Experimental study on uniaxial and nonproportionally multiaxial ratcheting of SS304 stainless steel at room and high temperatures

An experimental study was achieved for the cyclic properties of SS304 stainless steel subjected to uniaxial strain-controlled, uniaxial and nonproportionally multiaxial stress-controlled cyclic loading at room and high temperatures. The effects of cyclic strain amplitude, mean strain, temperature and their histories on the cyclic deformation behavior of the material were investigated under the uniaxial strain-controlled cyclic loading. The uniaxial and nonproportionally multiaxial ratcheting was researched under the asymmetrical stress-controlled cyclic loading with variable stress amplitudes, mean stresses, loading paths and their histories at room and high temperatures. It is shown that the uniaxial cyclic properties tinder strain-controlled cyclic loading and the ratcheting under asymmetric uniaxial and nonproportionally multiaxial stress-controlled cyclic loading depend not only on the current temperature and loading state, but also greatly on the previous loading history and the shape of loading path. The material presents much greater cyclic hardening and less ratcheting in the range of 400-600degreesC than at room temperature, due to the strong dynamic strain aging taken place in this temperature range. Some significant results were obtained for the constitutive modeling of cyclic plastic deformation such as ratcheting. (C) 2002 Elsevier Science B.V. All rights reserved.