SU1484433A1 - Method and apparatus for casting hollow ingots - Google Patents

Abstract

The invention relates to microcallurgy, in particular, to the production of hollow ingots. The aim of the invention is to increase production efficiency and improve the quality of hollow ingots. In the mold 2, installed on the pallet 1, with the lid 3 fixed on it through the central pipe 4 and channel 7, synthetic slag and metal are sequentially poured in, supplying argon through channel 8, while the slag and metal fill cavities 5 and 6, and the metal level occupies an intermediate position. After the channel 7 is closed, the pressure of argon in the cavity 6 increases and accordingly moves the metal, and then the slag from the cavity 6 of the central tube into the cavity 5 of the mold to form a hollow ingot body. By increasing the pressure of argon in cavity 6, the liquid metal is flushed with an inert gas, while argon is freely removed through channel 9 to the atmosphere. After that, the pressure of the inert gas is stabilized and maintained until a solid peel of the ingot is formed. The proposed method for producing hollow ingots and a device for its implementation, by increasing the duration of the contact of the liquid metal with synthetic slag and blowing the body of the ingot with argon, increase the efficiency and quality of the obtained hollow ingot. 2 sec. and 1 z. p. f-ly, 1 ill.

Description

The invention relates to metallurgy, in particular to the production of hollow ingots.

The purpose of the invention is to increase production efficiency and improve the quality of hollow ingots. - 5

The drawing shows a device for producing hollow ingots.

A mold 2 is mounted on the pallet 1 with a cover (extension) 3, to which a gas-tight central pipe 4 is inserted, which is inserted into the mold cavity to a depth of 0.96-0.98 of the height of this cavity, while the mold cavity 5 is in communication with the cavity 6 of the central pipe through the gap between the horizontally located lower end of the pipe and the pallet. Synthetic slag and liquid metal are poured sequentially in an inert argon gas medium, filling cavities 5, until the same melt level is established in these bands — 20 channels. Immediately after the metal has been drained into the mold, the drain hole 7 is hermetically sealed. Since the gas in the cavity 6 is continuously supplied under a pressure ΡΙ exceeding the pressure of the maximum melt column (H) in the cavity 5, which is equal to the sum of the heights of the metal column (h _M ) and the slag column (Ish) , i.e. when h „xf ^ + h ^ xr ^ irAe and is the specific gravity of the metal and slag in the liquid state), then after closing the hole 7, the gas pressure in the cavity 6 will begin to increase and, accordingly, move the metal,., and then the slag into the mold, forming body of a hollow ingot. Increasing the argon pressure, the liquid metal is purged with an inert gas, while argon is freely removed through the channel 9 into the atmosphere. Then the inert gas pressure is stabilized and held until a solid crust of the ingot is formed.

When a central pipe is inserted into the mold cavity by a value less than 0.96 of the height of this cavity, the immersion depth of the central pipe into the metal unreasonably decreases, and consequently, the interaction time of the reagents (slag and gas) with the liquid metal decreases and the thickness of the bottom layer of the ingot removed increases to the edge when opening the cavity of the ingot. Therefore, it is preferable to have the value of the parameter under consideration as high as possible, but it must be borne in mind that with a parameter value of more than 0.98, premature (before the completion of technological operations) metal solidification in the gap between the tray and the central pipe, leading to an uncontrolled change in the flow of reagents from central pipe into the mold, reducing the quality of the ingot. For the purpose of thermal protection of the pipe and prevention of solidification of the melt in its cavity, the inner surface and the lower end of the central pipe are provided with a heat-insulating layer. The cover 3 has a sealed hole 7 for draining the melt into the mold. The lid is communicated by channel 8 with cavity 6 of the pipe and channel 9 with cavity 5 of the mold. The outer surface of the lid 3 of the lining is designed to warm the profitable part of the ingot.

As a result of using the proposed method for casting hollow ingots and a device for its implementation, the production efficiency and quality of hollow ingots are increased.

Claims (3)

Claim 1. A method of casting hollow ingots, including pouring metal into a mold using a central pipe and slag, characterized in that, in order to increase the processing efficiency and improve the quality of hollow ingots, the metal is cast in an inert gas medium through a slag layer, 30, preliminarily filled through the central pipe, after establishing the same melt level in the cavity of the central pipe and the working cavity of the mold, the entire metal volume remaining in the central pipe, and then the slag is transferred by the pressure of inert gas into the working cavity until this gas enters the latter, after which the pressure is inert gas stabilize and withstand until the formation of a solid crust of the ingot. 2. Device for casting hollow ingots, 4Q containing a pan, a mold and a lid with channels and a central pipe in communication with a compressed gas supply system, characterized in that, in order to improve the quality of the ingot, the central pipe is inserted into the mold cavity by 0.96— 0.98 of its height, while 45, the mold cavity is in communication with a compressed gas removal system. 3. The device according to p. 2, characterized in that the lower end of the Central pipe, its upper outer and inner surfaces, as well as the inner surface of the lid are lined with a layer of heat-insulating mixture. Compose.! V. Romashin