JPH08334483A - Solidification simulation device and method therefor - Google Patents

Abstract

PURPOSE: To provide a solidification simulation device and a method therefor, by which, in addition to the macro and micro structural defects of large ingots of alloys, etc., the formation behavior and solidified states of oxides, sulfides, etc., and the solidified structures of ESR and VAR can be simulated. CONSTITUTION: This solidification simulation device comprises a refractory container 1 in which, to put a liquid metal for solidification simulation, a cooling device 3 provided at one end of the refractory container to cool the liquid metal, and a heating zone 4 surrounding the refractory container 1 at other than the cooling device, and has a function by which it can control the heating zone 4 to have a predetermined temperature gradient toward the depth of the refractory container 1, as viewed from the cooling device 3. It is preferable to control the temperature distribution within the heating zone to be in a time relationship with a preset temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solidification simulation apparatus and method for reproducing the solidification structure of a large ingot of metal or the like by a small test apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 7 which is a schematic view of a solidification structure of a vertical cross section of a ingot, a large ingot such as a high alloy steel has a macro segregation such as an inverse V segregation (also called A segregation) or a V segregation. Defects are noticeable. Since these defects have a significant adverse effect on the product quality, many studies have been made on the mechanism of their generation and many proposals have been made on their industrial measures. As a means to find these improvement measures, in addition to trial production using a large ingot of the actual size,
There is a method by solidification simulation in which the solidified structure of a large ingot is reproduced by a small test device.

FIG. 8 shows a solidification simulation method.
A method is known in which the conceptual diagram is shown in (Suzuki,
Miyamoto: Iron and Steel: 73 (1987), 1, p.53). In this apparatus, a refractory container 1 having an open upper end surface is placed in a furnace surrounded by a refractory heat insulating material 10 in the atmosphere, and a cooling device (air-cooling chiller) 3 is provided inside one longitudinal end surface. This is a method of arranging and heating the side surface of the refractory container 1 and the outside of the opposite surface on which the cooling device 3 is arranged by the electric heater 7 of single zone control. Molten metal 6
In the refractory container 1, the refractory container 1 is cast after reaching a predetermined temperature, and is heated by the electric heater 7 while being cooled and solidified from one direction by the cooling device 3. That is, in FIG. 8, the cooling device 3 corresponds to cooling from the mold wall surface,
The portion heated by the electric heater 7 corresponds to the inside of the steel ingot, so that a temperature gradient is provided to the side surface. Further, the exothermic powder placed on the upper portion of the molten steel prevents the upper portion from cooling and strengthens the side surface cooling. Because of. In this device, inverse V segregation often appears just below the riser part, so the purpose is to simulate that part with a 14 kg steel ingot.

[0004]

Many studies and proposals have been made on the control of solidification structure of ingots, but all of them only show improvement guidelines under specific conditions. With respect to the mechanism of V segregation, its mechanism and factors have not always been clarified. In the apparatus shown in FIG. 8 described above, which is for the study of inverse V segregation, the heating heater 7 has only one power source, and the heating temperature is controlled in one zone. A large temperature gradient cannot be applied to the opposite surface,
It simulates at most D / 4 (D is the diameter of the steel ingot). Therefore, it is difficult for the apparatus of FIG. 8 to simulate the entire solidification process from the mold surface of the ingot having several tens of tons to the center of the ingot.

Further, in the apparatus of FIG. 8, the heater 7 is
It is not installed on the upper surface and the lower surface of the refractory container 1, and that portion cools faster than the surface on which other electric heaters are installed, and heating and cooling cannot be controlled. As a result, solidification may start from a place other than the cooling device 3 (for example, the bottom surface), and it is not a device that sufficiently simulates (simulates) the solidified state of all actual ingots. Although the simulation method as described above can simulate the solidification process of a relatively small ingot,
Further improvements were needed to simulate the total solidification process of large ingots.

Further, regarding the production control of oxides that affect the cleanliness of steel and sulfides that affect the machinability of free-cutting steel, trial production was carried out using a large ingot of the actual size. At present, it is carried out empirically and by trial and error by cutting and investigating, and the improvement cost is great. In order to more accurately simulate the formation behavior of oxides, sulfides, etc. during solidification, it is desirable to evaluate the melting, casting, and solidification of the molten metal by cutting off the external oxygen and nitrogen. However, a device for controlling the atmosphere from melting to solidification and simulating it has not been realized so far. This is partly because the optimal coagulation simulator has not been developed.

