RU2285579C1 - Steel ingot casting apparatus - Google Patents

Abstract

FIELD: ferrous metallurgy, namely structures of ingot molds with tops.

SUBSTANCE: apparatus includes ingot mold with top whose metallic casing has wall of variable thickness and cross section of working cavity near upper base in the form of circle and near lower base - in the form of ellipse. Lower base has outer wing of U-shaped profile for filling it with cooling agent.

EFFECT: less loss of yield, shortened time period for forming bridge under top.

3 cl, 2 dwg, 1 tbl

Description

The invention relates to ferrous metallurgy, and in particular to devices for casting steel ingots with a profitable extension.

A device for casting steel ingots is known, described in German patent No. 1224449, 1966, in which a profitable extension is used, and at the junction between the mold and the profitable extension, a sealing ring or a groove-protrusion seal is installed outside, and the groove is filled with a heat insulating element. This device helps to retain heat in profit longer with the formation of a shrink shell in it, leaving the body of the ingot.

A device for a profitable extension (taken as a prototype) is protected by copyright certificate No. 1222401, 22 D 7/10, 1983. This profitable extension contains a conical metal casing with a variable wall thickness, and the working cavity in cross section at the upper end is made in the form circle, and at the bottom end - in the form of an ellipse, and the small axis of the ellipse is 1.0-3.0 circle diameter. The well-known profit device makes it possible to form a profitable bridge of dense metal, and is chosen by mass to provide the time required for the formation of the bridge, and not the complete crystallization of the ingot. The presence of a dense bridge prevents the oxidation of the metal formed in the ingot axial friability during its heating under forging.

The aim of the claimed device is to reduce the time of formation of a profitable bridge due to accelerated heat removal and increase the yield.

To achieve this goal, in a device for casting steel ingots, including a pallet, mold and a profitable extension with a metal casing made with a variable wall thickness and having a circumference in the cross section of the working cavity at the upper base and the lower base of the metal according to the invention, an ellipse, according to the invention the casing is equipped with an external shelf, made with a U-shaped profile, for filling at the right time with a cooler, such as water.

Instead of water, lead having an increased heat capacity can be used.

Forging ingots used for hollow forgings, especially long ones (such as hollow shafts or pipes), it is recommended to cast with a minimum volume of the profitable part, reducing it to 7-9% by weight of the ingot. At the same time, a further decrease in the volume of the profitable part to 5-6% is possible. To do this, it is necessary to strengthen the heat sink at the junction of the ingot body with its profit. This is achieved by an additional cooling element, for example, water, lead or another cooler placed in a cavity with a U-shaped section of the lower outer part of the casing of the profitable extension.

To explain the inventive device, a drawing is shown (Fig. 1), which shows a general view of the device assembly. The device comprises a mold 1, a pallet 2, a profitable extension with a metal casing 3, equipped with an external shelf 4 at the base with a U-shaped profile for filling with a cooler 5, for example, water.

Figure 2 shows a drawing of a profitable extension; AA - bottom view, B - top view. The inner cavity of the profitable extension in the upper section is limited by a circle, and in the lower section by an ellipse, and the small axis of the ellipse is equal to or greater than the diameter of the circle bounding the upper part of the internal cavity. At the same time, the walls of the profitable extension, bounding its internal cavity, have a variable thickness: minimum on the sides of the maximum axis of the ellipse and maximum on the sides of its minimum axis.

The thicker walls of the profitable extension in the narrowest lower section of its internal cavity additionally accelerate the crystallization of the metal in the lower part of the profit, which is required for the formation of a closed shrink shell in the body of the ingot.

The implementation of the claimed device is as follows. For casting a steel ingot, the device is assembled. A mold 1 is installed on a pallet 2, and a profitable extension with a casing 3 having an external U-shaped shelf 4 is installed on it. The device is ready for casting. After filling the molds with metal, fill the U-shaped shelf 4 with cooler 5, for example water. The ingot metal, cooling, gives off heat, incl. casing 3 profitable extension, which is heated. The excess heat of the casing is spent on heating and evaporation of water 5. The casing 3 loses heat, which increases its heat capacity and promotes accelerated crystallization of the near-profit dense metal bridge, which will form at an earlier stage than in the prototype and will separate the volumes of the ingot metal and profit. Therefore, the volume of the profitable part can be reduced.

6 elongated ingots were cast from the metal of one melt, with 3 ingots (Nos. 1, 2, 3) in accordance with the prototype, and 3 ingots (Nos. 4, 5, 6) using the inventive device. 30 minutes after the end of the casting, 12 liters of water were poured into the U-shaped cavities of ingots No. 4, 5, 6. The obtained characteristics of the ingots were processed and tabulated.

Analysis of the metal obtained ingots showed that axial friability is observed in the ingots. In ingots No. 4, 5, 6, cast using the proposed device, a narrow secondary shrinkage shell was formed, which is located under a profitable bridge. The location of defects of the axial zone in diameter did not exceed 5% of the diameter of the body of the ingot. With further processing of the ingot into a hollow billet, the axial zone will be removed and high-quality dense metal will be obtained in the forging billet, which was confirmed by ultrasonic testing in the study of forgings.

Using the proposed invention will allow to obtain savings by reducing the mass of profit and increase yield.

The table of characteristics of the ingots cast using the proposed device, in comparison with the characteristics of the ingots obtained using the prototype Ingot number Ingot mass, t The relative amount of profit, mm The diameter of the top profit,% The major axis of the lower profit section, mm The minor axis of the lower profit section, mm / multiplicity to the value of the upper diameter Yield,%: one 2 3 four 5 6 7 one 9,620 6.2 330 655 330 / 1,0 72.0 2 9,618 6.18 165 655 330 / 2.0 73.3 3 9,616 6.16 110 655 330 / 3.0 73.5 four 9.54 5.25 330 655 330 / 1,0 74.0 5 9.52 5.23 165 655 330 / 2.0 74,2 6 9.50 5.21 110 655 330 / 3.0 74.6

Claims (3)

1. A device for casting steel ingots, containing a pallet, mold and a profitable extension, the metal casing of which is made with a variable wall thickness and has a cross section of the working cavity at the upper base in the form of a circle, and at the lower base in the form of an ellipse, characterized in that the lower base of the metal casing is equipped with an external shelf made of a U-shaped profile, to fill it with a cooler after filling the mold with steel. 2. The device according to claim 1, characterized in that water is used as a cooler. 3. The device according to claim 1, characterized in that lead is used as a cooler.

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