JP2544411B2 - Drum type continuous casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention casts molten metal into the gap between the surfaces of two drums having parallel axes of rotation and holding the gap and rotating in opposite directions. The present invention relates to an improvement of an apparatus for manufacturing a plate by incorporating it, a so-called drum type continuous casting apparatus.

[Prior Art] The continuous casting apparatus for a thin metal plate is roughly classified into a belt type and a drum type, but a drum type is generally used for a continuous casting apparatus for a plate having a thickness of about 10 mm or less.

A conventional drum type continuous casting apparatus will be described with reference to FIG. Two drums 1a and 1b which are horizontally arranged and have mutually parallel rotation axes rotate in opposite directions in the directions of the arrows, and continuously pours the molten metal 2 into the gap between the two drums. Three
Is a pool of molten metal, and the molten metal starts solidifying at the portions in contact with the surfaces of the drums 1a and 1b, and moves downward as the drum rotates to manufacture the thin plate 4.

A weir is in contact with the end surfaces of the drums 1a and 1b so that the molten metal of the pool 3 does not leak, and the inner surfaces of the drums 1a and 1b are generally cooled.

[Problems to be solved by the invention]

The drum-type continuous casting apparatus is suitable for producing thin plates as described above, and includes low melting point metal to aluminum,
High melting point metals such as copper and their alloys and steel are used.

However, there are various technical problems with refractory metals such as steel, and although there are examples in which copper and its alloys have been put into practical use in terms of shape, steel has not yet been fully put into practical use.

The largest of these types of problems is the cracking of the plate surface during solidification by casting. If the frequency of occurrence of this crack is almost zero, a rolled product using a plate obtained by continuous casting as a base plate cannot be established.

The present invention is intended to prevent the occurrence of cracks in the plate in a drum type continuous casting apparatus.

[Means for solving problems]

The present invention relates to a drum-type continuous casting apparatus for producing a thin plate by casting a molten metal into a gap between surfaces of two drums having parallel axes of rotation and holding a gap and rotating in opposite directions. A plurality of circumferentially continuous small grooves are provided on the surface of the drum. The small groove corresponds to a concave portion and a convex portion on the opposite drum surface, and extends in a wavy form in the axial direction of the drum.

[Action]

In a drum-type continuous casting machine, the cause of cracks is that the solidification of the molten metal on the drum surface does not proceed uniformly in the axial direction of the drum at the same time. Direction tensile stress acts on the fragile part where solidification progresses late,
A vertical crack is generated in that portion.

The present invention, as described above, is continuous in a plurality of circumferential directions on the surface of the drum, and the concave portion and the convex portion of the opposing drum surface correspond to each other,
Moreover, the following effects can be obtained by providing the small groove that extends in a wavy form in the axial direction of the drum.

(1) The plate manufactured by the small grooves on the surface of the drum has a constant thickness and the surface has a corrugated shape. For this reason, the above-mentioned shrinkage stress only acts in a small range and is effective in preventing cracks.

Further, the cast slab to be cast has a fine wavy shape as described above, but the thickness is constant, and even if it is rolled, surface scratches do not occur.

(2) While the plate is in contact with the drum, the plate surface is corrugated and is in contact with the drum surface having small grooves, so the contraction of the plate is restricted by the wave crests formed by the small grooves on the drum surface. As a result, the influence of the contraction is prevented from spreading over a wide range, so that the stress is dispersed in a small range and its value becomes small.

(3) Since the shape of the plate is corrugated, when a tensile stress due to contraction of the solidified portion causes a crack to occur, the stress is relieved by the bellows effect due to the corrugated shape and the occurrence of cracks is prevented. .

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. In this embodiment, two drums 1a and 1b are provided as in the conventional apparatus shown in FIG. 4, and the molten metal is continuously poured into the gap between both drums. 5a and 5b are weirs contacting both end surfaces of both drums 1a and 1b to prevent molten metal from leaking, and drums 1a and 1b
Rotates in contact with this. Surface of drum 1a, 1b 1aSF, 1bSF
On each of a plurality of corrugated small grooves A, B, C, which are continuous in the circumferential direction.
...; A ', B', C '... are provided. Reference numeral 4 is a thin plate formed through the gap between the drum surfaces 1aSF and 1bSF.

2 is an enlarged view of a part of the drum surface shown in FIG. 1, and the pitch P of the waves formed by the small grooves A, B, C, ...
The thickness t of 1/2 to 4 times, that is, P = (1/2 to 4)
It is assumed to be t. The height h of the wave is in the range of 0.1 to 0.25 mm. The plate thickness t is usually in the range of 1 to 10 mm.

