US3311467A

US3311467A - Method of metal modification under pressure and arrangement to carry out same

Info

Publication number: US3311467A
Application number: US295319A
Authority: US
Inventors: Polishouk Vitalii Petrovich; Tsin Mark Rakhmilievich; Zatoulovsky Sergei Semenovich
Original assignee: INST LITEINOGO PROIZV AKADEMII
Current assignee: INST LITEINOGO PROIZV AKADEMII; INSTITUT LITEINOGO PROIZVODSTVA AKADEMII NAUK UKRAINSKOI SSR
Priority date: 1963-07-16
Filing date: 1963-07-16
Publication date: 1967-03-28
Anticipated expiration: 1984-03-28

Description

March 28, 1967 v, p, poL sHou ET AL METHOD OF METAL MODIFICATION UNDER PRESSURE AND ARRANGEMENT TO CARRY OUT SAME Filed July 16, 1963 f vA 1 iEEIIEQQ,

United States Patent i METHOD ()F METAL MODIFICATION UNDER PRESSURE AND ARRANGEMENT TO CARRY OUT SAME Vitalii Petrovich Polishouk, Mark Ralrhmilievich Tsin, and Sergei Semenovich Zatouiovsky, all of Kiev, U.S.S.R., assignors to Institut Liteinogo proizvodstva Akademii nauk Ukrainskoi S.S.R.

Filed July 16, 1963, Ser. No. 295,319 3 Claims. (Cl. 75-45) The present invention is related to improving metal properties and more particularlyto metal modification. It has now become a common practice to improve metal properties by treating molten metals by adding materials thereto.

Previous methods of metal modification include those in which the liquid metal is modified under pressure in an autoclave or in a ladle under self-pressure, or the method according to which the metal is modified under air pressure in a stream.

Among the disadvantages of the previous procedures is that the modifier is either introduced into a closed tank of metal under high pressure, that is metal modification according to this method is a batch process in which all metal mass in the tank is under pressure, which fact causes large energy consumption; or the modifier is introduced directly into a flowing stream of molten metal under normal pressure, which fact in turn causes costly waste of the modifier and nonuniform addition.

The object of the present invention is to provide a method permitting saving of the modifier and insuring continuous modification.

Another object of the invention is to provide a method of metal modification insuring high quality metal modification.

A further object of the invention is to provide an apparatus to carry out the proposed method.

According to the proposed method the metal is allowed to flow in a continuous stream. The pressure is produced by two electromagnetic fields induced by two coils, provided with magnetic cores and enclosed in a ceramic housing, along that portion of the stream to which the modifier is applied.

The method of the invention is illustrated in the accompanying drawing, in which:

FIGURE 1 is a view partly in vertical section and partly in elevation of an apparatus for practicing the method, and

FIGURE 2 is a horizontal cross-sectional view taken along line AA of FIGURE 1.

As stated, the drawing shows an apparatus to carry out the proposed method of modification. It comprises a vessel 1; an inclined duct 2 for admitting the liquid metal; a vertical passage 3 to provide an outlet for uncombined modifier vapours; a modification chamber 4 with an inlet 5 for admitting the modifier; two

coils

6 and 7 with magnetic cores 8 and 9, housed in a ceramic casing 16, and an outlet spout 11.

The arrangement functions in the following manner; the coils are primary windings of singlephase transformers whose common secondary winding is the ring of liquid metal in the chamber.

The ring of liquid metal extends between the two transformer magnetic cores 8 and 9 whose

primary coils

6 and 7 are connected in parallel. Thus, current is induced in the liquid metal by the upper coil and the lower coil. Since the arrangement comprises a secondary winding which is liquid metal and which is common to the two primary windings and is located between the latter, a compressive stress is produced in the liquid metal, due to which fact pressure is applied to the metal along 3,31 1,467 Patented Mar. 28, 1967 ice the short length of the stream where the modifier is added to the metal, said pressure being dependent on the current flow in the coils. The cross section of the ducts and the outlet port diameter are determined so as to allow molten cast iron or other metal to fill all the conduits during operation. The modifier is applied continuously throughout the modification process through the inlet port 5 in any known manner.

