Resumen
The regularities of the forming of oxynitride layers on the surface of titanium alloys at the controlled modification of preliminarily formed nitride coatings by oxygen are determined. The dependence of the surface colouring of titanium alloys depending on the composition of formed oxynitrides is showed. It is determined that oxynitriding provides the high corrosion resistance of the titanium alloys. The expediency of the differential approach to the choice of the phase-structural state of the surface layers of oxynitrated titanium depending on the aggressive environment is showed.