More recently, the demand for high quality has increased,
In addition to the conventional mold casting method using, for example, a casting, electroslag remelting (E
The number of melting and solidification methods such as SR) and vacuum arc remelting (VAR) is increasing. Control of the solidification structure is also important in these melting and solidification methods, but most furnaces used in actual production are at least in the 1-ton class or more, and large furnaces have several tens of tons. There is a demand for an apparatus that can simulate the solidification morphology with a small amount of melting, rather than cutting the ingot produced by these methods to examine the macrostructure or microstructure. Therefore, there is an advantage that the improvement cost can be significantly reduced if a solidification simulation apparatus and method capable of easily and appropriately performing solidification structures corresponding to individual materials and solidification conditions can be achieved.

Solidification form of die casting ingot, electroslag remelting (ESR), vacuum arc remelting (VA)
In order to accurately simulate the directional laminated solidification morphology of R),
It is necessary that the cooling device side of the solidification simulation device has a structure corresponding to the inner surface of the mold that becomes the solidification start point or the bottom surface of the ESR or VAR mold, and the solidification morphology in these furnaces is It is necessary to reproduce the characteristic of being cooled isotropically. The purpose of the present invention is to be able to simulate 1) macrostructure defects and microsolidification structures of large ingots such as alloys with one type of simulation device, 2) formation behavior and solidification morphology of oxides, sulfides, etc. inside the molten metal. Can be reproduced without being affected by the atmosphere, and 3) the multipurpose means of being able to more accurately simulate the solidification structure of electroslag remelting (ESR) or vacuum arc remelting (VAR) which takes the directional laminated solidification morphology. It is to provide a solidification simulation device and a method therefor.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been accomplished as a result of extensive studies to provide means for simply and accurately simulating the solidification process of a solid ingot. And using the method.

A first aspect of the present invention is a refractory vessel 1 containing a molten metal for simulating solidification, a cooling device 3 for cooling the molten metal at one end of the refractory vessel, and the refractory vessel. 1 is composed of a heating zone 4 which is surrounded by a device other than the cooling device, and a function capable of controlling the heating zone so as to have a predetermined temperature gradient toward the inner side of the refractory container 1 when viewed from the cooling device 3. It is a solidification simulation device characterized by having. The heating zone 4 has a plurality of heating zones divided in the longitudinal direction, and compares a temperature detected by a temperature detector 5 installed at a predetermined position of the refractory container 1 with a preset temperature. It is preferable that the solidification simulation device has a function of controlling the temperature so that the refractory container 1 has a predetermined temperature gradient toward the inner side when viewed from the cooling device 3. Further, it is desirable that the cooling device 3 also serves as the molten metal injection hole 2 of the refractory container 1. Further, the coagulation simulation device of the present invention is a device having a function of being supported by the rotating shaft 9 and the rotating shaft support 13 and capable of rotating approximately 90 degrees (so that the longitudinal direction of the refractory container 1 is vertical or horizontal). It is good to say

That is, if the longitudinal direction of the refractory container is made horizontal, the solidification in the ordinary metal mold can be reproduced, and if the longitudinal direction is made vertical, the cooling device becomes the lower surface and the refractory container is opened. By the heating zone 4 provided so as to surround,
The mold cooling of ESR and VAR (which is the cooling from the side surface) can be reproduced. Further, these coagulation simulation devices are arranged in a container 15 together with the melting furnace 14, and the container 15 is connected to an evacuation system to evacuate or evacuate it and then replace it with Ar gas or the like. It is desirable to have a means of creating an inert atmosphere. This embodiment of the present invention is most suitable for the study of solidification of a molten metal containing an active metal, which is particularly sensitive to the atmosphere, and the solidification of oxides and sulfides that are likely to be oxidized or nitrided in the normal atmosphere. It can be effective.

