SU1763125A1 - Method of electric arc surfacing of powders with use of magnetic arc field and device therefor - Google Patents

Abstract

Use: surfacing of powder materials in the manufacture of parts with a wear-resistant surface, restoration of worn surfaces. SUMMARY OF THE INVENTION: A welding current source is included, a working zone is supplied under a pressure of 0.2-f), 3 atm powder and a flammable liquid in a jet with a diameter of 0.5-1.0 mm. With the excitation of an arc from a powder under the influence of its magnetic field, an electrode is formed; hot liquid, combustion, protects the molten metal from oxidation. The device contains go-. a roll with a tube for supplying flammable liquid. The end of the tube is located within the nozzle at a distance of 15–20 mm from its cut. A shut-off valve is installed at the outlet of the powder bin. 2 nzff-ly, 3 Il.

Description

The invention relates to cladding and can be used to restore machine parts, metal-cutting tools, to weld heat-resistant and wear-resistant coatings.

The purpose of the invention is to improve the quality of the cladding by reducing the rubies of penetration.

Figure 1 shows the device, a general view; Fig. 2 shows a surfacing head, a slit; on fig.Z - bunker-feeder, section.

The device includes:

The body of the surfacing head 1 with a water-cooled nozzle, a tank 2 for storing flammable liquid, an ejector type feeder 3 for feeding powder into the body of the surfacing head.

The surfacing head 1 consists of a choke through which a flammable liquid (diesel fuel & o) is fed under a pressure of 0.2-0.3 atmospheres, fitting 5 for supplying powder with transported air under a pressure of 0.2-0.3 atmospheres. A part 6 and a part 7 are screwed into the housing, between which a cavity 8 with a height of 2 mm is formed. The flammable liquid enters it from the nozzle, which then passes through an opening of 2 mm in part 7 and enters the tube with an outer diameter of 2 mm and an inner diameter of 0.5-1 mm. The ignition liquid comes under pressure of 0.2-0.3 atmospheres to the nozzle of the surfacing head. The tube 9 does not reach the nozzle opening of 15-20 mm. The nozzle is made of copper and the nut nut is fastened to the surfacing head. The surfacing head is attached to a special suspension at 04 i.

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the power of the component 10. The suspension of the surfacing head allows its position to be changed in three mutually perpendicular planes.

The feeder hopper 3 contains a loading opening that is closed by a stopper I. In the hopper lid, a four-way clutch 12 is fastened as a collector into which the air enters through the tube 13. From the coupling 12, the air is distributed in three directions - along the tubes I, 15 and 16. arbitrary step.

The tube 15 is located on the axis of the bunner. On the sides of the tube diametrically opposite holes are drilled with a diameter of 1 mm with an arbitrary pitch. To prevent the powder of the yogi from entering the tube through the holes in the tube, screens 16 are fixed. Tube 17 equalizes the pressure between the inner cavity of the hopper and the pressure in the tubes. Through the holes in the tubes, air enters the powder under pressure and loosens the powder.

A casing 18 is fastened to the hopper 3, in which there is a dispenser and a cork valve 19. The dispensers are adjusted to the required amount of powder in the air, which is impossible to do with a crane.

The plug valve serves to start and stop the operation of the device.

The dispenser consists of a sleeve 20, mounted in the housing 18. The sleeve 20 has a through hole 21 with a diameter of 3 mm. When the adjustment screw 22 is rotated, the vertical hole may be opened more or less than the adjustment of the incoming powder is achieved.

The ejector 23 is fixed to the body of the crane 18.

An example of the operation of the device. ","

After all the preparatory work has been completed and the recommended modes of operation have been established by the screw 22 of the dispenser, the required ratio of powder in air is established. To do this, open the valve 19 and observe the stream of outgoing powder with air from the nozzle orifice with different rotation of the screw. Stru should be noticed0

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on the naked eye. Close valve 19. Check that the welding rectifier is switched on correctly according to the direct polarity scheme. Install the air communication reducer at a working pressure of 0.2-0.3 atmospheres. Position the filler head from the weld surface of the part approximately 1-2 mm apart. The cooling is switched on, the rectifier is opened, the valve 19 is opened, the electric arc is excited and its magnetic field, without a pause, the valve for the supply of flammable liquid is opened, and a stable process of surfacing begins.

The method is characterized by the following techniques.

Powder is fed to the surface of the weld part under pressure of 0.2-0.3 atm. and a flammable liquid with a diameter of 0.5-1 mm under a pressure of 0.2-0.3 atm. Under the action of the magnetic field of the arc, a so-called magnetic particle electrode is formed. The deposition process is conducted at the direct polarity, with a current of 100-150 A and a no-load voltage of 0-50 V. The deposition rate is 12-15 m / min.

In the proposed method, the deposition process proceeds as follows: after the arc is ignited, all the heat is generated by the arc at the end of the powder electrode and propagates at a slower rate than the electrode in the form of a rod, since individual grains of powder have different roughness and surface configuration. The total area of the powder electrode cross section, through which the heat flux will pass, can be divided into three parts, of which one part of the area where the flow passes through the oxidized films, the second consists of the area of the metal powder having good conductivity and the rest is area formed by air space that conducts heat poorly. Therefore, the heat transfer over the entire cross section of the powder electrode is not uniform, but is concentrated on a narrow contact area, which contributes to its rapid melting and transition to the surface of the part.

This is one of the reasons for the decrease in current strength during deposition and the decrease in metal residence time.

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Claims (2)

Claim 1. The method of electric arc powder deposition using the magnetic field of the arc, in which the powder and flammable liquid are supplied to the working area, which are separated by the fact that, in order to improve the quality of surfacing by reducing the penetration depth of the base metal, - the flammable liquid is supplied with a jet with a diameter of 0.5-1.0 mm and a pressure of 0.20.3 atm, and the powder is fed under a pressure of 0.2-0.3 atm. e ' 2. Device for electric arc surfacing of powders using the magnetic field of the arc, containing a torch with a nozzle for connecting a flammable liquid to the system and a powder hopper with a dispenser connected by a pipeline to a source of compressed air and a burner, as follows in order to increase the quality of surfacing by reducing the penetration depth of the base metal, the hopper is equipped with a shut-off valve installed at the outlet of the hopper, and the burner is equipped with a 20 of its axis with a tube for supplying a flammable liquid with an inner diameter of the hole equal to 0.5-1.0 mm, while the end of the tube is located inside the nozzle of the burner at a distance of 15-20 mm 25 from his slice.