High-temperature-resistant and corrosion-resistant shell material and manufacturing process thereof

Abstract

The invention relates to the technical field of preparation of high-temperature-resistant and corrosion-resistant shell materials, and discloses a high-temperature-resistant and corrosion-resistant shell material and a manufacturing process thereof, the high-temperature-resistant and corrosion-resistant shell material comprises chromium, nickel, molybdenum, aluminum, titanium, silicon, iron and rare earth elements; the alloy comprises the following components in parts by weight: 13-18 parts of chromium; 3 to 8 parts of nickel; 1 to 5 parts of molybdenum; 0.5 to 3 parts of aluminum; 0.2 to 2 parts of titanium; 0.5 to 2 parts of silicon; 0.1 to 0.5 part of iron; the rare earth elements are trace, chromium, nickel and molybdenum serve as main alloy elements, the high temperature resistance and corrosion resistance of the material can be greatly improved, chromium is excellent in performance in the high-temperature and oxidizing environment, nickel enhances the toughness and high-temperature strength of the material, molybdenum further improves the corrosion resistance of the material in a reducing medium, and aluminum, titanium and silicon serve as auxiliary alloy elements, so that the corrosion resistance of the material is improved. The rare earth elements are added to refine crystal grains, the strength and toughness of the material are improved, the trace rare earth elements are added to further refine the crystal grains, the uniformity of material components and the optimization of a microstructure are ensured, and the toughness and corrosion resistance of the material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of high-temperature and corrosion-resistant housing materials, specifically to high-temperature and corrosion-resistant housing materials and manufacturing processes. Background Art

[0002] High-temperature and corrosion-resistant housing materials refer to a class of special materials that can effectively resist corrosion erosion in high-temperature environments. They are usually used to manufacture housing structures that need to withstand high temperatures and corrosive environments. The high-temperature resistance is one of the important characteristics of such materials. They can maintain stable physical and chemical properties in high-temperature environments, are not easily deformed, melted or decomposed, ensuring that the housing can still maintain its structural integrity and functional effectiveness under high-temperature conditions;

[0003] The corrosion resistance is another key characteristic of such materials. They can resist the erosion of various corrosive media, such as oxidation, reduction, sulfidation and other chemical reactions, thus preventing material performance degradation, corrosion or exfoliation. The corrosion resistance ensures that the housing can still operate stably for a long time in harsh environments; High-temperature and corrosion-resistant housing materials are a class of materials with special properties, thus ensuring the structural integrity and functional effectiveness of the housing.

[0004] In many key fields of modern industry, such as energy power, petrochemical, aerospace and ocean development, the working environments faced by equipment are becoming increasingly extremely complex. On the one hand, in energy conversion devices such as boiler pipes in thermal power generation and hot-end components of gas turbines, high-temperature gas scours the housing for a long time, and the temperature is often thousands of degrees Celsius. Moreover, various oxidizing and reducing gases generated during the combustion process are intertwined. Traditional metal materials are extremely prone to oxidation, sulfidation and other corrosion reactions in this environment, resulting in material performance deterioration, seriously affecting the safe and stable operation and service life of the equipment. On the other hand, reaction kettles, storage tanks, etc. in the chemical industry often come into contact with strong acids, strong alkalis and various corrosive organic media. At the same time, some chemical processes are accompanied by heat release phenomena, making the housing need to be resistant to chemical corrosion and withstand a certain high temperature. Existing single materials or conventional manufacturing processes are difficult to meet these two harsh requirements, and safety accidents such as leaks and production stoppages caused by material failures frequently occur, resulting in huge economic losses.

