Preparation process of a structured anti-corrosion layer for titanium alloy blades

A preparation process, titanium alloy technology, applied in metal material coating process, coating, solid-state diffusion coating, etc., can solve the problem of affecting the working efficiency and safe operation of steam turbines, poor bonding between cemented carbide sheets and blade base, and difficult to control. Beam cracks and other problems, to achieve the effect of low friction coefficient, combined with mild high, good anti-adhesive wear and friction wear performance

Inactive Publication Date: 2018-03-23
ZHONGYUAN ENGINEERING COLLEGE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this way, the water erosion and water scouring of the titanium alloy final stage blades whose working area is the wet steam area are more serious. The steam flow carries a large number of water droplets. Cavitation often occurs at the top of the blade, resulting in reduced efficiency of the steam turbine, weakened blade strength, and increased vibration, directly affecting the working efficiency and safe operation of the steam turbine
[0004] The use of traditional brazed hard alloy sheets has a good anti-water erosion effect, but during the high-speed operation of the unit, the cemented carbide sheets may fall off due to the poor combination of the cemented carbide sheets and the blade matrix, resulting in serious quality accidents
Laser surface treatment technology has metallurgical bonding strength, but many processes are faced with difficulties in controlling defects such as cracks caused by beam lapping. At the same time, due to the continuous area and area of ​​high-energy laser beam action, large thermal stress causes workpiece deformation and warping

Method used

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  • Preparation process of a structured anti-corrosion layer for titanium alloy blades
  • Preparation process of a structured anti-corrosion layer for titanium alloy blades

Examples

Experimental program
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Effect test

Embodiment 1

[0032] The preparation process of the structured anti-corrosion layer of the titanium alloy blade in this embodiment, the steps are as follows:

[0033] (1) Carburizing treatment: The embodiment of the present invention is a titanium alloy (TC4) blade. Before carburizing treatment, the entire blade needs to be cleaned with ethanol and then dried. After drying, it is put into a vacuum tube furnace for solid carburizing. The carburizing agent is mainly composed of two types of substances evenly mixed, one is coal powder that produces activated carbon atoms, accounting for about 90% of the total mass; the other is the infiltration agent sodium carbonate, accounting for about 90% of the total mass About 9%, and the other 1% of the mass is the rare earth element La. The carburizing temperature is 850°C, the gas in the vacuum tube furnace is argon, and the carburizing time is 8 hours; the blade after carburizing treatment needs to determine the contour line to be treated at the stea...

Embodiment 2

[0037] The preparation process of the structured anti-corrosion layer of the titanium alloy blade in this embodiment, the steps are as follows:

[0038] (1) Carburizing treatment: The embodiment of the present invention is a titanium alloy (TC4) blade. Before carburizing treatment, the entire blade needs to be cleaned with ethanol and then dried. After drying, it is put into a vacuum tube furnace for solid carburizing. The carburizing agent is mainly composed of two types of substances evenly mixed, one is coal powder that produces activated carbon atoms, accounting for 90% of the total mass; the other is the infiltration agent sodium carbonate, accounting for about 9% of the total mass , the other 1% by mass is La as a rare earth element. The carburizing temperature is 930°C, the gas in the vacuum tube furnace is argon, and the carburizing time is 8 hours; the blade after carburizing treatment needs to determine the contour line to be treated at the steam inlet side of the la...

Embodiment 3

[0042] The preparation process of the structured anti-corrosion layer of the titanium alloy blade in this embodiment, the steps are as follows:

[0043] (1) Carburizing treatment: The embodiment of the present invention is a titanium alloy (TC4) blade. Before carburizing treatment, the entire blade needs to be cleaned with ethanol and then dried. After drying, it is put into a vacuum tube furnace for solid carburizing. The carburizing agent is mainly composed of two types of substances evenly mixed, one is coal powder that produces activated carbon atoms, accounting for about 90% of the total mass; the other is the infiltration agent sodium carbonate, accounting for about 90% of the total mass About 9%, and the other 1% of the mass is the rare earth element La. The carburizing temperature is 1010°C, the gas in the vacuum tube furnace is argon, and the carburizing time is 8 hours; the blade after carburizing treatment needs to determine the contour line to be processed at the s...

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Abstract

The invention discloses a preparation process for a structuralized water erosion preventing layer of a titanium alloy blade. The preparation process includes the following steps that (1) carburizing treatment is carried out, specifically, a carburized layer is prepared on the surface of the titanium alloy blade through the method that rare earth elements are doped into solid powder in a vacuum tube furnace to carry out carburizing treatment; (2) laser structuralizing nitriding treatment is carried out, specifically, laser scanning is carried out on an admission edge back arc of the carburized titanium alloy blade through a multifunctional laser generator, a discrete structuralized array area is obtained, and a discrete structuralized nitrided modified layer is obtained after treatment; and (3) fusing treatment is carried out, specifically, fusing is carried out on the discrete structuralized nitrided modified layer of the titanium alloy blade through the multifunctional laser generator, the structuralized water erosion preventing protecting layer which is in graded distribution both in the axis layer depth direction of the titanium alloy blade and the axis radius direction of the whole titanium alloy blade and with good surface quality is obtained. The abrasion resistance of the whole blade is obviously improved, and the overall hardness and abrasion resistance of the structuralized nitrided admission edge water erosion preventing modified layer are higher than those of base materials.

Description

technical field [0001] The invention provides a titanium alloy surface laser strengthening treatment process, which is suitable for strengthening the surface of titanium alloy blades, and is especially suitable for strengthening the surface of titanium alloy blades at the last stage of a steam turbine against water erosion. Background technique [0002] With the increasing capacity of steam turbines in power stations, the safety and reliability of blades and maintaining high efficiency are particularly important. The blade is one of the key parts of the steam turbine. The last-stage blades of the steam turbine are the longest and the heaviest group in the steam turbine unit. Under extremely harsh conditions, it withstands the combined effects of high temperature, high pressure, huge centrifugal force, steam force, steam excitation force, corrosion and vibration, and water droplet erosion in the wet steam area. [0003] TC4 belongs to the α+β series titanium alloy, which ha...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23C8/64C23C8/24C23C8/80
CPCC23C8/24C23C8/64C23C8/80
Inventor 郭士锐易云杰姚建华
Owner ZHONGYUAN ENGINEERING COLLEGE
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