475{\deg}C aging embrittlement of partially recrystallized FeCrAl ODS ferritic steels after simulated tube process

Tube processing and aging effects in FeCrAl ODS steels are investigated in four mechanical alloyed ferritic ODS steels, Fe15Cr (SP2), Fe15Cr5Al (SP4), Fe15Cr7Al (SP7) and Fe18Cr7Al (SP11). These steels were made into 0.3mm thick plates by simulated tube processing (STP). Strengthening after partial recrystallization was achieved after the last cold rolling and heat treatment step. However, the ductility reduced about one third of the as-extruded steels. The STPed steels were aged at 475{\deg}C in sealed vacuum tubes up to 2000 hrs and 10000 hrs, respectively. The yield stress and elongation were investigated by tensile tests. The results revealed that all the STPed steels fractured in a ductile manner irrespective of aging conditions. Aging hardening and ductility reduction in STPed steels are similar to as-extruded ones. The STPed ODS steels showed similar ageing embrittlement resistance as as-extruded steels, but much higher than the non-ODS steels. The aging hardening based on cut-through and bow-pass mechanisms were discussed. The time dependent hardening of overaged steel (beta prime only) was analyzed as well.