JP7131245B2 - Metal powder manufacturing apparatus and metal powder manufacturing method - Google Patents

Description

The present invention relates to a metal powder production apparatus and a metal powder production method.

For example, as shown in Patent Document 1, a metal powder manufacturing apparatus for manufacturing metal powder using a so-called gas atomization method and a manufacturing method using the apparatus are known. A conventional apparatus consists of a molten metal supply vessel for discharging molten metal, a cylindrical body installed below the molten metal supply vessel, and a flow of cooling liquid for cooling the molten metal discharged from the molten metal supply section. and a cooling liquid outlet portion formed on the inner surface of the cylindrical body.

The cooling liquid outlet sprays the cooling liquid in a tangential direction to the inner surface of the cooling cylinder, and causes the cooling liquid to swirl and flow down to the inner surface of the cooling container, thereby forming a cooling liquid layer. By using a cooling liquid layer, it is expected that droplets can be quenched and highly functional metal powder can be produced.

However, in the conventional apparatus, droplets of molten metal are rapidly cooled by supplying them toward the cooling liquid layer of the swirling flow formed on the inner surface of the cooling cylinder. It has a problem that the flight time until contact is long. Further, when the cooling liquid layer is formed on the inner surface of the cylindrical body, the cooled metal particles may come into contact with the inner surface of the cylindrical body. In order to obtain high-quality metal powder, it is preferable that the flight time for the droplets to contact the coolant layer is short, and that the cooled metal powder does not contact the inner surface of the cylindrical body.

JP-A-11-80812

The present invention has been made in view of such circumstances, and its object is to provide a metal powder manufacturing apparatus capable of manufacturing high-quality metal powder, and a metal powder manufacturing method using the same.

In order to achieve the above object, the metal powder manufacturing apparatus according to the present invention includes:
a molten metal supply unit for discharging molten metal;
a cylindrical body installed below the molten metal supply unit;
A metal powder production apparatus comprising: a cooling liquid outlet section for forming a flow of cooling liquid for cooling the molten metal discharged from the molten metal supply section inside the cylindrical body,
The cooling liquid lead-out portion is provided at the upper portion in the axial direction of the cylindrical body, and includes an outer space portion, an inner space portion, and a passage portion connecting the outer space portion and the inner space portion. and
The cooling liquid lead-out part has a frame that defines the shape of the inner peripheral surface of the inner space,
A nozzle is connected to the outer space,
The passage portion has a vertical width narrower than the vertical width of the outer space portion, and is configured to pass the cooling liquid from the nozzle from the outer space portion toward the inner space portion,
The cooling liquid discharged from the passage portion into the inner space portion flows toward the inner peripheral surface of the cylindrical body along the flow path inner peripheral surface of the frame body, and is reflected by the inner peripheral surface of the cylindrical body. and a flow path deflection surface is formed on the flow path inner peripheral surface of the frame so that the cooling liquid flows in an inverted conical shape from the cooling liquid discharge portion of the inner space toward the center of the cylinder. characterized by

Preferably, the passage portion is provided above the outer space portion in the axial direction.

Preferably, the vertical width (W1) of the passage is narrower than the vertical width (W2) of the outer space, and is ⅓ or less.

Preferably, the vertical width (W1) of the passage portion is narrower than the radial width (D1) of the coolant discharge portion, and is ⅓ or less.

Preferably, the radial width (D1) of the coolant discharge portion is narrower than the radial width (D2) of the main portion of the inner space, and is two-thirds or less.

Preferably, the inner peripheral surface of the flow path of the frame is provided with the flow path so that the radial width of the inner space gradually narrows from the main portion of the inner space toward the cooling liquid discharge portion. A concave first curvature surface is formed as a road deflection surface.

Preferably, the inner peripheral surface of the base end channel of the frame body has a concave shape so that the radial width of the inner space portion gradually narrows from the main portion of the inner space portion toward the passage portion. A second surface of curvature of is formed.

Preferably, a gas blowing member for blowing gas onto the molten metal discharged from the molten metal supply portion to make the molten metal into a large number of droplets is arranged between the molten metal supply portion and the cylindrical body. there is
It is configured such that the molten metal formed into droplets by the gas blowing member enters the interior of the cylindrical body.

