Preparation method of TRT blade surface laser cladding anti-corrosion and wear-resistant coating

Abstract

The invention relates to the technical field of TRT blade surface laser cladding anti-corrosion and wear-resistant coating preparation, and discloses a TRT blade surface laser cladding anti-corrosion and wear-resistant coating preparation method which comprises the following steps: preparing a nickel-based alloy raw material, putting the nickel-based alloy raw material into a planetary ball mill to be subjected to ball milling treatment after being combined, and preparing a nickel-based alloy coating; the mixed powder is bonded on a steel base material base plate to form a TRT blade, the TRT blade is put into a drying oven to be dried, high-energy-density laser beams of laser cladding equipment are used for irradiating the powder coated on the surface of the TRT blade to enable the powder to be fused, then an anti-corrosion layer is formed, a metal ceramic gradient material is melted or softened, the metal ceramic gradient material is sprayed to the surface of the anti-corrosion layer, and the metal ceramic gradient material is sprayed to the surface of the anti-corrosion layer. Then the boron nitride coating and the anticorrosive layer are fused together through laser cladding equipment, a transition layer is formed, the boron nitride coating is prepared, the surface of the transition layer on the TRT blade is evenly coated with the boron nitride coating, the surface of the transition layer on the TRT blade is fused together through the laser cladding equipment, and a wear-resistant layer is formed; through the preparation method, the service life of the TRT blade is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of anti-corrosion and wear-resistant coating by laser cladding on the surface of a TRT blade, and specifically relates to a method for preparing anti-corrosion and wear-resistant coating by laser cladding on the surface of a TRT blade. Background Art

[0002] TRT blades are a type of high-efficiency gas compression component used in the fields of aviation, aerospace, automobiles, ships, etc., especially in turbine devices that generate electricity from exhaust gas at the top of steel-making blast furnaces, where blades are key components.

[0003] TRT blades operate in harsh environments, especially under the influence of large amounts of smoke, corrosive gases, and washing water. The blades often suffer from wear and cracks due to erosion and corrosion. In addition, after dry dust removal, the fine dust, water vapor, oil mist, and acidic gases in the blast furnace gas may form a mixed fluid composed of "gas-vapor-solid". These media form an acidic water film on the surface of the blades, corroding the blades, resulting in reduced wear resistance and the appearance of gaps; in the blast furnace flue gas after dry dust removal, there are solid micro-particle dust, moisture, and a series of acidic substances, especially the chloride ion content, which fluctuates greatly. These substances wash the blades when passing through the TRT. At the same time, the temperature decreases after the flue gas energy is released for power generation, and condensed water will precipitate and form strong acid and high chlorine solutions with the acid radicals in the flue gas. These solutions adhere to the blades and penetrate into the gaps, thereby quickly corroding the blades and reducing the service life of the TRT blades.

[0004] To this end, we proposed a method for preparing anti-corrosion and wear-resistant coating on the surface of TRT blades by laser cladding. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a laser cladding anti-corrosion and wear-resistant coating on the surface of a TRT blade in order to increase the service life of the TRT blade.

[0006] The technical solution adopted by the present invention is as follows: A method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating comprises the following steps: Step 1: Prepare the raw materials of nickel-based alloy, including C powder, Cr powder, Si powder, B powder, Fe powder, rare earth oxide CeO2 powder and Ni powder, mix them according to a certain ratio and put them into a planetary ball mill for ball milling, so that the powders can be ground and mixed more evenly; Step 2: Use a binder to evenly bond the mixed powder to the steel substrate to ensure that the powder is evenly distributed without bubbles and impurities to form a TRT blade, and then put the TRT blade into an oven for drying to form a good bond between the powder and the substrate; Step 3: Using laser cladding equipment, the powder coated on the surface of the TRT blade is irradiated with a high-energy-density laser beam to melt it and form an anti-corrosion layer; Step 4: Melt or soften the metal ceramic gradient material, and spray it onto the surface of the nickel-based alloy anti-corrosion layer using thermal spraying technology to form a coating. Then, use a laser cladding device to irradiate the transition layer material powder coated on the surface of the nickel-based alloy anti-corrosion layer with a high-energy-density laser beam to melt it together with the anti-corrosion layer to form a transition layer. Step 5: Prepare the boron nitride material into powder, then mix the boron nitride powder with an organic solvent to prepare a boron nitride coating, and then use a brush, roller coating or spraying method to evenly apply the boron nitride coating on the surface of the transition layer on the TRT blade. Finally, use laser cladding equipment to irradiate the boron nitride coating coated on the transition layer with a high-energy density laser beam to melt it together with the transition layer to form a wear-resistant layer.

[0007] In a preferred embodiment of the invention, the nickel-based alloy is composed of the following raw materials: C powder: 0.3wt%~0.5wt%, Cr powder: 15wt%~18wt%, Si powder: 3wt%~5wt%, B powder: 0.5wt%~2.0wt%, Fe powder: 5wt%~8wt%, rare earth oxide CeO2 powder: 7wt%~10wt%, and Ni powder: balance.

