Analysis of in situ XRD measurements for low energy ion beam nitriding of austenitic stainless steel

From Micro to Nano Scales -Recent Progress in the Characterization of Nitrided Austenitic Stainless Steels

“…after 9~10 hours of nitriding. Very recently, Manova et al reported in-situ XRD patterns obtained during the ion beam nitriding of austenitic stainless steel AISI 316Ti at a low processing temperature at 400°C for a nitriding times up to 80 minutes [34]. The observed progressive shifting of the (111) and (200) diffraction peaks is consistent to those being observed by other researchers [32,33,61,65].…”

“…Several sputtering based spectroscopic analyses are available to measure the concentration and depth profile of nitrogen in nitrided surfaces, including Auger electron spectroscopy (AES) [26][27][28], Glow discharge optical emission spectroscopy (GDOES) [29][30][31][32][33][34], secondary ion mass spectroscopy (SIMS) [35], and nuclear reaction analysis [32,36]. As an example, Wu et al employed Auger electron spectroscopy to analyse the depth profiles of nitrogen concentration of AISI 316L steel sample which were gas-nitrided for 20 hours at different temperatures of 350°C, 420°C, 440°C and 450°C [28].…”

The investigation of strength and plasticity characteristics of composite layers in austenitic stainless steel subjected to ion-plasma treatment using the nanoindentation method

“…Наряду с этим, перспективным методом, позволяющим улучшить поверхностные свойства аустенитных нержавеющих сталей, является поверхностное упрочнение атомами внедрения (азотом, углеродом, бором) -азотирование, карбидизация, нитроцементация и борирование [6][7][8]. Эти обработки способствуют модификации структуры и фазового состава поверхностного слоя упрочняемого сплава и улучшению его физико-механических и эксплуатационных свойств [9][10][11]. Применение ионно-плазменных и электронно-лучевых технологий позволяет существенно повысить эффективность упрочнения по сравнению с традиционными обработками в газовой среде или соляной ванне [6][7][8].…”

Internal stress assisted nitrogen diffusion in plasma nitrided medical CoCr alloys

“…The insertion of nitrogen into CoCr base alloys by low temperature (below 400e450 C) plasma assisted nitriding leads to the formation of a hard and wear resistant surface layer [8e10]. This modified layer consists of metastable and high nitrogen (up to 35 at.%) content g N phase so-called expanded austenite or S phase and similar to the one obtained with ASS nitriding [11,12]. The incorporation of nitrogen into the original lattice on interstitial sites is associated with the expansion of the alloy lattice and an anomalous diffusion of nitrogen in CoCr base alloys [13,14].…”

“…The stress resulting from the gradient of the nitrogen concentration effects the diffusive flux of nitrogen through the modified layer [27], i.e. the stress gradient provides an extra driving force for nitrogen atoms to diffuse to larger depth [11]. Moreover, the change of volume of host lattice results the surface expansion or swelling (the change of linear dimensions) in nitrided alloy.…”