In order to achieve the above object, the method for producing metal powder according to the present invention comprises:
A step of forming a flow of cooling liquid on the inner surface of a cylindrical body installed below the molten metal supply section;
and discharging the molten metal from the molten metal supply unit toward the flow of the cooling liquid, wherein
Using the metal powder production apparatus according to any one of the above,
causing the cooling liquid in the outer space to pass through a passage having a vertical width narrower than the width of the outer space;
The cooling liquid that has passed through the passage portion flows along the inner peripheral surface of the flow path of the frame that defines the inner space, is reflected by the inner peripheral surface of the cylinder, and is directed toward the center of the cylinder. It is characterized by flowing in an inverted cone shape.

FIG. 1A is a schematic cross-sectional view including an axis of a metal powder manufacturing apparatus according to one embodiment of the present invention. FIG. 1B is an enlarged cross-sectional view of the main part of the metal powder manufacturing apparatus shown in FIG. 1A. FIG. 2 is a schematic cross-sectional view including a shaft core of a metal powder manufacturing apparatus according to another embodiment of the present invention. FIG. 3 is a schematic cross-sectional view including the axis of a metal powder manufacturing apparatus according to still another embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment As shown in FIG. 1A, a metal powder manufacturing apparatus 10 according to one embodiment of the present invention pulverizes a molten metal 21 by an atomizing method (gas atomizing method) to produce a metal powder composed of a large number of metal particles. Apparatus for obtaining powder. The apparatus 10 has a molten metal supply section 20 and a cooling section 30 arranged vertically below the metal supply section 20 . In the drawings, the vertical direction is the direction along the Z-axis.

The molten metal supply section 20 has a heat-resistant container 22 containing molten metal 21 . A heating coil 24 is arranged on the outer circumference of the heat-resistant container 22 to heat the molten metal 21 contained in the container 22 and maintain it in a molten state. A discharge port 23 is formed at the bottom of the container 22, and the molten metal 21 is discharged from there toward the inner surface 33 of the cylindrical body 32 constituting the cooling section 30 as dripping molten metal 21a. ing.

A gas injection nozzle 26 is arranged on the outside of the outer bottom wall of the container 22 so as to surround the discharge port 23 . The gas injection nozzle 26 is provided with a gas injection port 27 . A high-pressure gas is injected from the gas injection port 27 toward the dripping molten metal 21 a discharged from the discharge port 23 . The high-pressure gas is jetted obliquely downward from the entire circumference of the molten metal discharged from the discharge port 23, and the dripping molten metal 21a becomes a large number of droplets, which are then distributed along the inner surface of the cylindrical body 32 along the gas flow. carried towards.

The molten metal 21 may contain any element, and for example, one containing at least one of Ti, Fe, Si, B, Cr, P, Cu, Nb, and Zr can be used. These elements are highly active, and the molten metal 21 containing these elements is easily oxidized to form an oxide film by contact with air for a short period of time, making it difficult to refine the metal. . As described above, the metal powder production apparatus 10 uses an inert gas as the gas injected from the gas injection port 27 of the gas injection nozzle 26, so that even the easily oxidizable molten metal 21 can be easily pulverized. can.

The gas injected from the gas injection port 27 is preferably an inert gas such as nitrogen gas, argon gas or helium gas, or a reducing gas such as ammonia decomposition gas. It may be air.

In this embodiment, the axial center O of the cylindrical body 32 is inclined with respect to the vertical line Z at a predetermined angle θ1. Although the predetermined angle θ1 is not particularly limited, it is preferably 0 to 45 degrees. With such an angle range, the dripping molten metal 21a from the discharge port 23 can be easily discharged toward the cooling liquid flow 50 formed inside the cylindrical body 32 in an inverted conical shape.

The dripping molten metal 51 discharged into the cooling liquid flow 50 having an inverted conical shape collides with the cooling liquid flow 50, is further divided into fine particles, is cooled and solidified, and becomes a solid metal powder. A discharge portion 34 is provided below along the axis O of the cylindrical body 32 so that the metal powder contained in the cooling liquid flow 50 can be discharged to the outside together with the cooling liquid. The metal powder discharged together with the cooling liquid is separated from the cooling liquid in an external reservoir or the like and taken out. Cooling water is used as the cooling liquid, although it is not particularly limited.