[0005] Furthermore, when aerospace vehicles are passing through the atmosphere and flying in space, their shells are exposed to extreme temperature differences, ranging from more than 100 degrees Celsius below zero to thousands of degrees Celsius. They also have to resist potential damage from cosmic rays and micrometeoroid impacts, as well as erosion by atomic oxygen in the space environment, which poses extremely high challenges to the material's high temperature resistance, corrosion resistance, and toughness. In the field of marine development, the shells of deep-sea probes and submarine oil production equipment are in a high-pressure, low-temperature seawater environment rich in high-concentration salt and corrosive microorganisms. Existing materials often fail prematurely under such harsh working conditions coupled with multiple factors, making it difficult to meet the needs of long-term reliable service. For this reason, high-temperature and corrosion-resistant shell materials and manufacturing processes are proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a high temperature resistant and corrosion resistant shell material and a manufacturing process to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions: a high temperature and corrosion resistant shell material, comprising chromium, nickel, molybdenum, aluminum, titanium, silicon, iron and rare earth elements;

[0008] The composition weight ratio is:

[0009] Chromium: 13-18 parts;

[0010] Nickel: 3-8 parts;

[0011] The molybdenum: 1-5 parts;

[0012] Aluminum: 0.5-3 parts;

[0013] Titanium: 0.2-2 parts;

[0014] Silicon: 0.5-2 parts;

[0015] Iron: 0.1-0.5 parts;

[0016] The rare earth element: trace amount.

[0017] Preferably, the rare earth element mentioned above may be lanthanum or cerium.

[0018] The present invention also provides a process for manufacturing a high-temperature resistant and corrosion-resistant shell material, comprising the following steps:

[0019] S1. Prepare raw materials;

[0020] S2, raw material mixing and smelting;

[0021] S3, obtaining castings after casting and molding;

[0022] S4. heat treating the casting;

[0023] S5. Surface treatment.

[0024] Preferably, in S2, the raw materials are mixed and then added to a high-frequency induction furnace.

[0025] Preferably, in the high-frequency induction furnace, the smelting temperature of the raw materials is 1600 - 1800 °C.

[0026] Preferably, in S3, the casting temperature is 1400 - 1600 °C.

[0027] Preferably, after casting, the casting is slowly cooled, and the cooling rate is 10 °C / hour - 50 °C / hour.

[0028] Preferably, in S4, the heat treatment includes solution treatment and aging treatment;

[0029] The solution treatment temperature of the casting is 1050 - 1150 °C, and the holding time is 0.5 - 1.5 hours.

[0030] Preferably, the aging treatment temperature of the casting is 450 - 550 °C, and the aging time is 1 - 3 hours.

[0031] Preferably, in S5, the surface treatment is chrome plating or nickel plating on the surface of the casting, and the coating thickness is 50 μm - 200 μm.

[0032] Compared with the prior art, the present invention adopts the above technical solutions and has the following technical effects:

[0033] First, by using chromium, nickel, and molybdenum as the main alloying elements, the high-temperature resistance and corrosion resistance of the material can be greatly improved. Chromium performs excellently in high-temperature and oxidizing environments, nickel enhances the toughness and high-temperature strength of the material, and molybdenum further improves the corrosion resistance in reducing media. Aluminum, titanium, and silicon, as auxiliary alloying elements, can refine the grain, improve the strength and toughness of the material. The addition of trace rare earth elements further refines the grain, controls the smelting, casting, and heat treatment processes, ensures the uniformity of the material composition and the optimization of the microstructure, and improves the toughness and corrosion resistance of the material.

[0034] Second, by preheating the mold and precisely controlling the casting temperature, casting defects such as pores and cracks are reduced. Slow cooling ensures the release of internal stress in the casting and the optimization of the microstructure, avoiding residual stress and deformation caused by rapid cooling. The solution treatment and aging treatment in the heat treatment enable the alloying elements inside the casting to dissolve and precipitate fully, improving the hardness and strength of the material, while enhancing its toughness. Chrome plating or nickel plating on the surface not only improves the wear resistance of the casting but also enhances its corrosion resistance, protecting the matrix from erosion. Description of the Drawings

[0035] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0036] Figure 1 It is the process flow chart of the present invention; Specific embodiments

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] It should be noted that the structures, ratios, sizes, etc. shown in the accompanying drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present application. Therefore, they do not have technical substance significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present application can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present application.

