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Vsesojuzny Nauchno-issledovatelsky Proektno-konstruktorsky I

David Grigorievich Bykhovsky

Alexandr Yakovlevich Medvedev

Jury Alexandrovich Bogorodsky

Albert A Voropaev

Yakov Vulfovich Rossomakho

Alexandr Ivanovich Danilov

Arkady Leonidovich Bolotnikov

Alexandr N Panov

Konstantin P Alexeev

Vladimir A Alexandrov

Vladimir Nikolaevich Firsov

Vyacheslav G Sobolev

Viktor N Kiselev

Mikhail Isaakovich Zax

Alla V Lopatina

Evgeny F Olennikov

Eduard R Fomin

Gennady Egorovich Strepetov

Mikhail Shikovich Brodsky

Viktor S Kunin

Valentin N Nesterov

Alexandr Yakovlevich Finkelshtein

Aldexandr Ivanovich Danilov

Valery M Vassin

Apparatus for meter-feeding and heating of molten metal

Device for transfer of molten metal

A non-consumable electrode for use in arc and plasma devices in an inert gas atmosphere comprising a holder and an active portion made of a refractory metal with emission admixtures, the active portion being connected with the holder so that its outer side surface is exposed to a height exceeding 1/4 of a diameter thereof.

Non-consumable electrode

A non-consumable electrode for plasma-arc welding in an atmosphere of carbon dioxide or carbon-dioxide-based mixtures, includes a holder of copper or copper alloys and an active insert of hafnium embedded in the holder, with a hafnium oxycarbide layer disposed on the surface of the insert, the latter also including a graphite layer applied over the hafnium oxycarbide layer. A method of manufacturing the non-consumable electrode includes the steps of joining the holder of copper or copper alloys to the active insert of hafnium, connecting the holder to the negative pole of the power supply, placing the non-consumable electrode in an atmosphere of carbon dioxide, connecting an additional electrode to the positive pole of the power supply with an electric arc struck between the electrodes, forming a hafnium oxycarbide layer on the surface of the active insert at an electric arc current of up to 0.2 I, and subsequently forming a graphite layer over the previously formed hafnium oxycarbide layer as the current is increased from 0.2 I to I at a rate not exceeding 40 amperes per second, where I is the operating current of the non-consumable electrode.

Non-consumable electrode for plasma-arc welding

A method of producing a nonconsumable electrode comprising forming a blind hole in the working end face of a high-melting core of the electrode, partially filling the blind hole with doping agents and then filling the remaining portion of the hole with a mixture of the doping agents and high-melting core material. The mixture is then heated from the surface of the electrode until a fused surface layer is formed and an enclosed space with doping agents is provided in the electrode.

Method of producing nonconsumable electrode for use in arc techniques

A method of treating electrodes intended for operation in argon as electric arc cathodes. Each of the electrodes being treated consists of a holder with an active insert. The active insert comprises elements selected from the series of rare-earth elements, yttrium, alkali-earth elements, elements of Group IV A of the periodic system and compounds thereof, taken separately or in combination. The electrodes are treated in an electric arc burning in an atmosphere of argon and an active gas, such as nitrogen or oxygen. During the course of treatment the electrode functions as a cathode. A mixture of argon and oxygen or argon and nitrogen is fed to the cathode area of the arc. The duration of the electrode treatment cycle is at least 100 times less than that of the electrode operation time in an argon arc. Treatment is conducted by currents that do not exceed the maximum operating current values of the treated electrode. The volume concentration of the active gas in the mixture varies from 0.1 to 100%.

Method of treating electrodes intended for operation in argon as

A method of machining a workpiece after preheating consists in that the workpiece material to be removed by a cutting tool is subjected immediately before the removal operation to intense localized heating and notching by a plasma jet, with a groove being formed on the surface to be machined. To this end, a plasma torch is positioned ahead of the cutting tool so that the angle between the direction of the cutting speed and the plasma jet axis ranges from 0 to 45 degrees, and the angle between the direction of feed of the cutting tool and the plasma jet axis from 10 to 45 degrees.

Method of machining workpieces after preheating

A method of plasma multiarc welding by permanently burning direct-current arcs of different polarities makes use of a plasma forming gas and shielding mediums and the arcs are located so that the adjacent arcs have opposite polarities, consisting, according to the invention, in that all arcs are started between nonconsumable electrodes and a workpiece or some arcs are started between nonconsumable electrodes and a workpiece and other arcs are started between consumable electrodes and a workpiece, the currents of all arcs and the distance between the arcs being set so that the ratio of the product of the currents of two adjacent arcs to the distance therebetween is equal or more than 6.10.sup.3 A.sup.2 /cm.

