Vacuum melting control method for rare earth elements Y, La and Ce in high-temperature alloy

Abstract

The invention relates to the technical field of high-temperature alloy preparation, and particularly discloses a vacuum melting control method for rare earth elements Y, La and Ce in high-temperature alloy, and the method comprises the steps of S1, high-temperature alloy preparation, S2, rare earth element addition, S3, ultrasonic uniform distribution, S4, spectral analysis and S5, uniform cooling. After the high-temperature alloy is prepared, the rare earth elements are prepared into particle shapes through ball mill equipment, the rare earth elements are accurately controlled through a microfluid system, it is ensured that the rare earth elements are evenly added into the alloy, the particle-shaped rare earth elements are more easily dissolved and evenly dispersed into the high-temperature alloy, argon is introduced into a furnace body for protection, and the high-temperature alloy is obtained. The rare earth elements can be prevented from being burnt, the rare earth elements can be evenly and fully mixed with the high-temperature alloy through the ultrasonic equipment, the local concentration difference of the rare earth elements can be reduced, the uniformity of the alloy is improved, and the quality and performance of the alloy are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature alloy preparation, and in particular relates to a vacuum melting control method for rare earth elements Y, La and Ce in a high-temperature alloy. Background Art

[0002] Nickel-based superalloy is a multi-component alloy with a very complex composition. It usually contains more than ten alloying elements, has a high degree of alloying, and has excellent high-temperature performance. It is widely used in the manufacture of hot end components of aircraft engines and gas turbines. Adding rare earth elements (such as Ce, Y, La, etc.) to nickel-based superalloys can improve the alloy's oxidation resistance, hot corrosion resistance, and high-temperature creep resistance. At the same time, it can deeply deoxidize and improve the purity of the master alloy.

[0003] In the smelting process of the master alloy of traditional high-temperature alloys containing rare earth elements, the rare earth raw materials are often directly added to the furnace, and the rare earth element recovery rate is less than 30%. Due to the low density and activity of rare earth elements, they float on the surface of the alloy melt after being added, and at the same time, they come into contact with the atmosphere in the furnace to undergo oxidation reactions, resulting in the formation of oxide inclusions of some rare earths and the burning of some rare earths, which causes the rare earth elements to be unable to be fully integrated into the alloy melt, resulting in a low recovery rate and the inability to stably control their content, which ultimately results in the master alloy failing to meet the requirements of its chemical composition, slag and other indicators, and the product quality fluctuates greatly. If it is unqualified, the entire furnace will be scrapped, causing significant economic losses.

[0004] In the Chinese patent with publication number CN 114293037 A, a vacuum induction melting process for improving the rare earth element recovery rate of high-temperature alloys is mentioned. The invention weighs rare earth raw materials in proportion, wraps the weighed rare earth raw materials with nickel foil into a rare earth bag with a length of 60 to 120 mm and a width of 60 to 120 mm, and uses nickel wire to bind and fix the nickel plate and the rare earth bag for standby use; before adding the rare earth raw materials, the high-temperature alloy in the melting furnace is first refined for 2 to 5 minutes, and after the melt surface is filmed, argon is filled into the vacuum induction melting furnace to 0.4 to 3 kPa, and the fixed rare earth bag is added to the melting crucible, and the melting is continued for 3 to 8 minutes; after the melting is completed and the alloy liquid is completely clear, the alloy liquid is poured to complete the alloy melting. The present invention can increase the recovery rate of rare earth elements in the high-temperature alloy smelting process from less than 30% to more than 70%, and the distribution is uniform. At the same time, the smelted master alloy has high purity and is suitable for the production of high-temperature alloys with high requirements for the control of rare earth element content. Although the above scheme has many beneficial effects, the scheme uses nickel foil, nickel wire, and nickel plate to wrap and bundle rare earth raw materials, which cannot make the rare earth raw materials and the alloy fully and evenly mixed, resulting in the rare earth elements in the alloy cannot be evenly distributed, and the uniformity of the alloy is difficult to ensure.

[0005] In view of this, the inventors proposed a vacuum melting control method for rare earth elements Y, La, and Ce in high-temperature alloys to solve the above problems. Summary of the invention

[0006] The object of the present invention is to provide a vacuum melting control method for rare earth elements Y, La and Ce in a high temperature alloy 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 vacuum melting process control method for rare earth elements Y, La, and Ce in a high-temperature alloy comprises the following steps: S1. Prepare high-temperature alloys. Add iron, nickel, chromium, tungsten, aluminum, titanium and niobium alloy raw materials with a purity of not less than 99.9% into the crucible of the alloy melting furnace. Seal the alloy melting furnace and evacuate it to a vacuum degree of 10 -2 kPa or less, start the induction coil at the bottom of the outer side of the crucible to carry out vacuum induction melting, control the reaction temperature, melt the metal and alloy it; The mass percentages of the alloy raw materials are: 30% to 40% iron, 30% to 40% nickel, 12% to 16% chromium, 0.5% to 1% niobium, 3% to 7% tungsten, 3% to 5% titanium, and 1% to 2% aluminum. The reaction temperature is 1200 to 1300°C.

