Page 11 - дисертація Головчук

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wear resistance of electric arc coatings is due to nanodisperse inclusions of FeCrB

and FeCr 2B borides in the lamellae of the coating, the microhardness of which

reaches 1600 HV 0,3

According to the test results of coatings made from the developed PW, it was

found that their corrosion resistance correlates with the coefficient of

microheterogeneity and chromium content in the lamellae of the coatings. The lower

the microherogenic coefficient and the higher the chromium content in the lamellae

of the coating, the higher its corrosion resistance.

Tribocorrosion tests by the method of reciprocating motion of the ball

(HRC60) confirmed that even in aggressive corrosive media, the wear resistance of

coatings from the developed PW remains quite high. In particular, the width of the

friction track was the smallest in the hydrogen-sulfide medium, and the largest one

was in 3% NaCl solution. In a freely aerated aqueous 3% NaCl solution, the bind of

corrosion products to the surface of coatings is the weakest and therefore their

tribocorrosion resistance is the lowest.

In the hydrogen-sulfide-containing media on the surface of coatings obtained

from the developed PW, sulfide compounds were formed provided a solid lubricant

during friction, thus reducing the adhesive component of the contact interaction,

which decreased friction coefficients and therefore reduced material wear.

When testing in the ammonia-containing media on the surface of the coatings

there were films tightly bonded to them, which inhibited corrosion, creating the

conditions for increasing the coefficient of friction.

Based on the experimental studies of physico-mechanical properties and

structural-phase state of electric-arc coatings from the developed PW an important

scientific and technical problem is solved namely effective ways to increase wear

resistance and corrosion resistance of basic parts by electric-arc spraying on their

surface coatings made of high-alloyed PW.

Keywords: powder wire, electric-arc coatings, (lamellae) lamellar structure,

chemical microheterogeneity, porosity, corrosion resistance, abrasive wear

resistance, adhesion, corrosive environments