Specimens of Fe-15Cr-15Ni-2Mo, Fe-20Cr-15Ni-2Mo, Fe-15Cr-20Ni-2Mo and Fe-20Cr-20Ni-2Mo were covered with a thin layer of 59Fe, and diffusion-annealed in sealed quartz tubes containing Zr getter at 950 to 1250C. Alloying of γ-Fe with Cr and Ni increased the diffusion mobility of Fe at 950 to 1250C, and lowered the activation energy for self-diffusion (table 111):

Fe-15Cr-15Ni-2Mo:     D (cm2/s) = 1.40 x 10-1 exp[-60.70(kcal/mol)/RT]

Fe-20Cr-15Ni-2Mo:     D (cm2/s) = 3.10 x 10-2 exp[-56.90(kcal/mol)/RT]

Fe-15Cr-20Ni-2Mo:     D (cm2/s) = 9.50 x 10-2 exp[-59.20(kcal/mol)/RT]

Fe-20Cr-20Ni-2Mo:     D (cm2/s) = 2.80 x 10-1 exp[-62.50(kcal/mol)/RT]

The concentration variations (15 to 20%) of Ni and Cr did not affect DFe.

L.V.Pavlinov: Fizika Metallov i Metallovedenie, 1976, 41[2], 344-50