Abstract
This paper presents both the crack propagation behavior and the failure life of SUS304 austenitic stainless steel in two series of low-cycle fatigue tests under biaxial stress conditions at 550°C in air. One was performed in order to examine the effect of the cyclic principal stresses imposed to the specimen in parallel with the fatigue cracks on both the fatigue crack propagation behavior and the fatigue life, another the effect of rotation of the principal stress axes. From the tests, the following conclusions were obtained. (1) The effect of cyclic principal stressing in parallel with the fatigue crack on both the fatigue crack propagation rate and the fatigue life was not remarkable, and both the equivalent total strain range of Mises'type and the cyclic J-integral range were good parameters in comparing each other in biaxial low-cycle fatigue test data. (2) Rotation of the principal stress axes resulted in the decrease of both number of cycles to crack initiation and that to failure and also in the increase of the crack propagation rate.
