Appointment of Individual Coating Components SSSI-13

Appointment of individual coating components SSSI-13

Appointment of individual coating components SSSI-13 can be explained as follows. The main part of marble CaCO3 decomposes when heated to calcium oxide CaO, which goes into the slag, and gas CO2 to CO is partially restored. Carbon dioxide, CO2 produces oxidizing action of hydrogen and associates caught in the welding zone in water vapor H2O. Gases, CO2 and CO are practically insoluble in the metal. CO2 fills the welding zone, forcing the air out of it and creating a protective atmosphere. The oxidative effect of CO2 on the metal is compensated by strong deoxidizing agents in the weld pool. Fluorspar CaF2 lowers the melting point and viscosity of slag. When heated CaF2 partially decomposes, releasing hydrogen fluoride reacts with very strong hydrogen fluoride, do not dissolve in the metal.

Covering non-hygroscopic, does not include components containing hydrogen, and in the manufacture of calcined at a temperature of 300-400 ° C. As a result, the hydrogen content in weld metal is reduced to a minimum by eliminating the source of the formation of pores and cracks, it is several times smaller than the ore- acidic surfaces. Quartz is introduced into the coating to liquefy the slag and reducing burnout of silicon metal. Ferromanganese and ferrosilicon as an alloying element is introduced. Ferrotitanium containing about 23% Ti is introduced as a strong reducing agent and modifier of weld metal during welding titanium burns almost completely, and in the weld metal is practically undetectable.

Weight given the quality of coatings is 30-40% by weight of the electrode rod. To compile obmazochnoy paste to dry mixture was added 30% aqueous solution of sodium silicate density of 1.40 or 12-13% based on dry matter.

There are special electrodes that provide improved performance for weld metal. For this purpose, the electrode coating is added to iron powder, produced in special plants. The amount of iron powder varies in different electrodes from 5 to 50% by weight of the electrode rod, and more; coating weight can be up to 100-180% of the weight of the rod. The deposition rate increases up to 12-20 g / h, and against the common values ​​of 8-10 g / a, h, deposition rates can be increased by 1.5-2 times for the same current. The use of high-performance electrode with iron powder were low, and one of the reasons is that it is often the deciding factor is the rate of melting of the electrode is not, and the base metal.

See also:
Classification of covered electrodes
The composition of electrode coatings
Appointment of individual coating components SSSI-13
Manufacturing Electrodes
Welding Electrodes