JPS581729B2 - Method for estimating internal temperature of hot steel ingot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the internal temperature of hot steel ingots, etc. heated in a soaking furnace or heating furnace, and the This invention relates to a method for easily and quickly estimating the internal temperature of a hot steel ingot.

The above-mentioned estimation of the internal temperature of a hot steel ingot (or billet) is an extremely important work factor in predicting the baking of the steel ingot in the rolling blooming operation and in other rolling operations.

The present invention will be described below regarding estimation of the internal temperature of a hot steel ingot.

Conventionally, the estimation of the internal temperature of a hot steel ingot after heating is calculated based on the thermal conductivity of the steel ingot material, the heating temperature and time in a soaking furnace, the cooling time after mold removal, etc. things are being done.

Therefore, the method of measuring the steel ingot from the outside is only a mere estimation and prediction, and cannot be said to be the actual internal temperature of the hot steel ingot.It actually causes a considerable error, and the measurement of the internal temperature is virtually impossible. It was close to possible.

Of course, various thermometers have been developed, and since the surface temperature of a heated steel ingot can be easily measured, methods have been implemented to use the surface temperature as a substitute, or to estimate the internal temperature from the surface measurement temperature. However, none of these methods are accurate, and it is practically difficult to accurately estimate the internal temperature using a non-destructive method, so it has been considered impossible.

The method of the present invention was made to solve the above problems, and its characteristics are that an internal temperature measurement hole is drilled in advance in an experimental steel ingot from the outer surface to the inner center; A steel ingot is heated in a soaking furnace to form a hot steel ingot, and this heated steel ingot is carried out of the furnace and an internal temperature measuring device is inserted into the measurement hole to measure and record the internal temperature, and at the same time the hook tip is Grip the central part of the outer surface of the hot steel ingot with a hook equipped with a temperature sensor, wait for the temperature sensor to raise the temperature of that part, record the temperature increase change value from a constant temperature, and A temperature change diagram of the correlation between several kinds of internally measured temperatures of the ingot and the temperature increase change values from the constant temperature of the hook gripping part is created, and from this diagram, from now on, the practical thermal steel ingot will be calculated. A method for estimating the internal temperature of a hot steel ingot by gripping the hot steel ingot with the hook without measuring the internal temperature and correlating the measurement results of the temperature change value from a constant temperature with the diagram. Accordingly, embodiments of the method of the present invention will be described in detail below.

That is, in carrying out the method of the present invention, a steel ingot 1 for destabilization as shown in FIG. 1 is first used.

An internal temperature measurement hole 2 is drilled from the center of the outer surface of this test steel ingot 1 to the center of the inside.

Next, this steel ingot 1 is charged into a soaking furnace, heated to a required degree, and then transported out of the furnace as a heated steel ingot.

An internal temperature measuring device 3 such as a thermocouple is inserted into the internal temperature measurement hole 2 of the hot steel ingot 1 taken out of the furnace to measure and record the internal center temperature of the steel ingot.

On the other hand, the change in the external surface temperature of the hot steel ingot 1 is measured.

For this measurement, a hook 4 for grasping the hot steel ingot as shown in Fig. 2 A and B is used.

As shown in the figure, this hook 4 has a temperature detector 5 integrally attached to the tip thereof, so that the temperature of the object held at the tip of the hook and its changes can be detected.

Using this hook 4, the central part of the outer surface of the hot steel ingot 1 to be carried out of the furnace is gripped as shown in FIG. 2A.

In such a case, the temperature detector 5 provided at the tip of the hook detects the temperature from the center of the outer surface of the gripped hot steel ingot 1.

Therefore, by gripping the hook, the tip of the hook immediately begins to heat up due to the heat transfer action from the hot steel ingot 1, and the temperature sensor 5 indicates the temperature increase change.

Therefore, the temperature at which the tip of the hook is raised is, for example, 150°C at the beginning, 4°C.
lO from the time it reaches a certain temperature such as 00℃
The temperature increase value within seconds is read by the temperature detector 5 and recorded.

The above method was carried out several times using the test steel ingot 1, and the internal center temperature of each and the change in temperature over time from a constant temperature by the temperature detector 5 at the tip of the hook when the hook 4 was held in place were recorded. Then, for each test, the heating conditions (temperature, time, etc.) of the test steel ingot 1 in the soaking furnace are changed so that, for example, the internal temperature is 900°C or 80°C.
0°C, 700°C, and the above-mentioned constant temperature for measuring the temperature rise at the tip of the hook, for example, from 150°C, 400°C, for a predetermined time from that constant temperature ( Each temperature increase (within 10 seconds) is read and recorded separately.

Therefore, several types of test data can be obtained.

A diagram is obtained in which the temperature rise change values over time from a certain temperature when gripped with the tip of the hook 4 corresponding to the internally measured temperature of the hot steel ingot 1 for testing obtained by the above method are connected by one curve. It will be done.

