METHOD OF OBTAINING A WEAR-RESISTANT COATING ON AN ARTICLE FROM TOOL STEEL Russian patent published in 2019 - IPC C23C12/00 C23C2/04 C23C8/70 

FIELD: technological processes.

SUBSTANCE: invention relates to the technologies providing for increase in the cutting tool wear resistance, in particular screw drills made from tool steel due to changing the composition and structure of their surface layers. Method of obtaining a wear-resistant coating on an article from tool steel includes diffusion saturation of the surface with alloying elements in the melt, note here that ultrasound treatment of article surface with ultrasound oscillation frequency of reinforcing element of 22–24 kHz is carried out in two stages. Note here that it is pressed against processed surface by 1,000–3,000 N. First stage of ultrasonic treatment is performed before diffusion saturation of article surface with alloying elements in melt. Second stage is carried out after diffusion saturation of article surface with alloying elements in melt. Said melt contains the following elements, at the following ratio, wt%: bismuth – 47–52, nickel – 4–6, chromium – 6–8, lead – 38–39. After the second stage of ultrasonic treatment of the surface of the article, diffusion borating is additionally carried out at temperature of 900–950 °C and holding for 2–3 hours in powder mixture of boron carbide and sodium fluoride, with the following ratio, wt%: boron carbide 96–98, sodium fluoride 2–4.

EFFECT: higher tool durability, namely, microhardness and wear resistance of working surfaces of the cutting tool.

1 cl, 1 tbl, 3 ex