Table 2: Calculated diffusion distances after 1000 hours for Cr, Ni, and Fe in 17Cr-12Ni austenitic steel and the average oxide layer thickness obtained from EPMA line profiles of MA304LZ and SUS304L at 300 ℃ and 500 ℃.
| Test temp. | Diffusion distance (µm) | Oxide layer thickness (µm) | ||||||
| Lattice diffusion, D(L) | Grain boundary diffusion, D(GB) | |||||||
| Cr | Ni | Fe | Cr | Ni | Fe | MA304LZ | SUS304L | |
| 300 ℃ | 9.0 × 10-6 | 8.9 × 10-4 | 3.1 × 10-6 | 2.6 | 5.7 | 0.75 | 0.73 ± 0.08 | 0.45 ± 0.02 |
| 500 ℃ | 1.2 × 10-2 | 8.1 × 10-1 | 6.0 × 10-3 | 160 | 220 | 91 | 0.40 ± 0.02 | 1.90 ± 0.21 |