METHOD FOR CEMENTING PARTS FROM STRUCTURAL AND TOOL STEELS Russian patent published in 2020 - IPC C23C8/66 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular, to chemical-thermal treatment of structural and tool steels, and can be used for surface hardening of parts of machines and process equipment of dies, molds, draw plates in machine building and other industries. Cementation paste is applied on part surface, heated with subsequent holding, quenching and tempering. Cementation paste contains powdered components: sodium carbonate Na₂CO₃, bentonite, marshalite, soot DG-100 in the following ratio, wt%: sodium carbonate Na₂CO₃ 20–30, bentonite 5–10, marshalite 10–20, soot DG-100 is the rest, wherein the polyethylene-emulsion emulsion is used as a polyvinyl acetate emulsion in amount of 30–50 % of the weight of the powder components, prepared from PVA glue 60 %, 15 % methanol and 25 % water. Paste is applied on the part, dried at temperature of 80–90 °C, then the part is heated to 920–980 °C for 6–8 hours, then hardened and tempered at 200–550 °C for 2 hours.

EFFECT: enabling machining of parts of any size and shape, high uniformity of heating of parts and rate of their cementation, as well as high environmental safety of carbonation process.

1 cl, 1 ex