Effect of thermo-mechanical processing on oxidation of austenitic stainless steel 316L in supercritical water

• We used a novel process to alleviate the supercritical water oxidation of SS316L.
• The oxidation resistance of SS316L has been improved up to four times.
• Oxidation resistance of the samples enhanced with decreasing the grain size.
• The oxidation resistance was significantly improved for grain sizes below 3 μm.
• Exfoliation of oxide scale was retarded by the thermo-mechanical processing.

Oxidation resistance of thermo-mechanical processed stainless steel 316L was studied. The samples were oxidized in supercritical water with 150 ppb inlet-dissolved O2 at 600 °C and 25 MPa. Results show that the proposed thermo-mechanical processing improved the oxidation resistance by altering the microstructure of stainless steel 316L. It was observed that grain boundaries volume fraction and crystallographic orientation of austenite grains play an important role in oxidation resistance of the material. In addition, oxide exfoliation was completely prevented by applying 50% or more rolling reduction during the thermo-mechanical processing.