Low cycle fatigue tests of surface modified T91 steel in 10−6 wt% oxygen containing Pb45Bi55 at 550 °C

Low cycle fatigue tests in air and LBE containing 10−6 wt% dissolved oxygen were conducted with T91 steel at 550 °C. T91 was employed in two modifications, one in the as-received state, and the other after alloying FeCrAlY into the surface by pulsed electron beam treatment (GESA process). Tests were carried out with symmetrical cycling (R = −1) with a frequency of 0.5 Hz and a total elongation Δεt/2 between 0.3% and 2%. No influence from LBE on fatigue could be detected. Results in air and LBE showed similar behaviour. Additionally, no difference was observed between surface treated and none treated T91 specimens.