Creep fracture behavior of the Crofer 22 APU for the interconnect of solid oxide fuel cell under different temperatures.

Creep damage and creep crack growth (CCG) behavior of Crofer 22 APU as interconnect of solid oxide fuel cell at different temperatures are investigated by the continuum damage mechanics method through CT specimen. It is illustrated that the fracture time of CT specimen reduces with temperature increasing at the same stress level, they are 1297 h, 42 h, 1.8 h and 0.25 h, respectively, at 650, 700, 750 and 800 °C with stress level of 2.73 MPa ⋅ m . The slopes of creep fracture mechanics parameter C * to CCG rate a ˙ (C *- rate of a) are nearly the same at 650 and 700 °C. The slope of C *- a ˙ at 650 and 700 °C is smaller than that at 750 and 800 °C. It is concluded that the temperature effect on CCG behavior of Crofer 22 APU is more evident than that the stress effect. All the data of C *- a ˙ fall within the area of 95% prediction band, and the obtained equation of C * and CCG rate is a ˙ = 3.8 e 2 C ∗ 0.91 . Therefore, the a ˙ of Crofer 22 APU can be predicted under different stress levels and temperatures. • CCG behavior of Crofer 22 APU under different temperatures are investigated. • The Liu-Murakami constitutive equations of Crofer 22 APU are established. • Temperature effect of CCG behavior is more evident than that the stress effect. • All the data of C *- a ˙ fall within the area of 95% prediction band. [ABSTRACT FROM AUTHOR]