Crack Resistance Behavior of ODS and Standard 9%Cr–containing Steels at High Temperature

9%Cr–Oxide Dispersion Strengthened (ODS) steels are under intense research in the EU and other countries to extend the operation temperature range of ferritic alloys towards 600–650°C. Unfortunately, fracture toughness behavior in this high temperature range is missing. Therefore, the main objective of this work is to evaluate the crack resistance behavior of a 9%Cr ODS steel in the range of 300–650 °C and comparison to the standard non ODS Eurofer-97 steel. Test results on the ODS steel show a drastic decrease of both initiation toughness and tearing resistance with increasing test temperature. In particular, above 550°C, the crack resistance curve (J–R curve) of ODS Eurofer is extremely low while the standard Eurofer–97 exhibit a much higher crack resistance curve.