JP2607023Y2 - Metal melt sampling equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for sampling a molten metal.

[0002]

2. Description of the Related Art For example, in a molten aluminum (including an aluminum alloy, the same applies hereinafter), Al ₂ O ₃ , Mg
Inclusions composed of metal oxides such as O and Al ₂ MgO ₄ ,
Since it contains inclusions consisting of fragments of furnace refractories,
Various treatments for removing these inclusions have been applied to the molten aluminum. Then, in order to evaluate the effect of the inclusion removal treatment, usually, a sample is taken from the treated aluminum melt and analyzed.

[0003] Conventionally, as a molten metal sampling apparatus, a hollow suction body immersed in the metal melt, a suction pipe connected to the suction body via a suction pipe, and the suction body is immersed in the metal melt. It is provided with a metal melt storage tank which is made to come above the melt surface at the moment, and a vacuuming device connected to the storage tank, and a metal melt suction port is formed in the suction body, and the suction port is formed in the suction port. It is known that an inclusion trapping filter is detachably attached, and the inner peripheral surface of the storage tank is covered with a heat insulating material made of ceramic fiber paper (see Japanese Patent Publication No. 59-28832).

In this sampling device, a suction body is immersed in a metal melt, and a predetermined amount of the metal melt is sucked into a metal melt storage tank from a suction port of the suction body by a vacuum evacuation device. Is collected, the suction body is pulled out of the molten metal to solidify the metal melt therein, and then the filter is removed to analyze the number, type, size, etc. of inclusions. Further, the molten metal sucked into the storage tank is maintained in a liquid state by the action of a heat insulating material covering the inner peripheral surface thereof, and is discharged by appropriate means.

[0005]

However, in the conventional sampling device, the inner peripheral surface of the suction pipe is covered with a heat insulating material made of ceramic fiber paper, and the durability of the heat insulating material is not sufficient. Its life is shortened,
Need to be replaced in a short time. Therefore, there is a problem that the replacement must be performed frequently, and the work is troublesome. Further, when the diameter of the suction pipe is small, it is impossible to replace the coating material.

An object of the present invention is to provide a molten metal sampling apparatus which solves the above problem.

[0007]

The molten metal sampling apparatus according to the present invention comprises a hollow suction body immersed in the molten metal, a suction body connected to the suction body via a suction pipe, and the suction body being connected to the suction body. It has a molten metal storage tank that is made to come above the surface of the molten metal when immersed in the molten metal, and a vacuuming device connected to the storage tank, and a metal molten metal inlet is formed in the suction body. In addition, an inclusion trapping filter is detachably attached to the suction port, and is a metal melt sampling device that samples the metal melt and collects the inclusions at the same time, and the suction pipe has a graphite pipe body and And a coating material for covering the inner peripheral surface of the pipe main body, wherein the coating material is composed of 30 to 60% by weight of SiO ₂ and 20 to 50% of CaO.
It is formed of a fired body of SiO ₂ —CaO-based ceramics containing 0.1 % by weight .

In the above, the fired body of SiO ₂ —CaO-based ceramics is superior in durability to ceramic fiber paper used in a conventional apparatus. In addition, it is excellent in non-wettability with a molten metal and heat insulation. SiO ₂ and CaO in this ceramic
The reason for limiting the content as described above is that if the SiO ₂ content is less than 30% by weight, the coefficient of thermal expansion increases, and if it exceeds 60% by weight, the fire resistance may decrease. Further, if the CaO content is less than 20% by weight, the strength is reduced, and if it exceeds 50% by weight, the degree of embrittlement may increase.

Further , ceramics forming the above coating material
Preferably further contains Al ₂ O ₃ . When Al ₂ O _{3 is} contained in the above ceramics, its durability is further improved. However, an Al ₂ O ₃ content of 40
Exceeds wt%, the thermal conductivity becomes heat insulating property is greatly reduced, since the specific gravity is increased, the content of
It is preferably at most 40% by weight.

[0010]

The coating material covering the inner peripheral surface of the suction pipe is made of SiO ₂ 3
0-60% by weight and 20-50% by weight of CaO
Ri, and since a fired body of SiO ₂ -CaO based ceramics is excellent in durability as compared with the ceramic fiber paper which has been used in the conventional apparatus, the life of the dressing,
The life of the ceramic fiber paper used in the conventional apparatus is greatly increased. In addition, since this coating material is excellent in non-wettability with the molten metal, the molten metal does not remain in the suction pipe when the molten metal is discharged from the molten metal storage tank. Further, since this coating material has excellent heat insulating properties, when the molten metal is sucked into the molten metal storage tank, solidification of the molten metal existing in the suction pipe can be prevented.

