloy blade, and to ensure the safe operation of the longer blade of the large unit turbine.

[0050] The present application provides a spot welding process and working method in the dynamic characteristic test of titanium alloy turbine moving blade. The process method requires a thickness of 0.5mm titanium alloy thin skin, titanium alloy blade, fine sandpaper, industrial alcohol with a purity of more than 95%, degreasing cotton ball, micro spot welding machine and other corresponding tools. The titanium alloy thin skin is made by using the titanium alloy thin skin and the tool, the titanium alloy thin skin of a certain size is sheared, the middle part is folded and flattened, the double-layer titanium alloy clip for fixing the signal line is made, and the double-layer titanium alloy clip is not sharp and rolled to prevent scratching the signal line. The double-layer titanium alloy clip is polished by using sandpaper, and the titanium alloy blade and the double-layer titanium alloy clip are cleaned by using medical degreasing cotton ball and alcohol to remove the surface processing impurities, oil stains and the like, and it is confirmed that the titanium alloy surface is clean and free of impurities. The power supply of the micro spot welding machine is connected, the state of the spot welding machine is checked, the working voltage and current of the micro spot welding machine are adjusted to appropriate values, and the double-layer titanium alloy clip and the titanium alloy thin skin are spot welded to ensure that the outer titanium alloy is welded and the titanium alloy blade surface is not damaged. The fixing status of the double-layer titanium alloy clip at both ends after spot welding is checked and no abnormal situation is ensured, if there is a protruding part, it should be polished, the titanium alloy thin skin is covered on the double-layer titanium alloy clip which has been spot welded and fixed, and the titanium alloy thin skin is spot welded on the surface of the titanium alloy blade by using the micro spot welding machine. After checking the spot welding status of the double-layer titanium alloy clip at both ends and no abnormal situation is ensured, the titanium alloy thin skin is covered on the double-layer titanium alloy clip which has been spot welded and fixed, and the titanium alloy thin skin is spot welded on the surface of the titanium alloy blade by using the micro spot welding machine. The position of the titanium alloy thin skin after spot welding is polished by using fine sandpaper, all spot welding sites are checked again to ensure smooth spot welding. The tools and articles used in the above titanium alloy turbine blade spot welding process are arranged, and the work site is cleaned.

[0051] The process method of the application has strong practicability, can shorten the process and cycle of the dynamic characteristic test and monitoring of the turbine blade, reduces the preparation time and cost of the test, and can greatly improve the safety and usability of the titanium alloy turbine blade, avoids the damage of the titanium alloy material matrix and the subsequent operation failure risk caused by the conventional process, and has important engineering significance for the safety guarantee of the normal deep peak regulation operation of the large thermal power unit under the current situation.

[0052] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the specific embodiments of the present application can still be modified or replaced by the same, without departing from the spirit and scope of the present application, any modification or equivalent replacement, which should be covered within the protection scope of the claims of the present application.

Claims

1. A spot welding method for titanium alloy materials used in the dynamic characteristic testing of turbine blades, characterized in that, Includes the following steps: S1, make a thin titanium alloy skin adapted to the shape of the titanium alloy blade, and make a double-layer titanium alloy clip for fixing the signal line. S2, Grind and clean the double-layer titanium alloy clips; S3, adjust the working voltage and current of the micro spot welder so that when spot welding double-layer titanium alloy clips and titanium alloy thin skin, the outer titanium alloy can be welded without damaging the surface of the titanium alloy blade. S4, the titanium alloy sheet is covered on the double-layer titanium alloy clip, and the titanium alloy sheet is spot welded to the surface of the titanium alloy blade using a micro spot welding machine. S5, grind and polish the spot welding positions of the titanium alloy thin skin to complete the spot welding.

2. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 1, characterized in that, The thickness of the titanium alloy sheet is 0.25mm.

3. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 1, characterized in that, The specific method for making a double-layer titanium alloy clip for securing signal lines is as follows: Cut the titanium alloy sheet to the required size, fold and flatten it along the middle to make a double-layer titanium alloy clip to fix the signal line.

4. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 1, characterized in that, The double-layer titanium alloy clips were cleaned using industrial alcohol with a purity of over 95%.

5. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 1, characterized in that, After spot welding the titanium alloy thin film onto the surface of the titanium alloy blade using a micro spot welding machine, check the condition of the fixed positions at both ends of the spot-welded double-layer titanium alloy clips and ensure that there are no abnormalities.

6. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 5, characterized in that, If there are protruding parts at the fixed positions of both ends of the double-layer titanium alloy clip that have been spot-welded, then the protruding parts should be ground down.

7. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 1, characterized in that, Fine sandpaper was used to grind and polish the spot weld areas of the titanium alloy thin sheet.

8. The spot welding method for titanium alloy materials applied to the dynamic characteristic testing of turbine blades according to claim 1, characterized in that, After grinding and polishing the spot weld areas of the titanium alloy sheet, all spot weld areas are inspected again to ensure that the spot welds are smooth.

Images