The article presents the results of research on the ion nitriding process of the so-called difficult to nitride 316L austenitic steel. The main aim of these studies was to determine what influences the intensification of the nitriding process as a result of using an active screen. Two variants of placing the nitrided elements in the glow discharge chamber were adopted: directly on the cathode and on the cathode using an active screen. After the nitriding processes were carried out, the influence of the adopted process parameters on the depth of nitrogen diffusion into the nitrided substrate was analyzed. In the further part of the work, an ionizing nitriding mechanism with the active screen method was proposed, explaining the significant increase in the effectiveness of the nitriding process using the active screen.

The article presents the results of the research on the nitriding process of 316L austenitic steel and the change in surface properties resulting from this process used in medicine, orthopedics, and in fuel cells. The processes were carried out with the following parameters: time from 5 to 17 h, temperature from 430 °C to 490 °C. The study presents the results of tests of the 316L austenitic steel substrate layer subjected to plasma nitriding of a direct current glow discharge, i.e., in the area isolated from both the cathode and the anode. Additionally, the influence of the active screen on the nitriding process in this area of the direct current discharge was studied. The following tests were carried out: nitrogen diffusion depth test, hardness test, wear resistance test, microstructure analysis, corrosion resistance, and distribution of the element concentration in the surface layer. The research allowed for the conclusion that each variant of nitriding contributed to a change in the examined properties, while the observed scale and nature of the changes were different.

One of the technological problems in alloying molten steels with nitrogen is the precipitation of nitrogen into the gas phase upon the solidification of steels and the formation of nitrogen bubbles...

The study assessed the effect of ion nitriding on the properties of the surface layer of Grade 5 titanium alloy used, among others, in medicine. Titanium and its alloys have low hardness and insufficient wear resistance in conditions of friction which limits the use of these materials. The improvement of these properties is only possible by the appropriate modification of the surface layer of these alloys. The ion nitriding process was carried out in a wide temperature range, i.e., 530–590 °C, and in the time range 5–17 h. Two variants of nitriding were applied: cathodic (conventional) nitriding and nitriding using the active screen method. The research results presented in this article allow for stating that each of the applied nitriding variants improves the analysed properties (nitrogen diffusion depth, hardness, wear resistance, microstructure analysis and surface topography) of the surface layers in relation to the material before nitriding. The hardness increased in every nitriding variant (the use of the additional active screen increased the hardness to 1021 HK0.025). The greatest increase in titanium abrasion resistance was found for surfaces after cathodic nitriding with an active screen. Each of the applied nitriding variants resulted in surface development.

The main aim of the manuscript was to investigate the impact of modifying the parameters of the gas nitriding process of samples made from AISI 1085 steel on the course and results of the process carried out in a chemical reactor allowing for thermogravimetric measurements. The tested steel was subjected in a chemical reactor to the process of gas nitriding in the temperature range of 490–580 °C, using different sample heating rates (in the range of 1–25 °C/min) and various mixtures of nitriding gases (pure NH₃, or NH₃ with the addition of H₂ or N₂). To assess the impact of the tested process parameters on its efficiency, the thickness of the nitrided layers produced, the change in sample mass, the structure of the phases produced, the phase composition and the microhardness were examined. For the research methodology used, it was found that reducing the amount of NH₃ and/or using H₂ or N₂ admixtures adversely affects the thickness of the nitride layers produced. At the same time, the use of a lower maximum process temperature with the same gas mixture resulted in a significant difference in the thickness of the layers. It was also found that the use of pure NH₃ or a gas mixture (NH₃ + H₂) with higher NH₃ contents resulted in higher surface microhardnesses of the samples and that for these samples, the hardness increased to a greater depth.