The concentration profiles of 14C were determined by means of autoradiography. The Fe-based alloys exhibited an almost homogeneous behavior with regard to their C diffusion (table 83), and could be described by:
Fe-15Cr-15Ni: D (cm2/s) = 1.2 x 100 exp[-40(kcal/mol)/RT]
Fe-25Cr-15Ni: D (cm2/s) = 1.0 x 101 exp[-45(kcal/mol)/RT]
Fe-35Cr-15Ni: D (cm2/s) = 4.9 x 100 exp[-45.5(kcal/mol)/RT]
O.Demel: Radex Rundschau, 1977, 2, 201-9
Table 83
Apparent Diffusion Coefficients of 14C in Fe-Cr-Ni Alloys
Alloy (wt%) | Temperature (C) | D (cm2/s) |
Fe-15Cr-15Ni | 750 | 2.9 x 10-9 |
Fe-15Cr-15Ni | 850 | 1.7 x 10-8 |
Fe-15Cr-15Ni | 950 | 7.5 x 10-8 |
Fe-25Ni-15Cr | 750 | 2.3 x 10-9 |
Fe-25Ni-15Cr | 850 | 1.6 x 10-8 |
Fe-25Ni-15Cr | 950 | 8.6 x 10-8 |
Fe-35Ni-15Cr | 750 | 9.0 x 10-10 |
Fe-35Ni-15Cr | 850 | 6.6 x 10-9 |
Fe-35Ni-15Cr | 950 | 3.5 x 10-8 |