In the second invention, when the solidification simulation is carried out by using the apparatus described above, the refractory container 1 is heated by the heating zone 4 so that the liquidus temperature of the target alloy is -1.
A first step of soaking the temperature to a temperature of 00 ° C. or higher, and a second step of injecting the molten metal 6 of the target alloy into a space surrounded by the soaked refractory container 1 and the cooling device 3. It is a solidification simulation method comprising a third step of cooling by controlling the temperature distribution in the heating zone so that the temperature at a predetermined position of the refractory container 1 has a time relationship with a preset temperature.

[0013]

The first feature of the present invention is that the heating zone 4 is provided so as to surround the refractory container other than the cooling device. Therefore, it is possible to control the temperature of both the upper portion and the lower portion of the refractory container 1, and it is also possible to simulate the portion of the ingot that cannot be simulated by the conventional temperature control of only the side surface. For example, in the center (H / 2) part of the ingot in the longitudinal (H) direction, both the upper part and the lower part have the same temperature for a long time, and in such a case, the upper part and the lower part are almost the same temperature. It can be set. In the conventional apparatus shown in FIG. 8 and the like, since there is no heating zone especially in the lower portion, there is a possibility of cooling to the lower portion as well as the side surface, and therefore there are some portions that cannot be reproduced depending on the actual ingot portion.

A second feature of the present invention is a heating zone having a plurality of heating zones divided in the longitudinal direction. Since the heating zone is divided into a plurality of zones, the temperature distribution in each zone can be finely controlled, so that the heating temperature in each zone can be set according to the temperature change at each position in the practical ingot. In the conventional apparatus, for example, as shown in FIG. 8, since heating is mainly uniform in only one zone, it is substantially impossible to finely adjust the temperature in the longitudinal direction as viewed from the cooling apparatus.

A third feature of the present invention is that the cooling device 3 can also serve as the molten metal injection hole 2 of the refractory container 1. The cooling device 3 may be installed at one end of the closed refractory container, but if the one end is opened and the device 3 for cooling the molten metal in contact with the open end face is provided, the structure is simple. In addition to facilitating the work at the time of the first pouring, the cooling device 3 also serves as the molten metal injection hole 2 of the refractory container 1, so that the temperature inside the refractory container excluding the surface on the cooling device side can be improved. The effect is that pouring can be performed while maintaining the distribution balance.

The fourth feature of the present invention resides in the above-mentioned first and second features.
Although it is effective in combination with the characteristics of, it can also be used in a device that simulates ESR and VAR, which are vertical solidifications. This is because the direction of the ingot is achieved by rotating the refractory container and the cooling device together with the heating zone so that the refractory container is perpendicular to the longitudinal direction, and surrounds the refractory container. In combination with heating from the tropics, cooling in the heating zone direction is regarded as ESR or VAR mold cooling, and cooling from the cooling device (located at the bottom) is simulated by cooling from the ESR or VAR surface plate. be able to.

A fifth feature of the present invention is to provide an apparatus capable of performing solidification simulation in a vacuum or an inert atmosphere. Although it is an indispensable device for research on the morphology control of molten metal and inclusions containing active metals (Ti, Al, etc.) that easily react with atmospheric gas, in the present invention, the coagulation simulator is aligned with the melting furnace to form a vacuum container. It can be implemented by installing it inside. The simplest method is to replace the casting apparatus with the solidification simulation apparatus of the present invention in the vacuum induction melting equipment that performs melting and casting in the same vacuum container.

The present invention will be described in detail below with reference to FIG. 9 showing the state of solidification in a mold which is one of the objects of the present invention, and the basic apparatus of the present invention with reference to the drawings (FIGS. 1, 2 and 3). Figure 1
2 and 3 are conceptual views of an apparatus showing an example of the present invention, and FIG.
Fig. 1 is a central vertical cross-sectional view from the center of the ingot to the outer surface of the mold, showing a conceptual diagram showing the solidification process of a mold casting ingot that uses a casting mold. In FIG. 9, the arrow C indicates the coagulation progressing direction, and the solid line indicated by G indicates the position of the coagulation front surface at each time. The arrow E indicates the thermal convection of the molten metal, and the double arrow F indicates the moving direction of heat.

