JPS6188947A - Continuous casting device - Google Patents

Abstract

PURPOSE:To prevent cracking and to improve ingot quality by supporting the ingot from the ingot outlet of a continuous casting device forming a mold space by the outside circumferential surface of a rotary casting mold wheel and a metallic belt moving in contact with said surface up to pinch rolls by roller groups thereby maintaining the constant track of the ingot. CONSTITUTION:This casting device maintains the specified track of the ingot 3 drawn out of the mold space between the casting mold wheel 1 and the belt 2 by providing the roller groups 10a, 10b which are paired on the top and bottom or on the top and bottom as well as the right and left and can straighten the movement of the ingot to some extent between the outlet of the ingot 3 and the pinch rolls 4. The approximately constant ingot locus is thus maintained and the ingot crack is prevented even with the ingot which contains Pb and Se as impurities and have high sensitivity to cracking or when the casting speed is changed or fluctuates or when the ingot is not smoothly detached from the mold as a result of the mold deformation.

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention is directed to the casting of molten metal into a sacrificial form. Regarding continuous casting equipment that is manufactured continuously, there is a method in which the trajectory of the ingot from the ingot outlet to the pinch roll is kept constant to prevent the occurrence of ingot cracks.

(Prior art) In general, a continuous casting device d is used to continuously produce rod-shaped ingots from molten metal, and C is, as shown in FIG. A mold space is formed by a metal belt (2) that comes into contact with a part of the outer peripheral surface of the mold width (1), and molten N is injected from one end of the space, and an ingot with at least the outer surface solidified from the other end. Pinch roll (3) (4)
By 3! l! Subsequently, the wire is drawn out, passed through a cutter (5) and a coarse mill J1 (not shown in the figure) to produce rough drawn wire.

[Problem that the invention seeks to solve]

However, when the #R production speed is changed or the ingot is not sharpened smoothly due to mold deformation, cracks tend to occur on the inside of the ingot locus. Such a phenomenon does not appear much in continuous casting of Tough Pip 1t → (11"C), and the distance is 11m and the distance is 4 (It was bad, but it is like PB and Se!K-1) Continuous casting of TPO, which contains a large amount of elements that increase susceptibility to cracking, tends to cause cracks, resulting in a high temperature difference, and improvements in this area are strongly desired.

[Means for solving problems]

In view of this, as a result of various inspections, the present invention has found that cracks that occur in ingots during continuous casting occur when unsteady stress is applied, such as fluctuations in the trajectory of the ingot during solidification of the molten metal and subsequent brittleness. As a result of further study, we developed a continuous casting device that prevents the occurrence of cracks in the ingot. In a continuous casting device, a mold space is formed by a moving metal belt, molten metal is injected from one end of the space, and an ingot with at least the outer surface solidified is continuously pulled out from the outer end by a pinch roll. The ingot is supported by a group of rollers up to the rolls to maintain a constant trajectory of the ingot.

That is, the TPC molten metal containing impurities of each type is cast in the restraint mold (7) shown in Fig. 4, and the cracks (9) that occur in the center of the ingot (8) at that time are compared to determine whether the TPC metal contains impurities. The cracking susceptibility during solidification was investigated. As a result, Figure 5 (a)
, (D), it was found that the cracking susceptibility increased as impurities such as PB and Se increased. There is a laser measuring device (6) at the exit of the ingot (3) of the conventional equipment shown in Figure 3.
The displacement of the locus of the ingot (3) was measured using a method, and the relationship with cracking of the ingot was investigated. As a result, as shown in Figure 6,
i1! Although it is not so bad for TPC (a), which contains soppm of PB as an impurity (b
) and (C) containing 2011011 Se, it was observed that the larger the displacement width of the ingot locus, the easier it was to crack.

