JP3121721B2 - Method and apparatus for solidifying simulation of metal material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to grasp the surface state, solidification structure, crystal structure, precipitate behavior, scale formation behavior, etc. obtained after melting and solidifying steel materials such as ordinary steel and stainless steel. The present invention relates to a solidification simulation method and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, for the purpose of performing a tensile test under conditions close to the thermal history of an actual continuous casting or a hot rolling process subsequent to a continuous casting, a sample is once melted, and various heats are generated during a cooling process following solidification. A horizontal type tensile tester (Greble tester) that examines hot deformability by applying tensile deformation after giving a history
(The Iron and Steel Institute of Japan, “Journal of Continuous Casting Mechanics”, 8 ~
11, 1984, 10.).

Further, in order to know the surface temperature and the initial solidification structure of a continuous cast slab, a sample is melted by high-frequency induction heating as shown in FIG. An experimental method for casting a molten sample in one direction upward from the lower Cu surface and casting the molten sample in a quartz tube mold, and the results of the experiment are described in "Iron and Steel", 77th (1991) No. 10
No. 134-141. In this case, the temperature of the dissolved sample is determined by a two-color photometer, and the time change of the surface temperature of the solidified sample is determined by a silicon photodiode. The falling speed of the sample or the cooling condition is changed.

[0004]

However, in the case of the grease test, the initial solidification rate is about 20 ° C./sec as shown in FIG. 10 ³ ° C. / seconds about rapidly solidified material to the test material from the very poorly Kashiku and 10 ² ° C. /
It is difficult to stably control the solidification rate in seconds.

On the other hand, in the method shown in FIG. 4, the initial solidification rate can be controlled as fast as rapid solidification (10 ³ ° C./sec), but only the state of the sample at the time of solidification can be investigated, and the temperature and pressure after solidification can be reduced. Control cannot be performed. The present invention provides a means for solving such a problem. That is, in order to accurately grasp the precipitate behavior, solidification structure, crystal grain structure, precipitate formation behavior, scale formation behavior, and the like at the time of solidification, the present invention firstly solidifies the sample surface layer (a part 50 μm deep from the surface layer). The rate can be controlled as fast as rapid solidification (10 ³ ° C / sec), and after solidification, the solidified sample is further heated and quenched to reproduce desired temperature and cooling conditions, for example, the temperature and cooling conditions after solidification of twin roll cast slabs. To provide a simulation method and apparatus capable of performing the following.

Further, the present invention provides a simulation method capable of keeping a coagulated sample under pressure.

[0007]

According to the present invention, in order to achieve the above object, a thermocouple for measuring the temperature of a solidified sample is protruded and installed in a mold, and the thermocouple is cooled and solidified in the mold. The solidified sample is pushed up and placed in a heating and cooling apparatus, and the temperature of the solidified sample is controlled at a high temperature.

That is, the method and apparatus for solidifying a metal material according to the present invention have the following features. First, as a solidification simulation method for metal materials,
When grasping the solidification state of the metal material, a metal sample cut from the metal material is charged into a melting vessel, heated and melted by the heating device, and then placed in a mold vessel provided below the melting vessel. The molten sample is poured, and while measuring the temperature of the molten sample with a thermocouple protruding into the mold container from the lower bottom surface, when the molten sample solidifies and reaches a predetermined temperature, (1) the solidification While pushing the sample up from the mold container to the heating device installation position above it, and heating the solidified sample to the desired temperature, while adjusting the temperature,
Cooling, (2) the solidified sample is pushed up from the inside of the mold container to the position of the lowering device installed above the solidified sample, and the solidified sample is heated, cooled or cooled after applying a reduction to the solidified sample, or
(3) The solidified sample is pushed up from the inside of the mold container to the above-described heating device installation position, and the solidified sample is heated and cooled to a desired temperature. The method is characterized in that the sample is heated, cooled or cooled after applying a pressure to the sample.

