The effect of temperature on mechanical properties of oxide scales formed on a carbon steel in a simulated municipal solid waste incineration environment

• Composition and distribution of the phases in the scales formed at 573–773 K were not significantly different.
• Scale hardness and elastic modulus decreased as a negative exponential function of temperature.
• Mechanical properties of scales were mainly influenced by the defect density (porosity, holes, and cracks).
• Volatilization of iron chloride at temperatures ≥ 673 K decreased the mechanical integrity of scales.
• Mechanical properties of steel were strongly affected within 5–15 μm of the oxide–steel interface.

The effect of exposure temperature on the mechanical properties of scales in a carbon steel was investigated in a simulated waste incineration environment consisting of a gas mixture (N2-O2-H2O-HCl) with samples immersed in a salt (K2SO4-Na2SO4-ZnCl2-KCl) in the temperature range of 573 to 773 K. The microstructure, corrosion rate, elastic modulus (E) and hardness (H) of scales were determined by SEM, XRD, descaled weight loss and instrumented indentation technique. The results indicated that both the E and H decreased as a negative exponential function of temperature, thus obtaining a low mechanical and microstructural integrity of scales with high defect density between 673 and 773 K.