Visco-plastic behavior of stainless steel SUS 304 under cyclic loading at room temperature.

Abstract

The stress-strain relation of stainless steel SUS 304 depends strongly on the stress or strain rate even at room temperature. The stress controlled uniaxial creep-ratchetting tests of SUS 304 were conducted at room temperature to investigate the visco-plastic behavior in cyclic loading. The effects of the prestrain and the cyclic stress condition i.e., stress ratio, stress rate, maximum stress and its hold time, on strain accumulation are discussed. The asymptotic stress-strain curve in the tension subsequent to creep-ratchetting reaches the monotonic stress-strain curve. A creep strain rate is given as a function of the magnitude of total strain at the present time even if the material has been subjected to cyclic stressing prior to the creep. Consequently, the strain hardening of the material can be quantified by use of the accumulated strain by creep-ratchetting.