[0008] S2, rare earth element addition, weighing rare earth elements Y, La, Ce, preparing the rare earth elements into microparticles, introducing argon protection into the alloy melting furnace, and uniformly adding the rare earth elements into the alloy melting furnace through a microfluidic system; the rare earth elements are formed into microparticles with a particle size of 5 to 10 mm by a ball mill. The mass ratio of the rare earth elements Y, La, and Ce is 1:1:1.

[0009] The microfluidic system includes a microfluidic pipeline and a micro-sprinkler. The microfluidic pipeline is a pipeline used to add rare earth elements to an alloy melting furnace. One end of the microfluidic pipeline is connected to a ball mill, and the other end is connected to the alloy melting furnace. A micro-sprinkler is provided at the end of the microfluidic pipeline, and the rare earth elements are uniformly transported to the crucible through the micro-sprinkler.

[0010] S3, ultrasonic uniform distribution, applying ultrasonic waves to the alloy for ultrasonic treatment, controlling the ultrasonic waves and microfluidic system to ensure that the rare earth elements are evenly distributed in the alloy, and controlling the reaction temperature of the mixture to 1150-1200°C to avoid burning of the rare earth elements; The ultrasonic frequency is controlled to be 20-50kHz, the ultrasonic power is 1000-2000W, and the ultrasonic time is 10-20min. By controlling the action time and energy of the ultrasonic wave and the microfluidic system, the rare earth elements are ensured to be evenly distributed in the alloy.

[0011] S4. Spectroscopic analysis, using atomic absorption spectroscopy, after adding rare earth elements, samples are taken from the alloy and analyzed, and the concentration of rare earth elements in different parts is determined through spectral readings to evaluate its uniformity; S5. Cool evenly. After the alloy and rare earth elements are evenly melted, pour the molten steel into the mold to cool and solidify.

[0012] The alloy smelting furnace of the present invention is a high-temperature alloy reaction furnace body; a crucible is used to hold metal and provide a heating device; an induction coil is arranged at the bottom of the crucible and is used to perform induction heating on the crucible; a vacuum pump is used to create a vacuum environment in the smelting furnace; a ball mill is used to prepare rare earth elements into particle shapes; a microfluidic system includes a microfluidic pipeline and a micro-nozzle, which is used to control the uniform delivery of rare earth elements to the crucible; and an ultrasonic generator is used to generate ultrasonic waves to make the rare earth elements uniformly distributed in the alloy.

[0013] Compared with the prior art, the present invention has the following beneficial effects: After preparing the high-temperature alloy, the present invention prepares the rare earth elements into microparticles through a ball mill, and uses a microfluidic system to accurately control the rare earth elements to ensure that they are evenly added into the alloy. The rare earth elements in the form of microparticles are more easily dissolved and evenly dispersed into the high-temperature alloy. Argon gas is introduced into the furnace body for protection to prevent the rare earth elements from being burned. Ultrasonic equipment can make the rare earth elements evenly and fully mixed with the high-temperature alloy, which helps to reduce the local concentration difference of the rare earth elements, improve the uniformity of the alloy, and improve the quality and performance of the alloy. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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. Example

[0015] A vacuum melting process control method for rare earth elements Y, La, and Ce in a high-temperature alloy comprises the following steps: S1. Prepare high-temperature alloys. Add iron, nickel, chromium, tungsten, aluminum, titanium and niobium alloy raw materials with a purity of not less than 99.9% into the crucible of the alloy melting furnace. Seal the alloy melting furnace and evacuate it to a vacuum degree of 10 -2 kPa or less, start the induction coil at the bottom of the outer side of the crucible to carry out vacuum induction melting, control the reaction temperature to 1250°C, melt the metal and alloy it; The mass percentages of the alloy raw materials are: 38% iron, 35% nickel, 15% chromium, 0.8% niobium, 6% tungsten, 4% titanium, and 1.2% aluminum.

[0016] S2. Rare earth element addition: weigh rare earth elements Y, La, and Ce, prepare the rare earth elements into microparticles, introduce argon protection into the alloy melting furnace, and evenly add the rare earth elements into the alloy melting furnace through the microfluidic system; the rare earth elements are formed into microparticles with a particle size of 5-10 mm by a ball mill. The mass ratio of rare earth elements Y, La, and Ce is 1:1:1.

[0017] The microfluidic system includes a microfluidic pipeline and a micro-sprinkler. The microfluidic pipeline is a pipeline for adding rare earth elements to the alloy melting furnace. One end is connected to the ball mill and the other end is connected to the alloy melting furnace. A micro-sprinkler is provided at the end of the microfluidic pipeline to control the rare earth elements to be uniformly transported to the crucible. A control valve is provided on the microfluidic pipeline, and the control valve is connected to the PLC control system to facilitate the control of the flow rate and addition time of the rare earth elements Y, La, and Ce.

