JPH02220743A - Metal strip continuous casting device - Google Patents

Abstract

PURPOSE:To prevent the variation of running speed and meandering of endless belts and to stably execute a continuous casting operation by providing the ruggedness for preventing slipping on the back face of the endless belts and the surface of lower rolls for running the endless belts in an endless twin belt type continuous casting machine. CONSTITUTION:The endless belt 1 is shifted in a direction 8 with the upper and lower rolls 2, 3 and tension roll 9, and similarly, the endless belt 1' is shifted in a direction 8' with the upper and lower rolls 2', 3' and tension roll 9'. Molten steel 10 is poured into the pouring basin part formed with the upper and lower rolls at both sides and short side walls 4, 4' provided on the roll end parts and the continuously cast strip 7 is drawn out from a gap between the endless belts formed with the lower rolls 3, 3' narrowing the gap. In this case, the rugged part is formed on the surfaces of the lower rolls 3, 3' and the back faces of the endless belts 1, 1', and by sufficiently engaging the belt and the lower roll, the meandering and the variation of running speed of the endless belt are prevented and the continuously cast strip 7 having uniform thickness can be obtd. under a stable operation.

Description

[Detailed description of the invention] [Industrial application field] The present invention continuously produces metal ribbon directly from molten metal.

This invention relates to continuous metal ribbon casting equipment.

[Prior Art] It is preferable that a metal ribbon can be directly produced from molten metal because the rolling process can be greatly simplified.

FIG. 7 is a diagram showing an example of a belt type continuous casting machine. 7th
In Figure (C), a metal belt 1 is stretched between an upper roll 2 and a lower roll 3 at an angle and runs in the direction of an arrow 8. Similarly, the metal belt 1' is stretched between the upper roll 2' and the lower roll 3' and runs in the direction of the arrow 8'. 4.4' is the short side wall. The molten metal passes through the nozzle 5 to 1.1' and 4,
It is injected into a wide mold formed by 4', solidifies on the running endless belt 1, 1'', and is taken out from below as a slab 7.

JP-A No. 62-212042 discloses that in the belt-type continuous casting machine shown in FIG. Figure 7 (
Set it up as shown in A). It is stated that this groove prevents splashing as shown in FIG. 7 CB) and greatly reduces the occurrence of balls, hot water wrinkles, etc. on the surface of the slab 7.

However, according to the findings of the present inventors, for example, FIG.
) belt type continuous casting machine, unless special measures are taken, the metal belt 1 and the lower roll 3 tend to slip, causing the running speed of the metal belt to fluctuate, and the metal belt 1 tends to meander. The operation tends to become unstable both when the groove shown in FIG. 7(A) is not present or when the groove is present.

[Problems to be Solved by the Invention] The present invention discloses a belt-type metal ribbon continuous casting apparatus that prevents fluctuations in the running speed of an endless belt or prevents meandering of the endless belt.

[Means and effects for solving the problem] Fig. 1 is an explanatory diagram of a metal ribbon continuous casting apparatus, and (A) is a side view;
(B) is a diagram showing the XX cross section, and (C) is a diagram showing the YY cross section.

This continuous ribbon casting apparatus consists of an endless belt 1 which runs at an angle between an upper roll 2 and a lower roll 3, for example in the direction of arrow 8, and an upper roll 2' and a lower roll which are disposed facing the endless belt 1 and run in the direction of arrow 8, for example. 3' and an endless belt 1' running, for example, in the direction of arrow 8', the long side walls of the upper wide mold are formed. In the present invention, the endless belt 1 or 1' is, for example, a tension belt 3.
It is stretched under tension by rolls 9 and 9'. Reference numerals 4 and 41 designate short side walls, for example, an upper wide mold along the running path of the endless belts 1 and 1', which are sandwiched between the endless belts to form the short side walls of the upper wide mold. The molten metal lO is injected into this upper wide mold, but the back side of the endless belt is a cooling pad 11.11
'The solidified shell 1 inside the mold is cooled by
2.12' and solidified shell 12°1 at the lower end of the mold.
2' are combined to form a thin metal strip 7.

When the solidified shells 12 and 12' are combined, the lower rolls 3 and 3' press the solidified shells via the endless belts l and 1'. This pressurization adjusts the thickness and cross-sectional shape of the metal ribbon 7.

