1.4840 | GX15CrNi25-20
| Numeric designation | 1.4840 |
|---|---|
| Chemical designation | GX15CrNi25-20 |
| Etching | V2A-Beize @ 70°C und Murakami |
Austenitic microstructure with sigma phase (light brown/light grey) and a little Cr-rich M23C6 (blueish/dark brown). The amount of M23C6 increases near the oxidized surface whereas the sigma phase vanishes; the sample was carburized and oxidized in service. The precise service conditions are unknown, but we estimate the temperature around 800-900°C, because the sigma phase would not be stable above 900°C and the precipitations would be smaller at lower temperatures.
