Phase transformations of a nitrogen-implanted austenitic stainless steel (X10 CrNiTi 18-9)

Co-existence of γ'N phase and γN phase on nitrided austenitic Fe–Cr–Ni alloys- I. experiment

“…The applicability of expanded austenite relies on the combination of excellent wear resistance and excellent localized (pitting or crevice) corrosion performance. Dissolution of nitrogen into austenitic stainless steel is usually achieved by plasma nitriding [1][2][3][4], nitrogen ion beam implantation [5][6][7][8], plasma immersion ion implantation [9][10][11] or gaseous nitriding in an ammonia-based atmosphere [12], in the temperature range 650-720 K. At the atomic scale the structure of the nitrogen-modified surface zone is mainly reported as: i) a disordered nitrogen-supersaturated solid solution, wherein the N atoms are "trapped" by Cr atoms in octahedral interstices, thus forming a short-range ordered distribution [13][14][15][16][17]; ii) a zone containing both Cr-N short-range order and Fe 4 N-like long-range order of nitrogen atoms [18,19]; iii) a mixture of the stoichiometric nitrides γ ' -Me 4 N and/or ε-Me 2-3 N phases, in a disordered high nitrogen solid solution, and even the nano-scale CrN precipitates dispersed in an expanded Fe 4 N-like long-range ordered phase [2,20,21].…”

Friction and wear behavior of plasma nitrided 1Cr18Ni9Ti austenitic stainless steel under lubrication condition

“…Therefore, it is imperative to increase the wear resistance of the stainless steel making use of various surface-modification techniques. As an environmental friendly low temperature process, plasma nitriding has been found to be effective to increasing the hardness, and wear resistance of stainless steel without degrading the corrosion resistance [1][2][3][4][5][6][7][8]. Blawert and Mordike [9] reported that the oxide film (Cr 2 O 3 ) on the surface of the stainless steel was effectively removed by plasma nitriding, owing to the sputtering effect of the energetic positive ions, which accelerated the nitrogen mass transfer, and made it possible to carry out plasma nitriding in a wider range of temperature and at a faster nitriding rate than the conventional gaseous and salt bath nitriding processes.…”

Metal ion release from nitrogen ion implanted CoCrMo orthopedic implant material

“…It is generally accepted that nitrogen ion implantation is an excellent method to enhance the wear and corrosion resistance of a wide range of materials [11,12]. Several researchers have utilized ion beam techniques in the medical area [13,14], such as for orthopedic prostheses that require high wear resistance and excellent corrosion properties as well as biocompatibility.…”