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Ion nitriding technology, which relies on glow discharge, has been widely used since the 1970s. However, arcing of the workpiece during the ion nitriding process and the hollow cathode effect affect the quality of nitriding and can damage the surface of the treated workpiece; these are technical issues that must be overcome. Studies on the mechanism of ion nitriding suggest that the neutral atomic form of N2 and its vibrational molecular form are the main reactive species in the process of nitriding via glow discharge; this implies that it is not necessary to apply a cathode potential of several hundred volts or even thousands of volts to the workpiece during nitriding. Thus, the concept of active screen nitriding technology was proposed. Active Screen Plasma Nitriding (ASPN) is a new type of plasma nitriding technology that has emerged in Europe in recent years. It not only solves various technical problems associated with traditional DC plasma nitriding, such as arc formation, the hollow cathode effect, difficulties in temperature measurement, the inability to process workpieces of different sizes together, and high requirements for operators, but it also achieves nitriding results that are as good as those obtained through DC plasma nitriding. During the ion nitriding process on a reactive screen, a direct-current negative high voltage is applied to an iron cage, with the workpiece to be treated placed inside the cage and held in an electrostatic suspension state or under a negative bias voltage. Under the impact of ions, the cage is heated, and at the same time some nanoparticles are sputtered off and deposited on the surface of the workpiece for nitridation. Therefore, during the ion nitriding of the active screen, the cage serves both to heat the workpiece and to provide a nitriding carrier. The key component of the equipment is the active metal screen, namely the cage mentioned earlier. The current from either pulsed or direct-current power supplies is applied directly to this active screen; the heat generated thereby heats the parts undergoing nitriding evenly through radiation. At the same time, gas injected through nozzles creates plasma, and the active screen is surrounded by this plasma during the nitriding process. The plasma moves in a carefully designed direction, coming into contact with the parts being treated in a uniform and gradual manner, thus ensuring even nitriding. Mechanistic studies have shown that during the transport of nanoparticles sputtered from the active screen toward the surface of the workpiece, a large number of active nitrogen atoms are physically adsorbed on the particle surfaces. After these particles are deposited on the surface of the workpiece to be treated, the physically adsorbed nitrogen is released, and the liberated active nitrogen atoms diffuse into the steel matrix to form a nitrided layer. The main steps of the nitriding process are as follows: (1) The workpiece, free from dirt and rust, is placed on the workpiece holder platform, and the furnace is sealed; (2) The vacuum pump is started to reduce the pressure inside the furnace to 20 μbar; (3) An active screen current is applied; (4) The temperature inside the furnace is brought to a uniform level of 300–600 °C (for special alloys, the nitriding temperature can be set as high as 800 °C); (5) A mixture of nitrogen and neutral gases enters the area surrounding the active screen through nozzles, generating highly ionized ions, electrons, and other active, energetic neutral gas particles, which are used to nitride the workpiece; (6) The plasma generated by the active screen ensures that the workpiece remains continuously immersed in these active gas particles. In Europe, many large heat treatment plants have acquired active-screen ion nitriding equipment, which has proven to be effective and has **improved economic efficiency. In Japan, the diameter of such active screen nitriding furnaces reaches 1000 mm, the height is 1200 mm, and the maximum loading capacity for treatment is 2000 kg (including fixtures). After treatment, nitrogen at 80 kPa can be introduced for forced cooling. Using the conventional ion nitriding atmosphere (30% N2 + 70% H2) yields a γ’ + diffusion layer matrix structure; increasing the amount of N2 and methane results in the formation of an ε-phase layer; furthermore, the introduction of propane, hydrogen sulfides, carbon fluorides, etc., can produce nitrogen-carbide, oxynitrogen-carbon compounds, and sulfur-nitrogen hardened coatings. At present, this new technology is still unknown in our country, and we need to catch up urgently.