JPH06126390A - Drum of continuous casting equipment for metallic sheet - Google Patents

Abstract

PURPOSE:To enable stable long-time casting by forming the end face parts on the inner side of the end face parts of a drum in contact with a side weir of a hard and hardly seizable material and the end face parts on the outer side of a material having excellent thermal impact resistance. CONSTITUTION:The end face parts 5 of the drum are formed by, for example, Ni plating and the end face parts 6 on the inner side are formed by explosive thermal spraying or plasma spraying of, for example, Cr3C2(70%)-Ni Cr which is hard and hardly seizable and has the high thermal impact resistance. The end face parts 7 on the outer side are formed by explosive thermal spraying or plasma spraying of, for example, CoCrAlY which has the excellent corrosion resistance to molten steel and has the high thermal impact resistance as well. The wear speed of the refractories of the side weir decreases and the casting time of one time is prolonged. The casting quantity is greatly increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum for continuous casting equipment for thin metal sheets.

[0002]

2. Description of the Related Art In a twin-drum type thin plate continuous casting apparatus, a pair of water-cooling drums and a side weir in which a refractory material is buried and pressed against the end faces of the pair of water-cooling drums are used. The refractory of the side dam is worn by friction with the drum end surface due to the rotation of the drum, and the drum end surface is also worn. The maximum casting amount is determined by the time until wear corresponding to the convex height.

Since the wear rate is affected by not only the hardness of the refractory but also the roughness of the end face and the coefficient of friction between the refractory and the end face, a hard and seizure-resistant end face material is desired. Further, since the end face is exposed to the atmosphere after contacting with the side weir which is preheated periodically and sometimes comes into contact with the casting burr inserted in the gap between the side weir, the end face material must have excellent thermal shock resistance. Since the outermost edge of the end surface on the body surface side is in contact with the molten steel, corrosion resistance is also a characteristic feature.

[0004]

In the twin drum type thin plate continuous casting apparatus, the side dam is pressed against the end surface of the water cooling drum, and the refractory of the side dam is worn by the rotation of the drum to seal the molten steel. Therefore, surface roughness due to seizure, peeling due to thermal shock, and melting loss due to molten steel cause unevenness in the circumferential direction of the end face, and molten steel is inserted into the unevenness, causing casting burrs. Eventually, the cast burr will go around to the drum,
The molten steel seal by the side dam becomes impossible. If the pressing force of the side weir is increased in order to suppress the leakage of molten metal, the wear rate of the refractory material on the side weir increases, and it becomes difficult to achieve long-time casting. Therefore, it is necessary to frequently repair and maintain the end surface of the drum.

For example, when a metallic material is used as the end surface material, seizure causes surface roughness, which increases the wear rate. If an oxide type is used, peeling will occur due to thermal shock, and if the oxide type is used, and if a non-oxide type is used, the outermost edge is melted by the molten steel, so that the molten steel seal will be Leading to defects. Even in such a state, molten steel sealing may be possible by increasing the pressing force of the side weir, but the wear rate of the refractory of the side weir also increases remarkably, and long-time casting becomes difficult. Even if multi-component materials such as cermet are adopted, they do not make up for each other's disadvantages and are not perfect. Therefore, it is impossible to secure both the molten steel seal and the achievement of long-time casting by using one material for the end face. Therefore, Ni is built up by welding or the like, and further the end face is cared for by a grinder or the like. However, the frequency is very high, the efficiency is low, and the repair cost is required.

An object of the present invention is to obtain a water-cooled drum having an end surface which does not cause surface roughness due to seizure, peeling due to thermal shock, or melting loss due to molten steel in order to secure a molten steel seal and achieve long-time casting. It is in.

[0007]

The gist of the present invention is as follows.

A drum of a continuous casting facility for twin-drum type thin metal plates, characterized in that the end surface portion of the drum in contact with the side dam is made of different materials on the inside and the outside.

The drum of the continuous casting equipment for a thin metal plate described above, wherein the inner end face is made of a hard material that is hard to seize and the outer end face is made of a material having excellent resistance to molten steel.

