A hydrogen-free method has been proposed for nitriding metals and alloys in plasma that is generated by a low-energy electron beam in a low-pressure nitrogen-containing gas. Plasma nitriding increase shardness, wear resistance, fatigue strength, and corrosion resistance of structural materials such as steel, titanium, and titanium alloys. The electron beam-generated plasma makes it possible to avoid the disadvantages of ion nitriding, such as intense ion etching of the surface, which results in the increased surface roughness and higher friction coeffcient, and the effect of ion layer at the surface, which leads to uneven nitriding of odd-shaped products. The method provides low-temperature nitriding of stainless steels and titanium alloys.

An electron source with a plasma cathode and a single grid acceleration system is utilized to generate plasma with a high content of active nitrogen species. The method makes it possible to perform independent control of the electron beam current density (10–200 mA/cm²), initial electron energy (50–500 eV), composition and total pressure of gas mixtures (0.1–5 Pa), and to select a technique for heating the workpieces (electron beam heating, plasma ion heating or a combined method). The proposed method allows nitriding to be carried out at a low potential (0–100 V) or at a floating potential applied to the workpieces and makes it possible to decrease the time required for the nitriding process or to lower the temperature during treatment. The total area of the nitrided surface in the proposed device is 2 x 10³ cm².