In this embodiment, a coolant introduction portion (coolant lead-out portion) 36 for introducing coolant into the cylinder 32 is provided at the upper portion of the cylinder 32 in the direction of the axis O. As shown in FIG. Note that the cooling liquid introduction portion 36 can also be defined as a cooling liquid outlet portion from the viewpoint of discharging the cooling liquid from the upper portion of the cylindrical body 32 toward the inside of the cylindrical body 32 .

As also shown in FIG. 1B , the coolant introduction portion 36 has at least a frame 38 , and inside the coolant introduction portion 36 , an outer portion (outer space portion) located radially outside the cylinder 32 . 44 and an inner portion (inner space portion) 46 positioned radially inside the tubular body 32 . The outer portion 44 and the inner portion 46 are separated by the partition portion 40, and the outer portion 44 and the inner portion 46 are communicated with each other by the passage portion 42 formed above the partition portion 40 in the direction of the axis O. and the cooling liquid can flow. In addition, as shown in FIG. 1A, in the outer portion 44, the partition portion 40 is inclined with respect to the axis O at an angle of θ2. The angle θ2 is preferably within the range of 0 to 90 degrees, more preferably 0 to 45 degrees. In the inner portion 46 , the wall surface of the partition portion 46 is preferably flush with the inner surface 33 of the cylindrical body 32 , but it is not necessarily flush. good.

The outer portion 44 is connected to one or more nozzles 37 through which coolant enters the outer portion 44 . A coolant discharge portion 52 is formed below the inner portion 46 in the direction of the axis O, and the coolant in the inner portion 46 is discharged (led out) from there to the inside of the cylindrical body 32 . It's becoming

In this embodiment, the frame 38 of the cooling liquid introduction portion 36 is arranged above the cylindrical body 32 in the direction of the axis O and has a cylindrical shape with an outer diameter smaller than the inner diameter of the cylindrical body 32 . As shown in FIG. 1B, the outer peripheral surface of the frame 38 serves as a channel inner peripheral surface 38b that guides the flow of the coolant in the inner portion 46. As shown in FIG. The upper portion of the frame 38 in the direction of the axis O is connected to the inner peripheral end of a ring-shaped upper plate portion 39 having a plane substantially perpendicular to the axis O, and the outer peripheral end of the upper plate portion 39 is cylindrical. is connected to the upper end of the side plate portion 44a. The inner diameter of the side plate portion 44 a is preferably larger than the outer diameter of the cylindrical body 32 . A single or a plurality of nozzles 37 are connected near the outer peripheral end of the upper plate portion 39 .

The lower end of the side plate portion 44a in the direction of the axis O is connected to the outer peripheral end of a ring-shaped bottom plate portion 44b having an inner surface substantially perpendicular to the axis O. As shown in FIG. The inner peripheral end of the bottom plate portion 44 b is connected to the upper end portion of the cylindrical body 32 . A partition portion 40 is attached to the upper end of the cylindrical body 32 , and the partition portion 40 partitions the space of the outer portion 44 and the space of the inner portion 46 . Note that the upper end of the cylinder 32 itself may constitute the partition portion 40 . A space surrounded by the partition portion 40 , the bottom plate portion 44 b , the side plate portion 44 a and the upper plate portion 39 defines the outer portion 44 .

A space surrounded by the partition portion 40, the upper plate portion 39, the frame body 38, and the cylindrical body 32 defines an inner portion 46, and the frame body 38 defines the shape of the inner peripheral surface of the inner portion 46. It has become. Also, the upper plate portion 39 defines the shape of the ceiling surface of the inner portion 46 . The upper plate portion 39 extends from the inner portion 46 across the passage portion 42 to the outer portion 44 to define the shape of the ceiling surface of the outer portion 44 as well.