[0010]

The present invention significantly reduces the frequency of end face repair and maintenance by sticking to the drum end face a hard material that is hard to seize on the inner side (shaft side) and a material that has excellent molten steel resistance on the outer side (body surface). However, it is possible to improve the efficiency of the direct thin plate manufacturing by the twin drum method and reduce the drum repair cost.

As a characteristic required for the inner material, in addition to being hard and hard to seize, it is indispensable to have thermal shock resistance because it is exposed to the atmosphere after coming into contact with the side dam that is periodically heated. As materials having such properties, non-oxide type and cermet type having a high non-oxide content are generally known.

On the other hand, as the characteristics required for the outer material, in addition to corrosion resistance against molten steel, thermal shock resistance is also essential. As a material having such characteristics,
It is known that a metal type that forms an oxide film on the surface layer and a cermet type that does not have a very high oxide content.

On the end faces of the drums made of these different materials, when they come into contact with the heated side weir, if there is a difference in the coefficient of thermal expansion, edge breakage occurs at the boundary and eventually peeling occurs. Determine the combination of materials.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show an embodiment of the present invention. FIG. 1 is a structural view of a water-cooling drum, and FIG. 2 is a detailed view of an end surface of the drum.

As shown in FIG. 1, the molten steel 4 is sealed by pressing a side weir 3 in which a refractory is buried against the drum end surface portion 1.

As shown in FIG. 2, the end surface of the drum is made of Ni.
It is composed of a plating 5, an inner end face portion 6 and an outer end face portion 7. The inner end face portion 6 is hard and hard to seize, and is obtained by explosive spraying or plasma spraying of Cr ₃ C ₂ (70%)-Ni · Cr having high thermal shock resistance. The outer end face portion 7 is obtained by explosive spraying or plasma spraying CoCrAlY having excellent corrosion resistance against molten steel and high thermal shock resistance by forming an oxide film on the surface layer.

Using a water-cooled drum constructed with the above-mentioned two kinds of materials on the inside and outside of the end face portion, the heated side weir is pressed against the drum end face in the pre-stage of casting, and then the drum is rotated to start casting. did. As a result, stable casting could be performed without causing casting burrs and leakage of molten metal. The pressing force of the side weir is significantly reduced compared to the conventional one, and the wear rate of the refractory of the side weir is Cr ₃ C ₂ (70
%)-1 / Compared to the case where one material of Ni / Cr is applied
4. Compared with the case where the CoCrAlY material was applied, it was reduced to 1/6, and the casting time for one time was extended, and the casting amount could be greatly increased. In addition, the frequency of drum repairs such as drum end face repair and maintenance could be greatly reduced compared to the past.

The present invention is not limited to the combination of materials described in the embodiments and the construction structure.

[0019]

As described above, according to the present invention, the irregularities on the circumference of the drum end surface are remarkably reduced, so that stable long-time casting can be performed and the repair cost of the drum can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a water cooling drum.

FIG. 2 is a detailed view of a drum end surface.

[Explanation of symbols]

 1 Drum end face part 2 Water-cooled drum body 3 Side dam 4 Molten steel 5 Ni plating 6 Inner end face part 7 Outer end face part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideki Oka 3434 Shimada, Hikari City, Yamaguchi Prefecture Nippon Steel Co., Ltd. Inside the Nippon Steel Works (72) Inventor Takashi Arai 3434 Shimada, Hikari City, Yamaguchi Prefecture Nippon Steel Co., Ltd. Inside the Hikari Steel Works

Claims (2)

[Claims] 1. A drum of a twin drum type continuous casting equipment for a thin metal plate of a twin drum type, characterized in that an end surface portion of the drum which is in contact with the side dam is made of a different material on the inner side and the outer side. 2. The drum for continuous casting equipment for thin metal plates according to claim 1, wherein the inner end surface portion is made of a material that is hard and hard to seize, and the outer end surface portion is made of a material having excellent molten steel resistance.