The lattice and grain boundary diffusion coefficients of 22P were determined at between 932 and 1155K (tables 197 and 198) by using tracer/sectioning techniques. The Arrhenius plots for lattice diffusion exhibited discontinuities at temperatures close to the Curie temperature. This was also true of the grain boundary diffusion data, but the temperatures at which the discontinuities occurred were lower by some 100K. It was suggested that the discontinuities were caused by magnetic transformations in the bulk and at the grain boundaries. The effect of Si upon the diffusivities was small.
T.Matsuyama, H.Hosokawa, H.Suto: Transactions of the Japan Institute of Metals, 1983, 24[8], 589-94
Table 195
Diffusivity of H in Fe-Si
Si (wt%) | Temperature (C) | D (cm2/s) |
90 | 25 | 7.0 x 10-7 |
90 | 700 | 5.2 x 10-5 |
75 | 25 | 4.5 x 10-7 |
75 | 700 | 6.5 x 10-5 |
65 | 25 | 4.5 x 10-7 |
65 | 700 | 6.2 x 10-5 |
45 | 25 | 4.0 x 10-7 |
45 | 700 | 5.5 x 10-5 |
18 | 25 | 6.0 x 10-7 |
18 | 700 | 5.0 x 10-5 |