JPH06328203A - Continuous casting method and mold for continuous casting - Google Patents

Abstract

PURPOSE:To make possible the solidifying casting below stable molten metal surface by giving heating temp. in the upper half part direction of a mold with a heating body arranged at the back side of ceramic chips and continuously casting while keeping the vicinity molten surface to molten state. CONSTITUTION:The mold 1 is constituted with a copper 2 and the ceramic chips 3 as the main constituting member, and an Ni part 19 improving wear resistance and the heating body 4 arranged at the back side of the ceramic chips 3. Further, the cooling water passage 9 is arranged. By using this mold 1 for continuous casting, the necessary heating temp. is given in the width direction of the upper half part in the mold 1 with the heating body 4, the continuous casting is executed while keeping the molten metal 17 near the molten metal surface 18 to the molten state. Then, a temp. sensor 10 is arranged, and by inputting this temp. signal, the temp. of the ceramic chip 3 is controlled so as to become the necessary temp. by using a control circuit. By this method, the generating frequency of breakout can remarkably be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting method for continuously casting molten metal such as molten steel by under-solidifying and a mold therefor.

[0002]

2. Description of the Related Art Conventionally, continuous casting molds have been manufactured from thick copper plates for a long time, but in recent years, a mold which enables powderless casting by stretching ceramic chips on a copper plate has been disclosed in Japanese Patent Laid-Open No. 4-59153. It is known from the publication. A mold in which the thickness of the ceramic chip is changed according to the width and length of the mold is disclosed in JP-A-4-138844, and a mold in which a heating element is provided in the ceramics on the upper part of the mold is disclosed in JP-A-4-162.
It is known from Japanese Patent No. 941. As a result, it has become possible to heat the meniscus portion with the heating element, change the ceramic thickness in the width direction, and perform casting by solidification below the molten metal surface.

[0003]

However, in order to perform stable casting with under-solidification of molten metal, solidified shells of molten steel must never be formed at the molten metal surface portion where ceramics come into contact with molten steel. In addition, long-time solidification
The uniformity of the solidification shell thickness on each side of the short sides is particularly important, but the temperature distribution at the solidification initiation site is not uniform. The reason for this is that the molten steel flow at the long and short sides in the mold and at the ends and the center in the same plane differ due to the influence of the molten steel discharge flow from the immersion nozzle. As a result, a temperature difference within the mold will occur. At this time, if solidified nuclei are generated even in a partially unsolidified region, the nuclei also grow in the direction of the molten metal surface (the solidified growth in this way is called a metal bear), which causes casting failure. Become.

In the conventional casting method and mold, the material of ceramics was partially changed, the thickness thereof was changed, and a heating device was provided. It was not possible to apply heat as a measure to the site. That is, even if the solidification of the molten steel becomes uneven, it cannot be eliminated.

The problem to be solved by the present invention is to solve these problems in the prior art and to prevent the solidification shell from being generated at the ceramic part which is the molten metal surface, thereby causing the partial solidification non-uniformity of the molten metal. The object of the present invention is to provide a continuous casting method and a continuous casting mold for that purpose.

[0006]

Means for Solving the Problems The gist of the present invention, which has solved the above problems, is as follows: 1) A continuous casting mold in which a ceramic chip is stretched over the upper half of the mold and a heating element is arranged behind the ceramic chip. Continuous casting method characterized in that a required heating temperature is applied to the upper half width direction of the mold by the heating body to maintain the molten metal near the molten metal surface in a molten state, and the continuous casting method 2) Continuation characterized in that a ceramic chip is stretched in the upper half part, a heating body for heating the ceramic chip is provided behind the ceramic chip, and the heating temperature of the heating body can be adjusted in the width direction of the mold. Casting mold 3) Continuous casting mold according to the above 2), wherein a plurality of divided electric heaters in the width direction are provided behind the ceramic chip stretched to adjust the temperature at any position. ) A temperature sensor is provided on a mold copper plate or a ceramic chip, and a control circuit for controlling the temperature of the ceramic chip to a required temperature by inputting a temperature signal of the temperature sensor is provided. It is in a continuous casting mold.

[0007]

According to the present invention, the heating element is provided behind the ceramic chip and the heating temperature of the heating element can be adjusted in the width direction of the mold, so that a uniform temperature distribution can be obtained even if the temperature distribution is uneven. As a result, the ceramics can be locally heated on all four surfaces of the mold, and the molten state of the molten metal surface can be maintained. The mold has a cooling structure, but in the width direction of the mold, generally, the left and right sides of the width of the mold are cooled better than the central part, and a low temperature state occurs, causing uneven solidification of molten steel. Often. In this case, in the present invention, the temperature difference between the central portion and the side portion is sensed by a temperature sensor or the like installed in the ceramics, and the temperature is controlled so that the temperature of the heating body on the side portion, which is strongly cooled, rises. The heat retention state of can be maintained. In the opposite case, the temperature of the portion other than the side portion may decrease, but in that case, the temperature control can be performed in the same manner. Further, it becomes easy to make the four surfaces of the mold have a uniform temperature distribution and to adjust the heating temperature for each surface. In this way, it is possible to suppress the generation of a metal bear which is caused by non-uniform solidification, the solidification start position is uniform over the four surfaces of the mold in the entire circumferential direction, and stable under-solidification solidification casting can be performed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment shown in FIGS. 1 and 2 is an example showing a mold in which ceramic chips are divided and stretched on the upper half of the inner surface of the mold.
The ceramic chip was divided into 5 parts in the width direction, and the heating element of the electric heater was attached to the back surface of each ceramic chip, and the temperature sensor and the control circuit were used to heat the heating element on the left and right sides of the mold to a higher temperature. Here is an example. Figure 1
2 is a longitudinal sectional view of the mold of the embodiment, and FIG. 2 is a wiring explanatory view showing the arrangement of heating bodies and the heating temperature of the embodiment.

