SU450637A1 - Metal rod melted - Google Patents

Description

The invention relates to foundry and can be used in the manufacture of hollow castings using metal melted cores.

The known metal fusible rods, made hollow, ae provide such parameters as gas permeability, compliance and timely removal of the contact area of the contact area between the casting and the liquid phase core formed during solidification of the casting. In addition, the melting of the rod starts from the surface and, due to a sharp increase in the volume of the metal during the transition from the solid to the liquid state, is accompanied by an increase in pressure in the liquid phase.

If the pressure in the melt at the interface of the casting-rod is not timely reduced, a solid crust formed during crystallization and the core material will not break into the casting body. The greater the Dasnite in the core and cast material's melting temperatures, the greater the likelihood of this defect. due to a sharp increase in temperature in the contact layer of the rod immediately after pouring and in the process of heat release crystallization of the solid phase of the casting. To prevent the formation of cracks in casting, the hornet must be sufficiently pliable during the shrinkage process during its hardening and cooling. This is especially important for such variants of a core-rod, such as white iron aluminum, steel-aluminum, at which the melting point of materials and the rod is 600-900 ° C, and the solid state of the casting material is 1.5 -

The purpose of the invention is to increase gas permeability and compliance I and timely removal from the zone

the contact of the casting and the core of its liquid phase, formed during solidification of the casting.

For this, longitudinal surface grooves are closed in the design and gas parts of the rod, closed with melted inserts.

The number of recesses made in the rod, and their sizes are chosen depending on the weight, material and dimensions of the casting and the rod. The melted inserts covering the grooves are assembled with a rod

The external surface of the rod is connected with grooves of the slit-like channels.

FIG. I depicts a rod of alloy AL2 with inserts of the same alloy, a general view; figure 2 is the same, the section along aA; in FIG. 3, the metal mold and the rod are assembled to produce a steel casting.

The rod I, made by casting in a chill mold, has longitudinal grooves 2, which are closed from above by injection molding inserts 3. The inserts are made with protrusions 4, forming gaps (for example, fv 0 | 5 mm) connecting the outer surface of the rod with the slots 2. The rod has the sign 6 ..

Wire, for example, aluminum can be used as inserts.

When metal is poured into the chill mold 7, the chill air present in the working cavity escapes through the gaps 5 and the grooves 2 in the rod 1. In the same way, gases generated by the interaction of the liquid metal with the refractory coating of the rod and released from the metal during crystallization are removed. In the process of crystallization of the metal, the inserts 3 first melt and the resulting liquid metal flows out through the grooves 2 and out of the cavity of the mold. Upon subsequent fusion of the rod, its liquid phase is also removed through these grooves. Due to the presence of inserts and grooves in the rod 1, it becomes possible to remove air and gases from the working cavity of the mold through the core, and strictly sequentially melt the rod, eliminating the conditions for increasing pressure in the resulting liquid phase of the material of the rod, creates an easy shrinkage of the casting.

THE INVENTION OF THE INVENTION A metal melted rod for obtaining castings with cavities, characterized in that, in order to increase the gas permeability and flexibility of the rod and timely removal from the contact zone of the casting and the rod of its liquid phase formed during solidification and cooling of the casting, the casting and its liquid parts of the rod are made with longitudinal surface grooves covered with melted inserts.