High-entropy alloy with scale inhibiting and removing effects and preparation method thereof

Abstract

The invention provides a high-entropy alloy with scale inhibition and removal effects and a preparation method thereof, and relates to the technical field of scale inhibition materials, the high-entropy alloy comprises the following raw materials by weight: 15-25% of chromium, 13-15% of nickel, 4-6% of molybdenum, 2-4% of titanium, and the balance iron and inevitable impurities; high-purity metal blocks or powder is put into a vacuum smelting furnace according to a certain proportion and heated to the melting temperature in a high-vacuum environment, and it is ensured that various metal components are fully mixed and are in a uniform state by adjusting the heating temperature and time; the high-entropy alloy with the scale inhibition and removal effects is prepared through scientific proportioning and an optimized process, has the environment-friendly and efficient effects, achieves the scale inhibition effect by means of materials, can improve the operation efficiency and stability of a water network system, can reduce energy consumption, prolongs the service life of pipelines and equipment, and is suitable for large-scale popularization and application. Powerful guarantee is provided for safe operation of a power plant.

Description

Technical Field

[0001] The invention relates to the technical field of scale inhibition materials, and in particular to a high entropy alloy with scale inhibition and descaling effects and a preparation method thereof. Background Art

[0002] In today's world, electricity has become one of the indispensable infrastructures of modern society. As the core of energy production, the stability and efficiency of the operation of power plants are directly related to the development of the national economy and the quality of people's lives. The water network system of the power plant plays a vital role, responsible for supplying important media such as cooling water and circulating water to maintain the normal operating temperature of the power generation equipment and ensure the smooth operation of power production. However, with the extension of power plant operation time and the increase of operating load, the problems faced by the water network system have become more prominent. Among them, the scale problem is one of the most common and serious challenges. The dissolved substances contained in the water will crystallize and precipitate at high temperatures, gradually forming scale, which will adhere to the pipe wall and equipment surface, resulting in a decrease in heat transfer efficiency, an increase in energy consumption, and may even cause pipe blockage and equipment damage, which seriously threatens the safety and stable operation of the power plant.

[0003] In order to deal with this problem, traditional anti-scaling methods usually use chemical agents for treatment. However, these chemical agents not only pollute the environment, but also may cause potential harm to human health. In addition, the method of adding agents requires manual participation, which is inefficient and prone to errors. Therefore, the present invention proposes a high entropy alloy with anti-scaling and descaling effects and a preparation method thereof to solve the problems existing in the prior art. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to propose a high entropy alloy with scale inhibition and descaling effect and a preparation method thereof. This high entropy alloy with scale inhibition and descaling effect and a preparation method thereof have the advantage of waste recycling and solve the problems existing in the prior art.

[0005] To achieve the purpose of the present invention, the present invention is implemented through the following technical scheme: a high entropy alloy with scale inhibition and descaling effect, comprising the following raw materials in weight percentage: 15-25% chromium, 13-15% nickel, 4-6% molybdenum and 2-4% titanium, and the remainder is iron and unavoidable impurities.

[0006] A method for preparing a high entropy alloy having a scale inhibition and descaling effect comprises the following steps:

[0007] Step 1: Preparation and processing of raw materials

[0008] High-purity metal powders of nickel, molybdenum, iron, chromium and titanium are weighed in required proportions, dried, and then mixed using a ball mill to obtain a metal material;

[0009] Step 2: Vacuum melting

[0010] The metal material is placed in a crucible of a vacuum melting furnace and vacuum heated. After reaching a preset temperature, a stirrer is started to stir and mix to obtain a molten metal solution;

[0011] Step 3: Solidification and treatment of molten metal solution

[0012] The obtained molten metal solution is poured into a pre-prepared casting mold and cooled to ensure that it gradually solidifies and forms an alloy ingot. The alloy ingot is then homogenized to complete the preparation of a high entropy alloy with anti-scaling and descaling effects.

[0013] A further improvement is that in step 1, the drying method is: placing the high-purity metal powder in a vacuum drying oven and drying it at 80-100° C. for 2-4 hours.

[0014] A further improvement is that in step 2, the vacuum degree in the vacuum melting furnace is 10-3 to 10-6 Pa.

[0015] A further improvement is that in step 2, the heating method is: first increase the temperature to 1000°C at a rate of 200°C / min, maintain for 5 to 10 minutes, then quickly increase the temperature to 2700°C, maintain for 5 to 10 minutes, then cool down to 2000°C, maintain for 5 to 10 minutes, and start stirring for 5 to 15 minutes.

[0016] A further improvement is that in step three, before the molten metal solution enters the casting mold, the casting mold is preheated at 500-600° C. for 30 min to 50 min.