[0039] In the prior art, in many key fields of modern industry, such as energy power, petrochemical industry, aerospace, and ocean development, the working environment faced by equipment is becoming increasingly extremely complex. On the one hand, in energy conversion devices such as boiler pipes in thermal power generation and hot-end components of gas turbines, high-temperature gas scours the shell for a long time, with temperatures often reaching thousands of degrees Celsius, and various oxidizing and reducing gases generated during the combustion process are intertwined. Traditional metal materials are extremely prone to oxidation, sulfidation and other corrosion reactions in this environment, resulting in deterioration of material properties, seriously affecting the safe and stable operation and service life of equipment. On the other hand, reaction kettles, storage tanks, etc. in the chemical industry often come into contact with strong acids, strong alkalis and various corrosive organic media. At the same time, some chemical processes are accompanied by heat release phenomena, making the shell not only resistant to chemical corrosion but also tolerate a certain high temperature. Existing single materials or conventional manufacturing processes are difficult to take into account these two harsh requirements, and safety accidents such as leakage and production stoppage caused by material failure frequently occur, resulting in huge economic losses.

[0040] Furthermore, during stages such as when aerospace vehicles pass through the atmosphere and conduct space flights, the shell faces extreme temperature differences, ranging from over a hundred degrees Celsius below zero to over a thousand degrees Celsius. It also has to withstand potential damage caused by cosmic rays and micrometeorite impacts, as well as atomic oxygen erosion in the space environment, posing extremely high challenges to the high-temperature resistance, corrosion resistance, and toughness of the materials. In the field of ocean development, the shells of deep-sea detectors and subsea oil production equipment are in a seawater environment with high pressure, low temperature, and rich in high-concentration salts and corrosive microorganisms. Existing materials often fail prematurely under such harsh working conditions with multiple factors coupled, making it difficult to meet the requirements for long-term reliable service.

[0041] Embodiment

[0042] Please refer to Figure 1 , the present invention provides a technical solution: a high-temperature and corrosion-resistant shell material, which consists of chromium, nickel, molybdenum, aluminum, titanium, silicon, iron, and rare earth elements;

[0043] The weight ratio of the components is: chromium: 13 parts; nickel: 3 parts; molybdenum: 1 part; aluminum: 0.5 part; titanium: 0.2 part; silicon: 0.5 part; iron: 0.1 part; rare earth elements: trace amount.

[0044] The rare earth elements can be lanthanum or cerium.

[0045] As the main alloying element, chromium can significantly improve the hardness and corrosion resistance of the material, especially in high-temperature and oxidizing environments. Nickel can enhance the toughness and high-temperature strength of the material, and also helps to improve the corrosion resistance. The addition of molybdenum can further improve the corrosion resistance of the material, especially in reducing media. Aluminum, titanium, and silicon, as auxiliary alloying elements, can refine the grains, improve the strength and toughness of the material. Iron provides the main mechanical properties and processing properties of the material. The addition of rare earth elements can further refine the grains, improve the toughness and corrosion resistance of the material.

[0046] Chromium, nickel, and molybdenum, as the main alloying elements, can greatly improve the high-temperature resistance and corrosion resistance of the material. Chromium performs excellently in high-temperature and oxidizing environments. Nickel enhances the toughness and high-temperature strength of the material, and molybdenum further improves the corrosion resistance in reducing media. Aluminum, titanium, and silicon, as auxiliary alloying elements, can refine the grains, improve the strength and toughness of the material. The trace addition of rare earth elements further refines the grains, controls the smelting, casting, and heat treatment processes, and ensures the uniformity of the material composition and the optimization of the microstructure.

