JPH0719649Y2 - Hot water flow tester - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melt flow tester used for measuring melt flowability of molten metal, and more particularly to a melt flow tester suitable for measuring melt flowability of stainless steel melt.

[0002]

2. Description of the Related Art Since the flowability of molten metal is related to the viscosity of molten metal,
It is generally considered that the higher the temperature of the molten metal, the better the fluidity of the molten metal. However, in reality, the surface tension of the molten metal,
In addition to physical properties such as thermal conductivity, specific heat and latent heat of solidification, chemical properties such as oxidation and gas absorption are also involved, and when the temperature becomes excessively high, the flowability of the molten metal may decrease. Therefore, the measurement of the melt flowability of the molten metal is often carried out under conditions close to the actual casting conditions.

FIG. 3 (a) is a schematic side view showing an example of a conventional molten metal flow test apparatus, and FIG. 3 (b) is a plan view thereof. A molten metal flow path 11 is provided in a spiral shape in the mold (sand mold). A molten metal receiving portion 12 is arranged above the center of the molten metal flow passage 11, and the molten metal receiving portion 12 and the center side end portion of the molten metal flow passage 11 are connected by a runner 13.

In the molten metal flowability testing apparatus constructed as described above, molten metal having a predetermined temperature is poured into the molten metal receiving portion 12 from a ladle (not shown), and the molten metal flow path 1 is set until the molten metal solidifies.
The flowability of the molten metal is checked by measuring the distance flowing through the inside of 1. This molten metal flow tester is mainly used for measuring the molten metal flowability of cast iron and non-ferrous alloys.

FIG. 4A is a schematic side view showing another example of the conventional molten metal flow test apparatus, and FIG. 4B is a plan view thereof. A molten metal flow passage 21 is provided inside the mold, and a molten metal receiving portion 22 is provided above the spiral molten metal flow passage 21. The melt receiving portion 22 and the outer end of the melt flow path 21 are connected by a runner 23. In this apparatus, the molten metal is injected into the molten metal flow passage 21 through the lower side of the molten metal flow passage 21. This molten metal flow tester is mainly used for measuring molten metal flowability of steel.

In the conventional hot water flow tester,
The molten metal flow paths 11 and 21 are formed in a trapezoidal cross section (for example, the upper bottom is about 4 mm, the lower bottom is about 8 mm, and the height is about 4 mm).

[0007]

However, the above-described conventional melt flow test apparatus has a problem that the reproducibility is poor and it is difficult to measure the melt flow property with high accuracy. That is, in the molten metal flowability test, it is necessary to keep the pressure (head pressure) during pouring and the flow conditions (casting amount and surface tension) strictly constant. However, the temperature of the molten metal changes while the molten metal is poured from the ladle into the molten metal receiving portions 12 and 22, and the viscosity of the molten metal, surface tension,
Physical properties such as thermal conductivity, specific heat and latent heat of solidification, and chemical properties such as oxidation will change. Conventionally, since only the temperature of the molten metal in the ladle can be measured, the temperature during actual casting cannot be precisely controlled.

Further, when casting directly from the ladle, the pressure changes depending on the height of the ladle (the height at which the molten metal drops), and it becomes easier for the molten metal to flow when it is poured from a higher position.

Further, conventionally, since the cross-sectional shape of the molten metal flow path is trapezoidal, especially in the case of stainless steel, the corners of the trapezoid are not sufficiently filled with molten metal due to the surface tension. Also, since the cooling rate of the molten metal differs depending on the wall surface with which the molten metal contacts,
The pressure when passing through the molten metal flow path is not constant.

The present invention has been made in view of the above problems, and it is easy to keep the temperature and other conditions constant when pouring the molten metal into the molten metal flow path, and the reproducibility of the melt flowability test is good. It is an object of the present invention to provide a hot water flow test apparatus capable of measuring the hot water flow property with high accuracy.

[0011]

A molten metal flowability testing apparatus according to the present invention comprises a molten metal flow passage having a circular cross-sectional shape and arranged in a mold in a spiral shape, a spool cup for storing the molten metal, and this spool. It is characterized in that it has a runner connecting the cup and the end of the molten metal flow path, and a stopper capable of opening and closing the runner.

