[en] A study was made on kinetics of denitration of 20Kh, 9Kh18 steel melts. Two-stage mechanism of the process of nitrogen desorption out of iron-carbon melts at electron-beam melting in crystallizer was confirmed. The process of nitrogen desorption is interrelated in the first period with melt bubbling by carbon monoxide and is determined by separation rate of the latter and by carbon content in metal consequently. The process of nitrogen desorption is interelated in the second period with nitrogen evaporation from the melt surface and is limited by diffusion. Carbon and chromium effect on the rate of nitrogen evaporation is noted