SU1671400A1 - Hollow ingot production apparatus - Google Patents

Abstract

This invention relates to metallurgical production, in particular to the manufacture of hollow ingots and castings. The purpose of the invention is to improve the quality of the hollow ingot by creating circular oscillations of the mandrel. A device for producing hollow ingots comprises a pan, a mold in which a mandrel hollow is installed, an intermediate casting tank and a device for supplying cooling compressed gas. Inside the hollow mandrel, a centrifugal vibration exciter is installed coaxially with a gap and with the possibility of reciprocating motion (displacement), which creates circular oscillations of the mandrel in a horizontal plane, and the device for supplying cooling compressed gas is made in the form of pipelines with a gas inlet annular gap and a diffuser (socket) and a gas outlet tube concentric located relative to each other. 1 il.

Description

This invention relates to metallurgical production, in particular to the manufacture of hollow ingots.

The purpose of the invention is to improve the quality of the hollow ingot by creating circular oscillations of the mandrel in the horizontal plane.

The drawing shows the proposed device for the production of hollow slitxch

The device contains a pallet 1, a mold 2, an intermediate tank 3, a hollow mandrel 4. Inside the mandrel 4 there is a centrifugal vibration exciter 5. In the pallet 1 there is a device for supplying cooling compressed gas, made in the form of pipelines with a gas inlet annular gap 6, a bell mouth 7 and a gas outlet tube 8. To enable the reciprocating motion (movement), as well as remove it from the mandrel after the ingot partially or completely solidifies between the housing of the vibration exciter 5 and the inner turn NOSTA mandrel 4 there is a gap equal to the oscillation amplitude value of 0.15-0.5. The presence of a gap during the excitation of circular oscillations creates conditions for the impact (shaking) of the vibration exciter 5 on the mandrel 4. The vibration effects positively affect the crystallizing melt and contribute to the grinding of the grain, obtaining a dense uniform structure, removing gas and non-metallic inclusions. A hollow mandrel 4 with a centrifugal vibration exciter 5 placed inside it is mounted in PO-4.

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ABOUT

mold mold 2 before metal casting. The central vertical position of the mandrel 4 with the vibration exciter 5 integrated in it is fixed by means of a cylindrical recess in the tray 1 and an opening in the intermediate tundish 3.

The operation of the apparatus for producing hollow ingots is as follows.

Simultaneously with the pouring of the molten metal into the cavity of the mold 2, the centrifugal vibration exciter 5 is turned on, and compressed cooled gas (inert gas or nitrogen) is supplied through the annular gap. The centrifugal vibration exciter 5 forces the mandrel 4, the lower end of which rests on the base of the socket in the tray 1, and the upper one in the hole of the intermediate tank 3, to vibrate the impact on the crystallizing metal. As a result of circular oscillations combined with the impact, the mandrel 4 pushes the crystallized crust, with a gap between the crust and the surface of the mandrel. Upon further cooling of the ingot and cessation of vibro-impact effects due to shrinkage, the gap is completely selected (eliminated), which ensures free shrinkage of the crust without the formation of hot cracks in it, the metal fits and slightly compresses the mandrel, which, leaving the ingot, forms a cavity. The cooling gas entering the cavity of the mandrel through the annular gap 6 located in the pan 1, the socket (diffuser) 7 is pressed against the walls of the mandrel 4, cools it, thereby preventing the transition of the mandrel 4 in a plastic state and the loss of the original shape of a hollow cylinder (pipe) . The heated (exhaust) gas leaves the cavity of the mandrel 4 through the central tube 8 located inside the annular slot 6 in the tray 1. Initially, during the casting, the switched on vibration exciter 5 occupies the lower position in the mandrel 4 at a distance of 0.3 ingot height, and then filling the mold and further solidifying the ingot, it is moved to the middle or upper position at a distance of the entire height of the ingot, where it works until the vibro-impact effects are stopped and removed from the formed hole,

Such a working position (0.3-1.0 NSL) of a centrifugal vibration exciter and a diffuser (socket) protruding by 0.3 NSL ensures the creation of directional crystallization and preservation of the geometric (cylindrical) shape of the pipe forming the hole in the ingot.

Using the proposed device allows to obtain hollow ingots without

cracks, to improve the quality of their macrostructure, as well as the efficiency of cavity formation,

Claims (1)

Invention Formula A device for producing a hollow ingot, containing a casting container, a mold with a hollow mandrel coaxially placed in it, and a tray with a device for supplying a cooling gas in the form Two pipelines, characterized in that, in order to improve the quality of a hollow ingot by creating circular oscillations of the mandrel in a horizontal plane, it is equipped with a centrifugal vibration exciter, installed with a clearance inside the mandrel at a distance of 0.1 ... 0 , 3 of the height of the mandrel, with the possibility of vertical movement, moreover, the gas supply pipeline is provided with a gas inlet annular channel and a bell mouth, and the exhaust pipeline is located coaxially inside the annular channel. eight