[0017] A further improvement is that in step three, the cooling rate is 15-20°C / min.

[0018] A further improvement is that the specific method of the homogenization treatment is: placing the cooled metal ingot into a high-temperature furnace and heating it in an inert gas environment at a temperature of 1000-1200°C, keeping it warm for 8-10 hours, and then cooling it naturally to room temperature.

[0019] The beneficial effects of the present invention are as follows: the present invention places a variety of high-purity metal powders into a vacuum furnace in a certain proportion, heats them to a melting temperature in a high vacuum environment, and adjusts the heating temperature and time to ensure that the various metal components are fully mixed and reach a uniform state of composition. A high-entropy alloy with scale inhibition and descaling effect is obtained through scientific proportioning and optimized process. The high-entropy alloy has the effects of environmental protection and high efficiency, and relies on the material itself to have a scale inhibition effect, thereby improving the operating efficiency and stability of the water network system, reducing energy consumption, and extending the service life of pipelines and equipment, providing a strong guarantee for the safe operation of power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the steps of the present invention.

[0021] Figure 2 It is a schematic diagram of the structure of the Y-type scale inhibition equipment provided by the present invention. DETAILED DESCRIPTION

[0022] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0023] The following materials were purchased from commercial sources. High purity refers to purity ≥ 99.9%, and room temperature refers to 25 ± 5 °C.

[0024] Embodiment 1

[0025] according to Figure 1 As shown, this embodiment proposes a high entropy alloy with scale inhibition and descaling effect, including the following raw materials in weight percentage: 15% chromium, 15% nickel, 4% molybdenum and 2% titanium, and the balance is iron and inevitable impurities. Among them, chromium provides corrosion resistance and helps to prevent the formation of scale, nickel increases the toughness and oxidation resistance of the alloy, further improving the anti-scaling effect, and molybdenum strengthens the alloy's pitting resistance, which is particularly suitable for high temperature and high salt environments. Titanium improves the passivation ability of the material surface and reduces the adhesion of scale. Therefore, the high entropy alloy provided in this embodiment has the characteristic of preventing scale adhesion.

[0026] A method for preparing a high entropy alloy having a scale inhibition and descaling effect comprises the following steps:

[0027] Step 1: Preparation and processing of raw materials

[0028] High-purity metal powders of nickel, molybdenum, iron, chromium and titanium are weighed according to the required proportions, and then dried. The drying method is: the high-purity metal powders are placed in a vacuum drying oven at 80° C. for 2 hours to remove moisture in the metal powders and gas adsorbed on the surface, and then mixed in a ball mill to obtain metal materials. The ball milling time is 6 hours. The ball milling method is to pre-mix the raw materials.

[0029] Step 2: Vacuum melting

[0030] In this embodiment, a vacuum melting method is used for preparation. First, the metal material obtained in step 1 is placed in a crucible of a vacuum melting furnace for vacuum heating. Specifically, a vacuum pump of the vacuum melting furnace is started to remove the gas inside the melting furnace to ensure that the required high vacuum environment is achieved. -3 Pa, and then heated, first at a rate of 200℃ / min, rising to 1000℃, the purpose of which is to remove the surface residual gas and moisture in the material, and slowly preheating to reduce the risk of thermal shock of the material, after holding for 10 minutes, quickly heated to 2700℃, held for 10 minutes, the purpose of which is to quickly melt the metal material and form a liquid melt, then slowly cooled to 2000℃, held for 10 minutes, and started stirring, the stirring time is 15 minutes, which plays a role in uniform alloy composition;

[0031] Step 3: Solidification and treatment of molten metal solution

[0032] The obtained molten metal solution is poured into a pre-prepared mold. Before the molten metal solution enters the mold, the mold is preheated at 500°C for 50 minutes to reduce the temperature difference between the melt and the mold and avoid cracks caused by thermal shock. After entering, it is cooled by water cooling or air cooling at a cooling rate of 15°C / min. Compared with natural cooling, this embodiment can accelerate the cooling process, refine the grains, and improve the scale inhibition and descaling performance. After cooling, an alloy ingot is obtained, and then the alloy ingot is homogenized. Specifically, the cooled metal ingot is placed in a high-temperature furnace and heated in an inert gas (argon) environment at a temperature of 1000°C. It is kept warm for 10 hours and then naturally cooled to room temperature. The purpose of homogenization is to make the structure uniform and improve the scale inhibition and descaling performance.

[0033] Embodiment 2

[0034] according to Figure 1 As shown, this embodiment proposes a high entropy alloy with scale inhibition and descaling effects, including the following raw materials in weight percentage: 20% chromium, 15% nickel, 6% molybdenum and 4% titanium, and the remainder is iron and inevitable impurities.

