阅读说明：本技术 一种铁镍钼软磁粉末的制备方法 (Preparation method of iron-nickel-molybdenum soft magnetic powder ) 是由 周永川 李兆波 周启轩 张帆 管弦 陈建 谢州 罗小涵 于 2021-06-24 设计创作，主要内容包括：本发明公开了一种铁镍钼软磁粉末的制备方法,包括步骤1：将质量百分比为75～85wt％的镍、2～5wt％的钼、13～23wt％的铁元素通过中频感应炉熔炼成合金熔液；步骤2：将步骤1得到的合金熔液流入高压水气联合雾化装置中,在高压水流和高压气体的联合冲击作用下雾化破碎,制得铁镍钼合金粉末。步骤3：在惰性气体保护下,采用还原气体对步骤2得到的合金粉末进行还原退火,退火温度为400～800℃。步骤4：冷却后,即得粒度为10～50μm的铁镍钼软磁粉末。本发明采用高压水气联合雾化装置进行雾化造粒,制备得到的铁镍钼软磁粉末,具有粒径小、粒径分布均匀、综合磁性能好的特点。(The invention discloses a preparation method of iron-nickel-molybdenum soft magnetic powder, which comprises the following steps of 1: smelting 75-85 wt% of nickel, 2-5 wt% of molybdenum and 13-23 wt% of iron element into molten alloy through a medium-frequency induction furnace; step 2: and (3) enabling the alloy melt obtained in the step (1) to flow into a high-pressure water-gas combined atomization device, and carrying out atomization and crushing under the combined impact action of high-pressure water flow and high-pressure gas to obtain iron-nickel-molybdenum alloy powder. And step 3: and (3) under the protection of inert gas, reducing and annealing the alloy powder obtained in the step (2) by adopting reducing gas, wherein the annealing temperature is 400-800 ℃. And 4, step 4: and cooling to obtain the iron-nickel-molybdenum soft magnetic powder with the granularity of 10-50 mu m. The invention adopts a high-pressure water-gas combined atomization device for atomization and granulation, and the prepared iron-nickel-molybdenum soft magnetic powder has the characteristics of small particle size, uniform particle size distribution and good comprehensive magnetic property.)

1. The preparation method of the iron-nickel-molybdenum soft magnetic powder is characterized by comprising the following steps of:

step 1: smelting 75-85 wt% of nickel, 2-5 wt% of molybdenum and 13-23 wt% of iron element into molten alloy through a medium-frequency induction furnace;

step 2: enabling the alloy melt obtained in the step 1 to flow into a high-pressure water-gas combined atomization device, and carrying out atomization and crushing under the combined impact action of high-pressure water flow and high-pressure gas to obtain iron-nickel-molybdenum alloy powder;

and step 3: under the protection of inert gas, reducing and annealing the alloy powder obtained in the step 2 by adopting reducing gas, wherein the annealing temperature is 400-800 ℃;

and 4, step 4: and cooling to obtain the iron-nickel-molybdenum soft magnetic powder with the granularity of 10-50 mu m.

2. The method for preparing iron-nickel-molybdenum soft magnetic powder according to claim 1, wherein the high-pressure water-gas combined atomization device in the step 2 comprises an atomizer main body (8), wherein a molten steel cavity (9), a tightly-coupled atomization nozzle structure and a high-pressure ultrasonic circumferential weld nozzle structure are sequentially arranged on the atomizer main body (8) from top to bottom, a molten steel leakage opening (1) is formed in the bottom of the molten steel cavity (9), the molten steel leakage opening (1) is communicated with the tightly-coupled atomization nozzle structure and the high-pressure ultrasonic circumferential weld nozzle structure, the tightly-coupled atomization nozzle structure is used for injecting high-pressure water flow to break alloy liquid drops leaking from the molten steel leakage opening (1), and the high-pressure ultrasonic circumferential weld nozzle structure is used for injecting high-pressure air flow to secondarily atomize the broken alloy liquid drops.

3. The method for preparing iron-nickel-molybdenum soft magnetic powder according to claim 2, wherein the tightly coupled atomizing nozzle structure comprises a water inlet (2), a water guide cavity (3) and a water atomizing cavity (4) which are sequentially arranged on a nozzle body I (10) from outside to inside, the water guide cavity (3) is communicated with the water inlet (2) and the water atomizing cavity (4), the water atomizing cavity (4) is of an annular hole structure, and a lower port of the water atomizing cavity (4) is communicated with the molten steel leakage opening (1) and is a jet orifice of high-pressure water flow.

