Effects of pre-oxidation on the microstructural and electrical properties of La0.67Sr0.33MnO3−δ coated ferritic stainless steels

► We evaluate the pre-oxidation effects for the LSM-coated SOFC interconnects. ► Pre-oxidised interconnect has a stronger effect on the resistance of Cr diffusion. ► Pre-oxidised layer, (Mn, Cr)3O4, could significantly suppress chromium penetration. ► Pre-oxidation could lower the increasing rate of ASR at high temperatures.