THE MEASUREMENT OF CARBON DIFFUSION-COEFF ICIENTS IN STEELS BY SURFACE OXIDATION METHOD

In the present paper the results of measurements of carbon diffusion c oefficients in Fe-C-Cr-Mn-Si steels are reported. The diffusion anneal s were carried out at temperatures 900-1100 degrees C in ambient air. The measurement of carbon concentration in subsurface layers of oxidiz ed samples and the metallographic investigation have shown that the st eels expressively decarburize in the course of oxidation. The evaluati on of measured carbon concentration curves N(x,t) yielded the diffusio n coefficients D of carbon. They depend on temperature T and on chemic al composition of steels. The dependence of D on the concentration of alloying elements i is expressed by the use of diffusion interaction c oefficients beta(C)(i).