JPS60250856A - Mold for continuous casting - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to improvements in continuous casting molds.

(Prior art and its problems) Appropriately controlling the level of the molten metal in the mold is an extremely important issue in continuous casting. The level control of the molten metal inside the mold will be explained based on FIG. 4b.

In the figure, ti+ is a mold, and in the mold (1), the position of the fluctuation range of the molten metal level is, for example, 11YOs or @0aO.
A detector (3), such as a Ha mini scintillator, for detecting the amount of radiation transmitted is provided outside the mold (υ) on the other side opposite thereto. , based on the amount of radiation transmitted through the mold (1
) is detected, and the hot water level is controlled based on this detected value. By the way, on the back side of the copper plate (4) that constitutes the inner wall surface of the mold (1) on the side of the radiation source (2) and the detector (3), a groove (5) is provided to prevent the attenuation of the radiation from becoming large. Because the mold [
When the cooling water No. 11 is discharged upward from the lower slit (6) through the groove (5), the flow rate of the cooling water becomes 9. 6 m
/mxb- was not only drastically reduced to 1.58 m/sec, but also the temperature of the copper plate at the groove (5) became high, causing a problem that cracks were generated at the bottom of the groove (5).

To deal with this, in the past, the presence of cracks was checked using an ultrasonic flaw detector from the plated surface (7) of the copper plate (4) in combination with the periodic locking type (1). .

However, in Method 5, when a crank is detected, the operation must be stopped for a long time and the mold (1) must be replaced. In other words, the mold (11) was dismantled and the copper plate (4)
must be replaced, which will disrupt operations.

■Mold repair costs increase. ■ Problems such as reduced mold life remained, but the fundamental problem was not resolved.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a continuous casting mold that can prevent the occurrence of cracks in the concave grooves of a mold copper plate as much as possible. It is.

(Structure of the Invention) The present invention provides a continuous casting mold in which a radiation source and a radiation detector for detecting a metal surface level are disposed facing each other in the mold. The gist is that a flow rate adjustment member made of a material with low radiation attenuation is provided in the groove to prevent the flow rate from decreasing when the cooling water passes through the groove. This is a casting mold.

(Example) The present invention will be described below based on an example shown in FIG. Note that the same numbers as in FIG. 4 indicate the same or corresponding parts, and detailed explanations will be omitted.

In the drawing, (8) is a flow rate adjusting member attached to a groove (5) provided on the back side of a copper plate (4) constituting the inner wall surface of the mold (1), and the flow rate adjusting member (8) is, for example, A material such as plastic with low radiation attenuation and excellent wear resistance is used for the layer. The flow rate adjusting member (8) allows the cooling water flowing through the plurality of slits (6) provided at predetermined intervals in the vertical direction on the back surface of the copper plate (4) to flow into the groove (5). The shape is such that the flow velocity is reduced within the tube.

For example, as shown in Fig. 1, the total cross-sectional area of the slit (6) communicating with the groove (5) and the cross-sectional area of the portion where cooling water flows inside the groove (5) are approximately the same. A protrusion (9) is provided. At this time, the thickness of the protrusion (9) may be appropriately determined depending on the desired flow rate of the cooling water.

In this example, plastic is used as the flow rate adjusting member, but it is not limited to this, and other synthetic resins or natural rubber may be used as long as they have low radiation attenuation and excellent wear resistance. Of course, high tensile strength thin steel, alloy steel, etc. may also be used. In this case, for example, if steel is used, consideration must be given to making the box hollow to prevent radiation attenuation.

(Effects of the Invention) As described above, in the present invention, since the flow rate adjusting member is installed in the groove provided on the back surface of the inner wall of the mold, the speed of the cooling water flowing through the groove is not slowed down, which causes a temperature increase. It is possible to prevent the occurrence of cracks in the concave groove portion, and it is possible to solve the problems of conventional continuous casting molds.

Incidentally, the temperature of the concave groove in the mold of the present invention equipped with the flow rate adjusting member (made of plastic) having the shape shown in Fig. 1 was 59°C on the radiation source side and 93°C on the radiation detector side, compared to the conventional mold. (See Figure 2). Also, as is clear from Figure 3, by lowering the copper plate temperature,
Cracks can be suppressed.

[Brief explanation of drawings]

Fig. 1 is a drawing showing the configuration of the groove portion in the mold according to the present invention, (a) is a front view, (b) is a side view, and Figs. 2 and 3 show the effects of the mold according to the present invention. FIG. 2 is a diagram showing the temperature drop in the groove, FIG. 3 is a diagram showing the relationship between the mold temperature and the 0.2 inch proof stress of the copper plate, and FIG. 4 is an explanatory diagram of a conventional mold. (1) is the mold, (2) is the radiation source, (3) is the detector, (
4) is a copper plate, (5) is a groove, (6) is a sulin), +81
is a flow rate adjustment member. Patent applicant: Sumitomo Metal Industries, Ltd. (a) Figure 1 (b) Figure 2, continued from page 1 @ Inventor: Takazabe Amagasaki, Yukinai, Wakayama

Claims (1)

[Claims] (Engineering), a continuous casting mold in which a radiation source and a radiation detector for detecting the level of the molten metal are placed facing each other in the mold, and a recess provided on the back surface of the inner wall of the mold on the side of the radiation source and radiation detector. For continuous casting, characterized in that a flow rate adjustment member made of a material with low radiation attenuation is provided in the groove to prevent the flow rate from decreasing when cooling water passes through the groove. template.