Therefore, in the present invention, as shown in FIG. and pinch rolls (4), which are paired vertically or vertically and horizontally (the figure shows the vertical and horizontal cases), and are capable of correcting the movement of the ingot to some extent (10a), (10b).
) to keep the trajectory of the ingot (3) constant.

[For production]

In the apparatus of the present invention, the trajectory of the ingot pulled out from the mold space by the pinch rolls is maintained almost constant between the ingot outlet and the pinch rolls by a pair of upper and lower rolls or a pair of upper and lower and left and right rolls. Therefore, even if the ingot is highly susceptible to cracking and contains Pb or Se as impurities, the tiyA trajectory will remain almost constant even if the casting speed changes or fluctuates, or even if the ingot is not released smoothly due to mold deformation. is,
Ingot cracking can be effectively prevented.

(Actual example) Example 1 As shown in Fig. 1, a casting apparatus of the present invention (A
TPO is continuously cast using the casting apparatus (B) of the present invention in which a pair of upper and lower rolls are provided between the pinch rolls at the ingot outlet and the conventional casting apparatus (C) shown in FIG. The range of variation of the ingot at the outlet was measured using a laser measuring device, and the amount corresponding to the range of displacement was determined and is shown in Figure 2.

As can be seen from the figure, the device of the present invention (
It can be seen that the displacement range of the ingot in A) and (B) is considerably smaller than that in the conventional device (C).

Example 2 TP containing 1100 ppb of PB in the same manner as in Example 1
Continuous R casting of TPO containing O and 25 ppIl + Se,
This was finished into a rod-shaped material with a diameter of 2 om by hot rolling, and the rod-shaped material was inspected using an eddy current flaw detector.

The number of defects generated per unit time (minutes) during manufacturing was measured. The results are shown in Table 1.

Table 1 Note) S scratches: small cracks M scratches: medium cracks L scratches: large cracks As is clear from Table 1, the devices of the present invention (A) and CB) are superior to the conventional devices. Compared to (C), it can be seen that the number of defects is significantly reduced and the quality of the ingot is significantly improved.

〔Effect of the invention〕

As described above, according to the device of the present invention, P
In the continuous casting of TPO, etc., which contains a large amount of impurities such as b, Se, etc., it prevents the ingot from cracking, stably forms a rough drawing line, and has remarkable industrial effects such as kagukiru.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an example of the device of the present invention, Fig. 2 is a diagram showing the distribution of ingot displacement width of the device of the present invention and the conventional device, and Fig. 3 is a diagram showing an example of the device of the present invention.
Figure 3 is an explanatory diagram (q) showing an example of a conventional device, Figure 4 is an explanatory diagram showing the occurrence of cracks due to a restrained mold, and Figures 5 (a), l).
It's not! The relationship between the amount of material and the size of the person is difficult to understand (
A) shows the size of the crack when Pb is included as an impurity, (B) shows the size of cracking when SE is included as an impurity, and FIG. 2 is a drawing showing the relationship between the displacement of the locus of an ingot of TPC containing Se and ingot cracking. 1...Rotating mold width 2...Metal belt 3...
・Ingot 4...Pinch roll 5...Cutter 6...Laser measuring device 7...Restricted mold 8...Ingot 9...Crack
10a... Upper door U-Role 10b... Left and right [1-Rule Fig. 1 Fig. 2 Fig. 1 it A*'p= (mm) Fig. 4 Opening Fig. 5 (A) (B) Pb t (ppm ) Sex (pp
m) Friendship width of Zeni 1 Tadakoki

Claims (1)

[Claims] A mold space is formed by a rotating mold ring having a casting groove on the outer peripheral surface and a metal belt that comes into contact with a part of the outer peripheral surface of the mold ring,
In a continuous casting device in which molten metal is injected from one end of the space and an ingot with at least the outer surface solidified is continuously pulled out from the other end by pinch rolls, the ingot from the ingot outlet to the pinch rolls is supported by a group of rollers. A continuous casting device characterized in that the locus of the ingot is maintained constant.