The outer portion 44 and the inner portion 46 are communicated with each other by a passage portion 42 provided in the upper portion of the partition portion 40 in the axial center O direction. The passage portion 42 is a gap between the upper plate portion 39 of the cooling liquid introduction portion 36 and the upper end of the partition portion 40, and the vertical width W1 (see FIG. 1A) of the passage portion 42 in the direction of the axis O is the axis It is narrower than the vertical width W2 in the direction of the core O. W1/W2 is preferably 1/3 or less, more preferably 1/4 or less. Such a range facilitates the formation of an inverted conical flow 50 due to the reflection of the cooling liquid on the inner surface 33 of the cylindrical body 32, which will be described later.

In this embodiment, a nozzle 37 is connected to the outer portion 36 of the coolant introduction portion 36 . By connecting the nozzle to the outer portion 44 of the cooling liquid introduction portion 36 , the cooling liquid enters the outer portion 44 inside the cooling liquid introduction portion 36 from the nozzle 37 . The coolant that has entered the outer portion 44 passes through the passage portion 42 and enters the inner portion 46 .

The frame 38 has an inner diameter smaller than the inner surface 33 of the cylinder 32 . As shown in FIG. 1B, the lower end 38a of the frame 38 is formed with an outward protrusion 38a1 that protrudes radially outward from the flow path inner peripheral surface 38b of the frame 38. As shown in FIG. A ring-shaped gap between the tip of the outward convex portion 38 a 1 and the inner surface 33 of the cylindrical body 32 serves as the coolant discharge portion 52 . A channel deflection surface 62 is formed on the upper surface of the outward projection 38a1 on the channel side. The flow path deflection surface 62 forms a concave first curvature surface, and the radial width of the inner portion 46 formed between the flow path deflection surface 62 and the inner surface 33 of the tubular body 32 is equal to the width of the inner portion 46 . It is gradually narrowed from the main portion toward the coolant discharge portion 52 . The minimum inner diameter of the flow channel deflection surface 62 substantially matches the minimum inner diameter of the main portion of the flow channel inner peripheral surface 38 b of the frame 38 .

In the present embodiment, as described above, the coolant discharge portion 52 is formed in the gap between the outer convex portion 38a1 at the lower end 38a of the frame 38 and the inner surface 33 of the cylindrical body 32, and has a radial width of D1. is narrower than the radial width D2 at the main portion of the inner portion 46 . D1/D2 is preferably 2/3 or less, more preferably 1/2 or less, and preferably 1/10 or more. The radial width D1 of the coolant discharge portion is wider than the vertical width W1 (see FIG. 1A) of the passage portion, and W1/D1 is preferably 1/3 or less, more preferably 1/4 or less, It is preferably 1/20 or more.

The inner diameter of the coolant discharge portion 52 matches the maximum outer diameter of the flow path deflection surface 62 , and the outer diameter of the coolant discharge portion 52 substantially matches the inner diameter of the cylindrical body 32 . Note that the inner diameter of the coolant discharge portion 52 is not the maximum inner diameter of the flow path deflection surface 62, but rather the convex curvature surface formed on the outer diameter side bottom surface of the lower end 38a of the frame 38 as shown in FIG. may be the smallest inner diameter of 1B, the outer diameter of the coolant discharge portion 52 may be the same as the inner surface 33 of the cylinder 32, but as shown in FIG. It may be matched with the minimum inner diameter of the concave third curved surface 66 formed on the inner peripheral surface of a certain partition 40 . Although the inner diameter of the inner surface 33 of the cylinder 32 is not particularly limited, it is preferably 50 to 500 mm.

As shown in FIG. 1B, in the present embodiment, the inner surface of the corner between the upper end of the frame 38 and the inner peripheral end of the upper plate portion 39 (the side of the inner peripheral surface 38b of the inner portion 46) has a concave shape. A second surface of curvature 64 is formed. The concave second curvature surface 64 is formed on the frame body 38 so that the radial width of the inner space portion 46 gradually narrows along the axis O from the main portion of the inner space portion 46 toward the passage portion 42 . It is formed toward the inner surface of the upper plate portion 39 from the inner peripheral surface 38 b of the base end flow path.