[0012]

In the molten metal flow test apparatus according to the present invention, the runner is closed by the stopper to store a certain amount of molten metal in the spool cup. Then, after setting the molten metal temperature to a predetermined temperature, the runner is opened and the molten metal is injected into the molten metal flow path. Thereby, the molten metal temperature, the injection amount, and the pressure when pouring the molten metal into the molten metal flow path can be kept constant. Further, in the present invention, since the cross-sectional shape of the molten metal flow path is circular, the temperature drop of the molten metal when passing through the molten metal flow path becomes uniform in the circumferential surface direction, and the surface tension etc. becomes uneven in the circumferential direction. Can be avoided. Therefore, the molten metal flow test apparatus according to the present invention has an excellent reproducibility of the molten metal flowability test and can measure the molten metal flowability with high accuracy.

[0013]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 (a) is a schematic side view showing a molten metal flow test apparatus according to an embodiment of the present invention, and FIG. 1 (b) is FIG.
It is sectional drawing by the AA line of (a). Also, FIG.
2A is a side view showing the core plug, and FIG. 2B is a bottom view of the same.

In the present embodiment, in a mold (sand mold),
The molten metal flow path 1 having a circular cross section is spirally arranged.
A spool cup (gate) 2 is disposed above the center of the melt flow path 1, and the spool cup 2 and the center side end of the melt flow path 1 are connected via a runner 3. There is. The runner 3 is provided with steps so that the diameter on the spool cup 2 side is large and the diameter on the molten metal flow path 1 side is small.

The core plug 4 is formed of a cold box method and has a steel rod at the center, and a diametrically-protruding closing portion 5 is provided in the vicinity of its lower end. The closing portion 5 is fitted to the upper portion of the runner 3 so that the runner 3 can be closed.

A thermocouple is provided on the wall surface of the spool cup 2 so that the temperature of the molten metal charged in the spool cup 2 can be measured.

Next, a molten metal flowability test method using the molten metal flowability testing apparatus of this embodiment having the above-described structure will be described.

First, the core plug 4 is fitted and disposed on the upper portion of the runner 3 and the runner 3 is closed. Then spool cup 2
A certain amount (for example, 5 kg) of molten metal is poured therein. Next, the temperature of the molten metal is measured by a thermocouple provided on the wall surface of the spool cup 2, and when the temperature reaches a predetermined temperature, the core plug 4
And the molten metal is poured into the molten metal flow path 1. Then, the distance that the molten metal flows until it solidifies is measured.

In this embodiment, since the molten metal is temporarily stored in the spool cup 2, it is easy to make the molten metal injection amount constant, and the pressure at the time of pouring can be made constant. In addition, since the molten metal is injected into the molten metal flow path after the spool is heated to a predetermined temperature in the spool cup 2, physical properties such as viscosity, surface tension, thermal conductivity, specific heat and latent heat of solidification, and chemicals such as oxidation, etc. Can be constant. Further, since the cross-sectional shape of the molten metal flow passage 1 is circular, when the molten metal passes through the molten metal flow passage 1, the cooling rate in the circumferential direction of the molten metal flow passage 1 becomes uniform, and the temperature and pressure in the circumferential direction become uniform. become. Therefore, in the apparatus of this embodiment, good reproducibility can be obtained, and the molten metal flowability can be measured with high accuracy.

[0021]

As described above, according to the present invention, there is provided a stopper capable of opening and closing a runway for connecting a molten metal flow passage arranged in a mold with a spool cup storing the molten metal. Therefore, it is easy to make the conditions such as the temperature and pressure of the molten metal injected into the molten metal flow path constant.
Moreover, since the cross-sectional shape of the molten metal flow path is circular, the cooling rate in the circumferential direction of the molten metal passing through the molten metal flow path becomes uniform.
This makes it possible to measure the melt flowability with high accuracy.

[Brief description of drawings]

1 (a) and 1 (b) are a schematic side view and a sectional view, respectively, showing a molten metal flow test apparatus according to an embodiment of the present invention.

2A and 2B are a side view and a bottom view showing a core plug, respectively.

3 (a) and 3 (b) are respectively a schematic side view and a plan view showing an example of a conventional molten metal flow tester.

4 (a) and 4 (b) are respectively a schematic side view and a plan view showing another example of the conventional molten metal flow tester.

[Explanation of symbols]

 1, 11, 21; Molten metal flow path 2; Spool cups 3, 13, 23; Runway 4; Core plugs 12, 22; Molten metal receiving portion

Claims (1)

[Scope of utility model registration request] 1. A molten metal flow passage having a circular cross-sectional shape, which is spirally arranged in a mold, a spool cup for storing the molten metal, and a runner which connects the spool cup and an end of the molten metal flow passage. And a stopper for opening and closing the runner, which is a flowability tester.