Effect of Multiaxial Stress State on High-Temperature Low-Cycle Fatigue Properties of SUS304 Steel
Katsuyuki TOKIMASA and Tadahiro TANI
Abstract:Fully reversed strain-controlled low-cycle fatigue tests, so called PP tests, were conducted on thin-walled tubular specimens of SUS304 austenitic stainless steel at 973 K in air under proportional and nonproportinal loading conditions. Push-pull straining, cyclic torsion straining and in-phase straining of push-pull and cyclic torsion were selected as proportional loading, and 90 deg out-of-phase straining of push-pull and cyclic torsion as nonproportional loading. Experimental data were analyzed by using both the Manson-Coffin equation and the critical plane model proposed by Brown and Miller, and the effects of the multiaxial stress state on the strain range versus life relationship were discussed. As the results, a new parameter was proposed that has a hopeful potential to estimate the effect of nonproportional loading on creep-fatigue life quantitatively based on the strain range partition- ing method. Key Words:Multiaxial fatigue, Nonproportional loading, Life prediction, Multiaxiality factor, Critical plane model, SUS304