In the solidification process of the mold casting ingot, especially the upper half of the ingot where the above-mentioned macroscopic segregation defects are likely to occur, the unsolidified molten metal is transferred to the mold surface side through the already solidified solidified shell. Solidification proceeds with heat transfer. At the same time, on the solidification front, complex phenomena such as solute concentration in the residual liquid phase, solute movement such as diffusion into the unsolidified liquid phase, temperature, and convection in the unsolidified liquid phase due to density difference are interrelated. Macroscopic and microscopic segregation occurs as a result of these phenomena.
The heat transfer during this period is an unsteady heat transfer process involving a phase change, and the cooling rate and temperature gradient of each part change from moment to moment.

Therefore, in order to simulate the solidification process in the case of a metal mold casting ingot, particularly a large ingot having a cross-sectional diameter of 500 mmφ or more, a refractory material conventionally used as shown in FIG. 8 is used. The heater that heats the container is controlled in only one zone, or the entire surface other than the cooling device surface is not heated.
It is not enough to cool the upper and lower surfaces of a refractory container by only lowering the temperature, so it is important to use a simulation device that can control cooling according to the cooling rate and temperature gradient of each part that occurs in actual die casting. Is. In the solidification process, the cooling rate R (° C / min) of each part, the temperature gradient G (° C / cm),
There is a relation of R = G × V 2 between the solidification rates V (cm / min), and the solidification process can be controlled if two elements of R, G and V can be controlled.

For example, in the refractory container 1 so that the temperature of the molten metal in contact with the five surfaces of the refractory container 1 excluding the cooling device surface shown in FIG. 1 coincides with the molten metal temperature at the position corresponding to the actual large mold. If the temperature at each of the predetermined positions can be controlled, heat transfer becomes preferential heat transfer to the cooling end surface. Further, by appropriately selecting the cooling capacity of the cooling device, it is possible to realize the heat transfer of the mold casting ingot to the mold. According to the device of the present invention, the surface of the cooling device that comes into contact with the molten metal is selected from materials having different thermal conductivities according to the actual cooling rate of the molten metal, and the amount of heat removed by adjusting the thickness thereof. Can be adjusted. On the other hand, this condition can be realized relatively easily by appropriately controlling the temperature distribution in the heating zone surrounding the outside of the refractory container in time. Specifically, the temperature at a predetermined position from the end surface of the cooling device to the back side of the refractory container was continuously measured by a temperature detector, and was adjusted in advance to the temperature change at the position to be simulated with a large ingot. It can be realized by automatically controlling the heater for each zone of the heating zone so as to match the set temperature.

This is as described in the embodiments described later.
For example, the cooling conditions are obtained in advance by the solidification calculation by the computer with respect to the elapsed time and the temperature change immediately after the casting at the specific height position of the ingot, at the D / 4 position, and at the center position of the ingot until the solidification is completed. deep. Next, the temperature and the time relationship are automatically controlled by the heaters in the heating zone consisting of a plurality of zones in the solidification simulation apparatus of the present invention.

Furthermore, by appropriately adjusting the temperature control in the refractory container, the temperature gradient of the molten metal can be intentionally adjusted, and the phenomenon associated with the nonuniform temperature distribution, such as the influence of the structure due to convection of the molten metal, can be simulated. can do. Moreover, it is possible to provide an effective means for examining the hot top method. Controlling the temperature distribution in the furnace is the easiest means to control the heater in multiple zones, but for example, using a heater and a gas cooling pipe for the cooling device, combine them appropriately, such as from the cooling device end face to the cooling device end face. 50 to 500 between the sides
It is also possible to give a temperature difference of about ° C and control it temporally. Further, the cooling device has a higher heat transfer capacity than the heat transfer capacity of the material forming the refractory container, and can be appropriately selected from materials that are not damaged by the molten metal, and steel plates, cast iron plates depending on the target cooling rate and temperature gradient. Besides, graphite, magnesia brick, and the like can be used.

The tolerance of the preheating of the refractory container before pouring the molten metal varies depending on the material and size of the container, but cooling from the refractory container at the initial stage of pouring the molten metal, especially the bottom surface, side surface and top surface of the refractory container Cooling from should be reduced as much as possible,
It is necessary to soak the liquidus temperature of the target alloy at -100 ° C or higher, preferably at the liquidus temperature of -50 ° C or higher. The material of the refractory container must have sufficient corrosion resistance and strength against the molten metal, and must withstand the long-term heating of the liquidus temperature of the target alloy −100 ° C. or more. It is desirable to be made of refractory such as magnesia. As for the thermal conductivity, a material having a relatively low thermal conductivity of 0.24 W / m ° K or less is desirable.