The second curvature radius R2 of the concave second curvature surface 64 may be the same as or different from the curvature radius R1 of the flow path deflection surface 62 that forms the concave first curvature surface. It is preferably larger than the vertical width W1. The passage portion 42 and the second curved surface 64 are positioned at the same height along the axis O, and the coolant that flows from the outer portion 46 through the passage portion 42 into the inner portion 46 flows into the second curved surface 64. is preferably the first to collide with part or all of the .

In this embodiment, the cooling liquid that is primarily stored in the outer portion 44 from the nozzle 37, passes through the passage portion 42 from there and enters the inner portion 46 first collides with part or the entire surface of the second curved surface 64. , along the inner peripheral surface 38b of the flow path of the frame 38 and downward from the axial center O. As shown in FIG. The cooling liquid that flows inside the inner portion 46 along the flow path inner peripheral surface 38 b below the axis O next flows along the flow path deflection surface 62 of the frame 38 and reaches the inner surface 33 of the cylindrical body 32 . collide and reflect. As a result, the coolant is discharged from the coolant discharge portion 52 into the cylindrical body 32 in an inverted conical shape as shown in FIG. 1A to form a coolant flow 50 .

Note that the coolant flow 50 flowing out from the coolant discharge portion 52 is an inverted conical flow that advances straight from the coolant discharge portion 52 toward the axis O, but may be a spiral reverse conical flow. As shown in FIG. 1B, the angle θ4 of the reverse conical flow direction F of the coolant flow 50 with respect to the axis O is the curvature radius R1 of the concave first curvature surface at the maximum outer diameter portion of the flow path deflection surface 62 and the tangential angle It is determined according to θ3 and the like, and is preferably 20 to 80 degrees. The tangential angle θ3 is an angle with the axis O, and is substantially the same as the angle θ4 of the reverse conical flow direction F of the coolant flow 50 with respect to the axis O, but may be different.

As shown in FIG. 1A, the axial length L1 of the frame 38 may be a length that covers the width W1 of the passage portion 42 in the direction of the axis O. As shown in FIG. It is preferable that the outer protrusion 38 a 1 at the lower end 38 a of the cylinder 32 is long enough to face the inner surface 33 of the cylinder 32 . However, as shown in FIG. 3, the axial length of the frame 38 of the cooling unit 230 may be such that the lower end 38a of the frame 38 reaches the lower position of the partition 40. The length may be such that it covers the width W1 in the axial center O direction. However, it is preferable that the frame 38 is sufficiently long in the axial direction so that the flow path deflecting surface 62 does not face the passage portion 42 in the axial direction.

In this embodiment, as shown in FIG. 1B, the cooling liquid that has entered the outer portion 44 from the nozzle 37 is primarily stored in the outer portion 44 and passes through the passage 42 from there, thereby increasing the flow velocity and increasing the flow speed of the inner portion. Enter 46. In the inner portion 46, the cooling liquid that has passed through the passage 42 collides with the second curved surface 64 formed on the flow path inner peripheral surface 38b of the frame 38, and the direction of the flow is changed, and the cooling liquid flows along the axis O. turned into a downward flow along the

The cooling liquid flowing downward along the axis O inside the inner portion 46 is then guided along the flow path deflection surface 62, and the cross section of the flow path is narrowed, thereby increasing the flow velocity. Then, the coolant collides with the inner surface of the cylinder 32 in a state where the flow velocity is increased, is reflected, and is discharged from the coolant discharge part 52 into the cylinder 32 in an inverted conical shape as shown in FIG. 1A. to form a coolant stream 50 . Droplets of the dripping molten metal 21a shown in FIG. It is cooled by flowing with the cooling liquid inside.

In the metal powder manufacturing apparatus 10 and the metal powder manufacturing method according to the present embodiment, the inlet of the dripping molten metal 21a is formed at the upper opening of the cylindrical body 32, and the upper opening of the cylindrical body 32 is provided with an inlet of the molten metal 21a. A conical cooling water flow 50 is formed. An inverted conical cooling water flow 50 is formed at the upper opening of the cylindrical body 32, and the cooling liquid is discharged from the discharging portion 34 of the cylindrical body 32. Suction pressure to the inside of is obtained. For example, a suction pressure with a differential pressure of 30 kPa or more from the outside of the cylindrical body 32 can be obtained.

