METHOD AND DEVICE FOR THERMO-CHEMICAL HARDENING OF PARTS Russian patent published in 2019 - IPC C23C8/36 

FIELD: technological processes.

SUBSTANCE: invention relates to method and device for thermochemical hardening of parts. Said method includes at least one carbonisation stage in carbon-containing gas atmosphere with pressure less than 50 mbar, wherein parts are held at temperature from 900 to 1050 °C, and at least one stage of nitriding in nitrogen-containing gas atmosphere with pressure less than 50 mbar, wherein parts are held at temperatures from 800 to 1050 °C, nitrogen-containing gas atmosphere contains molecular nitrogen (N₂) as a donor gas and is excited by discharge plasma. Time intervals between two successive technological stages make less than 15 minutes, and parts during these time intervals are held in gas atmosphere with pressure less than 300 mbar. Said device comprises 2 to 10 low-pressure heating chambers, a gas supply source connected therewith to supply said heating chambers with at least one nitriding gas and for carbonisation, selected from a group comprising N₂, carbon-containing donor gases, which are C₂H₂, CO₂ and CH₄, and carrier gases, which are H₂ and argon, transfer chamber, to which each low pressure heating chamber is connected, and the lock chamber and the quenching chamber, which are connected to the transfer chamber, or bifunctional sluice-quenching chamber connected to transfer chamber, or sluice chamber and hardening chamber, made with possibility of movement and connection with each low pressure heating chamber, or bifunctional sluice-quenching chamber, made with possibility of movement and connection with each low pressure heating chamber.

EFFECT: accurate control of the carbon and nitrogen content profile in the surface area of the part, high efficiency and flexible loading, as well as reduced energy consumption and environmental impact.

21 cl, 6 dwg