Open AccessTHERMODYNAMICS OF LIQUID NITROGEN SOLUTIONS IN CHROMIUM
Author(s) -
L. A. Bolshov,
С. К. Корнейчук
Publication year - 2019
Publication title -
izvestiâ vysših učebnyh zavedenij. černaâ metallurgiâ
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.3
H-Index - 7
eISSN - 2410-2091
pISSN - 0368-0797
DOI - 10.17073/0368-0797-2019-5-387-393
Subject(s) - dissolution , thermodynamics , solubility , chemistry , enthalpy , enthalpy change of solution , chromium , lattice constant , nitrogen , liquid nitrogen , activity coefficient , solubility equilibrium , octahedron , lattice (music) , crystal structure , crystallography , aqueous solution , organic chemistry , physics , diffraction , optics , acoustics
A simple theory of thermodynamic properties of liquid nitrogen solutions in Fe – Cr alloys is proposed based on lattice model of the considered solutions. The model assumes a FCC lattice. In the sites of this lattice are the atoms of Fe and Cr. Nitrogen atoms are located in octahedral interstices. The nitrogen atom interacts only with the metal atoms located in the lattice sites neighboring to it. It is assumed that the energy of this interaction depends neither on the composition nor on the temperature. It is supposed that the solution in the Fe – Cr system is perfect. Within the framework of the proposed theory, a relation is obtained that expresses the value of the Sieverts law constant for solubility of N in liquid Cr through the similar constant for the solubility of N in liquid Fe and the Wagner N – Cr interaction coefficient in liquid Fe. A relation is also obtained to express the partial enthalpy of nitrogen dissolution in liquid Cr through the similar quantity for N in liquid Fe and Wagner N – Cr interaction coefficient in liquid Fe. A formula is deduced that establishes a connection between the Wagner N – Fe interaction coefficient in liquid Cr and N-Cr interaction coefficient in liquid Fe. Using the formulas obtained, value of the Sieverts law constant for the solubility of nitrogen in liquid Cr, the enthalpy of dissolution of N in liquid Cr and value of the Wagner N – Fe interaction coefficient in liquid Cr extrapolated to a temperature of 1873 K are calculated. The calculation results are compared with results of the experimental study of nitrogen solubility in liquid Cr carried out by different researchers using different methods. The theory results are in the best agreement with experimental data obtained by the sampling method. Values of the Wagner N – N interaction coefficient in liquid Cr and liquid Fe are discussed.