This continuous casting apparatus can produce thin metal ribbon with high efficiency. However, according to the knowledge of the present inventors, unless special measures are taken, the operation of this continuous casting apparatus tends to become unstable.

FIG. 2 is a diagram showing an example of the combination of the solidified shells 12 and 12' in the lower rolls 3 and 3'.

FIG. 2(A) shows an example of coalescence in which unsolidified molten metal 6 is present between solidified shells 12 and 12'. In this example, even if the solidified shells are combined to a predetermined thickness with the lower rolls 3 and 3'', the static pressure of the molten metal 6 from the meniscus 13 will cause the JIM bulge 14 that is likely to occur after the combination. If this occurs, the thickness of the metal ribbon becomes unstable, and if it is pulled out with a large force P, the resistance when passing through the rollers 15, for example, is large, and if the plate thickness is thin, the metal ribbon will break.

FIG. 2(B) shows an example in which the solidified shells are combined using the apparatus of the present invention, and is a C1 combination in which there is little unsolidified molten metal between the solidified shells 12 and 12'. For example, by adjusting the cooling strength of the cooling pad 11 and the running speed of the endless belt, there will be no unsolidified molten metal between the solidified shells 12 and 12' before reaching the lower rolls 3 and 3', as shown in FIG. ) is obtained. At this time, solidified shells a, b, c, and d, each having an approximate trapezoidal cross section with an upper part t and a lower part t2, are guided and rolled down by lower rolls 3 and 3'' via an endless belt 1 and 1''. As a result, a metal ribbon with a thickness of t2 is obtained. In the example shown in FIG. 2(B), the body bulge 14 does not occur, so the thickness of the metal ribbon can be accurately controlled.

Also, since the metal ribbon is not pulled with a large force, even thin metal ribbons will not break.

In FIG. 2(B), the driving force of the lower roll 3 is transmitted to the endless belt 1 by the frictional force between the surface of the lower roll 3 and the back surface of the endless belt 1 (the surface in contact with the lower roll 3). ′
11 Induce and roll down solid shells a, b, a, and d. If the frictional force between the surface of the lower roll 3 and the back surface of the endless belt 1 is small, the lower roll 3 and the endless belt 1 will slip.

When this slip occurs, even if the lower roll 3 rotates,
The endless belt 1 stops or runs at an irregular speed, making it difficult to continue casting.1 In the present invention, the back surface of the endless belt 1 (1'') and the surface of the lower roll 3 (3') Although unevenness is provided to prevent slipping, for example, the recessed part of the endless belt and the convexed part of the lower roll fit together to prevent slipping, and the strong driving force of the lower roll 3 (3') is applied to the endless belt. 1 (1').

Figure 3 shows the solidified shell (
FIG. 2 is a schematic diagram showing an example of temperature distribution of a cast slab. 16 is a high temperature section immediately after solidification, 17 is a medium temperature section, and 18 is a low temperature section. The slab with the temperature distribution shown in Fig. 3 has an endless belt l (1'
) and is guided and rolled down by the lower roll 3 (3').1 For example, the short side wall 4 side in FIG. , the low-temperature portion 18 occupies a large proportion of the short side wall 4'' side, making it difficult to undergo plastic deformation.For example, when the slab with uneven temperature shown in Fig. 3 is guided and rolled down by the lower roll via an endless belt, it becomes endless. The belts 1 and 1' often meander.In the second aspect of the present invention, in order to prevent the endless belt l (1') from meandering, the back surface of the endless belt l (1') and the lower roll For example, the concave portion of the endless belt and the convex portion of the lower roll fit together to prevent meandering of the endless belt.

FIG. 4 is a diagram showing an example of anti-slip irregularities provided on the back surface of the endless belt 1 and the surface of the lower roll 3. The depth of this unevenness is preferably 0.2 to 2+a+a.

If the depth is less than 0.2 mm, it is insufficient to prevent slipping, and if the depth is 2+am or more, the thickness of the endless belt 1 becomes too large, which is not preferable.

FIG. 5 is a diagram illustrating an example of irregularities for preventing meandering according to the present invention, corresponding to FIG. 1(C). In this example.

Three grooves 20 for preventing meandering are cut in the circumferential direction on the surface of the lower roll 3. Also, there is a concave groove 2 on the back side of the endless belt 1.
Three protrusions 19 are provided at positions corresponding to 0 in the length direction of the endless belt. The concave groove 20 and the protrusion 19 fit together to prevent the endless belt 1 from meandering. The depth of the unevenness for preventing meandering is preferably 0.2 to 2 m.