In order to more accurately simulate the formation behavior of oxides, sulfides, etc., melting, casting, and solidification of the molten metal should be performed in a vacuum free from the influence of external oxygen and nitrogen, or in an inert atmosphere. Is desirable. Further, in recent industrial production of alloys, methods such as vacuum melting vacuum casting and ladle refining are applied, and low oxygen content and high purification are measured. Also, for example, there are alloys in which vacuum melting is essential, such as super heat resistant alloys. In order to improve the solidification structure of these various alloys, it is preferable to melt, cast or solidify the steel or alloy in a vacuum free from the influence of external oxygen or nitrogen or in an inert atmosphere.

In order to simulate these, as shown in FIG. 3, for example, a melting furnace and a solidification simulation device are arranged in the same container, and the inside of the container can be vacuumed or an inert atmosphere. Can be used. Further, it is possible to simulate the solidification morphology of the mold casting ingot and the directional solidification morphology of electroslag remelting (ESR) and vacuum arc remelting (VAR). In this case, in the solidification simulation device of the present invention, the cooling device end of the solidification simulation device in vacuum is set to approximately 90 ° from the state of FIG. 1 to the state of FIG. 2 so as to be the solidification start point of the melting method that is actually performed. It can be rotated so that the cooling device is the bottom surface. In such a posture, the influence of gravity (convection of molten metal) can be taken into consideration.

[0027]

Embodiments will be described in detail below with reference to embodiments. 1, 2, and 3 are conceptual views of the essential parts showing an embodiment of the device of the present invention. Of these devices, the heating zone 4 is divided into four zones in the longitudinal direction, and the entire circumference of the refractory container 1 installed in the zone can be individually heated by the heater 7, which is an electric heating zone. Is. Of the heating zones divided into four zones, three zones near the cooling device 3 heat the outer peripheral surface of the refractory container 1, and the other one zone heats the surface on the opposite side of the cooling device 3. The heater used in this example was MoSi ₂ based in the air, and graphite was used in a vacuum or an inert gas atmosphere. However, it is necessary to limit the heater as long as it is a material that can withstand each atmosphere. There is no.

In addition to this, for example, high-frequency induction heating can be used as a heat source, but in this case, an electromagnetic force is generated, and an action of stirring the molten metal in the refractory container by externally applying an electromagnetic force to the molten metal is provided. Therefore, it is necessary to consider the shield. The heater output of each zone is 5 KW on the opposite side (the innermost part of the refractory container) when viewed from the cooling device side, and 25 KW for each of the other zones. The temperature of each zone was controlled by measuring the temperature with a temperature detector 5 installed near the heater and controlling the heater current with a program controller. As a method of holding the refractory container in the heater, both ends of the refractory container in the longitudinal direction were held by fitting the cooling device and the adiabatic refractory material held by the adiabatic refractory material of the heating zone.

In the solidification simulation device of the present invention, the surface of the cooling device, which is the solidification starting point, corresponds to the angle of the mold surface such as the shape of the upper part of the mold ingot, or electroslag remelting (ESR). ) And vacuum arc remelting (VA
(2) The refractory container 1 shown in FIG. 2 has a vertical longitudinal direction and the cooling device 3 serves as the bottom surface so that the solidified state by a water-cooled surface plate with a horizontal bottom surface such as R) can be faithfully simulated. It has a structure that enables Specifically, as shown in FIG. 1, a refractory container 1 having a horizontal longitudinal direction is shown in FIG. 2, and a cooling device 3 supported by a rotating shaft 9 and a rotating shaft support 13 is provided. It is a structure that can rotate about 90 ° together with the tropical zone 4 as shown in FIG. The fixing at the time of rotation was performed by a lock bolt attached to the shaft portion. The heating zone 4 covered the outer surface of the heater with a refractory heat insulating material 10 to prevent heat from flowing out of the heating zone. Further, a partition refractory heat insulating material 11 was installed between the respective heaters for the purpose of preventing interference of temperature control between the respective zones. The refractory heat insulating material, the heater, and the cooling device are fixed to a stainless steel furnace shell 12 to which a rotating shaft is attached. An induction melting furnace was used as the melting furnace for obtaining the molten metal.