[0035] A method for preparing a high entropy alloy having a scale inhibition and descaling effect comprises the following steps:

[0036] Step 1: Preparation and processing of raw materials

[0037] High-purity metal powders of nickel, molybdenum, iron, chromium and titanium are weighed in the required proportions and then dried. The drying method is as follows: the high-purity metal powders are placed in a vacuum drying oven at 100° C. for 2 hours to remove moisture in the metal powders and gas adsorbed on the surface, and then mixed in a ball mill to obtain metal materials. The ball milling time is 4 hours. The ball milling method is to pre-mix the raw materials.

[0038] Step 2: Vacuum melting

[0039] In this embodiment, a vacuum melting method is used for preparation. First, the metal material obtained in step 1 is placed in a crucible of a vacuum melting furnace for vacuum heating. Specifically, a vacuum pump of the vacuum melting furnace is started to remove the gas inside the melting furnace to ensure that the required high vacuum environment is achieved. -6 Pa, and then heated, first at a rate of 200℃ / min, rising to 1000℃, the purpose of which is to remove the surface residual gas and moisture in the material, and slowly preheating to reduce the risk of thermal shock of the material, after holding for 5 minutes, quickly heated to 2700℃, held for 5 minutes, the purpose of which is to quickly melt the metal material and form a liquid melt, then slowly cooled to 2000℃, held for 5 minutes, and started stirring, the stirring time is 5 minutes, which plays a role in uniform alloy composition;

[0040] Step 3: Solidification and treatment of molten metal solution

[0041] The obtained molten metal solution is poured into a pre-prepared mold. Before the molten metal solution enters the mold, the mold is preheated at 600°C for 30 minutes to reduce the temperature difference between the melt and the mold and avoid cracks caused by thermal shock. After entering, it is cooled by water cooling or air cooling at a cooling rate of 20°C / min. Compared with natural cooling, this embodiment can accelerate the cooling process, refine the grains, and improve the scale inhibition and descaling performance. After cooling, an alloy ingot is obtained, and then the alloy ingot is homogenized. Specifically, the cooled metal ingot is placed in a high-temperature furnace and heated in an inert gas (argon) environment at a temperature of 1200°C. It is kept warm for 8 hours and then naturally cooled to room temperature. The purpose of homogenization is to make the structure uniform and improve the scale inhibition and descaling performance.

[0042] Embodiment 3

[0043] The invention comprises the following raw materials in weight percentage: 25% of chromium, 13% of nickel, 5% of molybdenum and 3% of titanium, and the balance is iron and inevitable impurities.

[0044] A method for preparing a high entropy alloy having a scale inhibition and descaling effect comprises the following steps:

[0045] Step 1: Preparation and processing of raw materials

[0046] Weigh high-purity metal powders of nickel, molybdenum, iron, chromium and titanium according to the required proportions, and then perform drying treatment. The drying treatment method is: place the high-purity metal powder in a vacuum drying oven at 90° C. and dry it for 3 hours to remove moisture in the metal powder and gas adsorbed on the surface. Then, use a ball mill to mix it to obtain a metal material. The ball milling time is 5 hours. The ball milling method is to pre-mix the raw materials.

[0047] Step 2: Vacuum melting

[0048] In this embodiment, a vacuum melting method is used for preparation. First, the metal material obtained in step 1 is placed in a crucible of a vacuum melting furnace for vacuum heating. Specifically, a vacuum pump of the vacuum melting furnace is started to remove the gas inside the melting furnace to ensure that the required high vacuum environment is achieved. -5 Pa, and then heated, first at a rate of 200℃ / min, rising to 1000℃, the purpose of which is to remove the surface residual gas and moisture in the material, and slowly preheating to reduce the risk of thermal shock of the material, after holding for 8 minutes, quickly heated to 2700℃, held for 8 minutes, the purpose of which is to quickly melt the metal material and form a liquid melt, then slowly cooled to 2000℃, held for 8 minutes, and started stirring, the stirring time is 10 minutes, which plays a role in uniform alloy composition;

[0049] Step 3: Solidification and treatment of molten metal solution

[0050] The obtained molten metal solution is poured into a pre-prepared mold. Before the molten metal solution enters the mold, the mold is preheated at 550°C for 40 minutes to reduce the temperature difference between the melt and the mold and avoid cracks caused by thermal shock. After entering, it is cooled by water cooling or air cooling at a cooling rate of 18°C / min. Compared with natural cooling, this embodiment can accelerate the cooling process, refine the grains, and improve the scale inhibition and descaling performance. After cooling, an alloy ingot is obtained, and then the alloy ingot is homogenized. Specifically, the cooled metal ingot is placed in a high-temperature furnace and heated in an inert gas (argon) environment to a temperature of 1100°C. It is kept warm for 9 hours and then naturally cooled to room temperature. The purpose of the homogenization treatment is to make the structure uniform and improve the scale inhibition and descaling performance.

