Experimental data on the growth rate of ’ and  layers which formed during gaseous nitriding were assessed. The atomic mobility of N in ’ at 777 to 843K was found to be approximately independent of the composition, and could be described by:

D(cm2/s) = 2.7 x 10-6exp[-88.3(kJ/mol)/RT]

H.Du, J.Agren: Zeitschrift für Metallkunde, 1995, 86[8], 522-9