SU831465A1 - Electrode coating composition - Google Patents

Description

(54) COMPOSITION OF ELECTRODE COATING

I

The invention relates to welding, in particular, to the composition of the electrode coating used mainly for welding aluminum bronze.

Various compositions of electrode coatings are known, for example, a coating t containing the following components, w / v: Cryolit15-30

Sodium Chloride 25-45

Fluorspar15-20

Marble3-7

Charcoal3-7

Sodium Fluoride5-15

MarganeGetal 7-15 However, when welding using the known electrode coating, the weld metal has insufficient strength.

Closest to the proposed composition is an electrode coating 2, containing the following components, wt. ° / o: Cryolit10-20

Navigator Shchpat10-20

Potassium Chloride8-15

Aluminum powder2-5

Nickel22-30

Manganese metal 25-35

Iron powder4-6

Gr.app2-6

Liquid glass having a density of 1.32-1.34 g / cm is used as a binder. Potassium chloride is introduced into the batch as an aqueous solution.

The composition of the electrode coating eliminates the possibility of press fabrication of electrodes, so that known electrodes can be made by dipping. In addition, these electrodes have low welding and technological properties. The slag crust is removed with a chisel, forming the weld metal without a slush, without a smooth transition to the base metal. This also leads to a decrease in welding performance.

To improve the manufacturability of electrodes and the quality of the deposited metal, the composition of the electrode coating additionally contains marble, sodium fluoride, potassium fluoroborate and carboxymethyl cellulose, and as an alkali metal chloride, a component selected from the group sodium chloride, potassium chloride, in the following ratio of components, weight. % Cryolite26-37

Fluorspar4-15

Component selected from the group of sodium chloride, potassium chloride 0.4-3 Nickel12-18

Manganese20-30

Iron powder3-6

Marble4-9

Sodium fluoride4-15

Fluoroborate potassium 0.4-3

Carboxymethylcellulose 0.2-1.2 BrAMU 9--2 grade wire is used as a rod.

The introduction of manganese in the electrode coating allows for a reduction in the mass ratio of the coating and the fading of aluminum during welding. The introduction of corboxymethylcellulose into the electrode coating composition reduces the viscosity of the coating. Introduction to the composition of the electrode coating of marble, sodium fluoride and potassium fluorine borate is capable of increasing the gas-slag protection of the weld metal.

After drying for 24 hours at room temperature, the electrodes are calcined at 680 ° K for 1.5 hours. The weight ratio of the coating after calcination is 0.25.

The prepared electrodes are used to weld a steel plate 25 mm thick onto the edge. Surfacing height 35 mm. A welding rectifier was used as a power source. The weld is in reverse polarity, the welding current is 190-210 A, the voltage across the arc is 24.27 V. The arc is burning steadily, without noticeable splashing.

OK

0.21.3 0.2

The slag covers the deposited metal with an even thickness crust, which cracks as it cools and separates from the surface of the weld bead. After completion of the welding, the slag is easily removed with a metal brush. The weld metal has a small flaked surface without bruising with a smooth transition to the base metal. No pores, cracks and slag inclusions were detected either during the external examination, or after machining and testing the mechanical properties of the weld metal. Chemical analysis revealed that the weld metal has the following composition,% M 7.02; Ni 2.6; Mp 5.1; Fe 0.85; Si 0.43. The weld metal after heat treatment of 900 ° K - 4 h and 640 ° K - 3 h has the following mechanical properties:

 .РР-35А MT.

518-bi0..nn,

l. 12,7-16.8 at 13.

gf "fl-w

The boundary and optimal values of the composition of the coating applied to the rod of aluminum bronze of the brand Br. AMC 9-2, determined by checking the welding-technological properties of the electrodes and are presented in the table.

20

thirty

20 15 3.8

24

18 12

sixteen

6

3

0.4

Claims (1)

Claim The composition of the electrode coating is mainly for welding aluminum bronzes, containing cryolite, fluorspar, alkali metal chloride, nickel, manganese and iron powder, characterized in that, in order to improve the manufacturability of the electrodes and the quality of the deposited metal, it additionally contains marble, sodium fluoride, potassium fluoroborate and carboxymethyl cellulose, and as an alkali metal chloride, a component selected from the group of potassium chloride, sodium chloride, in the following ratio of components, weight. %: Cryolite26—27 Fluorspar4-15 A component selected from the group of sodium chloride, potassium chloride 0.4-3 Nickel 12-18 Manganese20-30 Iron powder3-6 Marble 4-9 Sodium fluoride 4-15 Potassium fluoroborate0.4-3 Carboxymethyl cellulose 0.2-1.2