4. The method for preparing the iron-nickel-molybdenum soft magnetic powder, according to claim 2, wherein the high-pressure ultrasonic circular seam nozzle structure comprises an air inlet (5), an air guide cavity (6) and an air flow spraying cavity (7) which are sequentially arranged on a second nozzle body (11) from outside to inside, the air guide cavity (6) is communicated with the air inlet (5) and the air flow spraying cavity (7), the air flow spraying cavity (7) is of a Laval circular seam structure, and the lower port of the air flow spraying cavity (7) is communicated with the molten steel leakage opening (1) and is a jet orifice of high-pressure air flow.

5. A method for preparing an iron-nickel-molybdenum soft magnetic powder according to claim 3, characterized in that said close-coupled atomizing nozzle structure is distributed uniformly in a plurality in a ring shape on the atomizer body (8).

6. The method of preparing an iron-nickel-molybdenum soft magnetic powder according to claim 1, wherein a water pressure of the high pressure water flow is 100 to 150Mpa, the high pressure gas is argon gas, and a flow rate of the high pressure gas is 5000 to 6000L/min.

7. The method for preparing an iron-nickel-molybdenum soft magnetic powder as claimed in claim 1, wherein the temperature of the melting in the step 1 is 1500-.

8. The method of claim 1, wherein the reducing gas in the step 3 is hydrogen gas or a mixture of hydrogen gas and nitrogen gas.

Technical Field

The invention belongs to the technical field of metal-based soft magnetic materials, and particularly relates to a preparation method of iron-nickel-molybdenum soft magnetic powder.

Background

The soft magnetic material is an important basic functional material in the development of modern economic society, plays the role of energy transfer conversion and coupling in devices, has the function of electromagnetic conversion, and is widely applied to the fields of communication, power equipment, information technology, automatic control and the like. The soft magnetic material can be divided into metal soft magnetic material, soft magnetic composite material and ferrite soft magnetic material, wherein the soft magnetic composite material is prepared into magnetic powder cores with different shapes by the processes of insulating coating, annealing, press forming and the like of metal soft magnetic powder particles. The iron-nickel-molybdenum magnetic core has the characteristics of high resistivity, low hysteresis loss and low eddy current loss, and has the best comprehensive performance in soft magnetic materials.

The iron-nickel-molybdenum magnetic core is prepared by iron-nickel-molybdenum soft magnetic powder particles through processes of insulation coating, annealing, press forming and the like, the manufacturing technology of the iron-nickel-molybdenum soft magnetic powder is the basis for preparing the magnetic powder core with good performance, the smaller the particle size of the iron-nickel-molybdenum soft magnetic powder is, the smaller the eddy current is, the lower the loss value is, and the higher the quality factor of the obtained magnetic powder core is.

The existing preparation methods for preparing the iron-nickel-molybdenum soft magnetic powder are widely an air atomization method and a water atomization method. The water atomization method utilizes high-pressure water flow to act on molten iron-nickel-molybdenum alloy, and spray atomization is carried out, so that the iron-nickel-molybdenum alloy forms fine powder with small particle size, but the prepared iron-nickel-molybdenum powder has irregular shape, more satellite particles and higher loss. The gas atomization method is characterized in that inert gas flow with certain air pressure and flow velocity acts on molten iron-nickel-molybdenum alloy flow, the kinetic energy of the gas flow is converted into surface energy of liquid iron-nickel-molybdenum alloy, the iron-nickel-molybdenum alloy is crushed into fine molten liquid, and alloy powder is obtained after the iron-nickel-molybdenum alloy is rapidly cooled and solidified. The iron-nickel-molybdenum powder prepared by the method is in a regular spherical shape, the loss is lower than that of a water atomization method, but the gas pressure is limited, and only the powder with large particle size can be prepared.

Disclosure of Invention

The invention aims to: aiming at the problems, the invention provides a preparation method of iron-nickel-molybdenum soft magnetic powder, which adopts a high-pressure water-gas combined atomization device to carry out atomization and granulation to obtain the iron-nickel-molybdenum soft magnetic powder with high sphericity, small granularity and uniform particle size distribution.