[0008] In a preferred embodiment of the invention, the drying temperature of the TRT blade in the oven is 150° C., and the drying time is 1 hour.

[0009] In a preferred embodiment of the invention, the organic solvent is any one of a heated hydrofluoric acid solution or a concentrated sodium fluoride solution.

[0010] In a preferred embodiment of the invention, the content of the boron nitride powder is 9wt% to 13wt%.

[0011] In a preferred embodiment of the invention, the thickness of the anti-corrosion layer is 0.2-0.4 mm, the thickness of the transition layer is 0.1-0.3 mm, and the thickness of the wear-resistant layer is 0.3-0.4 mm.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. In the present invention, in the preparation of the anti-corrosion layer of the TRT blade, by adding rare earth element CeO2 powder, a dense oxide layer can be formed on the metal surface. This oxide layer can effectively prevent the TRT blade from contacting with oxygen, water and other harmful substances in the environment, thereby inhibiting the corrosion process of the metal, thereby improving the service life of the TRT blade and enhancing its durability; by adding rare earth element CeO2 powder and improving the bonding force between the coating and the TRT blade, the coating is made more stable and not easy to peel off; by adding rare earth element CeO2 powder, impurities at the grain boundaries are effectively removed, the growth of columnar crystals is inhibited, the wettability and fluidity of the molten pool material are increased, the surface of the cladding layer after solidification is made smoother and flatter, the uniformity and density of the coating are improved, and the corrosion resistance and service life of the TRT blade are improved.

[0013] 2. In the present invention, the metal-ceramic gradient material has good mechanical properties and bonding strength. Due to the continuous changes in the components and structure of the gradient material, the connection between the anti-corrosion layer and the wear-resistant layer is more secure. This strong connection can prevent the coating from peeling or cracking during use, thereby ensuring the long-term stability and effectiveness of the coating. At the same time, the design of the metal-ceramic gradient material can achieve a smooth transition between the anti-corrosion layer and the wear-resistant layer, avoiding interface problems between the two layers caused by sudden changes in materials and properties, and helping to reduce stress concentration at the interface and the possibility of crack formation, thereby improving the stability and durability of the entire coating, thereby increasing the service life of the TRT blade.

[0014] 3. In the present invention, boron nitride has high hardness and high wear resistance, which enables it to effectively resist external friction and wear in the wear-resistant layer of TRT blades; at the same time, boron nitride has excellent thermal conductivity, which can effectively conduct heat away from the blades to prevent the TRT blades from being damaged by thermal stress; and boron nitride has good electrical insulation, which enables it to effectively reduce the occurrence of electrical faults and short circuits in TRT blades working in an electrical environment, thereby increasing the service life of the TRT blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of the steps for preparing the anti-corrosion and wear-resistant coating by laser cladding on the surface of a TRT blade. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The following will be combined Figure 1 A method for preparing a corrosion-resistant and wear-resistant coating by laser cladding on the surface of a TRT blade according to an embodiment of the present invention is described in detail.

[0018] Reference Figure 1 , Example

[0019] Reference Figure 1 A method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating comprises the following steps: Step 1: preparing raw materials of a nickel-based alloy, including C powder, Cr powder, Si powder, B powder, Fe powder, rare earth oxide CeO2 powder and Ni powder, mixing them in a certain ratio and putting them into a planetary ball mill for ball milling treatment, so that the powders can be ground and mixed more evenly; the nickel-based alloy is composed of the following raw materials, C powder: 0.3wt%~0.5wt%, Cr powder: 15wt%~18wt%, Si powder: 10wt%~20wt%, and Fe powder: 20wt%~30wt%. Powder: 3wt%~5wt%, B powder: 0.5wt%~2.0wt%, Fe powder: 5wt%~8wt%, rare earth oxide CeO2 powder: 7wt%~10wt%, Ni powder: balance; Step 2: Use a binder to evenly bond the mixed powder to the steel substrate to ensure that the powder is evenly distributed without bubbles and impurities to form a TRT blade, and put the TRT blade into an oven for drying to form a good bond between the powder and the substrate, and use laser cladding equipment through high energy density The powder coated on the surface of the TRT blade is irradiated with a laser beam of 10000 degrees to melt it and form an anti-corrosion layer. The drying temperature of the TRT blade in the oven is 150°C and the drying time is 1 hour. The thickness of the anti-corrosion layer is 0.2-0.4mm. Specifically, in the preparation of the anti-corrosion layer of the TRT blade, a dense oxide layer can be formed with the metal surface by adding rare earth element CeO2 powder. This oxide layer can effectively prevent the TRT blade from contacting with oxygen, water and other harmful substances in the environment, thereby inhibiting the corrosion process of the metal, thereby improving the service life of the TRT blade and enhancing its durability; by adding rare earth element CeO2 powder and improving the bonding force between the coating and the TRT blade, the coating is made more stable and not easy to peel off; by adding rare earth element CeO2 powder, grain boundary impurities are effectively removed, the growth of columnar crystals is inhibited, the wettability and fluidity of the molten pool material are increased, the surface of the cladding layer after solidification is smoother and flatter, the uniformity and density of the coating are improved, and the corrosion resistance and service life of the TRT blade are improved.

