Page 22 - НАЦІОНАЛЬНА АКАДЕМІЯ НАУК УКРАЇНИ

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износа слабо связаны с поверхностью покрытий и незначительно влияют на
их трибокорозионную стойкость.

Ключевые слова: порошковая проволока, электродуговые покрытия,
ламельная структура, химическая микрогетерогенность, пористость,
коррозионная стойкость, абразивная износостойкость, адгезия, коррозионные
среды.

SUMMARY

Golovchuk M. Ya. Influence of the diameter of high-alloyed flux-cored
wires on the structure and physical and mechanical characteristics of electric
arc coatings - Manuscript.

A thesis for obtaining a scientific degree of candidate of technical sciences,
specialty 05.02.01 - Science of Materials. - Karpenko Physico-Mechanical Institute

of the NAS of Ukraine, 2020.
The thesis is devoted to determination of regularities of wear-resistant electric
arc coatings formation from flux-cored wires (CW) of Fe-Cr-B-C system. The
effect of high content of alloying elements in flux-cored wires on corrosion

resistance of coatings in neutral aqueous environments has been investigated.
It is shown that lamella thickness, amount of oxide phase, porosity,
microhardness and abrasion wear resistance of coatings grow by 1.5-2 times when

diameter of CW increases from 1.6 mm to 2.4 mm and filling factor of wires
increments.
It is revealed that corrosion resistance of electric arc coatings correlates with

the coefficient of microheterogeneity and the concentration of chromium in the
lamellae of coatings. The lower is the microheterogeneity coefficient and the
higher is the content of chromium in the lamellae, the higher is corrosion resistance

of the coatings. It has been found that sulfidеs are formed on the surface of
coatings in hydrogen sulfide containing environment, which act as a solid lubricant
under friction, and reduce the adhesive component of contact interaction. It reduces
the coefficients of friction and wear of coatings. Tightly connected surface films

are formed in ammonia-containing aqueous environment, which inhibits corrosion,
but contributes to the growth of the coefficient of friction. The corrosion products

of the coatings in freely aerated 3% NaCl aqueous solution are slightly connected
with surface, which makes their tribo-corrosion resistance low.
Keywords: flux cored wire, electric arc coating, lamella structure, chemical
microheterogeneity, porosity, corrosion resistance, abrasive wear resistance,

adhesion, and corrosive environment.