The technical scheme adopted by the invention is as follows:

a preparation method of iron-nickel-molybdenum soft magnetic powder comprises the following steps:

step 1: smelting 75-85 wt% of nickel, 2-5 wt% of molybdenum and 13-23 wt% of iron element into molten alloy through a medium-frequency induction furnace;

step 2: enabling the alloy melt obtained in the step 1 to flow into a high-pressure water-gas combined atomization device, and carrying out atomization and crushing under the combined impact action of high-pressure water flow and high-pressure gas to obtain iron-nickel-molybdenum alloy powder;

and step 3: under the protection of inert gas, reducing and annealing the alloy powder obtained in the step 2 by adopting reducing gas, wherein the annealing temperature is 400-800 ℃;

and 4, step 4: and cooling to obtain the iron-nickel-molybdenum soft magnetic powder with the granularity of 10-50 mu m.

Further, atomizing device is united to high-pressure aqueous vapor in step 2, including the atomizer main part, from last steel liquid chamber, close coupling atomizing nozzle structure and the high-pressure supersound circumferential weld nozzle structure of down being equipped with in proper order in the atomizer main part, the bottom in steel liquid chamber is equipped with the molten steel leak source, the molten steel leak source is linked together with close coupling atomizing nozzle structure and high-pressure supersound circumferential weld nozzle structure, close coupling atomizing nozzle structure is used for spraying the alloy liquid drop that high-pressure rivers leaked the molten steel leak source, high-pressure supersound circumferential weld nozzle structure is used for spraying high-pressure draught and carries out the secondary atomization to broken alloy liquid drop.

Further, tight coupling atomizing nozzle structure includes water inlet, water guide chamber and the water atomization chamber that sets gradually on nozzle main part one from outside to inside, water guide chamber intercommunication water inlet and water atomization chamber, the water atomization chamber is the annular ring structure, the lower part port and the molten steel leak orifice intercommunication in water atomization chamber, and be the jet of high-pressure rivers.

Further, the high-pressure ultrasonic circular seam nozzle structure comprises an air inlet, an air guide cavity and an air flow spraying cavity which are sequentially arranged on the nozzle main body II from outside to inside, the air guide cavity is communicated with the air inlet and the air flow spraying cavity, the air flow spraying cavity is of a Laval circular seam structure, and a lower port of the air flow spraying cavity is communicated with the molten steel leakage opening and is a jet orifice of high-pressure air flow.

Furthermore, the close coupling atomizing nozzle structure is annularly and uniformly distributed on the atomizer main body.

Further, the water pressure of the high-pressure water flow is 100-150 Mpa, the high-pressure gas is argon, and the flow rate of the high-pressure gas is 5000-6000L/min.

Further, the temperature of the smelting in the step 1 is 1500-.

Further, the reducing gas in the step 3 is hydrogen or a mixed gas of hydrogen and nitrogen.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention adopts the raw material proportion with high iron content to prepare the iron-nickel-molybdenum soft magnetic powder, which has low magnetic loss value, high resistivity and excellent direct current superposition characteristic.

(2) The invention adopts the high-pressure water-gas combined atomizing device for atomizing and granulating, when the alloy melt flows out from the molten steel leakage opening, the high-pressure water flow is sprayed by the tightly-coupled atomizing nozzle structure to crush the alloy liquid drops, and the high-pressure gas is sprayed by the high-pressure ultrasonic circumferential seam nozzle structure to carry out secondary atomization on the crushed alloy liquid drops, so that the prepared iron-nickel-molybdenum soft magnetic powder has the characteristics of small particle size, uniform particle size distribution and good comprehensive magnetic property, is ideal raw material powder for manufacturing magnetic powder cores, has low preparation process cost and is suitable for mass production.

Drawings

Fig. 1 is a schematic structural diagram of the high-pressure water-gas combined atomization device.

Labeled as: 1-molten steel leakage opening, 2-water inlet, 3-water guide cavity, 4-water atomization cavity, 5-air inlet, 6-air guide cavity, 7-air flow spraying cavity, 8-atomizer main body, 9-molten steel cavity, 10-nozzle main body I and 11-nozzle main body II.

Detailed Description

The present invention will be described in further detail in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

A preparation method of iron-nickel-molybdenum soft magnetic powder comprises the following steps:

step 1: smelting 81 wt% of nickel, 2 wt% of molybdenum and 17 wt% of iron element into molten alloy at 1700 ℃ through a medium-frequency induction furnace;

step 2: enabling the alloy melt obtained in the step 1 to flow into a high-pressure water-gas combined atomization device, and carrying out atomization and crushing under the combined impact action of high-pressure water flow with the pressure of 150Mpa and argon flow with the flow of 5000L/min to obtain iron-nickel-molybdenum alloy powder;

and step 3: under the protection of inert gas, reducing and annealing the alloy powder obtained in the step 2 by adopting hydrogen, wherein the annealing temperature is 600 ℃;

and 4, step 4: and cooling to obtain the iron-nickel-molybdenum soft magnetic powder with the granularity of 10-50 mu m.