In addition, as a solidification simulation device for a metal material, a mold container is disposed immediately below a heating device, and a melting container that is vertically movable within and above the heating device is disposed. And
(1) A solidification sample supporter having a temperature detection terminal and capable of supporting a solidification sample formed in a mold container and being movable up and down is mounted on the mold container. (2) In particular, (1)
A thermocouple protection tube having a thermocouple inserted therein, which vertically penetrates the bottom surface of the mold container and is movable up and down, is suitable as the coagulated sample support. (3) In these (1) and (2), it is preferable to provide an apparatus for lowering the solidified sample formed in the mold container above the mold container.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic partial cross-sectional view of the present invention, showing a state before a sample is dissolved. In the figure, a mold 2 is a holding table 2-
1, a heating device, for example, a high-frequency heating coil 1 is provided directly above the heating device 1, and a melting vessel 3, for example, a quartz crucible is provided so as to be vertically movable so that it can be disposed in the heating coil 1. 3-1 is a holder for the quartz crucible 3, and 5 is a sample. Reference numeral 6 denotes a gas tube for dropping a sample, the tip of which is open in the quartz crucible 3.

On the other hand, a thermocouple protection tube 8 on which a thermocouple 7 is mounted is penetrated at the bottom of the mold 2. The protection tube 8 is held by a thermocouple holder 9, and the holder 9 is moved up and down. Accordingly, the thermocouple 7 moves up and down between the mold 2 and the heating coil 1. The thermocouple 7 is connected to a control device 10, and the control device 10 is connected to the air cylinder 4. The air cylinder 4 includes a melting vessel holder 3-1 and a thermocouple holder 9.
The holders 3-1 and 9 are moved up and down via the control device 10 by the temperature obtained by the thermocouple 7.

The coagulating sample pressing device 11 is provided between the heating coil 1 and the mold 2, and the pressing bar 12 is moved from left and right toward the center by a hydraulic cylinder 13. The mold holder 2-1 is provided so as to be vertically movable, and when the dissolved sample 5-1 is injected into the mold 2, the holder 2-1 is raised to bring the mold 2 closer to the quartz crucible 3 as much as possible. You may do so.

FIG. 2 shows a state in which the temperature of the solidified sample is being controlled. Reference numeral 14 denotes a sample cooling medium tube, and reference numeral 15 denotes a sample cooling medium ejection hole. When the coagulated sample is large as shown in FIG. 3, a support 16 for maintaining the coagulated sample is inserted through the bottom of the mold separately from the thermocouple 7, and one end of the support 16 is attached to the thermocouple holder 9 to be connected to the thermocouple. It may be provided so that it can move up and down together.

Next, the test method of the present invention will be described.
In FIG. 1, a sample 5 cut out from a metal material to be measured
Is put in the quartz crucible 3, and the air cylinder 4 is operated to set the crucible 3 in the heating coil 1. Next, a high-frequency output is input to the heating coil 1 to completely melt the sample 5 by induction heating, and then a pressurized gas is supplied to the quartz crucible 3 from the sample dropping gas pipe 6 and the tip of the quartz crucible 3 The melted sample 5-1 is poured into the casting mold 2 through the provided holes and solidified. After pouring, the high-frequency input to the heating coil is shut off.

The mold 2 can be used for cooling the melted sample at a rate of 10 ³ ° C / sec or more by appropriately selecting the material, shape, temperature, etc., or for a normal cooling rate of about 10 to 10 ² ° C / sec. It has a structure that can change the cooling conditions so that it can cope with the case of solidification by the method. The cooling rate of the solidified sample can be changed by adjusting the current and voltage of the heating coil, or by appropriately selecting the amounts of He gas and cooling water supplied to the sample cooling medium tube 14 shown in FIG. Since the thermocouple 7 is previously provided at the bottom of the mold 2, the temperature of the dissolved sample 5-1 during solidification is measured.
The measured temperature is sent to the control device 10.

A temperature pattern is input to the control device 10 in advance. According to the temperature pattern, when the measured temperature reaches a target temperature, for example, a specific temperature after solidification, the thermocouple is sent from the control device 10 to the air cylinder 4. A command to raise the holder 9 and the quartz crucible 3 is issued, and the quartz cylinder 3 and the thermocouple protection tube 8 are raised by the operation of the air cylinder 4 as shown in FIG. The solidified sample 5-2 rises together with the thermocouple protection tube 8 in a state where the thermocouple is buried in the heating coil 1 after the quartz crucible 3 has retreated. At the same time, a sample cooling medium tube 14 is provided inside the heating coil 1.