FIG. 6 shows another example of the unevenness provided on the back surface of the endless belt.
1 and provided with protrusions corresponding to the recesses 21 on the surface of the lower roll 3 and combined, these recesses and recesses are fitted to form recesses and recesses that prevent slipping and meandering.

In the present invention, the shape of the unevenness is not particularly limited, but the unevenness can be easily provided by machining, pressing with a roll, welding, or the like.

Upper roll 2 (2') and tension roll 9 (9) in Figure 1
') can also be provided with a convex part or a concave part that fits with the concave or convex pattern provided on the back side of the endless belt 1 (1'), but this will prevent the endless belt 1 (1') from slipping or meandering. It is further preferred in that the prevention effect is improved and wear on the unevenness on the inner surface of the belt 1 (1') can be prevented.

[Example] Using a casting machine having the structure shown in Fig. 1, with a belt wall thickness of 2 am and a belt width of 800 mm, SOS 30 was produced.
Molten steel having a stainless steel composition of 4 at a temperature of 1490° C. was poured into a tundish to produce a metal ribbon having a wall thickness of 4+a+a and a plate width of 600 mm. As shown in FIG. 2(B), the lower roll 3
and 3', casting was carried out by controlling the slab to be constantly rolled down with a force of 300 kgf. Initially, when casting was carried out with both the inner surface of the belt and the surface of the roll smooth, problems such as slipping between the belt and the roll and meandering of the belt frequently occurred. Therefore, recesses of 12 mm in diameter and 0.3 mm in depth are provided on the inner surface of the belt at intervals of 40 mm in both the width and length directions, as shown in Fig. 6, and the lower roll 3 (3') and upper roll 2 (2') and the surface of the tension roll 9 (9') were provided with a convex part that fit into the above-mentioned concave part on the inner surface of the belt.

As a result, the problems of belt slipping and meandering have been resolved, and since the lower roll section performs light rolling of the slab, it is possible to obtain slabs with good surface quality and excellent plate thickness accuracy. did it.

[Effects of the Invention] By carrying out the present invention, a metal ribbon with a precisely controlled thickness can be obtained without causing body bulges in the metal ribbon. Furthermore, in the apparatus of the present invention, fluctuations in the running speed of the endless belt and meandering are also prevented, allowing stable operation.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the continuous metal ribbon casting apparatus, Fig. 2 is a diagram illustrating the coalescence of solidified shells, Fig. 3 is a diagram showing an example of temperature distribution of the solidified shell (slab), Fig. 4 FIG. 5 is a diagram showing an example of unevenness for preventing slippage, and FIG. 5 is a diagram showing an example of unevenness for preventing meandering. Fig. 6 shows an example of other irregularities on the back surface of the belt, and Fig. 7 shows an example of a known belt type continuous casting machine. Fig. 1 (1'): Endless belt, 2 (2'): Upper roll, 3 (3'): Lower mouth, 4: Short side wall, 5: Nozzle, 6: Molten metal, 7
: Slab, metal ribbon, 8 (8'): Belt running direction,
9 (9'): Tension roll, 10: Molten metal, 11
(11'): Cooling pad, 12 (12'): Solidified shell, 13: Meniscus, 14: Body bulge, 15: Roller, 16: High temperature section, 17: Medium temperature section, 18: Low temperature section, 19 : Protrusion, 20: Concave groove, 21: Concave. Patent applicant Nippon Steel Corporation

Claims (2)

[Claims] (1) An endless belt 1 that is stretched and runs obliquely between an upper roll 2 and a lower roll 3, and an upper roll 2 that is stretched
Endless belt 1 running inclined between ' and lower roll 3'
In a continuous casting apparatus, the endless belts 1 and 1' run at synchronized speeds to form the long side walls of the upper wide mold. 3')
Continuous casting machine for metal ribbon, characterized by having anti-slip irregularities on its surface. (2) An endless belt 1 that is stretched across and runs at an angle between an upper roll 2 and a lower roll 3;
Endless belt 1 running inclined between ' and lower roll 3'
In a continuous casting apparatus, the endless belts 1 and 1' run at synchronized speeds to form the long side walls of the upper wide mold. 3')
Continuous casting machine for metal ribbon, characterized in that the surface of the metal ribbon is provided with unevenness to prevent meandering.