Example 1 A box-shaped high alumina refractory container as shown in FIG. 1 was prepared, and one end face in the longitudinal direction was machined into a steel plate having a thickness of 50 mm. Cooling air of 500 Nl / min was passed through the cooling device. The refractory container was adjusted so that the longitudinal direction was horizontal. Next, the heating zone starts to heat up, and the furnace temperature is 1400 ° C.
Up to 12 hours and then held for 3 hours. on the other hand,
JI melted in a high frequency induction furnace at this time
90 kg of molten metal S SKD11 (1.5C-13Cr steel) was cast at a molten metal temperature of 1500 ° C through a molten metal injection hole.

In the molten metal and refractory container in the cooling process when the cooling conditions are set in advance by the solidification calculation by the computer for the representative positions a, b, c and d of each zone of the heating zone and the temperature of each zone is controlled. Fig. 4 shows the time change of the temperature of each part of the side surface (in the molten metal: solid line, refractory side surface temperature measurement position control: ▲). As shown in the figure, there was no side heat transfer, and a wide range of solidification conditions could be simulated, such as a molten metal cooling rate of 10 ° C./min or more and 0.5 ° C./min or less near the opposite side of the cooling device. As a result of investigating the central longitudinal section of the obtained solidification simulation ingot by S-printing and an optical microscope, it was found that the reverse V
Regarding the segregation, it was confirmed that the generation state can be reproduced as shown in FIG. 5 and the microstructure can also reproduce the structure in the mold casting ingot as shown in FIG.

(Example 2) The molten metal to be cast is JIS
An experiment was conducted under the same conditions as in Example 1 except that it was SUM5 (sulfur free-cutting steel). According to the experiment, the sulfide distribution and shape of the obtained ingot sufficiently reproduced that of the actual mold casting ingot. (Embodiment 3) As shown in FIG. 3, the melting furnace 14 and FIG.
The coagulation simulation device in the state shown in FIG.
The temperature inside the heating zone 4 was started after the pressure inside the container reached 1 Pa. On the other hand, a melt of Inconel 718 alloy (nickel-based super heat-resistant alloy) previously melted in a melting furnace 14 in vacuum was cast from a melt injection hole. This example is a simulation of vacuum arc remelting, and the procedure at the time of casting is to place a cooling device on the bottom surface and forcibly cool it to reproduce the rapidly cooled state near the water-cooled surface plate of the solid ingot. The zone heating was adjusted so that the time from the molten metal to the solidification was shortened from the bottom to the top of the refractory container heated to the temperature. According to the experiment, the solidified structure of the obtained ingot was a directional solidified structure similar to vacuum arc remelting (VAR).

[0033]

EFFECTS OF THE INVENTION According to the present invention, the structures corresponding to the respective parts inside the ingot, which had no means other than cutting and investigating the conventional ingot, were compared even in the case of a large ingot of 1000 mmφ or more. Reverse V can be simulated easily and accurately
It is also possible to reproduce macroscopic defects such as segregation and microstructure. Further, continuous temperature measurement at positions corresponding to various parts of the ingot can be easily performed. Furthermore, it is possible to more accurately simulate the formation behavior of oxides, sulfides, etc. in combination with atmosphere control, and it is also suitable for research on highly clean steel and free-cutting steel.

In addition, electroslag remelting (ES
R), vacuum arc remelting (VAR), and other vertical directional solidification morphologies can also be accurately simulated. Further, the coagulation simulation apparatus of the present invention is a multipurpose apparatus in that, if one apparatus is installed, a wide range of industrially used coagulation means can be simulated only by the rotation of the apparatus or the transfer apparatus to the vacuum container of the apparatus. However, it has a significant economic effect. As described above, a trial experiment using a solid ingot, which has conventionally required a great deal of cost, can be carried out easily and at a relatively low cost, and a microstructure and a macrostructure corresponding to each material, shape condition, and melt-casting condition. It is possible to easily perform multi-purpose studies such as optimization of oxide, sulfide morphology, etc., and its industrial effect is very high.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an apparatus used in first and second embodiments, in which A is a horizontal sectional view thereof and B is a vertical sectional view thereof.

