RU148383U1 - Smelting and casting crucible - Google Patents

Abstract

1. A melting and casting crucible containing a housing on which a lid is mounted, characterized in that the lid is made in the form of a plate in the form of a segment, the radius of which is equal to the outer radius of the upper part of the housing, while the width of the lid is 0.7-1.3 from outer radius of the upper part of the body, and a through groove is made in the lid, forming a drain hole in contact with the crucible body along the inner radius. 2. The melting and casting crucible according to claim 1, characterized in that the through groove is made of a rectangular or oval shape. The melting and casting crucible according to claim 1 or 2, characterized in that the lid is made in the form of a plate.

Description

The utility model relates to the field of foundry, namely, to designs of melting and pouring crucibles, and can be used in vacuum induction melting and pouring plants for the production of castings from heat-resistant steels and alloys based on nickel (and cobalt) in batch-casting-melting.

Known crucible for casting parts of heat-resistant steels and alloys, containing a housing in the upper part of which there is a drain hole (utility model patent No. 119081 from 11.28.2011, IPC F27B 14/10, publ. 08/10/2012 bull. No. 22).

The disadvantage of this design is the increased length of the path of the melt during its flow through the drain cavity, associated with the presence of an extension in the crucible in its upper part, which leads to kneading of slag in the flow of the melt being poured and thereby pollution of the castings.

The closest is a melting and pouring crucible containing a body on which the lid is mounted (Copyright certificate No. 92376 of 09/18/1950, IPC B22D 35/00, F27B 14/10, publ. 01.01.1951).

The disadvantages of this device are the small area of the open mirror of the melt (in the lid there are two small windows - a loading window for a charge and an unloading window for a flux), which makes it difficult to control the process of melting and pouring metal; as well as in the manufacture of a crucible and a lid of this design from refractory materials (for example, mullite corundum) for melting and pouring of heat-resistant steels and alloys, the walls of the crucible will be destroyed due to the expansion of the lid material during its radiant heating during the melting process (while the crucible is cooled from the inductor).

The technical result of the utility model is to improve the quality of the obtained castings by preventing clogging with slag and other non-metallic inclusions present in the liquid metal and penetrating the mold during its pouring, as well as extending the life of the lid and the crucible itself.

The technical result is achieved by the fact that the melting and pouring crucible contains a housing on which the lid is mounted.

New is that the lid is made in the form of a plate in the form of a segment, the radius of which is equal to the outer radius of the upper part of the housing, while the width of the lid is 0.7-1.3 from the external radius of the upper part of the housing, and a through groove is made in the lid, forming in contact with the body of the crucible along the inner radius of the drain hole.

The through groove is rectangular or oval.

The cover is made in the form of a plate.

The figures show:

FIG. 1 - melting and pouring crucible;

FIG. 2 is a top view of a melting and pouring crucible;

FIG. 3 - melting and casting crucible in the process of pouring the melt into the mold when it is tilted at an angle α.

The melting and pouring crucible contains a housing 1, which can be made in the form of a hollow cylinder or a truncated cone with a spherical or flat bottom (Fig. 1). On the housing 1 is installed a cover 2 in the form of a plate, made in the form of a segment.

The cover has a radius equal to the outer radius R of the upper part 3 of the housing 1 (Fig. 2).

The width h of the cover 2 is 0.7-1.3 from the outer radius of the upper part 3 of the housing 1: h = (0.7-1.3) R.

A through groove 5 is made at the edge 4 of the lid 2, conjugated with the crucible body 1. A groove 5 is made at the top of the segment, at a distance equal to the width h of the lid 2 from the chord 6. The groove 5 can be made rectangular or oval (dashed) in shape and forms in contact with the body 1 of the crucible (namely, with the inner radius r of the body 1) drain hole (Fig. 1, 2).

If the width h of the lid 2 is less than 0.7R, then it is insufficient to create a melt pressure above the drain hole. As a result, funnel formation and kneading of the slag into the metal being drained may occur. If the width h of the lid is more than 1.3 R, then the free surface area of the melt in the crucible becomes insufficient to observe the course of the melting, as well as to melt the melt along the course of the melting.

When the crucible rotates to drain the melt into a mold, the angle of inclination α at each moment of time must correspond to a predetermined pressure head N of the molten metal above the drain hole formed by the groove 5 of the lid 2 and the inner radius r of the crucible body 1 (Fig. 3). The pressure N corresponds to the flow rate Q of the liquid from the crucible in the ratio:

;

;

where s is the area of the drain hole formed by the groove 5 of the lid 2 and the inner radius r of the crucible body 1 (Fig. 2);

φ is the discharge coefficient of the drain hole, its value is 0.6-0.7;

g is the acceleration of gravity.

The value of Q is defined as the technological parameter of pouring a specific form.

Smelting - casting crucible works as follows.

During metal melting, a slag layer 7 is formed on the free surface of the melt (Fig. 3) as a result of the interaction of the metal with the atmosphere of the furnace, crucible material and deoxidizing additives. Slag during the discharge of the melt can penetrate the castings and be a source of non-metallic inclusions. When using the melting and pouring crucible of the claimed design and installing the lid 2 after the preparation of the melt for pouring, the crucible is rotated to drain to ensure a predetermined pressure H in the crucible. In this case, the slag 7 is delayed, since it has a density of 1.5-2 times lower than the metal and moistens the walls of the crucible body 1 and the lid 2 well, and the melt clean of slag is poured into the mold (Fig. 3).

Experimental melts using a crucible of the claimed design showed the absence of defects slag blockage and oxide film during x-ray and lumontrol of the obtained castings.

Due to the fact that the lid is made in the form of a segment with a radius equal to the outer radius of the upper part of the casing, the width of the lid is 0.7-1.3 from the external radius of the upper part of the casing, a through groove is made in the lid at the top of the segment, the quality of the resulting castings is improved by warning clogging with slag and other non-metallic inclusions present in the liquid metal and penetrating into the mold during its pouring, as well as extending the life of the lid and the crucible itself.

Claims (3)

1. A melting and casting crucible containing a housing on which a lid is mounted, characterized in that the lid is made in the form of a plate in the form of a segment, the radius of which is equal to the outer radius of the upper part of the housing, while the width of the lid is 0.7-1.3 from outer radius of the upper part of the body, and a through groove is made in the lid, forming a drain hole in contact with the crucible body along the inner radius. 2. The melting and casting crucible according to claim 1, characterized in that the through groove is made of a rectangular or oval shape. 3. The melting and pouring crucible according to claim 1 or 2, characterized in that the lid is made in the form of a plate.

Images