Since the pipe body of the suction pipe is made of graphite, the high temperature strength is high, and no contamination is caused by contact with the molten metal.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, up, down, left, and right
The upper and lower sides and the left and right sides of FIG.

FIGS. 1 and 2 show an embodiment of the sampling device according to the present invention.

1 and 2, the apparatus for sampling a molten metal has a hollow suction body (1) made of graphite or ceramics, the inside of which is formed as a molten metal passage (1a). The right end of the molten metal passage (1a) is open to the right end of the suction body (1). This opening is indicated by (2). In the upper part of the peripheral wall of the suction body (1), a vacuum suction port (3) and a molten metal suction port (4) are formed from the left side. On the right side of the suction port (4),
A through-hole that extends vertically to include the molten metal passage (1a)
(5) is formed. The opening (2) at the right end and the through hole (5) of the molten metal passage (1a) serve as a metal molten metal discharge port.

A molten metal storage tank (8) is connected to the vacuum outlet (3) through a suction pipe (7) extending vertically, in a communicating manner. The suction pipe (7) is made of a graphite pipe body (9) whose inner peripheral surface is coated with a heat-resistant coating material (11) that has excellent wettability with metal melt, heat insulation, and durability. is there. Graphite has high strength at high temperatures, does not generate contamination due to contact with a molten metal, and has excellent workability. Also, when the molten metal is aluminum,
Examples of the coating material (11), for example, Si O ₂ -CaO ceramic or its at most 40 wt% Al, containing SiO ₂ 30 to 60 wt% and CaO20~50 wt%
SiO ₂ —CaO—Al ₂ O containing ₂ O ₃
What consists of a fired body of ₃ series ceramics is used.
The thickness of the coating material (11) is preferably 4 mm or more. Although not shown, a male screw formed at the lower end portion of the outer peripheral surface of the pipe body (9) is formed on the peripheral surface of the vacuum port (3) and is screwed into the screw, so that the suction pipe ( 7)
Is fixed to the suction body (1). Since graphite has excellent workability for screws and the like, the screws can be easily formed in the pipe body (9).

In the molten metal storage tank (8), for example, the inner peripheral surface of a stainless steel main body (12) is made of a heat-resistant coating material (13) excellent in non-wettability, heat insulation and durability with the molten metal. It is coated. If the molten metal is molten aluminum, the coating material (13), like the dressing of suction tube (7) (11), for example, a SiO ₂ 30 to 60 wt% CaO2
Consisting fired bodies Si O ₂ -CaO ceramic or its SiO ₂ -CaO-Al ₂ O ₃ based ceramics are Al ₂ O ₃ of 40 wt% at most was the additional inclusion, containing 0-50 wt% Things are used. This coating
The thickness of (13) is preferably 5 mm or more. Although not shown, the screw is formed on the inner peripheral surface of the downwardly projecting small-diameter portion (12a) provided at the lower end of the main body (12), so that the screw is connected to the suction pipe.
The lower end of the storage tank (8) is fixed to the suction pipe (7) by being screwed into a male screw formed at the upper end of the outer peripheral surface of the pipe body (9) of (7). Since graphite is excellent in workability of screws and the like, the above screws can be easily formed in the pipe body (9). A packing (14) made of, for example, ceramic fiber paper is interposed between the lower end surface of the storage tank (8) and the upper end surface of the suction pipe (7).

An evacuation device (16) is connected to the top lid (15) of the storage tank (8). Vacuum evacuation equipment
(17) and a vacuum pump (not shown) attached to the tip of the vacuum tube (17). A vacuum gauge (18), a vacuum valve (19), and a leak valve (21) are provided in the middle of the evacuation tube (17) from the storage tank (8) side.