Therefore, the droplets of the dripping molten metal 21a are sucked into the cylinder 32 from the upper opening of the cylinder 32 in a self-aligning manner (even if they are slightly displaced, they are automatically sucked in), and are cooled in an inverted cone shape. entrained in the water stream 50; Therefore, the flying time of the droplets of the dripping molten metal 21a from the discharge port 23 of the molten metal supply section 20 to the cooling water flow 50 is shortened. When the flight time is shortened, the droplets of the dripping molten metal 21a are less likely to be oxidized, promoting refinement of the metal powder and improving the quality of the metal powder. Moreover, the quenching effect is accelerated, and the amorphization of the metal powder is improved.

In addition, in this embodiment, the droplets of the dripping molten metal 21a are taken into the flow of cooling liquid in an inverted conical shape instead of the flow of cooling liquid along the inner surface 33 of the cylindrical body 32. The residence time of the cooled metal particles inside can be shortened, and the inner surface 33 of the cylinder 32 is less damaged. In addition, there is little damage to the cooled metal particles themselves.

Furthermore, in this embodiment, the inner surface 33 of the cylindrical body 32 is not processed in any way, nor is it necessary to attach anything. A coolant flow 50 may be formed. Also, the inner diameter of the upper opening of the cylindrical body 32 can be sufficiently large.

Second Embodiment As shown in FIG. 2, a metal powder manufacturing apparatus 110 and a metal powder manufacturing method according to a second embodiment of the present invention are the same as those of the first embodiment except for the following points. Common member names and reference numerals are given to members, and descriptions of common parts are partially omitted.

In the present embodiment, the metal powder manufacturing apparatus 110 has the nozzle 37 attached to the side plate portion 44 a instead of the upper plate portion 39 in the cooling portion 130 , and the axial position of the nozzle 37 is positioned closer to the axis than the passage portion 42 . It is located below along O. Moreover, the partition portion 40 is integrated with the bottom plate portion 44b. Also in this embodiment, as shown in FIG. 2, an inverted conical cooling liquid flow 50 similar to that of the first embodiment can be formed inside the cylinder 32 .

Third Embodiment As shown in FIG. 3, a metal powder manufacturing apparatus 210 and a metal powder manufacturing method according to a third embodiment of the present invention are the same as those of the first or second embodiment except for the following. Common members are given common member names and reference numerals, and descriptions of common parts are partially omitted.

In the cooling part 230 of the present embodiment, the outer convex part 38a1 formed at the lower end 38a of the frame 38 has the maximum outer diameter part of the partition part 40 defined as a part of the inner peripheral surface 33 of the cylindrical body 32. facing the inner peripheral surface of the Further, a concave third curved surface 66 is formed on the inner peripheral surface of the partition portion 40 .

In this embodiment, as shown in FIG. 3, the cooling liquid that has entered the outer portion 44 from the nozzle 37 is primarily stored in the outer portion 44 and passes through the passage 42 from there, thereby increasing the flow velocity and Enter 46. In the inner portion 46, the cooling liquid that has passed through the passage 42 collides with the second curved surface 64 formed on the flow path inner peripheral surface 38b of the frame 38, and the direction of the flow is changed, and the cooling liquid flows along the axis O. turned into a downward flow along the

The cooling liquid flowing downward along the axis O inside the inner portion 46 is then guided along the flow path deflection surface 62, and the cross section of the flow path is narrowed, thereby increasing the flow velocity. Then, in a state in which the flow velocity is increased, the coolant collides with the inner peripheral surface of the partition portion 42, which is an extension of the inner surface of the cylinder 32, and the concave third curved surface 66 and the convex lower end 38a of the frame 38 collide with each other. As shown in FIG. 1A, the cooling liquid flow 50 is discharged from the cooling liquid outlet 52 into the cylindrical body 32 in an inverted conical shape.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

For example, in the embodiment described above, the nozzle 37 is connected to the top plate portion 39 or the side plate portion 44a, but may be connected to the bottom plate portion 44b.

Also, by adjusting the mounting direction of the nozzle 37, it is possible to add a spiral flow to the cooling liquid flow 50 having an inverted conical shape.

The present invention will be described below based on more detailed examples, but the present invention is not limited to these examples.