The invention adopts the raw material proportion with high iron content to prepare the iron-nickel-molybdenum soft magnetic powder, which has low magnetic loss value, high resistivity and excellent direct current superposition characteristic. The defects of pure water atomization and gas atomization can be well overcome by adopting a high-pressure water-gas combined atomization device for atomization and granulation, and the iron-nickel-molybdenum soft magnetic powder with small particle size and regular and uniform shape can be obtained.

The high-pressure water-gas combined atomizing device adopted by the invention comprises an atomizer main body 8, wherein a molten steel cavity 9, a tightly-coupled atomizing nozzle structure and a high-pressure ultrasonic circumferential weld nozzle structure are sequentially arranged on the atomizer main body 8 from top to bottom, a molten steel leakage opening 1 is arranged at the bottom of the molten steel cavity 9, the molten steel leakage opening 1 is communicated with the tightly-coupled atomizing nozzle structure and the high-pressure ultrasonic circumferential weld nozzle structure, the tightly-coupled atomizing nozzle structure is used for spraying high-pressure water flow to crush alloy liquid drops leaked from the molten steel leakage opening 1, and the high-pressure ultrasonic circumferential weld nozzle structure is used for spraying high-pressure air flow to secondarily atomize the crushed alloy liquid drops.

The tight coupling atomizing nozzle structure comprises a water inlet 2, a water guide cavity 3 and a water atomizing cavity 4 which are sequentially arranged on a nozzle main body 10 from outside to inside, the water guide cavity 3 is communicated with the water inlet 2 and the water atomizing cavity 4, the water atomizing cavity 4 is of an annular hole structure, the diameter of the throat part of an annular hole is 1mm, and the lower port of the water atomizing cavity 4 is communicated with a molten steel leakage opening 1 and is a jet orifice of high-pressure water flow.

The high-pressure ultrasonic circular seam nozzle structure comprises an air inlet 5, an air guide cavity 6 and an air flow spraying cavity 7 which are sequentially arranged on a nozzle main body II 11 from outside to inside, the air guide cavity 6 is communicated with the air inlet 5 and the air flow spraying cavity 7, the air flow spraying cavity 7 is of a Laval circular seam structure, the diameter of the throat part of a circular seam is 0.6mm, and the lower port of the air flow spraying cavity 7 is communicated with a molten steel leakage opening 1 and is a jet orifice of high-pressure air flow.

4 above-mentioned close coupling atomizing nozzle structures and 1 above-mentioned high-pressure supersound circumferential weld nozzle structure of at least are evenly distributed to the annular on atomizer main part 8.

When the device works, water flow is input from the water inlet and conveyed to the water atomization cavity of the annular hole structure through the communicated water guide cavity, and alloy liquid drops leaked from the molten steel leakage opening are crushed. Meanwhile, gas is input from the gas inlet and is accelerated by the gas flow spraying cavity of the Laval circular seam structure, and secondary atomization is carried out on the crushed alloy liquid drops, so that the purpose of atomized particle refinement is achieved.

And the water guide cavity communicated with the water inlet and the water atomization cavity and the air guide cavity communicated with the air inlet and the air flow spraying cavity can play a role in stabilizing pressure intensity, so that atomized alloy powder is more uniform.

The invention adopts the high-pressure water-gas combined atomizing device to carry out atomizing granulation, when the alloy melt flows out from the molten steel leakage opening, the alloy liquid drop is crushed by the high-pressure water flow sprayed by the tightly-coupled atomizing nozzle structure, and simultaneously, the high-pressure ultrasonic annular seam nozzle structure positioned at the lower part of the tightly-coupled atomizing nozzle structure sprays high-pressure gas to carry out secondary atomization on the crushed alloy liquid drop, so that the obtained alloy powder has small granularity, uniform grain size distribution and good sphericity, and can well remove satellite grains.

The above-mentioned embodiments only express the specific embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, without departing from the technical idea of the present application, several changes and modifications can be made, which are all within the protection scope of the present application.