Development of a thermite electrode coating for welding steels in installation conditions

E. Izotova Ukrainian Engineering and Pedagogical Academy https://orcid.org/0000-0002-6585-6681

Keywords: electrodes, coating, termite, current, welding

Abstract

DOI: https://doi.org/10.32820/2079-1747-2019-23-122-129

in the installation conditions, using low-current and 50-V alternating current sources by changing the deoxidation system, the slag and gas system for protecting the weld metal with electrode coating components.

To optimize the deoxidation system and the gas-slag coating system, ferromanganese, silicocalcium, talc, clay, soda, marble and wood meal are additionally introduced into the composition containing hematite.

Studies have shown that the use of silicocalcium as a deoxidizer and slag-forming electrode coating provides an additional deoxidation of the metal seam, improving its quality and stable re-ignition of the arc due to the occurrence of the termite reaction with hematite and the release of additional heat, which goes to the heating of the electrode.

The technology for manufacturing electrodes with a new coating composition does not differ from the known one, which is used for analogous electrodes. Welding of plates made of steel VSt3sp was carried out in the lower position with alternating current of 60-80 A.

The results of testing the welding-technological properties and mechanical characteristics of the deposited metal are given in the paper. As a result of tests of welding-technological properties of electrodes and mechanical characteristics of welded metal, it has been established that the optimal composition of the coating has electrodes 2, 3, 4, which have the best results. Thus, the introduction of these components and proposed a certain ratio of coating components provides a total effect, which was expressed in improving the welding and technological properties of the electrodes and the mechanical characteristics of the weld metal.

The high welding and technological properties of the electrodes allow welding of the responsible structures from carbon and low-alloy steels to constant and alternating current at 50V single-voltage power sources and also to perform assembly joints in all spatial positions without defects. In addition, the use of the termite effect can reduce the strength of current, which significantly reduces the cost of welding electricity.

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