RU2355791C2 - Method of manufacturing of high reactivity metals and alloys ingots and vacuum-arc-refining furnace for manufacturing of reactivity metals and alloys ingots - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to area of special electrometallurgy, particularly to vacuum-arc remelting of high-reactivity metals and alloys and can be used during melting of first-melt ingot with maximal inclusion of shaving into the remelting process. In the manufacturing method of ingots as far as electrode alloying in vacuum-arc-refining furnace into annular gap between the electrode and mold wall it is cycling fed titanium shaving, which is molten simultaneously with consumable electrode. Vacuum-arc-refining furnace is outfitted by mixture bin for cycling feeding into mold titanium shaving, connected to furnace mold by means of reducing flange with window and implemented with grid in the bottom part of receiving cone and tray at out from the mixture bin, surface of which is implemented in the form of two grooves, separating come in mold shaving for two streams.

EFFECT: accessory inclusion (up to 26% and higher) of shaving in to melting process of titanium alloy ingots.

4 cl, 1 tbl, 2 dwg, 1 ex

Description

The invention relates to the field of special electrometallurgy, namely to a vacuum arc remelting of highly reactive metals and alloys, and can be used in the smelting of ingots of the first remelting with the maximum involvement of chips in the remelting process.

The most common (about 45% of the total mass of industrial metal waste) and the most difficult to recycle type of waste is shavings, the difficulty of preparing it for processing lies in the fact that it takes up a large amount and is usually contaminated.

A known method of producing consumable electrodes using 10-15% shavings of titanium alloys, the rest is a titanium sponge (Kiparisov S.S. et al. Processing of titanium scrap. - M. 1984, issue 1).

The disadvantage of this method is the use of a significant amount of expensive titanium sponge, as well as insufficient mechanical strength of the electrodes, which can lead to their destruction during remelting.

The closest in technical essence and the achieved result to the claimed invention is a method for the manufacture of ingots from non-compact steel wastes (RU 2148665, MPK7 С22В 9/18, publ. 2000 Bull. No. 13) - prototype. The method includes loading into the crystallizer of a vacuum electric arc furnace a consumable electrode pressed from waste materials with flux portions pressed into blocks and gradually melting the waste and flux together, combining electroslag remelting processes and vacuum arc remelting.

The disadvantage of this method is the impossibility of obtaining a single molded electrode with a length of more than two meters and, therefore, the inability to obtain by vacuum arc remelting an ingot with maximum chip involvement, to which the claimed invention is directed.

Known vacuum arc furnace for smelting ingots of highly reactive metals and alloys, containing a vacuum chamber, electrode holder, mold, pan and current supply (Andreev A.L., Anoshkin N.F. and other titanium alloys. Melting and casting of titanium alloys. - M. : Metallurgy, 1994, p.151-152, Fig. 54) - prototype.

A disadvantage of the known furnace is that this furnace is intended for remelting only the consumable electrode. Adding additional charge materials during the melting of the electrode is structurally impossible.

The problem to which this invention is directed, is to increase the share of secondary waste involved, in particular shavings, in the process of smelting ingots with the possibility of obtaining ingots of the required chemical composition.

The problem is solved in that in the method of manufacturing ingots of highly reactive metals and alloys, comprising loading a pressed consumable electrode into a mold of a vacuum arc furnace and gradually fusing the electrode, according to the invention, as the molded pressed consumable electrode is fused, titanium is portioned into the annular gap between the electrode and the wall of the mold of the furnace shavings and melt it simultaneously with a consumable electrode. In addition, after loading the consumable electrode into the mold, at least one portion of titanium shavings is poured onto its tray.

The problem is also solved in that a vacuum arc furnace for the manufacture of ingots of highly reactive metals and alloys, containing a vacuum chamber, an electrode holder, a mold, a pan and a current lead, according to the invention is equipped with a charge hopper for portion feeding of titanium shavings into the mold, connected to the mold of the furnace through a transition flange with a window and made with a grate in the lower part of the receiving funnel and a tray at the exit of the feed hopper, the surface of which is made in the form of two streams dividing the chips entering the mold into two streams. In addition, the furnace additionally contains two drives and two time relays, which drive, both alternately and together, a grill and a tray.

The essence of the invention is illustrated by graphic materials. Figure 1 shows a diagram of the proposed vacuum arc furnace with a feed hopper.

