Interdiffusion studies in titanium 304 stainless steel system

The interdiffusion characteristics of various elements in Ti-304SS system have been investigated in the temperature range between 976 and 1123 K by employing metallographic and electron probe microanalysis techniques. The diffusion zone of the couple has been found to be of solid solution type and the layer growth can be presented by two linear lines with change of slope lying in the region of Curie temperatures of the alloys. The layer growth kinetics (in the temperature range of 1023-1123 K) can be expressed by the following Arrhenius relationship: X = 2.3 x 10(5) exp(-73.96 kJ/mol/RT)t(1/2), m. The concentration and temperature dependence of effective interdiffusion coefficients are evaluated and the diffusion parameters are established. It is observed that the minimum activation energy value for interdiffusion of Ti (78.05 kJ/mol at 60 at.% Ti) and Fe (74.05 kJ/mol at 20 at.% Fe) and the activation energy for layer growth (73.96 kJ/mol) are in good agreement, suggesting that growth kinetics is controlled by the migration of the plane having the composition of similar to 60% Ti, similar to 20% Fe, similar to 10% Ni and similar to 10% Cr, (C) 1998 Elsevier Science B.V. All rights reserved.