Page 41 - Microsoft Word - avtoref_Винар_друк

39

SUMMARY
Vynar V.А. «Scientific basis of friction interaction of metals under the action of
corrosion and hydrogen factors. – Manuscript.
Thesis for a Doctor’s Degree in Technical Sciences (specialty 05.17.14 – materials
chemical resistance and corrosion protection). – Karpenko Physico-Mechanical Institute of
the NAS of Ukraine, Lviv, 2020.
The dissertation presents a solution of an important scientific and practical problem
of establishing mechanisms of frictional interaction of contact surfaces under the action of
corrosion and hydrogen factors, the solution of which expands the understanding of
tribocorrosion mechanisms, which allows a scientifically well-grounded approaching to
choose methods to improve tribopairs.

The method of measuring the electrode potential in tribocorrosion studies using a
capillary probe was improved, which made it possible to more accurately assess the
potential of different sections of the friction track and undeformed surface.
An empirical relationship between the width of the friction track in tribocorrosion
and the polarization current at the corrosion potential has been established, which makes it
possible to quickly assess the degree of its wear by the electrochemical properties of the
friction pair.
It is established that the ratio between the values of corrosion potential, tribopotential
and freshly renewed surface potential can be used to assess the frictional properties of
secondary structures and the wear mechanism, in particular the D16T alloy The dual effect
of cathodic polarization on the tribocorrosion of D16T alloy and steel 08Х18Н10Т is
shown: reduction of corrosion rate and fracture inhibition at the potentials below the
juvenile surface potential and increase of corrosion-mechanical wear during hydrogen
depolarization. Anodic polarization intensifies the formation of secondary structures and
increases wear. The coefficient of friction decreases insignificant. It was shown for the
first time that the frictional interaction under anodic polarization initiates the shift of the
pitting potentials of the 08H18H10T alloy towards the corrosion potential. It is established
that the parameters of fine crystalline structure, phase composition and micromechanical
properties of surface layers of metals change due to electrolytic hydrogenation, which
determine their tribological behavior and wear mechanisms:
 It is shown that the concentration of residual hydrogen in the surface layer of
armco iron increases from 3 to 16 ppm with increasing current density from 0.5 to 2
2
A/dm . It causes embrittlement and destruction of the friction surface by the dispersion
mechanism. Therefore, in the conditions of dry friction, the wear of pre-hydrogenated
iron-armko increases by 40…60%, and in the case of friction with simultaneous
hydrogenation - by 10%.
 hydrogenation of aluminum and copper does not cause a significant change

in their tribotechnical characteristics. Copper and aluminum are characterized by oxidative
wear, which is insensitive to hydrogen.
 titanium interacts with hydrogen and brittle hydride phases are formed ,

which reduce the wear resistance of the metal both after hydrogenation and in its process.
The friction force during the scratch tests is reduced by ~ 3 times, and the material losses
increase by 30-50%.