2 is a view showing a state in which the refractory container shown in FIG. 1 is rotated by about 90 ° together with a cooling device and a heating zone, A is a vertical sectional view thereof, and B is a vertical sectional view seen from the other direction. is there.

FIG. 3 is a conceptual diagram of an apparatus used in a third embodiment.

FIG. 4 is a diagram showing an experimental example of Example 1, in which the solid line shows the time change of the temperature distribution of each part in the molten metal, and the ▲ shows the time change of the temperature at the representative position (FIG. 1A-I) of each zone. . Numbers in the figure represent the time after casting corresponding to the solid line, the vertical axis is the temperature,
The horizontal axis represents the distance mm from the cooling end of the solidification simulation ingot.

FIG. 5 is a diagram showing a result of sulfur-printing a central cross-sectional view of the solidification-simulating ingot obtained in the first example. The strips of sulfur in the center of the figure show inverse V segregation.

FIG. 6 is a view showing a microstructure photograph of a central longitudinal cross-sectional view of a solidification-simulating ingot obtained in the first example, which is shown in comparison with a microstructure at each cross-sectional position of a 10-ton solid ingot. It is a thing.

FIG. 7 is a schematic diagram showing a vertical cross-sectional structure of an upwardly spread killed ingot.

FIG. 8: 1 of coagulation simulation device which is a conventional method
It is a figure which shows two examples.

FIG. 9 is a schematic view showing the movement of heat and molten metal in the mold when a casting mold is used, the solid line of G indicates the position of the front surface of solidification at each time, and the arrow of J indicates the direction of solidification. The double arrow at F indicates the heat flow, and the single arrow at E indicates the direction in which the molten metal flows.

[Explanation of symbols]

1 refractory container, 2 molten metal injection hole, 3 cooling device, 4
Heating zone, 5 temperature detector, 6 molten metal, 7 heater,
9 rotation shaft, 10 refractory heat insulating material, 11 partition refractory heat insulating material, 12 stainless steel furnace shell, 13 rotation shaft support tool, 14 melting furnace, 15 container, 16 heat retaining agent, i, ro, ha, d container surface Temperature measurement point, hot metal flow, high heat flow, g solidification front position, g solidification progress direction

Claims (6)

[Claims] 1. A refractory container 1 for containing a molten metal for simulating solidification, a cooling device 3 for cooling the molten metal at one end of the refractory container, and the refractory container 1 other than the cooling device. It is characterized in that it comprises a heating zone 4 surrounded by, and has a function of controlling so that the heating zone has a predetermined temperature gradient toward the inner side of the refractory container 1 when viewed from the cooling device 3. Coagulation simulation device. 2. The heating zone 4 has a plurality of heating zones divided in the longitudinal direction, and the temperature detected by a temperature detector 5 installed at a predetermined position of the refractory container 1 and a preset temperature. The solidification simulation device according to claim 1, which has a function of controlling the temperature so as to have a predetermined temperature gradient toward the inner side of the refractory container 1 when viewed from the cooling device 3 in comparison with. 3. The solidification simulation apparatus according to claim 1, wherein the cooling device 3 also serves as the molten metal injection hole 2 of the refractory container 1. 4. A device comprising a refractory container 1, a cooling device 3, and a heating zone 4 is supported by a rotating shaft 9 and a rotating shaft support 13, and the longitudinal direction of the refractory container 1 is vertical. The coagulation simulation apparatus according to any one of claims 1 to 3, wherein the coagulation simulation apparatus is rotatable about 90 degrees so as to be horizontal. 5. The simulation apparatus according to any one of claims 1 to 4, wherein the container 1 is provided together with the melting furnace 14.
5 is a solidification simulation apparatus which is arranged in the container 5 and has a means for making the container 15 a vacuum or an inert atmosphere. 6. When performing a solidification simulation using the apparatus according to any one of claims 1 to 5, the refractory container 1 is heated by a heating zone 4 to obtain a liquidus temperature of the alloy of interest −100. A first step of soaking the temperature to a temperature of ℃ or more, a second step of injecting the molten metal 6 of the target alloy into a space surrounded by the soaked refractory container 1 and the cooling device 3, and refractory A solidification simulation method comprising a third step of cooling by controlling the temperature distribution in the heating zone such that the temperature at a predetermined position of the product container 1 has a time relationship with a preset temperature.