[0018] S3, ultrasound is evenly distributed. The ultrasonic generator is started. The ultrasonic vibration rod of the ultrasonic generator extends into the alloy solution to propagate ultrasound in the alloy. The ultrasound and microfluidic system are controlled to ensure that the rare earth elements are evenly distributed in the alloy. The reaction temperature of the mixture is controlled at 1180°C to avoid burning of the rare earth elements. The ultrasound frequency is controlled to 25Hz, the ultrasound power is 1500W, and the ultrasound time is 15min. By controlling the action time and energy of the ultrasound and microfluidic system, the rare earth elements are evenly distributed in the alloy.

[0019] S4. Spectral analysis. After adding rare earth elements, samples are taken from the alloy and analyzed by atomic absorption spectroscopy. The concentration of rare earth elements in different parts is determined by spectral readings to evaluate its uniformity.

[0020] S5. Cool evenly. After the alloy and rare earth elements are evenly melted, pour the molten steel into the mold to cool and solidify.

[0021] The specific steps of atomic absorption spectroscopy (AAS) are as follows: Sample collection: obtain samples from different parts of the smelted alloy to ensure that the samples can fully represent all areas of the alloy; Sample processing: dissolve and dilute the samples to obtain samples suitable for AAS analysis; AAS analysis instrument calibration: prepare standard solutions of rare earth elements and use the standard solutions to establish the standard curve required for AAS analysis; calibrate the AAS instrument based on the standard curve; AAS analysis: The processed samples are placed in the AAS instrument for testing; Reading and recording: The concentration readings of rare earth elements in samples at different locations are obtained through AAS measurement and recorded; Uniformity assessment: Compare the rare earth element concentration readings at different locations and assess their uniformity through data comparison; Data processing: Statistical analysis is performed to evaluate the distribution of rare earth elements in the alloy; based on the AAS analysis results, the uniformity of rare earth elements in the alloy is evaluated, and based on the analysis results, the operations in the alloy preparation process are adjusted and improved to improve the uniform distribution of rare earth elements.

[0022] From the above, it can be seen that after the preparation of the high-temperature alloy, the rare earth elements are prepared into a particle shape by a ball mill. The rare earth elements are precisely controlled by a microfluidic system to ensure that they are evenly added to the alloy. The rare earth elements in the form of particles are easier to dissolve and evenly dispersed in the high-temperature alloy. Argon gas is introduced into the furnace body for protection to prevent the rare earth elements from being burned. Ultrasonic equipment can make the rare earth elements evenly and fully mixed with the high-temperature alloy, which helps to reduce the local concentration differences of the rare earth elements, improve the uniformity of the alloy, and improve the quality and performance of the alloy.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vacuum melting control method for rare earth elements Y, La, and Ce in a high-temperature alloy, characterized in that: The following steps are involved: S1. Prepare high-temperature alloys. Add iron, nickel, chromium, tungsten, aluminum, titanium and niobium alloy raw materials with a purity of not less than 99.9% into the crucible of the alloy melting furnace. Seal the alloy melting furnace and evacuate it to a vacuum degree of 10 -2 kPa or less, start the induction coil at the bottom of the outer side of the crucible to carry out vacuum induction melting, control the reaction temperature, melt the metal and alloy it; S2, adding rare earth elements, weighing rare earth elements Y, La, and Ce, preparing the rare earth elements into microparticles, introducing argon gas protection into the alloy melting furnace, and uniformly adding the rare earth elements to the alloy melting furnace through a microfluidic system; S3, ultrasonic uniform distribution, applying ultrasonic waves to the alloy for ultrasonic treatment, controlling the ultrasonic waves and microfluidic system to ensure that the rare earth elements are evenly distributed in the alloy, and controlling the reaction temperature of the mixture to 1150-1200°C to avoid burning of the rare earth elements; S4. Spectroscopic analysis, using atomic absorption spectroscopy, after adding rare earth elements, samples are taken from the alloy and analyzed, and the concentration of rare earth elements in different parts is determined through spectral readings to evaluate its uniformity; S5. Cool evenly. After the alloy and rare earth elements are evenly melted, pour the molten steel into the mold to cool and solidify.

2. The vacuum melting control method of rare earth elements Y, La and Ce in a high temperature alloy according to claim 1, characterized in that: The mass percentages of the alloy raw materials described in S1 are: 30% to 40% iron, 30% to 40% nickel, 12% to 16% chromium, 0.5% to 1% niobium, 3% to 7% tungsten, 3% to 5% titanium, and 1% to 2% aluminum.

3. The vacuum melting control method of rare earth elements Y, La and Ce in a high temperature alloy according to claim 1, characterized in that: The reaction temperature in S1 is 1200-1300°C.

4. The vacuum melting control method of rare earth elements Y, La and Ce in a high temperature alloy according to claim 1, characterized in that: The mass ratio of rare earth elements Y, La and Ce in S2 is 1:1:

1.

5. The vacuum melting control method of rare earth elements Y, La and Ce in a high temperature alloy according to claim 1, characterized in that: The microfluidic system in S2 includes a microfluidic pipe and a micro-nozzle. The microfluidic pipe is a pipe used to add rare earth elements to the alloy melting furnace. One end of the microfluidic pipe is connected to the ball mill, and the other end is connected to the alloy melting furnace. A micro-nozzle is provided at the end of the microfluidic pipe, and the rare earth elements are evenly transported to the crucible through the micro-nozzle.