Effect of Surface Roughness on Oxidation Resistance of Stainless Steel AISI 316Ti During Exposure at High Temperature

In the present work, the influence of surface roughness on oxidation kinetics of AISI 316Ti stainless steel and its consequences in term of oxidation resistance were investigated. Namely, the effect of surface roughness on oxidation resistance was evaluated during different types of cyclic oxidation tests at 900 and 1000 degrees C. The obtained results revealed that alloy possessing higher surface roughness showed longer lifetime compared to that with lower surface roughness. It was also found that more severe cyclic conditions suppressed the positive effect of surface roughness on sample's lifetime. The better oxidation resistance of rougher alloy was correlated with suppressed formation of Fe-rich nodules on ground surfaces and explained by the combined effect of introduced defects in the near-surface region and possible increase in residual stresses caused by mechanical surface preparation.