Arshuk M. Titanoaluminized and chromoaluminized coatings with titanium nitride barrier layer on steel 12X18H10T

Thesis deals with the study of phase and structural transformations of the surface zone and the basis on steel 12X18H10T during the deposition of multilayer diffusion titanoaluminized and chromoaluminized coatings with a barrier layer of titanium nitride TiN. To obtain the coatings we proposed combination of the method of physical vapor deposition of titanium nitride TiN followed by diffusion titanium and aluminum metallization, chromium and aluminum metallization, nitriding with subsequent diffusion titanium and aluminum metallization. Physical and chemical conditions and rational modes of diffusion metallization process are established, the phase and chemical composition, structure and microhardness, growth kinetics and mechanism of structure formation of coatings are researched. Heat resistance, corrosion resistance and wear resistance of steel 12X18H10T with obtained coatings are defined. It has been found that the main structural components that determine high microhardness, heat resistance, corrosion resistance, wear resistance in sliding friction conditions without lubrication are the barrier layer of titanium nitride TiN formed in a complex coating and connection area. The barrier properties of TiN layer which reduces diffusion penetration of saturating elements into the basis and elements of the basis into the coating at titanoaluminizing, chromoaluminizing are defined. Key words: steel 12Х18Н10Т, titanoaluminizing, chromoaluminizing, titanium carbide, titanium nitride, barrier layer, coating, microhardness, heat resistance, corrosion resistance, wear resistance