METHOD OF LOCAL MATERIAL TREATMENT WITH EFFECT OF HOLLOW CATHODE DURING IONIC NITRIDING Russian patent published in 2014 - IPC C23C8/36 

FIELD: machine building.

SUBSTANCE: method of nitriding of the steel part in plasma of the glow discharge includes the steel part and perforated screen location in the vacuum chamber, cathode spraying, vacuum heating of the part in plasma of the glow discharge containing mixture of nitrogen-containing and inert gases creating areas with different steel structure; at that the transient area between the areas with different structure has microheterogeneous structure with gradual change of one type to the another one. The heterogeneous structure is formed in form of the macroheterogeneous steel structure using the perforated screen with holes diameter d, at that 2 l < d < 4 l, where l is thickness of cathode layer, and closely fitting to the treated part to ensure the possibility to obtain on the surface of areas nitrided in the glow discharge that alternate with unnitrided areas.

EFFECT: improvement of contact durability and wear resistance of the strengthened layer due to local treatment and creation of macroheterogeneous material structure.

5 dwg, 1 ex