Page 46 - НАЦІОНАЛЬНА АКАДЕМІЯ НАУК УКРАЇНИ

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titanium and iron powders was created. Nanosized (50...150 nm) precipitates of titanium,
chromium and iron borides are formed in the coating structure, which ensures an increase
in the physical and mechanical properties of the coatings. Complete fusion of the CW
charge components and the shell is achieved by adding 1 wt.% of a mixture of low-
melting powders of eutectic composition (FeSi + FeMn + В 2О 3) to the CW charge, which
ensures the formation of homogeneous coatings of the required structural and phase
composition. The wear resistance of coatings sprayed in the supersonic mode is twice as
high as this characteristic for U12 steel with a hardness of 840 HV 0.3.
A series of flux cored wires based on the Fe-Cr-Si-Mn-B-C alloying system with an
exothermic charge has been developed. These powders provide exothermic reactions
between the components of their charge. The agricultural, food, municipal, transport and
defense industries have different needs for the restoration of bulk-type parts. To meet
these needs, a technological procedure for arc spraying coatings from the developed
short-circuit currents has been developed.

Based on the results of experimental studies and pilot tests carried out on real
products of different enterprises, three variants of CWs for restoration of shaft-type
parts were proposed:
• CW 90Cr6MnSi – the coating formed by its spraying had a hardness of
(450…600) HV 0.3 and is recommended for restoration of bearing seats, bushings,
gears and any shaft-type parts for operation in relatively light (without access to
abrasive) conditions;
• CW 90Cr6BMnSi – the coating formed by its spraying had a hardness of
(800...1000) HV 0.3 and is recommended for the restoration of shaft-type parts
operated in difficult (with access to abrasive) conditions;
• CW 90Cr17BMnSi – the coating formed by its spraying had a hardness of
(850...1000) HV 0.3 and is recommended for the restoration of shaft-type parts
operated in extremely difficult (with access to both abrasive and corrosive
environment) conditions.

Keywords: anodized layer, aluminum hydroxide, plasma electrolytic oxidation, arc
thprayed coating, supersonic air jet, dispersion-strengthening phases, lamellas in
coatings