Microstructure and property evolution of PIM-processed Fe-30Cr alloys for SOFC/SOEC interconnectors under simulated operational conditions

Solid oxide fuel cells (SOFCs) and electrolyzer cells (SOECs) require advanced interconnector materials that can withstand extreme conditions while ensuring both efficiency and durability. Although Crofer 22 has been widely studied, its lack of commercial powder limits its use in Powder Injection Moulding (PIM), a promising manufacturing route for cost-effective, high-performance interconnectors with complex geometries. In contrast, Crofer 30 is commercially available in powder form, enabling full utilization of PIM, yet its in-service performance remains untested. This study addresses this gap by evaluating its microstructure evolution, oxidation resistance, hydrogen embrittlement susceptibility, and mechanical integrity under simulated SOFC conditions. PIM-processed Crofer 30 exhibits a suitable thermal expansion coefficient and maintains competitive electrical conductivity due to the formation of a fine, stable chromia layer after 200 h in air. While prolonged high-temperature exposure enhances hardness without compromising ductility, hydrogen exposure induces embrittlement. Overall, this work positions Crofer 30 as a viable alternative to Crofer 22 for next-generation SOFC/SOEC interconnectors, supporting the development of more durable and efficient energy systems through advanced designs and accelerating the transition to green energy technologies. • PIM enables cost-effective shaping of Crofer 30 into interconnects for SOFC/SOEC. • PIM-processed Crofer 30 exhibits oxidation kinetics and electrical performance comparable to Crofer 22. • EIS is validated as a fast, non-destructive method to assess oxide scale resistance in Crofer 30 alloy. • Exposure to H2 reveals susceptibility to embrittlement via sigma phase precipitation and grain boundary degradation. • Industrial validation of Crofer 30 powders for next-generation interconnect manufacturing via scalable technologies.