[0047] The present invention also provides a manufacturing process for the high-temperature and corrosion-resistant shell material, including the following steps:

[0048] S1. Prepare raw materials;

[0049] S2. Mix and smelt the raw materials;

[0050] After the raw materials are mixed, they are added to a high-frequency induction furnace, and the smelting temperature of the raw materials in the high-frequency induction furnace is 1600 °C;

[0051] Prepare the raw materials for mixing to ensure the uniform distribution of various elements. The mixed raw materials are added to a high-frequency induction furnace for smelting. The high-frequency induction furnace uses the magnetic field generated by high-frequency current to cause eddy currents in the metal in the furnace and heat it, thus achieving rapid and efficient smelting; the smelting temperature in this embodiment is 1600 °C. Too high a temperature may cause excessive oxidation or incomplete melting of the raw materials, while too low a temperature may not fully dissolve various elements, affecting the compositional uniformity and properties of the material;

[0052] S3. Obtain the casting after casting and forming;

[0053] The casting temperature is 1500 °C. After casting is completed, the casting is slowly cooled at a cooling rate of 10 °C / hour.

[0054] During the casting process, the molten metal is poured into a preheated mold. The molten metal cools and solidifies in the mold to form a preliminary casting. In order to ensure the release of internal stress and the optimization of the microstructure of the casting, a slow cooling method is adopted. The cooling rate is precisely controlled at 10 °C / hour, which can not only ensure that the metal elements inside the casting have enough time to diffuse and homogenize, but also prevent residual stress and deformation caused by rapid cooling.

[0055] After cooling is completed, the casting can be removed from the mold and subjected to subsequent processing and inspection. By preheating the mold and precisely controlling the casting temperature, casting defects such as pores and cracks are reduced. Slow cooling ensures the release of internal stress and the optimization of the microstructure of the casting, avoiding residual stress and deformation caused by rapid cooling.

[0056] S4. Heat-treat the casting;

[0057] The heat treatment includes solution treatment and aging treatment;

[0058] The solution treatment temperature of the casting is 1050 °C, and the holding time is 0.5 hours.

[0059] The casting is heated to 1050 °C and held for 0.5 hours to fully dissolve the alloy elements inside the casting into the matrix to form a uniform solid solution. The formation of the solid solution helps to improve the hardness and strength of the material and enhance its corrosion resistance. Holding ensures that the elements can be fully dissolved.

[0060] The aging treatment temperature of the casting is 450 °C, and the aging time is 1 hour.

[0061] After solution treatment is completed, the casting is cooled to room temperature at a certain rate, and then aging treatment is carried out. The aging treatment temperature is 450 °C, and the holding time is 1 hour. At this stage, the alloying elements inside the casting will precipitate in the form of dispersed phases, and the dispersed phases can hinder the movement of dislocations, thereby improving the strength and toughness of the material.

[0062] Solution treatment and aging treatment in heat treatment enable the alloying elements inside the casting to dissolve and precipitate fully, improving the hardness and strength of the material, and at the same time enhancing its toughness. Surface chromium plating or nickel plating not only improves the wear resistance of the casting, but also enhances its corrosion resistance, protecting the matrix from erosion.

[0063] S5, Surface treatment.

[0064] The surface treatment is chromium plating or nickel plating on the surface of the casting, and the coating thickness is 100 μm.

[0065] The chromium plating layer has extremely high hardness and wear resistance, which can significantly improve the wear resistance of the casting. At the same time, the chromium layer also has good chemical stability and corrosion resistance, and can protect the matrix from erosion in a variety of corrosive media. The nickel plating layer has excellent corrosion resistance and good weldability, and is suitable for castings that require welding processing.

[0066] Perform high-temperature tensile strength tests on the prepared high-temperature and corrosion-resistant shell material, and conduct tests at different temperatures (600 °C, 700 °C, 800 °C, 900 °C, 1000 °C). The data are as follows:

[0067]

[0068]

[0069] It can be seen from the above data that as the temperature increases, the tensile strength of the material in this embodiment decreases somewhat, but it can still maintain a relatively high strength at 1000 °C, indicating that the material has good high-temperature strength performance.