[0020] Reference Figure 1, melt or soften the metal ceramic gradient material, and use thermal spraying technology to spray it onto the surface of the nickel-based alloy anti-corrosion layer to form a coating, and then use laser cladding equipment to irradiate the transition layer material powder coated on the surface of the nickel-based alloy anti-corrosion layer with a high-energy density laser beam, so that it is melted together with the anti-corrosion layer to form a transition layer; the thickness of the transition layer is 0.1-0.3mm. Specifically, the metal ceramic gradient material has good mechanical properties and bonding strength. Due to the continuous change of the composition and structure of the gradient material, the connection between the anti-corrosion layer and the wear-resistant layer is more firm. This strong connection can prevent the coating from peeling off or cracking during use, ensuring the long-term stability and effectiveness of the coating; at the same time, the design of the metal ceramic gradient material can achieve a smooth transition between the anti-corrosion layer and the wear-resistant layer, avoiding interface problems caused by sudden changes in materials and properties between the two layers, and helping to reduce the possibility of stress concentration and crack formation at the interface, thereby improving the stability and durability of the entire coating.

[0021] Reference Figure 1 , preparing the boron nitride material into powder, then mixing the boron nitride powder with an organic solvent to prepare a boron nitride coating, then using a brush, roller coating or spraying method to evenly apply the boron nitride coating on the surface of the transition layer on the TRT blade, and finally using a laser cladding device to irradiate the boron nitride coating coated on the transition layer with a high-energy-density laser beam to melt it together with the transition layer to form a wear-resistant layer; the content of the boron nitride powder is 9wt% to 13wt%, and the organic solvent is any of the heated hydrofluoric acid solution or the concentrated sodium fluoride solution. In one embodiment, the thickness of the wear-resistant layer is 0.3-0.4 mm. Specifically, boron nitride has high hardness and high wear resistance, which enables it to effectively resist external friction and wear in the wear-resistant layer of TRT blades; at the same time, boron nitride has excellent thermal conductivity, which can effectively conduct heat away from the blades to prevent the TRT blades from being damaged by thermal stress; and boron nitride has good electrical insulation, which enables it to effectively reduce the occurrence of electrical faults and short circuits in TRT blades working in an electrical environment, thereby increasing the service life of the TRT blades.

[0022] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0023] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a corrosion-resistant and wear-resistant coating on a TRT blade surface by laser cladding, characterized in that: The steps include: Step 1: Prepare the raw materials of nickel-based alloy, including C powder, Cr powder, Si powder, B powder, Fe powder, rare earth oxide CeO2 powder and Ni powder, mix them according to a certain ratio and put them into a planetary ball mill for ball milling, so that the powders can be ground and mixed more evenly; Step 2: Use a binder to evenly bond the mixed powder to the steel substrate to ensure that the powder is evenly distributed without bubbles and impurities to form a TRT blade, and then put the TRT blade into an oven for drying to form a good bond between the powder and the substrate; Step 3: Using laser cladding equipment, the powder coated on the surface of the TRT blade is irradiated with a high-energy-density laser beam to melt it and form an anti-corrosion layer; Step 4: Melt or soften the metal ceramic gradient material, and spray it onto the surface of the nickel-based alloy anti-corrosion layer using thermal spraying technology to form a coating. Then, use a laser cladding device to irradiate the transition layer material powder coated on the surface of the nickel-based alloy anti-corrosion layer with a high-energy-density laser beam to melt it together with the anti-corrosion layer to form a transition layer. Step 5: Prepare the boron nitride material into powder, then mix the boron nitride powder with an organic solvent to prepare a boron nitride coating, and then use a brush, roller coating or spraying method to evenly apply the boron nitride coating on the surface of the transition layer on the TRT blade. Finally, use laser cladding equipment to irradiate the boron nitride coating coated on the transition layer with a high-energy density laser beam to melt it together with the transition layer to form a wear-resistant layer.

2. The method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating according to claim 1, characterized in that: The nickel-based alloy is composed of the following raw materials: C powder: 0.3wt%-0.5wt%, Cr powder: 15wt%-18wt%, Si powder: 3wt%-5wt%, B powder: 0.5wt%-2.0wt%, Fe powder: 5wt%-8wt%, rare earth oxide CeO2 powder: 7wt%-10wt%, and Ni powder: balance.

3. The method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating according to claim 1, characterized in that: The drying temperature of the TRT blade in the oven is 150° C., and the drying time is 1 hour.

4. The method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating according to claim 1, characterized in that: The organic solvent is any one of a heated hydrofluoric acid solution or a concentrated sodium fluoride solution.

5. The method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating according to claim 1, characterized in that: The content of the boron nitride powder is 9wt% to 13wt%.

6. The method for preparing a TRT blade surface laser cladding anti-corrosion and wear-resistant coating according to claim 1, characterized in that: The thickness of the anti-corrosion layer is 0.2-0.4 mm, the thickness of the transition layer is 0.1-0.3 mm, and the thickness of the wear-resistant layer is 0.3-0.4 mm.

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