Creep-Fatigue Crack Propagation in Austenitic Stainless Steel

Abstract

The inclusion of tensile hold periods during cyclic loading did not detrimentally affect rate of crack propagation in solution-annealed type 304 steel and 20 percent cold-worked type 316 steel at 427 C (800 F). But at 593 C (1100 F), increases in hold time caused higher crack growth rates (da/dN), for a given stress intensity factor range (ΔK), for both steels. In terms of da/dt, hold periods decreased growth rates for the type 304 steel. The number of cycles to failure of the type 304 steel decreased and the time to failure increased with increasing hold times; but the trends were not the same for the type 316 steel. Hold periods caused a shift in cracking mode from transgranular to intergranular.