This is the diagram shown in FIG.

This diagram shows that, for example, when the internal temperature of the heated steel ingot is 900°C, the temperature of the gripping part at the tip of the hook is about 1% from 400°C.
The temperature increase change in 0 seconds is shown by the curve at the top of the diagram.

Further, when the internal temperature is 700°C, the value of temperature increase from a constant temperature of 150°C is shown by the lowest curve in the diagram.

Therefore, the diagram in Figure 3 shows the correlation of the temperature increase over time from a constant temperature at the tip of the hook corresponding to several kinds of internal temperatures of the hot steel ingot 1 that were actually measured, as shown in the diagram. It will be.

Therefore, the diagram shown in FIG. 3 is the actual measured value, and from then on, without measuring the internal temperature of the hot steel ingot for practical use, the central part of the surface of the hot steel ingot 1 is placed on the hook with the temperature detector 5. 4 and read the temperature change value from the constant temperature of the hook tip indicated by the detector 5, the temperature change value is compared with that of a specific line diagram, and its value is determined. By finding something that matches the curve,
The desired internal center temperature of the hot steel ingot can be easily derived and estimated based on the diagram in an extremely short time of 10 seconds.

In this way, the method of the present invention involves drilling an internal temperature measurement hole in a test steel ingot in advance, placing it in a soaking furnace to create a heated steel ingot, and carrying it out of the furnace to perform the measurement. An internal temperature measuring device is inserted into the hole to measure the internal temperature, and at the same time, the steel ingot is held in place by a hook with a temperature sensor integrated at the tip of the hook, and a certain temperature at the tip of the hook is measured. By reading and recording the temperature change value of the heated steel ingot, it is possible to determine the temperature change value of the hook tip that corresponds to the internal temperature of the heated steel ingot. After the diagram has been created, without measuring the internal temperature of the hot steel ingot, grip the center of the outer surface of the hot steel ingot with a hook equipped with the aforementioned temperature sensor at the tip of the hook.
By measuring the short-time temperature rise temperature change value from a constant temperature with the temperature detector, comparing it with the above-mentioned diagram, and finding a specific temperature rise curve that matches it, the temperature rise can be achieved within a short time of 10 seconds. The internal temperature of the hot steel ingot connecting the temperature curves can be easily and immediately estimated, and the estimated internal temperature is extremely accurate and close to the actual measured value.

Therefore, according to the present invention, the actual internal temperature of a hot steel ingot and several kinds of temperature change values from a constant temperature at the tip of a hook gripping it are measured in advance using a test steel ingot. Since it is based on a diagram created based on the actual measured values, the internal temperature of the hot steel ingot that is closest to the actual measured value and has a small error is shown in the diagram based on the temperature rise change when gripped with the hook. It exhibits excellent effects that can be estimated easily and within a short period of time.

As a result, it is possible to estimate the internal temperature of the steel ingot before charging it into the soaking furnace in the blooming process, which eliminates filtration and soaking in the soaking furnace and under-baking, thereby achieving the desired baking of the steel ingot. In addition, effective information in the hot rolling process can be obtained by estimating the internal temperature of the hot steel ingot, improving rolling accuracy.
The benefits of improving quality, streamlining Kawanobe work, saving fuel, and making effective use of furnaces are truly significant.

[Brief explanation of drawings]

The drawings are for explaining the embodiment of the method of the present invention. Fig. 1 is a perspective view showing a test steel ingot and the method for measuring its internal temperature, and Fig. 2 A shows a hot steel ingot being gripped with a hook equipped with a temperature sensor. FIG. 3 is a diagram showing the correlation between the temperature increase from a constant temperature at the tip of the hook and several kinds of internally measured temperatures. 1 is an experimental steel ingot, 2 is an internal temperature measuring hole, 3 is an internal temperature measuring device, 4 is a hook, and 5 is a temperature detector.

Claims (1)

[Claims] 1 An internal temperature measurement hole is drilled in advance in the experimental steel ingot from the outer surface to the center of the inside, the steel ingot is heated in a soaking furnace to form a hot steel ingot, and this heated steel ingot is carried out of the furnace. Insert an internal temperature measuring device into the measurement hole to measure and record the internal temperature, and at the same time grasp the central part of the outer surface of the hot steel ingot with a hook provided with a temperature detector at the tip of the hook to measure and record the internal temperature. Wait for the temperature of the part to rise, record the temperature rise change value from the constant temperature, and correlate with the temperature rise change value from the constant temperature of the hook gripping part corresponding to several types of internally measured temperatures of the hot steel ingot. Create a temperature change diagram for each section, and use this diagram to grasp the hot steel ingot with the hook without measuring the internal temperature of the practical hot steel ingot and calculate the temperature increase from the constant temperature. A method for estimating the internal temperature of a hot steel ingot, characterized in that the internal temperature of the hot steel ingot is specified by associating the measurement results with the above-mentioned diagram.