METHOD OF SURFACE TREATMENT OF STEEL PART BY NITRATION OR NITROGEN-CARBONISATION, OXIDATION, AND THEN WITH IMPREGNATION Russian patent published in 2019 - IPC C23C28/00 C23C8/56 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of surface treatment of a steel part to provide high resistance to wear and corrosion. Nitriding or nitrogen-hardening is performed to form composite layer with thickness of at least 8 mcm, formed from iron nitrides of phases ε and/or γ', an oxidation step for forming a layer of oxides with thickness of 0.1 to 3 micrometers and a soaking step for at least 5 minutes in an impregnation bath formed from at least 70 wt. % plus or minus 1 % of the solvent, formed from a mixture of hydrocarbons from the alkane fraction C9-C17, from 10-30 wt. % plus or minus 1 % of at least one paraffin oil consisting of the C16-C32 alkane fraction, and at least one additive such as a synthetic phenol additive in concentration of 0.01 % to 3 wt. % plus minus 0.1 % at ambient temperature. Said method enables to obtain a steel part having high resistance to wear and corrosion, which contains a composite layer with thickness of at least 8 mcm, a layer of oxides with thickness of 0.1–3 mcm and a layer of impregnation dry to touch.

EFFECT: higher corrosion resistance and wear resistance of steel parts.

18 cl, 3 tbl