Further, the phase difference between the wave of the drum 1aSF and the wave of 1bSF formed by the plurality of small grooves A, B, C, ...; A ′, B ′, C ′, ... Is 0 ° to 180 °. Although it is set appropriately within the range, as shown in FIG. 2, when one is convex, the other is concave,
It is best to have a constant thickness on any part of the plate 4.

Since this embodiment is configured as described above, as shown in FIGS. 1 and 3, a corrugated plate is formed through the gap between the drums 1a and 1b. As shown in FIG. 3, the plate 4 during casting is cooled by the surfaces 1aSF and 1bSF of both drums to form solidified portions 4-1 and 4-2 from both surfaces, and the unsolidified molten metal is formed in the central portion. Part 4-3 is present.

As described above, during casting, the solidification of the molten metal on the surfaces of the drums 1a and 1b does not always proceed uniformly in the axial direction of the drum, and therefore the solidified portions 4-1 and 4-2
Thickness distribution is not uniform in the axial direction of the drum.
For this reason, the shrinkage of the portion where the solidification has proceeded first is large, which causes tensile stress in the lateral direction of the plate.

However, since the plate manufactured by the apparatus of the present embodiment has a corrugated surface, the tensile stress only acts in a small range. Further, the plate 4 is the surface 1aS of the drums 1a, 1b.
While in contact with F, 1bSF, the contraction of the plate 4 is caused by the wave peaks formed by the small grooves A, B, C, ...; A ', B', C '... on the drum surface. It is restrained and the effect of contraction is prevented from spreading widely.

Furthermore, since the plate 4 has a corrugated surface,
Due to the bellows effect, the contraction can relax the tensile stress. As described above, in the present embodiment, the influence of the solidification / shrinkage of the plate does not extend over a wide range, and the value of the tensile stress due to this can be made small, so that the occurrence of the plate crack can be prevented.

 An example using the apparatus according to this example will be described below.

Pitch (P) = 3 m on the surface of a drum with a diameter of 600 mm and a width of 600 mm
m, wave height (h) = 0.8 mm, and a plurality of continuous small grooves were provided in the circumferential direction. Using this drum, the casting temperature is 1510 ° C, the casting speed is 63m / min (drum peripheral speed), and the plate thickness is 2.6mm.
A plate of 900% 9% Ni stainless steel was cast.

As a result, no vertical cracking was observed in the plate, confirming the effect of the present invention.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention, in the drum type continuous casting apparatus, is continuous in the circumferential direction on the drum surface, the concave portions and the convex portions on the opposing drum surface correspond to each other, and the waveform is formed in the axial direction of the drum. By providing a plurality of small grooves extending and casting a plate with a corrugated surface, it is possible to prevent the effect of shrinkage due to the solidification of the molten metal from spreading over a wide range, and to relax the tensile stress due to shrinkage. It is possible to prevent cracks from being generated in the cast plate.

Further, the slab cast by the drum type continuous casting apparatus according to the present invention has a constant meat and summer, and therefore the slab cast by the apparatus according to the present invention does not cause surface scratches even when rolled. .

[Brief description of drawings]

1 is an explanatory view of an embodiment of the present invention, FIG. 2 is an explanatory view of a drum surface of the above embodiment, FIG. 3 is a sectional view showing a solidified state of a plate solidified by the drum surface of the above embodiment, FIG. 4 is an explanatory view showing the principle of the conventional drum type continuous casting apparatus. 1a, 1b …… drum, 1aSF, 1bSF …… drum surface, 2 …… molten metal, 3 …… molten pool, 4 …… plate, 5a, 5b …… weir, A, B, C, A ′, B ′, C '... small groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadashiro Oda 2-5-1, Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Heavy Industries, Ltd. (72) Shunji Omori 4-6, Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima No. 22 Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (72) Inventor Keiichi Yamamoto 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Research Institute (56) Reference JP 62-254953 (JP, A)

Claims (1)

(57) [Claims] 1. A continuous casting apparatus for producing a plate by casting a molten metal into a gap between surfaces of two drums having parallel axes of rotation and holding a gap and rotating in opposite directions. The drum has a plurality of circumferentially continuous small grooves on its surface, the concave and convex portions of the opposing drum surface corresponding to the small grooves, and extending in a wavy form in the axial direction of the drum. Drum type continuous casting equipment.