Abstract
Effects of phase difference and slit geometry on high temperature fatigue crack growth of SUS 304 stainless steel were examined under multiaxial conditions. Fatigue crack growth tests were conducted by using DC electrical potential drop method. "Tensile type" crack, which propagates along the direction, φ, perpendicular to the maximum principal stress, σ_1 and "Shear type" crack, which propagates along the direction of maximum shear stress, γ_<max> were observed under these conditions. The appearance of crack growth type was affected by both slit geometry and phase difference of loading waveform, as well as multiaxial condition, Δγ/Δσ. In case of the slit with low stress concentration, "Shear type" crack growth tends to be appeared. The experimental results were discussed with the results of elastic-creeping FE analyses for under combined loading conditions. The characteristics of both type of fatigue crack were discussed.