The molten metal storage tank (8) has a level sensor (22) for detecting the level of the molten metal in the tank (8). The level sensor (22) is composed of a plurality of sheath thermocouples of different lengths penetrating through the top lid (15) of the storage tank (8).
(23) and measuring instrument with all sheathed thermocouples (23) connected
(24). The temperature measuring contact at the lower end of each thermocouple (23) is
They are at different height positions. And storage tank (8)
When the molten metal sucked into the thermocouple (23) touches the temperature measuring contact of each thermocouple (23), the temperature detected by the thermocouple (23) reaches the temperature of the molten metal and the molten metal surface is You can see that you have reached the height. In addition, each thermocouple (23)
Since the temperature measuring contacts at the lower end of the thermocouple (23) are located at different heights, the temperature measuring contacts at the lower end of each thermocouple (23) are sucked in such a way that they are on the molten metal surface. The amount can be varied. And also in this case, the molten metal surface comes into contact with the temperature measuring contact of any thermocouple (23) located on the molten metal surface corresponding to each sampled amount, and the temperature detected by this thermocouple (23) It can be seen that a desired amount of molten metal was sucked in when the temperature of the molten metal reached the temperature of the molten metal.

A cylindrical filter receiving member (25) made of graphite or ceramics having a male screw formed over the entire outer peripheral surface thereof is screwed to the molten metal inlet (4) of the suction body (1). . The upper part of the filter receiving member (25)
A filter (26) made of porous graphite or porous ceramics is mounted on the upper surface of the filter (26) via ceramic fiber packing (29). The filter (26) is fixed by a graphite or ceramic filter holding member (27) screw-fitted onto the upper projecting portion of the filter receiving member (25).
The filter holding member (27) has a cap nut shape, and its top wall (27a)
A through hole (28) is formed in the center of the. Ceramic fiber packing (3) is also provided between the top wall (27a) and the filter (6).
0) is interposed. The filter (26) is sandwiched between the upper end surface of the receiving member (25) and the top wall (27a) of the pressing member (27). Also, a ceramic fiber packing (31) is interposed between the lower end of the peripheral wall of the holding member (27) and the upper surface of the suction body (1).

A stopper plug (32) made of graphite or ceramic is densely inserted into the upper and lower through holes (5) of the molten metal suction body (1). The stopper (32) also closes the right end opening (2) of the molten metal passage (1a). A stick-shaped operating member (33) extending upward is integrally formed with the stopper (32). Operation members
The upper portion of (33) projects above the molten metal surface when the suction body (1) is immersed in the molten metal.

Next, a method for sampling the molten aluminum (M) in the molten metal holding layer and analyzing the inclusions using the above-mentioned sampling apparatus will be described. First, the suction body (1)
The filter (26) is immersed in the molten aluminum (M) until the filter (26) is completely immersed in the molten aluminum (M).
Is preheated until the temperature reaches 680 ° C. or higher. The immersion depth is preferably 40 mm or more at the filter (26). At this time, the molten aluminum surface (L) comes to the middle of the length of the suction pipe (7) and the operation member (33)
Is above the molten metal surface (L). Since the high temperature strength of the pipe body (9) of the suction pipe (7) is large, breakage of the body is prevented. In addition, the occurrence of contamination due to contact between the pipe body (9) and the molten metal is prevented. Immediately before immersing the suction body (1) in the molten aluminum (M), the aluminum oxide on the molten metal surface (L) is removed.

Next, the leak valve (21) is closed and the vacuum valve (19) is opened, and the pressure inside the apparatus is reduced by a vacuum pump. Then, the molten aluminum (M) is sucked into the molten metal passage (1a) of the suction body (1) through the suction port (4), and the inclusions are separated and collected by the filter (26). The molten aluminum (M) is further sucked into the storage tank (8) through the suction pipe (7). The molten metal suction speed was 700
g / min is preferred. When the level sensor (22) detects that the amount of molten metal in the storage tank (8) has reached a predetermined amount, the vacuum valve (19) is closed and the vacuum pump is stopped. Thus, the work of collecting the molten aluminum (M) is completed.