On entering the cast iron, the metallic modifier evap orates much slower than under air pressure, because the metal in the chamber 4 is under pressure. Modifier vapour bubbles move upwards and treat the metal in chamber 4 and passage 3. Uncompounded vapours are withdrawn through passage 3 and pass to the ventilationsystern. The metal treated in the above described manner is discharged through the outlet passage 11.

As the metal flows down through the chamber 4 at a certain velocity, it entrains the ascending modifier bubbles. Consequently, their passage through the metal becomes longer. Adequately chosen pressure in the modification chamber and the velocity of the metal fiow permit high-rate modifier assimilation in the metal at any temperature of the metal and with any amount of the modifier applied.

The invention described herein is characterized by the following advantages:

(1) The arrangement permits a continuous treatment of liquid metal by modifier under pressure.

(2) The treatment takes place when the metal is discharged from a furnace into the ladle, and therefore does not require additional time.

(3) The gradual application of the modifier combined with the high pressure in the modification chamber with the opposite flows of modifier bubbles and metal and a relatively high column of metal to be treated, provide best conditions for high-rate modifier assimilation and metal saturation with the modifier to a large extent.

(4) A possibility to treat any weight of metal and to alter the volume of metal treated per unit time and the amount of the modifier added.

(5) The absence of moving parts in the modification chamber permits reliable sealing of the area under the pressure of the liquid metal, which fact permits a safe operation of the arrangement.

(6) The arrangement is small and is installed in a limited space.

(7) The currents induced in the metal heat the metal during the treatment procedure.

(8) The arrangement is easily controlled and adjusted for a wide range of parameters.

(9) The operation of the arrangement can be completely automated by a self-adjusting regulation system.

Although the present invention has been described in connection with the preferred embodiment, it will be understood that modifications and variants may occur without departing from the spirit and scope of the invention.

Such modifications and variants are considered to be within the scope of the invention and the appended claims.

What we claim is:

l. A method of continuous treatment of molten metals with additives comprising: providing a continuous flow of molten metal through a closed channel defining a treating zone; imposing electromagnetic fields on the continuous flow of metal in said closed channel at two axially spaced points so as to induce in the liquid metal in said channel two opposite electromagnetic forces, which create a high pressure zone in said channel between the points where said electromagnetic fields are applied; continuously supplying additives which are vaporizable at the temperature of the molten metal to the flowing metal in said high pressure zone, whereby the additives evaporate at a slow rate under the effect of high pressure, thereby prolonging the time of contact between vapors of the additives and the molten metal.

2. An apparatus for continuous treatment of molten metals with additives comprising: a closed channel having an inlet for admitting molten metal and an outlet for discharging molten metal from said channel; two electromagnets positioned to create a high pressure zone in the molten metal while it flows through said channel, said electromagnets being mounted on said channel spaced from each other and producing forces which act in 0pposite directions; an opening in said closed channel between said electromagnets for continuously feeding said additives to the molten metal while it is flowing through the high pressure zone of said channel.

3. An apparatus for continuous treatment of molten metal with additives according to claim 2, wherein said closed channel is a flow chamber having a annular cross section, and said electromagnets are two coils arranged adjacent the ends of said chamber and energized from an AC. source and fitted on magnetic cores which project into the space surrounded by said chamber.

References Cited by the Examiner UNITED STATES PATENTS BENJAMIN HENRIN, Primary Examiner.

Claims

1. A METHOD OF CONTINUOUS TREATMENT OF MOLTEN METALS WITH ADDITIVES COMPRISING: PROVIDING A CONTINUOUS FLOW OF MOLTEN METAL THROUGH A CLOSED CHANNEL DEFINING A TREATING ZONE; IMPOSING ELECTROMAGNETIC FIELDS ON THE CONTINUOUS FLOW OF METAL IN SAID CLOSED CHANNEL TWO AXIALLY SPACED POINT SO AS TO INDUCE IN THE LIQUID METAL IN SAID CHANNEL TWO OPPOSITE ELECTROMAGNETIC FORCES, WHICH CREATE A HIGH PRESSURE ZONE IN SAID CHANNEL BETWEEN THE POINTS WHERE SAID ELECTROMAGNETIC FIELDS ARE APPLIED; CONTINUOUSLY SUPPLYING ADDITIVES WHICH ARE VAPORIZABLE AT THE TEMPERATURE OF THE MOLTEN METAL TO THE FLOWING METAL IN