JPH08215792A - Top pouring ingot-making method - Google Patents

Abstract

PURPOSE: To produce a cast ingot having good surface equal to a bottom pouring ingot-making method with little equipping cost and working burden by arranging a cylindrical splash preventing tube in a mold. CONSTITUTION: The splash preventing tube 4 is hung down on the upper surface of the mold 2 set on a molding plate 7 through a holding tool 3. Molten steel 5 is poured into the mold 5 by molten steel pouring flow 1 from the upper part. The splash 6 is cut off with the splash preventing tube 4 and is not spattered in the inner surface of the mold 2. Even in the case of operating with a top pouring ingot-making method, the molten steel surface is quietly ascended as the same condition as the bottom pouring ingot-making method. Therefore, the steel ingot having good surface can be produced. The splash preventing tube 4 is melted in accordance with the ascendent of molten steel surface. The material of the splash preventing tube 4 is selected under consideration of the component variation of the base molten steel 5. Thus, in the case of selecting the material of the splash preventing tube 4 with a low m.p. refractory, this tube is melted and floated up on the molten metal surface and the effect is not given to the component of the base molten steel 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for casting a steel ingot, and more particularly to an upper casting method for producing a steel ingot having a good surface texture.

[0002]

2. Description of the Related Art Casting methods for steel ingots are roughly classified into a lower casting method and an upper casting method. The bottom casting method is a method in which molten steel is poured into a refractory injection pipe and runner brick, and the molten steel is cast from the bottom of the mold. According to this method, it is relatively easy to manufacture a steel ingot having a good casting surface, but it takes a lot of time to set the runner brick before casting, and there is a problem in working efficiency.
Further, the problem of waste such as brick scraps generated after casting cannot be ignored.

On the other hand, the upper pouring ingot method is a method of pouring molten steel into the mold directly from above the mold. According to this method
Although it is excellent in work efficiency because it saves the trouble of setting the runway brick, etc., it generally produces a steel ingot with rough skin. Therefore, the steel ingot manufactured by the top casting ingot method requires maintenance work on the surface of the steel ingot in the subsequent step, which causes problems such as deterioration of yield and reduction of work efficiency of the maintenance work.

A method using an immersion nozzle is known as a method for producing a steel ingot having a good skin equivalent to that of the lower pouring ingot method by the upper pouring ingot method. Since it is necessary to move the mold up and down, the casting work becomes complicated and there is a problem that the facility load increases.

[0005]

DISCLOSURE OF THE INVENTION The present invention is a top pouring ingot method without increasing facility load or work load.
It was devised to produce a steel ingot having a good casting surface equivalent to that of the bottom casting method.

The cause of the rough surface of the steel ingot produced by the upper casting method is the splash scattered from the molten steel surface to the casting wall during casting.

An object of the present invention is to prevent splashing splashes by a simple method.

[0008]

The above object is achieved by placing a cylindrical splash prevention tube in a mold and performing top casting.

[0009]

In the present invention, the molten steel is poured into the splash prevention pipe arranged in the mold during the top casting. The poured molten steel passes through the splash prevention pipe and is cast into the mold, so that the splash does not scatter on the casting wall. Therefore, it is possible to manufacture a steel ingot having a good surface texture similar to that of the lower casting method.

[0010]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory view of a top pouring ingot method for carrying out the method of the present invention. Molten steel 5 is poured onto the mold 2 and the surface plate 7 by a pouring flow 1 from above. At this time, the pouring flow 1 is poured into the splash prevention tube 4 which has been set in the mold 2 before casting. The splash prevention tube 4 is held by the holding tool 3. Since the splash 6 generated when pouring is not scattered on the casting wall,
The surface of the molten metal rises gently as in the bottom casting method. For this reason,
A steel ingot having good skin can be manufactured.

The splash prevention tube 4 melts as the molten metal rises. When the splash prevention pipe is made of metal, it should be selected in consideration of the composition change of the molten base steel, but the use of carbon steel pipes causes few practical problems. The material of the splash preventive tube is made the same as that of the melt molten steel when the change in the composition of the melt molten steel due to melting of the splash preventive tube is disliked. Alternatively, when the splash prevention pipe is made of a refractory material having a low melting point, the melted splash prevention pipe floats on the molten metal surface, so that the casting can be performed completely separated from the molten steel.

[0013]

EFFECTS OF THE INVENTION According to the present invention, it is possible to manufacture a steel ingot having a skin as good as the lower pouring ingot method by the upper pouring ingot method at a low cost with less facility and work load. It is possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an upper casting method according to one embodiment of the present invention.

[Explanation of symbols]

1 ... Pouring flow, 2 ... Mold, 3 ... Grasping tool, 4 ... Splash prevention tube, 5 ... Molten steel, 6 ... Splash, 7 ... Surface plate.

Claims (1)

[Claims] 1. A top casting ingot method for pouring molten steel directly into a casting mold, characterized in that a cylindrical splash prevention tube is arranged in the casting mold.