After the collection operation, the stopper (32) is pulled out of the through hole (5) by pulling the operation member (33) upward, and the right end opening (2) of the through hole (5) and the molten metal passage (1a) is drawn. And the vacuum valve (19) and the leak valve (21) are opened. Then, the molten aluminum (M) in the storage tank (8) passes through the suction pipe (7) and the molten metal passage (1a), passes through the through hole (5) and the right end opening (2) of the molten metal passage (1a) to the outside. And the molten metal surface in the sampling device is
(M) has the same height as the melt surface (L). After that, the entire sampling device was pulled out of the molten aluminum (M),
All the remaining molten aluminum (M) is discharged from the through hole (5) and the right end opening (2) of the molten metal passage (1a). At this time,
Since the inner peripheral surfaces of the storage tank (8) and the main body (12) (9) of the suction pipe (7) are covered with the coating material (13) (11) as described above, the storage tank (8) And molten metal in the suction pipe (7)
(M) is prevented from remaining and solidifying. Next, after removing the filter holding member (27) and the filter (26), the filter (26) is cut. Finally, after polishing the cut surface, observation with an optical microscope and EPMA analysis
The amount, size, type, etc., of the inclusions collected by the filter (26) are analyzed. Thus, the evaluation of the molten aluminum (M) is performed. A packing (29) (30) is interposed between the filter (26), the filter receiving member (25) and the filter holding member (27), and the filter holding member (27) and the suction body (1) Since the packing (31) is interposed between the filter and the filter (26), the solidification metal is prevented from being present between the filter receiving member (25) and the filter pressing member (27), The filter (26) can be easily removed.

In order to increase the sampling amount, a sampling operation is performed after the sampling operation is completed. In this case, as described above, first, the aluminum melt (M) in the sampling device is externalized until the molten surface in the sampling device is at the same height as the molten surface (L) of the external aluminum melt (M). When discharged, the molten aluminum (M) remaining in the sampling device is maintained in a liquid state without solidifying due to the heat of the external molten aluminum (M), and thereafter the stopper (32) is operated by the operating member (33). Is inserted into the through hole (5), the through hole (5) and the right end opening (2) of the molten metal passage (1a) are closed, and the leak valve (21) is closed to perform the same sampling operation as described above.

When the sampling of the required amount is completed, the molten aluminum in the sampling device is processed in the same manner as described above.
(M) is completely discharged, and the amount, size, type, etc. of the inclusions collected in the filter (26) are analyzed. Thus, the evaluation of the molten aluminum (M) is performed.

[0026]

According to the molten metal sampling apparatus of the present invention, as described above, the life of the coating material covering the inner peripheral surface of the pipe main body of the suction pipe is improved as compared with the conventional apparatus. Therefore, the number of times of changing the coating material can be reduced as compared with the conventional apparatus, and the operation can be simplified. In addition, if the diameter of the suction pipe is small, it is not possible to replace the coating material. Therefore, the entire suction pipe must be replaced. However, the number of replacements is smaller than that of the conventional apparatus, and the cost is lower. Become.
Further, since the coating material is excellent in non-wettability with the molten metal, when the molten metal is discharged from the molten metal storage tank, the molten metal remains in the suction pipe and can be prevented from solidifying. . Further, since the coating material has excellent heat insulating properties, it is possible to prevent solidification of the molten metal existing in the suction pipe when the molten metal is sucked into the molten metal storage tank.

The pipe body of the suction pipe is made of graphite,
Since the high-temperature strength is large, the life of the suction pipe when it is immersed in the molten metal is extended. Moreover, the pipe body is
Since contamination does not occur due to contact with the molten metal, contamination of the molten metal can be prevented.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the sampling device of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow coating material 4 Suction port 7 Suction pipe 9 Tube main body 11 Coating material 16 Vacuum evacuation device 26 Inclusion collection filter

────────────────────────────────────────────────── ─── Continued on the front page (56) References Utility model registration 2582156 (JP, Y2) Utility model registration 2565115 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F27D 21/00 C22B 9/00 C22B 21/06 G01N 1/10

Claims (1)

(57) [Scope of request for utility model registration] A hollow suction body immersed in a molten metal, and a suction body connected to the suction body through a suction pipe and above the molten metal surface when the suction body is immersed in the metal melt. And a vacuuming device connected to the storage tank. The suction port has a metal melt suction port, and an inclusion trapping filter is attached to and detached from the suction port. A metal melt sampling device that is freely mounted and that simultaneously samples and collects inclusions from the metal melt, wherein the suction pipe comprises a graphite pipe main body and a coating material covering the inner peripheral surface of the pipe main body. The coating material is composed of 30 to 60% by weight of SiO ₂ and 20 to 50% by weight of CaO.
% Of a molten metal formed from a sintered body of SiO ₂ —CaO-based ceramics containing 0.1 % by weight.