Cyclic behavior of a type 304 stainless steel in biaxial stress states at elevated temperatures

The results of companion, incremental/decremental, and stepup fatigue experiments on austenitic stainless steel tube (type 304) are presented. The experiments include proportional and nonproportional loading conditions at ambient as well as elevated temperatures. Empirical relations are developed between von Mises effective stress and strain, and these relations are shown to describe the cyclic behavior during proportional companion as well as incremental/decremental tests. In case of nonproportional incremental/decremental experiments, the material behavior is not accurately modeled either by using the von Mises effective stress and strain, or by relating Tresca's maximum shear stress and strain.