JPS6330150A - Continuous casting method for metallic pipe - Google Patents

Abstract

PURPOSE:To obtain a cast pipe having good the inner and outer surface conditions by executing drawing of the cast pipe as shaking a mold toward drawing direction of the cast pipe. CONSTITUTION:The mold 3 is arranged as inserting into a guide, which guides vertically the mold 3, and is supported to a crank shaft mechanism 6 at the upper part thereof. While shaking the mold 3 by the crank shaft mechanism 6, the cast pipe 4 is drawn by pinch rollers 5 at the constant velocity without stopping. Then, the moving condition and stopping condition at relative relation between the mold 3 and the cast pipe 4 are repeated alternately. In this way, as the molten metal 7 in the mold 3 is stirred and the pipe thickness having homogeneous structure and little thickness is obtd.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a continuous casting method for metal tubes.

Conventional technology In conventional pull-type continuous casting, a water-cooled copper mold with good heat transfer coefficient is used as the casting mold, and the metal tube is cast by intermittently pulling out the cast tube with pinch rollers.

Problems to be Solved by the Invention According to the above-mentioned conventional configuration, in order to obtain a good internal and external surface condition, it is necessary to repeat the movement and stop with high precision at a synchronization rate of about 10Hz. The time the shell remains in the mold must be controlled to about 5 seconds oD. However, it is difficult to stop and stop the pinch rollers with an accuracy of about OD 5 seconds, and when the casting tube is stopped, vibrations occur in the casting tube, causing breakouts in the solidified shell. .

The present invention solves the above-mentioned problems, and aims to provide a continuous casting method for metal pipes, which manufactures cast pipes with good internal and external surface conditions while continuously drawing out the cast pipes.

Means for Solving the Problems In order to solve the above-mentioned problems, the invention is such that the casting tube is drawn out while the mold is oscillated in the drawing direction of the casting tube.

Function In the above configuration, while the solidified shell continuously moves in the direction in which the casting tube is pulled out, by moving the mold in the same direction as the casting tube, there is a relative gap between the mold and the solidified shell. VC between the mold and the solidified shell may be caused by stopped blindness or by moving the mold in the opposite direction to the solidified shell.
@A situation arises.

Therefore, by controlling the swinging of the mold, it is possible to create the required stagnation and dynamic lip between the solidified shell and the mold.

EXAMPLE Hereinafter, an example of the present invention will be described based on the drawings. In Figure 1, the inner recess of the water cooling jacket (1) is covered with refractory material (
The mold (3) covered by the mold (2) is provided so as to be swingable in the drawing direction of the casting tube (4).

Pinch rollers (5) for pulling out the cast tube (4) are arranged above the mold (3). As shown in Fig. 2, the mold (3) is arranged so as to fit into a guide (5) that guides the mold (3) in the vertical direction, and the crankshaft mechanism (6) is disposed in the upper part of the mold (3). ) is supported.

In the above configuration, while the mold (3) is oscillated by the crankshaft mechanism (6), the casting tube (4) is pulled out at a constant speed by the pinch roller (5) without stopping.

At this time, a dynamic state and a stationary state are repeated between the mold (3) and the casting tube (4) in their relative relationship. This state is shown in Figure 3 between the mold speed Vm and the drawing speed (casting speed IVa).
Shown in relation to. In FIG. 3, the regions TN and T where Vm>Va completely indicate the state in which the casting tube (4) is pushed down relative to the mold (3) while the mold (3) is moving upward. However, if Vm'yVa, it can be effectively regarded as the time during which the casting tube (4) is stopped relative to the mold (3). And the oscillation synchronization T of the mold (3). When the proportion of TNsA in the NST rate is expressed as α, α=T
The mold (
By selecting the oscillation amplitude and oscillation frequency in 3), it is possible to create the desired static lip and dynamic deafness. Then, due to the swinging of the mold (3), the molten metal (7) inside the mold (3)
is stirred, resulting in a homogeneous structure and uniform tube wall thickness with little unevenness. Furthermore, the height of the inner surface knots is also reduced, and a favorable inner surface condition can be obtained. Incidentally, Fig. 4 shows the influence of the same wave number of oscillation on the unevenness of the wall thickness of a cast pipe and the height of the inner joint. As is clear from Fig. 4, the oscillation @ the same wave number is 15 to 4.
At Hz, irregularities in tube thickness and inner node height are also small.

Effects of the Invention As described above, according to the present invention, by swinging the mold in the drawing direction of the casting pipe, static and dynamic states are created in the relative relationship between the mold and the casting pipe,
It is possible to cast a cast pipe with good internal and external surface conditions.

[Brief explanation of the drawing]

Fig. 1 is an overall groove diagram showing one embodiment of the present invention, Fig. 2 is a side view of the main part of Fig. 1, Fig. 3 is a diagram showing the relationship between mold speed and drawing speed 2, and Fig. 4 is a diagram showing the relationship between mold speed and drawing speed. FIG. 3 is a diagram showing the influence of the dynamic wave number on the unevenness of the wall thickness of a cast pipe and the height of the inner node. (3)...mold, (4)...casting pipe, (5)...
Pinch roller, (6)... Crankshaft mechanism representative Yoshihiro Morimoto Fig. 4-, 4i sound s, - Pinch roller Fig. 2 b-
) Run 2 Shi Y, Futo Machine Punishment (Inner Section Tomb N)

Claims (1)

[Claims] 1. A method for continuous casting of metal tubes, characterized in that the casting tube is pulled out while swinging the mold in the drawing direction of the casting tube.