[0070] Immerse the prepared high-temperature and corrosion-resistant shell material in an acidic solution (10% HCl solution) and an alkaline solution (10% NaOH solution) respectively for immersion corrosion tests. The immersion time is 72 hours, and calculate the corrosion rate. The data are as follows:

[0071]

[0072] The corrosion rate of the high-temperature and corrosion-resistant shell material produced in this embodiment is lower than that of common materials on the market in both acidic and alkaline environments, and it has more excellent corrosion resistance.

[0073] In summary, by using chromium, nickel, and molybdenum as the main alloying elements, the high-temperature resistance and corrosion resistance of the material can be significantly improved. Chromium performs excellently in high-temperature and oxidizing environments, nickel enhances the toughness and high-temperature strength of the material, and molybdenum further improves the corrosion resistance in reducing media. Aluminum, titanium, and silicon, as auxiliary alloying elements, can refine the grain size, improve the strength and toughness of the material. The addition of trace rare earth elements further refines the grain size, controls the smelting, casting, and heat treatment processes, ensures the uniformity of the material composition and the optimization of the microstructure, and improves the toughness and corrosion resistance of the material.

[0074] By preheating the mold and precisely controlling the casting temperature, casting defects such as pores and cracks are reduced. Slow cooling ensures the release of internal stresses in the casting and the optimization of the microstructure, avoiding residual stresses and deformations caused by rapid cooling. Solution treatment and aging treatment in heat treatment enable the alloying elements inside the casting to dissolve fully and precipitate, improving the hardness and strength of the material while enhancing its toughness. Surface chromium plating or nickel plating not only improves the wear resistance of the casting but also enhances its corrosion resistance, protecting the substrate from erosion.

[0075] Those skilled in the art can understand that the features recited in the various embodiments and / or claims of the present invention can be combined or / and combined in various ways, even if such combinations or combinations are not explicitly recited in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features recited in the various embodiments and / or claims of the present invention can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present invention.

Claims

1. A high-temperature and corrosion-resistant housing material, characterized in that, It consists of chromium, nickel, molybdenum, aluminum, titanium, silicon, iron and rare earth elements; The weight parts ratio of the composition is as follows: The chromium: 13 - 18 parts; The nickel: 3 - 8 parts; The molybdenum: 1 - 5 parts; The aluminum: 0.5 - 3 parts; The titanium: 0.2 - 2 parts; The silicon: 0.5 - 2 parts; The iron: 0.1 - 0.5 parts; The rare earth elements: trace amounts.

2. The high-temperature resistant and corrosion-resistant housing material according to claim 1, characterized in that: The rare earth elements can be lanthanum or cerium.

3. The manufacturing process of the high-temperature and corrosion-resistant housing material according to any one of claims 1 or 2, characterized in that, It includes the following steps: S1. Prepare raw materials; S2. Mix and smelt the raw materials; S3. Cast and form to obtain a casting; S4. Heat-treat the casting; S5. Surface treatment.

4. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 3, characterized in that: In S2, after the raw materials are mixed, they are added to a high-frequency induction furnace.

5. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 4, characterized in that: The temperature for smelting the raw materials in the high-frequency induction furnace is 1600 - 1800 °C.

6. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 3, characterized in that: In S3, the casting temperature is 1400 - 1600 °C.

7. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 6, characterized in that: After casting is completed, the casting is slowly cooled, and the cooling rate is 10 °C / hour - 50 °C / hour.

8. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 3, characterized in that: In S4, the heat treatment includes solution treatment and aging treatment; The solution treatment temperature of the casting is 1050 - 1150 °C, and the holding time is 0.5 - 1.5 hours.

9. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 8, characterized in that: The aging treatment temperature of the casting is 450 - 550 °C, and the aging time is 1 - 3 hours.

10. The manufacturing process of the high-temperature and corrosion-resistant housing material according to claim 3, characterized in that: In S5, the surface treatment is chromium plating or nickel plating on the surface of the casting, and the coating thickness is 50 μm - 200 μm.

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