SU784979A2 - Mould for continuous centrifugal casting unit - Google Patents

Description

(54) CRYSTALIZER FOR INSTALLATIONS OF CONTINUOUS CENTRIFUGAL CASTING

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The invention relates to foundry equipment and can be used in continuous and continuous centrifugal methods for casting ingots.

According to the main author. St. No. 632472 is known for a mold for continuous centrifugal casting plants, equipped with a gating system made in the form of supplying longitudinal channels connected to a transverse sprue run with a slit directed to the inner surface of the crystallizer, and the configuration of the slit and gating stroke corresponds to the shape of the inner surface of the crystallizer. The presence of the indicated gating. The system provides high-quality casting by stabilizing the process.

However, the described gating system hinders the possibility of increasing the casting speed in the production of ingots using both continuous and continuous centrifugal casting methods. This is because during the casting of ingots compared to 20 with the casting of pipes (at the same rate of extrusion of the casting), the rate of outflow of metal from the slit-like exit of the runner. system increases dramatically as the volume of metal flowing through the gap increases. This leads to increased erosion of the gap, and consequently, to a reduction in service life.

The purpose of the invention is to increase the service life of the gating system and the productivity of plants in the production of ingots.

This is achieved by providing a supply channel in the center of the gating system in the direction of the mold axis, the configuration of which corresponds to the configuration of the internal surface of the mold, the channel cross-sectional area being 1.2-2 times larger than the output slit area of the gating system.

The presence of the central channel of the said spatter allows the passage of the volume of metal necessary to maintain the optimum flow rate through the exit slit when casting ingots (it was established experimentally that this speed should be 2-6 times greater than the speed of casting). Such a solution also avoids a sharp increase in the rate of outflow through the gap with increasing ingot extrusion speed, which reduces the possibility of erosion of the runner system.

Matching the configuration of the channel to the configuration of the inner surface of the mold ensures uniform heating of the gating system, which reduces the thermal stresses in it.

The drawing shows a diagram of the described mold.

The mold 1 with the potting device 2 contains a cooling system 3 (e.g., water-air) and a gating system 4 made of a refractory material. In the center of the gating system 4 in the direction of the mold axis, channel 5 is made, the configuration of which corresponds to the configuration of the inner surface of the mold (i.e., for casting square ingots — a square, for round ones — a circle, etc.). The cross-sectional area of the channel 5 is made 1.2-2 times larger than the cross-sectional area of the exit slit 6 of the gating system 4. This ratio of the dimensions of the central channel and the exit slit provides a uniform supply of molten metal through the slit at a speed of at least twice the speed extrusion casting.

As experiments have shown, when the ratio of the specified areas is less than 1.2, there is an increased rate of metal outflow through the slit, which leads to its thickening, and at a ratio of more than 2, due to the decrease in the rate of metal outflow through the slit, its frosting is possible.

The redist works as follows.

Before starting to pour into the mold 1, the gating system 4 is introduced into the exit slit 6 (not shown) and the cooling system 3 is turned on. Then liquid metal is continuously poured through the casting device 2 with automatic dosing with a predetermined flow rate.

The molten metal fills the gating system 4. Blast from the output slit 6 and channel 5 the metal fills the space before the seed and is welded to it. On the inner surface of the cooling mold I begins the growth of the crust. Upon expiration of the estimated time during which the solid metal crust is formed, a mechanism for casting extrusion is turned on (not shown).

Example. During continuous casting of a round cast iron ingot with an outer diameter of 100 mm, the cross-sectional area of the exit slit was 9.45 cm (slot height 3 mm), the central channel area was 15 cm (diameter 44 mm). The channel cross-sectional area here is about 1.6 times larger than the slit cross-sectional area (15 cm 2;; 9.45 cm 1.596). These dimensions provide an outflow rate through the exit slit 4 times more than the rate at which the casting is drawn.

The presence of a central channel of the indicated dimensions to the tiling system provides for an increase in its durability, since the erosion of the gap by the liquid metal decreases and the heating uniformity of the entire runner system is improved. This provides an increase in the productivity of the installation when casting ingots.

Claims (1)

Invention Formula Mold for continuous centrifugal installations for auth. St. No. 632472, characterized in that, in order to increase the service life of the gating system and productivity, a channel is made in the center of the gating system in the direction of the mold axis, the configuration of which corresponds to the configuration of the inner surface of the mold, 1.2-2 times the cross-sectional area of the channel larger cross-sectional area of the exit slit of the gating system. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 632472, cl. B 22 D 13/10, 1977 (prototype). I ///////// Shch Vyt givanie omavSKu: I-I V Ш 5