Method of plasma multiarc welding by permanently burning direct-current

A method of DC reverse polarity plasma-arc machining of electrically conductive materials with the aid of a plasmatron the plasmatron having a nonconsumable electrode with an insert made from a high-melting point material, the method being in that the material being machined is heated by the heat of an electric arc burning between the positive nonconsumable electrode of the plasmatron and the material being machined, with the supply of the plasma-forming gas, the intensity of the working current of the arc being selected such that its ratio to the diameter of the nozzle channel is within 50 to 100 A/mm on condition that at least a portion of the near-the-electrode zone of the arc is maintained in electric contact with the high-melting point insert of the electrode. In an apparatus for plasma-arc machining of electrically conductive materials, the electrode of the plasmatron, with a nozzle arranged coaxially therewith, is coupled to the positive terminal of a power supply source, whose negative terminal is coupled to the material being worked, at least a portion of the end face surface of the electrode of the plasmatron being made from a high-melting point material, and the diameter of the electrode at least 1.1 times the diameter of the nozzle channel.

Method and apparatus for DC reverse polarity plasma-arc working of

A plasma arc torch is of a two-part design and comprises two detachable and tightly joined parts mating with each other of which one part contains an electrode holder with an electrode, a nozzle disposed coaxially of said electrode and having means for supplying an electric current thereto. An insulator is located between said electrode holder and said nozzle, wherein there are also provided passages for the supply of plasma-generating gas and coolant, these being brought out onto the mating surface of the first part. The second part of the torch accommodates means for supplying an electric current to the electrode holder and means for supplying coolant and plasma-generating gas through passages brought out onto the mating surface of the second part so that they match with the corresponding passages of the first part on the surface of the joint thereof.

Plasma arc torch

An apparatus for plasma working of electrically-conductive materials wherein a gas-cooled non-consumable electrode, insulator and a gas-cooled nozzle of a plasmatron are interlinked with one another so as to form a chamber subdivided by a gas-permeable partition so that one of its parts communicates with the atmosphere through a central passage of the nozzle serving to discharge plasma-forming gas and the other part of the chamber communicates with a source of plasma-forming and cooling gas and also with the atmosphere through an additional passage, the non-consumable electrode passing through this partition and being disposed coaxially with the central passage of the nozzle.

Apparatus for plasma working of electrically-conductive materials and

A method of producing electrode units for plasmatrons, according to which a direct-current arc is struck between a tungsten electrode and a melt, so that the electrode acts as a cathode, prior to dipping the electrode into the molten metal, intended e.g. for an electrode holder. Then the electrode is dipped into the melt, and the arc is extinguished.

Method of producing electrode units for plasmatrons

In a method for striking a main arc between the electrode and nozzle of a plasmatron there is initiated with the aid of high-frequency discharge an intermittently-arcing pilot arc whose flame bridges under the influence of a gas fed into the plasmatron the gap between the electrode of plasmatron and workpiece, completing thereby the circuit of main arc. The amplitude of pilot arc current is selected so as to be roughly equal to the steady current of the main arc whereas the frequency and on-off time ratio of the current are selected so as to assure that the flame of pilot arc is sustained unceasingly throughout the arcing of visually-monitored pilot arc. The method for striking a main arc is embodied in an apparatus wherein the electrode and nozzle of the plasmatron are connected to opposing terminals of a source of power so that interconnected between the electrode and nozzle of plasmatron there is an oscillator and between the nozzle and source of power is a RC-circuit serving as a switching device in the electrode-to-nozzle circuit and, further, the nozzle and workpiece are interconnected by the RC-circuit and an inductance, L, connected in series.

Method for striking main arc between the electrode of plasmatron and

An electrode assembly for a plasmatron, comprising a holder being cooled having a high-heat insert mounted therein in contact with a near-the-electrode zone of an arc at one side thereof and in thermal and electrical contact with the cooled holder at the other side thereof; a chamber formed in said holder between said high-heat insert and cooled holder extending symmetrical to the insert axis and filled with a substance whose coefficient of thermal conductivity is lower than that of the material of the cooled holder, the substance filling the chamber being in constant contact with the high-heat insert. Used as a substance filling the chamber is a gaseous element, and as a high-heat insert is a metal selected from groups IV, V, or VI of the Periodic System, or an alloy based thereon.

Growing community of inventors

Saint-Petersburg, Russia

David Grigorievich Bykhovsky