Interdiffusion of Cr, Mo, and W in Iron

Abstract

The diffusion rates of chromium, molybdenum, and tungsten in α- and γ-iron have been determined by electron-probe microanalysis. Alloy concentrations up to 28·3 at.-% Cr, 5·05 at.-% Mo, 2·9 at.-% W have been investigated over the range 675 to 1485° C. At any temperature in either ferrite or austenite, D Mo > D Cr > D w. Interdiffusion in each alloy system was found to be independent of concentration for the composition ranges studied. Data from the present investigation have been combined with existing reliable data so that diffusion in these alloy systems may be described by the following values of frequency factor (Do ) and activation energy (Q), with errors given at the 95% confidence limits.