Figure 2 presents a diagram of the tray with partitions dividing it into two streams for feeding chips into the mold of the furnace.

The furnace contains a vacuum chamber 3, a mold 5, a pan 6, as well as an electrode holder 1 to which the electrode 2 is attached. The furnace is connected via a transition flange 4 and a tray 11 to a charge hopper 7, which in its lower part has a receiving funnel 8 with her lattice 9. The lattice 9 and the tray 11 are driven by vibrators 10. The chips in the mold 5 of the furnace is fed through the window 12, located in the transitional flange 4.

Vacuum arc furnace operates as follows.

The vacuum chamber 3, the transition flange 4, the mold 5 are fixed to each other stationary. At the bottom of the mold is a pan 6, on which a portion of the chip is poured. Consumable extruded electrode 2 is welded to the electrode holder 1. The furnace is evacuated. Before turning on the arc power source and pointing the molten metal bath, the polarity of arc burning was changed from direct to reverse. After the first portion of the chip and part of the pressed electrode are melted, a portion supply of chips from the charge hopper is performed. Chip from the feed hopper 7 enters through the grate 9 located in the receiving funnel 8 onto the tray 11 and through the window 12 located in the transitional flange 4 is poured by two streams into the gap between the consumable electrode 2 and the mold wall 5. The surface of the tray 11 is made in the form of two streams . The vibrators 10 of the grill 9 and the tray 11 are used in the process both alternately and simultaneously. With the help of two time relays installed on the working panel of the smelter, the mass of poured chips is regulated. Batch feed of chips occurs during the entire melting process until the electrode is completely fused. After cooling, the ingot is unloaded.

An example implementation of the method.

The ingot was melted in a VD 650 vacuum electric arc furnace using a pressed consumable W6 titanium alloy electrode with a mass of 520 kg, diameter 390 mm, and length 1120 mm. The total amount of waste in the pressed electrode was 38%, including 18% of titanium chips, which corresponds to 94 kg of electrode mass. In the process of melting, batch pouring of chips of W6 alloy in an amount of 226 kg was performed. Thus, the total amount of chips in the smelted ingot was 44%.

The resulting ingot was subjected to two additional remelts in a vacuum arc furnace.

The chemical composition of the obtained ingot is given in the table.

Alloy No. of swimming trunks Selection area FROM N N 0 Al V Fe Mi Si Zr Sn Cu Cr Tue6 0-24-8056 Top 0.015 0.014 0.003 0.157 6.19 3.56 0.26 0,029 0.02 <0.02 0.006 0.011 0.056 Bottom 0.016 0.014 0.003 0.158 6.22 3.64 0.3 0,041 0,024 <0.02 0.007 0.015 0,064 GOST 19807-91 Min 5.3 3,5 Max 0.10 0.05 0.015 0.20 6.8 5.3 0.60 - 0.10 0.30 - - -

The chemical composition of the ingot corresponded to GOST 19807-91 “Titanium and wrought titanium alloys. Stamps. "

The proposed method for the manufacture of ingots and a vacuum arc furnace for its implementation, in comparison with the known ones, allows for additional (up to 26% or more) involvement of charge materials in the form of shavings in the manufacturing process of ingots and to obtain ingots with the required chemical composition for further use in the metalworking industry .

Claims (4)

1. A method of manufacturing ingots of highly reactive metals and alloys, comprising loading a pressed consumable electrode into the mold of a vacuum arc furnace and gradually melting the consumable electrode, characterized in that as the pressed consumable electrode is melted, titanium shavings are portioned into the annular gap between the electrode and the wall of the furnace mold and melt it simultaneously with a consumable electrode. 2. The method according to claim 1, characterized in that after loading the consumable electrode into the mold, at least one portion of titanium shavings is poured onto its tray. 3. A vacuum arc furnace for the manufacture of ingots of highly reactive metals and alloys, containing a vacuum chamber, an electrode holder, a mold, a tray and a current lead, characterized in that it is equipped with a charge hopper for portioned supply of titanium shavings to the mold connected to the furnace mold by means of a transition flange with a window and made with a grate in the lower part of the receiving funnel and a tray at the outlet of the feed hopper, the surface of which is made in the form of two streams separating the tallizator chips into two streams. 4. The vacuum arc furnace according to claim 3, characterized in that it further comprises two actuators and two time relays, which set in motion both alternately and together the grate and the tray.

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