Creep failure of a solution-annealed 15-15Ti steel exposed to stagnant lead-bismuth eutectic at 550 and 600 °C.

Uniaxial creep-to-rupture tests at 550 and 600 °C under a constant load of 300 MPa have been performed to study the effect of lead-bismuth eutectic (LBE) on the creep failure behavior of a solution-annealed 15-15Ti steel. The results show that the secondary creep rate of the steel tested in LBE at 550 and 600 °C is 56 and 6 times higher than that tested in air at the same temperatures, respectively. The transition time from the primary creep to the secondary creep is largely shortened by LBE. As a consequence, the creep life of 15-15Ti in contact with LBE is reduced remarkably. The severe degradation of the creep performance is attributed to uniform dissolution corrosion (elemental leaching) and especially localized intergranular cracking. • A novel machine is constructed for in-situ creep testing in LBE. • Creep deformation rate of 15-15Ti is remarkably accelerated by LBE. • Uniform dissolution corrosion is enhanced by tensile stress. • Localized dissolution at crack tips leads to fast intergranular cracking. [ABSTRACT FROM AUTHOR]