METHOD OF SULPHOCEMENTATION OF STEEL PARTS Russian patent published in 2019 - IPC B23H1/00 B23H9/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to electrophysical and electrochemical treatment, in particular to electro-erosion alloying (EEL) of surfaces of steel parts, and can be used for treatment of surfaces of heat treated steel parts to increase their hardness, wear resistance, prevention of setting during friction and to improve resistance to atmospheric corrosion. Method includes electro-erosion alloying of steel part surface with graphite electrode at discharge energy W_d=0.52–6.8 J and capacity 1.0–3.0 cm²/min. Prior to electro-erosion alloying with graphite electrode on surface of part subject to sulphocementation, sulfuric ointment is applied with addition of aluminum powder, after which, prior to drying of applied ointment, process of electro-erosion doping with graphite electrode is performed. A sulfuric ointment with an aluminum powder content of not more than 56 % is used.

EFFECT: invention increases hardness and wear resistance of parts and provides prevention of setting during friction and improved resistance of parts of atmospheric corrosion and sea water, as well as protection of parts from oxidation at high temperatures.

4 cl, 4 dwg, 3 tbl