Oxidation After Breakdown of the Chromium-Rich Scale on Stainless Steels at High Temperature: Internal Oxidation

• DOI: 10.1007/s11085-016-9610-7
• Publication Date: 2016-01-20T06:50:03Z
• Authors: T. Jonsson; S. Karlsson; H. Hooshyar; M. Sattari; J. Liske; J.-E. Svensson; L.-G. Johansson
• Keywords: Internal oxidation; High-Temperature Corrosion

Breakaway oxidation of alloy 304L at 600 °C was studied in four environments (O2 + H2O KCl, O2 SO2 H2 Ar, K2CO3) for up to 168 h. The resulting scales were investigated by FIB/SEM, SEM/EDX, STEM/EELS, STEM/EDS and elucidated thermodynamic calculations (Thermo-Calc). initial thin protective scale broke down all cases. After breakaway, the consisted two layers, i.e. an inward growing spinel/reaction zone outward iron-rich layer. general features microstructure after breakaway similar explained terms of: (1) Different diffusivities Cr3+ Fe2+ spinel oxide. (2) appearance a miscibility gap FeCr FeCrNi oxides. (3) equilibrium composition (at low pO2 Ni is not present spinel).