Since the volume of the coagulated sample 5-2 is reduced by coagulation, the coagulated sample 5-2 is easily separated from the mold and rises. In such a state, the high-frequency output is re-input to the heating coil 1 to induction-heat the high-temperature coagulated sample 5-2 to adjust it to a target temperature pattern. Thereafter, an inert gas, for example, He gas or cooling water is pumped into the sample cooling medium pipe 14 and sprayed from the sample cooling medium ejection hole 15 onto the solidified sample 5-2 to perform temperature adjustment to the target temperature or rapid cooling. Alternatively, after the above-described coagulation or after heating or temperature adjustment to the target temperature, the coagulated sample 5-2 is lowered by the air cylinder 4 to the position of the reduction device 11 and reduced by the reduction bar 12 and naturally cooled, or the air cylinder 4 is cooled. Thus, the sample 5-2 is raised again to the position of the heating coil 1 and cooled while performing temperature control such as reheating. Further, the temperature control and the step of reducing are repeated.

As shown in FIG. 1, a required gas type can be supplied to the atmosphere gas at the time of dissolving the sample and adjusting the temperature through an atmosphere gas pipe 17 provided with an atmosphere gas solenoid valve 18. As described above, since the heat treatment can be performed while changing the heating and cooling conditions variously, it is possible to reproduce the initial solidification and obtain a desired rapidly solidified material. Furthermore mold material and shape, by controlling the temperature, solidification cooling rate of dissolution sample may reproduce the temperature pattern of the slab to be cast in existing continuous casting facilities 10 to 10 ³ ° C. / sec.

[0019]

EXAMPLE 4 g of a sample 5 cut from a hot-rolled steel sheet was put into a quartz crucible 3 and the sample was melted by high-frequency induction heating of a heating coil 1.
Was supplied from the sample dropping gas pipe 6 and the molten sample was poured into the mold 2. The mold 2 was set such that the cooling rate at a depth of 50 μm from the surface layer of the dissolved sample could be cooled at a cooling rate of 3000 ° C./sec. The temperature during solidification of the melted sample is measured by a thermocouple (R-0.2 mmφ) disposed in the mold, and the temperature is sequentially sent to the controller 10. When the target temperature reaches 1250 ° C., the air cylinder 4 is turned off. The solidified sample 5-2 was activated to move up into the heating coil 1.

Here, the atmosphere was switched from Ar to Air atmosphere by the atmosphere gas solenoid valve 18. Next, the solidified sample was heated to 1300 ° C.
After cooling from 0 ° C to 1200 ° C at 10 ° C / sec,
Subsequently, H was added to the solidified sample from the ejection hole of the sample cooling medium tube 14.
e gas was sprayed to cool to room temperature at a cooling rate of 70 ° C./sec. FIG. 5 shows cooling conditions set in this case and cooling curves obtained by experiments.

[0021]

[0022]

FIG. 6 shows the set values when the rolling was performed at a rolling reduction of 30%, the cooling curve and the rolling curve obtained by the apparatus of the present invention, and FIGS. 7 and 8 show the metal structures of the sample at a temperature of 1250 ° C. It was shown to. FIG. 9 shows the set values in the case of cooling to 500 ° C., reheating to 1050 ° C., and then cooling to room temperature, and the cooling curve and rolling curve obtained by the apparatus of the present invention after further reducing the rolling by 30%. Show. From the above, it became clear how accurately the simulation of the various factors of the rapidly solidified material when performed by the method of the present invention could be reproduced.

[0024]

As described in detail above, the present invention can accurately reproduce the simulation of the precipitation behavior and scale formation behavior during rapid solidification of a rapidly solidified material.
In particular, it is possible to properly grasp the surface quality, solidification structure and grain structure after heat treatment or rolling of a slab cast by a near net shape continuous method such as strip casting, thereby stably producing a high quality product. The industrial effect is extremely large because it can be manufactured.

Of course, if the cooling conditions of the mold of the present invention are changed to ordinary continuous casting conditions, a simulation of the quality-related behavior of such a slab after heat treatment can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view showing an example of the present invention before sample dissolution.

FIG. 2 is a schematic partial cross-sectional view showing a state after solidification of a sample in the embodiment of FIG. 1;

FIG. 3 is a schematic partial sectional view showing another embodiment of the present invention.

FIG. 4 is a schematic sectional view of a comparative example.

FIG. 5 is a diagram showing a set cooling curve and a cooling curve obtained by the apparatus of the present invention.