Example 1
Using the metal powder production apparatus 10 shown in FIGS. 1A and 1B, Fe—Si—B (experiment number 6), Fe—Si—Nb—B—Cu (experiment number 7), Fe—Si—BP— Metal powders consisting of Cu (experiment number 8), Fe--Nb--B (experiment number 9) and Fe--Zr--B (experiment number 10) were produced. In the device 10 shown in FIGS. 1A and 1B, the inner diameter of the inner surface of the cylinder 32 is 300 mm, W1/W2 is 1/4, D1/D2 is 1/2, the angle θ1 is 20 degrees, the angle θ2 is 0 degrees, The angle θ3 was 50 degrees and the angle θ4 was 50 degrees.

In each experiment, the dissolution temperature was constant at 1500° C., the injection gas pressure was 5 MPa, the type of gas used was argon, and the water flow conditions from the nozzle 37 were a pump pressure of 7.5 kPa. In the example, it was possible to produce a metal powder with an average particle size of about 24 μm. The average particle size was obtained by measuring using a dry particle size distribution analyzer (HELLOS). Also, the crystal analysis of the metal powders produced in Experiment Nos. 6 to 10 was evaluated by the powder X-ray diffraction method. The magnetic properties of the metal powder were measured by measuring the coercive force (Oe) with an Hc meter. Table 1 shows the results. Also, the coolant flow 50 was confirmed to be in the shape of an inverted cone, and the suction pressure was 40 kPa.

Reference example 1
The same metal powder production apparatus as in Example 1 was used, except that the lower end 38a of frame 38 did not have an outward convex portion having flow path deflection surface 62, and D1=D2 (the same D1 dimension as in Example 1). Then, metal powders (Experiment Nos. 1 to 5) were produced in the same manner as in Example 1, and similar evaluations were performed. Table 1 shows the results. The coolant flow 50 became a flow along the inner peripheral surface of the cylindrical body 32 .

Comparing the example and the reference example in Evaluation Table 1, the particle size is smaller and the magnetic properties are improved. It is considered that this is because in the example, the cooling liquid flow becomes an inverse conical flow compared to the reference example, and the flight distance of the droplets of the dripping molten metal 21a is shortened.

DESCRIPTION OF SYMBOLS 10, 110, 210... Metal powder manufacturing apparatus 20... Molten metal supply part 21... Molten metal 22... Vessel 23... Discharge port 24... Heating coil 26... Gas injection nozzle 27... Gas injection port 30, 130, 230... Cooling part 32... Cylindrical body 33... Inner surface (inner peripheral surface)
34... Discharge part 36... Coolant introduction part (coolant lead-out part)
37... Nozzle 38... Frame body 38a... Lower end 38a1... Outer convex part 38b... Flow path inner peripheral surface 39... Upper plate part 40... Partition part 42... Passage part 44... Outer part (outer space part)
44a... Side plate part 44b... Bottom plate part 46... Inside part (inner space part)
50... Coolant flow 52... Coolant discharge part 62... Flow path deflection surface (first curvature surface)
64... Second curvature surface 66... Third curvature surface

Claims (10)