In the figure, 1 is a mold, 2 is a copper plate which is a main component of the mold 1, 3 is a ceramic chip, 4, 5, 6,
7 and 8 are heating elements which are electric heaters, 9 is a cooling water channel, 1
Reference numerals 0, 11, 12, 13, and 14 are temperature sensors using thermocouples, 15 is a control circuit, 16 is a solidified shell, 17 is molten steel, 18 is a molten metal surface, and 19 is a Ni portion for enhancing wear resistance.

In this embodiment, ceramic chips 3 are stretched in multiple stages on the upper part of a mold 1, and a heating element 4 using an electric heater is provided in the uppermost ceramic chip 3.
Five, six, seven, and eight are installed by dividing them into five in the width direction.
In addition, a temperature sensor 10,1 using a thermocouple behind it
1, 12, 13, 14 are provided. Each temperature sensor 1
0, 11, 12, 13, 14 measure the temperature of each ceramic chip 3 and input it to the control circuit 15, heating element 4 to 800 ° C, heating element 5 to 750 ° C, heating element 6 to 700 ° C. The heating element 7 to 750 ° C and the heating element 8 to 800
It is controlled using well-known electric circuit means so as to be heated to ° C. As a result, the left and right side portions of the mold 1 that are cooled more strongly by the cooling water passage 9 are heated more strongly, and it is possible to prevent partial solidification and seizure of molten steel. In the above-mentioned embodiment, the sensor is attached inside the ceramic, but the sensor may be attached to the copper plate portion in contact with the ceramic.

[0011]

As described above, according to the present invention, the temperature of the inner surface of the mold can be made uniform by adjusting the heating element to an appropriate heating temperature, and the solidified shell is not generated at the ceramic portion. As a result, it is possible to prevent partial solidification and seizure of molten steel, maintain the molten state of the molten metal surface, and achieve stable solidified casting below the molten metal surface. Further, the solidification temperature below the surface of the molten metal can be made constant, and securing a uniform shell thickness can greatly reduce the frequency of breakouts.

[Brief description of drawings]

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

FIG. 2 is a wiring explanatory diagram showing an arrangement of heating elements and an example of heating temperature of the heating elements according to the embodiment.

[Explanation of symbols]

 1 Mold 2 Copper Plate 3 Ceramic Chip 4 Heating Body 5 Heating Body 6 Heating Body 7 Heating Body 8 Heating Body 9 Cooling Channel 10 Temperature Sensor 11 Temperature Sensor 12 Temperature Sensor 13 Temperature Sensor 14 Temperature Sensor 15 Control Circuit 16 Shell 17 Molten Steel 18 Hot Water Surface 19 Ni part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tomoji Shimogasa, Inventor, 1-1 Tobata-cho, Tobata-ku, Kitakyushu, Fukuoka Prefecture Inside Nippon Steel Co., Ltd. Yawata Works (72) Inuma, Kazuma Inaoka Tobata, Tobata-ku, Kitakyushu, Fukuoka 1 in town 1 Nippon Steel Co., Ltd. Yawata Works (72) Inventor Kazumi Daitoku 1 in 1 Hibatacho, Tobata-ku, Kitakyushu, Kitakyushu, Fukuoka 1 Inside Nippon Steel Co., Ltd. Yawata Works (72) Inventor Fujiya Nogami 1-1 Hibata-machi, Tobata-ku, Kitakyushu, Fukuoka Prefecture (72) Inventor, Yawata Works (72) Sakae Teraoka 5-5, Shinsone, Kosane-Minami-ku, Kitakyushu, Fukuoka Company Machining Division (72) Inventor Kazuhiko Fukuhara 5-1 Shinsone, Kokuranan-ku, Kitakyushu, Fukuoka Mishima Kosan Co., Ltd. Mechanics Division (72) Inventor Sumihiko Kurita Nishi-Matsuura-gun, Saga Prefecture Town 1664 address Corporation Koransha research and development portion (72) inventor Masumi Nakajima Co., Ltd., Saga Prefecture Nishimatsuura District Arita address 1664 Koransha research and development portion

Claims (4)

[Claims] 1. A continuous casting mold in which a ceramic chip is stretched over the upper half of the mold and a heating body is arranged behind the ceramic chip, and the heating body is used to obtain a desired width in the upper half of the mold. A continuous casting method characterized by continuously casting while applying a heating temperature to maintain a molten metal near a molten metal surface in a molten state. 2. A ceramic chip is stretched on the upper half of the mold, a heating body for heating the ceramic chip is provided behind the ceramic chip, and the heating temperature of the heating body can be adjusted in the width direction of the mold. A mold for continuous casting, characterized in that 3. The continuous casting mold according to claim 2, wherein an electric heating body divided into a plurality in the width direction is provided behind the ceramic chip stretched so that the temperature can be adjusted at any position. 4. A mold copper plate or a ceramic chip is provided with a temperature sensor, and a control circuit for controlling the temperature of the ceramic chip to a required temperature by inputting a temperature signal of the temperature sensor is provided. Or a continuous casting mold as described above.