FIG. 6 is a diagram showing a set cooling curve, a cooling curve obtained by the apparatus of the present invention, and a rolling-down curve.

FIG. 7 shows the microscopic metallographic structure of the sample of the present invention, and (A)
Shows the metal structure when the rolling reduction is 0%, and (B) shows the metal structure when the rolling reduction is 30%.

FIG. 8 shows the cross-sectional metallographic structure of the sample of the present invention, wherein (A) shows the metallic structure when the rolling reduction is 0%, and (B) shows the metallic structure when the rolling reduction is 30%.

FIG. 9 is a diagram showing a set cooling curve, a cooling curve obtained by the apparatus of the present invention, and a rolling curve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heating coil 2 ... Mold 2-1 ... Mold holder 3 ... Melting container 3-1 ... Melting container holder 4 ... Air cylinder 5 ... Sample 5-1 ... Dissolved sample 5-2 ... Coagulated sample 6 ... Dropping sample Gas pipe 7 ... Thermocouple 8 ... Thermocouple protection tube 9 ... Thermocouple protection tool 10 ... Control device 11 ... Press-down device 12 ... Press-down bar 13 ... Hydraulic cylinder 14 ... Sample cooling medium tube 15 ... Sample cooling medium ejection hole 16 ... Solidification Sample support 17 ... Atmosphere control gas pipe 18 ... Atmosphere adjustment solenoid valve 19 ... Hydraulic generator

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mamoru Ikeda 6-2-22 Fujimi, Tsurugashima City, Saitama Prefecture Inside Fuji Radio Machinery Co., Ltd. (72) Inventor Hitoshi Iino 6-22-22 Fujimi, Tsurugashima City, Saitama Prefecture (56) References JP-A-2-275348 (JP, A) JP-A-5-96365 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 25/02-25/06

Claims (6)

(57) [Claims] When grasping the solidification state of a metal material, a metal sample cut out of the metal material is charged into a melting vessel, heated and melted by a heating device, and then provided below the melting vessel. Pouring the melted sample into the mold container, measuring the temperature of the melted sample by a thermocouple protruding into the mold container from the lower bottom surface, when the melted sample solidifies and reaches a predetermined temperature, A method for simulating solidification of a metal material, comprising: pushing up the solidified sample from the inside of a mold container to a position above the heating device, heating the solidified sample to a desired temperature, and then cooling while adjusting the temperature. 2. When grasping the solidification state of a metal material, a metal sample cut out of the metal material is charged into a melting vessel, heated and melted by a heating device, and then provided below the melting vessel. Pouring the melted sample into the mold container, measuring the temperature of the melted sample by a thermocouple protruding into the mold container from the lower bottom surface, when the melted sample solidifies and reaches a predetermined temperature, The solidified sample is pushed up from the inside of the mold container to the position of the rolling device above it,
A method for simulating solidification of a metal material, comprising heating, cooling or cooling after applying pressure to the solidified sample. 3. When grasping the solidification state of a metal material, a metal sample cut out of the metal material is charged into a melting vessel, heated and melted by a heating device, and then provided below the melting vessel. Pouring the melted sample into the mold container, measuring the temperature of the melted sample by a thermocouple protruding into the mold container from the lower bottom surface, when the melted sample solidifies and reaches a predetermined temperature, The solidified sample is pushed up from the inside of the mold container to the above-mentioned heating device installation position, and after heating and cooling the solidified sample to a desired temperature, the solidified sample is moved to the rolling device installation position, and the solidified sample is pressed down. A solidification simulation method of a metal material, wherein the method comprises heating, cooling or cooling after the addition of water. 4. A simulating apparatus for solidifying a metal material in which a mold container is disposed immediately below a heating device and a vertically movable dissolving container is disposed in and above the heating device, wherein a temperature detecting terminal is provided; A solidification simulation apparatus for a metal material, wherein a solidification sample supporter, which supports a solidification sample formed in a mold container and is vertically movable, is mounted on the mold container. 5. The metal according to claim 4, wherein the solidified sample support is a thermocouple protection tube having a thermocouple inserted therein, which penetrates a bottom surface of the mold container in a vertical direction and is vertically movable. Simulator for solidification of materials. 6. The apparatus for solidifying a metal material according to claim 4, wherein an apparatus for reducing a solidified sample formed in the mold container is provided above the mold container.