a molten metal supply unit for discharging molten metal;
a cylindrical body installed below the molten metal supply unit;
A metal powder production apparatus comprising: a cooling liquid outlet section for forming a flow of cooling liquid for cooling the molten metal discharged from the molten metal supply section inside the cylindrical body,
The cooling liquid lead-out portion is provided at the upper portion in the axial direction of the cylindrical body, and includes an outer space portion, an inner space portion, and a passage portion connecting the outer space portion and the inner space portion. and
The cooling liquid lead-out part has a frame that defines the shape of the inner peripheral surface of the inner space , and an upper plate that is connected to the upper end of the frame ,
A nozzle is connected to the outer space,
The passage portion has a vertical width narrower than the vertical width of the outer space portion, and is configured to pass the cooling liquid from the nozzle from the outer space portion toward the inner space portion,
A first curved surface is formed at the lower end of the frame for directing the cooling liquid radially outward from the flow path inner peripheral surface of the frame,
A concave second curvature surface is formed on the inner surface of the corner between the upper end of the frame and the inner peripheral end of the upper plate,
The cooling liquid discharged from the passage portion into the inner space portion collides with the second curved surface, and flows along the flow path inner peripheral surface of the frame and the first curved surface, and flows along the inner peripheral surface of the cylindrical body. The flow path of the frame body flows toward the surface, reflects on the inner peripheral surface of the cylinder body, and flows in an inverted conical shape from the coolant discharge part of the inner space toward the center part of the cylinder body. A metal powder production apparatus, wherein a channel deflection surface forming the first curvature surface is formed on an inner peripheral surface. 2. The apparatus for manufacturing metal powder according to claim 1, wherein the passage portion is provided in the upper portion of the outer space portion in the axial direction. 3. The metal powder manufacturing apparatus according to claim 1, wherein the vertical width (W1) of the passage portion is narrower than the vertical width (W2) of the outer space portion and is 1/3 or less. 4. The metal powder manufacturing apparatus according to claim 1, wherein the vertical width (W1) of the passage is narrower than the radial width (D1) of the cooling liquid discharge section and is 1/3 or less. 5. The metal powder according to any one of claims 1 to 4, wherein the radial width (D1) of the coolant discharge portion is narrower than the radial width (D2) of the main portion of the inner space, and is 2/3 or less. manufacturing device. The flow path deflection surface is provided on the flow path inner peripheral surface of the frame so that the radial width of the inner space portion gradually narrows from the main portion of the inner space portion toward the cooling liquid discharge portion. 6. The apparatus for producing metal powder according to claim 5, wherein a concave first curvature surface is formed as a surface. The inner peripheral surface of the frame on the base end side of the flow path has a second concave shape so that the radial width of the inner space portion gradually narrows from the main portion of the inner space portion toward the passage portion. 7. The apparatus for producing metal powder according to claim 1, wherein a curved surface is formed. a molten metal supply unit for discharging molten metal;
a cylindrical body installed below the molten metal supply unit;
A metal powder production apparatus comprising: a cooling liquid outlet section for forming a flow of cooling liquid for cooling the molten metal discharged from the molten metal supply section inside the cylindrical body,
The cooling liquid lead-out portion is provided at the upper portion in the axial direction of the cylindrical body, and includes an outer space portion, an inner space portion, and a passage portion connecting the outer space portion and the inner space portion. and
The cooling liquid outlet has a frame that defines the shape of the inner peripheral surface of the inner space,
A nozzle is connected to the outer space,
The passage portion has a vertical width narrower than the vertical width of the outer space portion, and is configured to pass the cooling liquid from the nozzle from the outer space portion toward the inner space portion,
A first curved surface is formed at the lower end of the frame for directing the cooling liquid radially outward from the flow path inner peripheral surface of the frame,
The cooling liquid discharged from the passage portion into the inner space portion flows toward the inner peripheral surface of the tubular body along the flow path inner peripheral surface of the frame body and the first curvature surface, The flow path inner peripheral surface of the frame has the first curvature so that it is reflected on the inner peripheral surface of the frame and flows in an inverted conical shape from the coolant discharge portion of the inner space toward the center of the cylindrical body. 1. A metal powder manufacturing apparatus characterized in that a flow path deflection surface forming a surface is formed. A gas blowing member is arranged between the molten metal supply unit and the cylindrical body to blow a gas onto the molten metal discharged from the molten metal supply unit to form a large number of droplets of the molten metal,
8. The apparatus for producing metal powder according to claim 1, wherein said molten metal formed into droplets by said gas blowing member enters into said cylindrical body. A step of forming a flow of cooling liquid on the inner surface of a cylindrical body installed below the molten metal supply section;
and discharging the molten metal from the molten metal supply unit toward the flow of the cooling liquid, wherein
Using the metal powder production apparatus according to any one of claims 1 to 9,
causing the cooling liquid in the outer space to pass through a passage having a vertical width narrower than the width of the outer space;
The cooling liquid that has passed through the passage portion flows along the inner peripheral surface of the flow path of the frame that defines the inner space, is reflected by the inner peripheral surface of the cylinder, and reaches the center of the cylinder. A method for producing metal powder, characterized in that the powder is poured in an inverted conical shape.

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