@Article{cmes.2022.017729,
AUTHOR = {Bogusław Bożek, Lucjan Sapa, Katarzyna Tkacz-Śmiech, Marek Danielewski, Janusz Rybak},
TITLE = {A Mathematical Model and Simulations of Low Temperature Nitriding},
JOURNAL = {Computer Modeling in Engineering \& Sciences},
VOLUME = {130},
YEAR = {2022},
NUMBER = {2},
PAGES = {777--803},
URL = {http://www.techscience.com/CMES/v130n2/45946},
ISSN = {1526-1506},
ABSTRACT = {Low-temperature nitriding of steel or iron can produce an expanded austenite phase, which is a solid solution of a large amount of nitrogen dissolved interstitially in fcc lattice. It is characteristic that the nitogen depth profiles in expanded austenite exhibit plateau-type shapes. Such behavior cannot be considered with a standard analytic solution for diffusion in a semi-infinite solid and a new approach is necessary. We formulate a model of interdiffusion in viscoelastic solid (Maxwell model) during the nitriding process. It combines the mass conservation and Vegard’s rule with the Darken <i>bi</i>-velocity method. The model is formulated in any dimension, <i>i.e.</i>, a mixture is included in , <i>n</i> = 1, 2, 3. For the system in one dimension, <i>n</i> = 1, we transform a differential-algebraic system of 5 equations to a differential system of 2 equations only, which is better to study numerically and analytically. Such modification allows the formulation of effective mixed-type boundary conditions. The resulting nonlinear strongly coupled parabolic-elliptic differential initial-boundary Stefan type problem is solved numerically and a series of simulations is made.},
DOI = {10.32604/cmes.2022.017729}
}