[0051] Combined with the high entropy alloys prepared in Example 1 and Example 2, the scale inhibition performance was tested by static experiment. Specifically, referring to the GB / T 16632-2019 test method, anhydrous calcium chloride and sodium bicarbonate were used to prepare the preparation water, and ρ(Ca 2+ ) and total alkalinity of 500 mg / L (calculated as CaCO3) were 500 mg / L (calculated as CaCO3) containing antiscalant test solution and blank test solution. The pH was adjusted with borax, and the solution was kept at 80℃ for 10 hours and then filtered while hot. The pH was adjusted with KOH solution, and calcium carboxylic acid was used as an indicator. The Ca of the filtrate after the insulation was determined with EDTA standard solution (0.01 mol / L). 2+ The concentration and scale inhibition rate (η(%)) are calculated as follows:

[0052]

[0053] Where:

[0054] ρ: actual Ca in prepared water 2+ Mass concentration (mg / mL);

[0055] ρ1: Ca after blank test solution is kept warm 2+ Mass concentration (mg / mL);

[0056] ρ2: Ca after heat preservation of the test solution containing scale inhibitor 2+ Mass concentration (mg / mL).

[0057] The high entropy alloy material synthesized in this embodiment was tested through static experiments, and its calcium carbonate scale inhibition rate reached more than 90%.

[0058] For the high entropy alloy provided in this embodiment, its application method is as follows: Figure 2 As shown, a Y-type scale-inhibiting device is designed, and the high entropy alloy material prepared by the present invention is arranged in its inner lining, and the pre-formed calcium carbonate scale is deposited at the bottom without affecting the subsequent system. The device is arranged in the reverse osmosis water inlet mother pipe of the power plant water system, and after long-term stable operation, the dosage of the scale inhibitor is reduced by more than 50%.

[0059] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the framework and scope of application of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A high entropy alloy with scale inhibition and descaling effect, characterized in that: The invention comprises the following raw materials in weight percentage: 15-25% chromium, 13-15% nickel, 4-6% molybdenum and 2-4% titanium, and the balance is iron and inevitable impurities.

2. A method for preparing a high entropy alloy with scale inhibition and descaling effect as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Preparation and processing of raw materials High-purity metal powders of nickel, molybdenum, iron, chromium and titanium are weighed in required proportions, dried, and then mixed using a ball mill to obtain a metal material; Step 2: Vacuum melting The metal material is placed in a crucible of a vacuum melting furnace and vacuum heated. After reaching a preset temperature, a stirrer is started to stir and mix to obtain a molten metal solution; Step 3: Solidification and treatment of molten metal solution The obtained molten metal solution is poured into a pre-prepared casting mold and cooled to ensure that it gradually solidifies and forms an alloy ingot. The alloy ingot is then homogenized to complete the preparation of a high entropy alloy with anti-scaling and descaling effects.

3. The method for preparing a high entropy alloy having a scale inhibition and descaling effect according to claim 2, characterized in that: In the step 1, the drying process is as follows: placing the high-purity metal powder in a vacuum drying oven and drying it at 80 to 100° C. for 2 to 4 hours.

4. The method for preparing a high entropy alloy having a scale inhibition and descaling effect according to claim 2, characterized in that: In the step 2, the vacuum degree in the vacuum melting furnace is 10 -3 ~10 -6 Pa.

5. The method for preparing a high entropy alloy having scale inhibition and descaling effect according to claim 2, characterized in that: In the step 2, the heating method is: first increase the temperature to 1000°C at a speed of 200°C / min, maintain for 5 to 10 minutes, then quickly increase the temperature to 2700°C, maintain for 5 to 10 minutes, then cool down to 2000°C, maintain for 5 to 10 minutes, and start stirring for 5 to 15 minutes.

6. The method for preparing a high entropy alloy having a scale inhibition and descaling effect according to claim 2, characterized in that: In the step three, before the molten metal solution enters the casting mold, the casting mold is preheated at 500-600° C. for 30-50 minutes.

7. The method for preparing a high entropy alloy having scale inhibition and descaling effects according to claim 2, characterized in that: In the step 3, the cooling rate is 15-20°C / min.

8. The method for preparing a high entropy alloy with scale inhibition and descaling effect according to claim 2, characterized in that: The specific method of the homogenization treatment is: placing the cooled metal ingot into a high-temperature furnace and heating it in an inert gas environment at a temperature of 1000-1200°C, keeping it warm for 8-10 hours, and then naturally cooling it to room temperature.

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