The internal oxidation of alloys which contained 0.43 or 0.90wt%Ti was investigated at 1023 to 1123K. A parabolic rate law was found to hold and the rate constant for penetration of the oxidation front, and the Ti concentration in the layer, were determined. The diffusivity of O in α-Fe,

D (cm2/s) = 3.78 x 10-3 exp[-21.9(kcal/mol)/RT]

was deduced from the rate equation for the internal oxidation.

J.Takada, S.Yamamoto, M.Adachi: Zeitschrift für Metallkunde, 1986, 77[1], 6-11

The best linear fits to the solute diffusion data ([783] to [785], [793] to [796], [822] to [825], [830] to [832], [835] to [844], [848] to [855]) yield:

C: Ln[Do] = 1.23E – 28.8 (R2 = 0.995); Cu: Ln[Do] = 0.36E – 15 (R2 = 0.64);

H(l): Ln[Do] = 0.45E – 7.5 (R2 = 0.97); N: Ln[Do] = 0.20E – 8.3 (R2 = 0.97);

Ni: Ln[Do] = 0.58E – 37.4 (R2 = 0.24); O: Ln[Do] = 0.29E – 12 (R2 = 0.96);

S: Ln[Do] = 0.40E – 19.6 (R2 = 0.76)