JPH02220764A - Unidirectional solidifying mold - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mold capable of unidirectional solidification and zone melting for small lots.

[Prior Art and Problems to be Solved by the Invention] With the increase in demand for various steel plates, it is expected that small-lot slabs and diversification of slabs will become more popular in the future. With current continuous slab casting machines, there is a problem that when different steel types are produced, defects (crops) due to this increase, resulting in a decrease in yield. That is, when changing the component system of a slab in continuous casting (continuous casting in which the tundish is replaced continuously), if the operation continues as it is, slabs that do not meet the specifications will occur due to the difference in components. (Because mixing of both components occurs). For this reason, an iron plate is inserted between the two slabs to separate them, but about 3 meters of the slab inevitably ends up being scrapped. Furthermore, in continuous casting of steel grades with large differences in freezing point temperature, there is a risk of breakout occurring.

Furthermore, if it is almost impossible to continuously cast different types of wood from the viewpoint of quality and operation, the continuous casting will be divided, resulting in a decrease in efficiency. In this way, current continuous slab casters are basically unsuitable for small-lot production and multi-product production.

Furthermore, if there is segregation in the slab, the segregation has been significantly improved by segment EMS and light reduction techniques, but segregation has not completely disappeared.

The present invention was made in view of the above circumstances, and its purpose is to provide a unidirectional solidification mold that can manufacture slabs without segregation in small lots and improve the yield of slabs. It is about providing.

[Means and effects for solving the problem] That is, the unidirectional solidification mold of the present invention is a mold in which a rectangular slab manufacturing cavity is formed by combining the front and rear plates, both side plates, and the bottom plate of the mold. , each of the plates is formed of a material having a higher melting point than the slab, the both side plates are provided so that their positions can be adjusted according to the width of the slab to be manufactured, and the bottom plate is formed according to the length of the slab to be manufactured. It is characterized in that it is provided so that its position can be adjusted, and furthermore, a heating source for heating the molten metal and the slab is arranged on the outside of these side plates and the front and rear plates.

With this structure, since the inside of the mold is heated, unidirectional solidification can be performed. Furthermore, zone melting becomes possible. This mold reduces the difference in the cooling rate between the center and the periphery1 and slowly cools the slab to produce a slab, which prevents the formation of evacuation cavities as in the case of ingot formation using a normal mold. This also eliminates segregation and improves yield.

[Example] The present invention will be explained below based on examples.

FIG. 1 is a perspective view of a mold according to the present invention.

This mold is made by combining the front plate 11, rear plate 12, side plates 13, 14, and bottom plate 15 of the mold to form a rectangular slab manufacturing cavity 1B (for example, thickness 220 mm x width 70 mm).
0~2100 as length 2000~9000 ga+
) can be formed. Each of the plates 11 and 12
, 13 and 14 are each made of a material having a higher melting point than the slab. This material is not limited to metal, and may be metal coated with ceramic. The image side plates 13 and 14 are provided so that their positions can be adjusted in the left and right directions depending on the width of the slab to be obtained. In addition, the bottom plate 1
5 indicates front and rear plates 11.12. It is arranged with a gap of about 0.3 cm from both side plates 13 and 14, and its position can be adjusted in the vertical direction depending on the length of the slab to be obtained. That is, the rod 17 is attached to the lower surface of the bottom plate,
This rod is connected to a drive source (not shown) so that the bottom plate can be moved up and down via the rod. Furthermore, these side plates 13.14 and front and rear plates 11.1
A heating source 18 for heating the mold and molten metal is placed at a predetermined position surrounding the outside of the mold. In this example, an induction heating coil was used as the heating source. The heating by the heating source is adjusted depending on the freezing point of the slab to be manufactured, and the position of the heating source is adjusted as appropriate depending on the applied processing (for example, unidirectional solidification, zone melting).

In order to manufacture small-lot slabs using this mold, first we need to produce slabs for small lots and a wide variety of products, such as ultra-low carbon steel, ultra-low nitrogen steel, chromium-manganese steel, 1% carbon steel, high manganese steel, high Prepare molten metal such as nickel steel. The heating source 18 is turned on to heat the mold. In this state, the molten metal is sequentially charged into the mold cavity 1B. When the heating source is turned off sequentially from the bottom, unidirectional solidification is achieved.

This slow unidirectional solidification eliminates shrinkage cavities and segregation. In addition, the yield of slabs can be improved to almost 100%.

Effects of the Invention] According to the present invention, the bottom plate of the mold is movable and the molten metal and slab are heated, so a small loft can be manufactured without cavities or segregation, and the yield can be improved. It has a remarkable effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention.

Claims (1)

[Claims] In a mold in which a rectangular slab manufacturing cavity is formed by combining front and rear plates, side plates, and a bottom plate of the mold, each plate is formed of a material having a higher melting point than the slab, and the both sides The plate is provided so that its position can be adjusted according to the width of the slab to be manufactured, and the bottom plate is provided so that its position can be adjusted according to the length of the slab to be manufactured. A unidirectional solidification mold consisting of a heating source that heats the metal and slab.