Multiaxial Time-Dependent Cyclic Deformation of Stainless Steel at High Temperatures

The multiaxial time-dependent cyclic deformation behavior of stainless steel (i.e., 1Cr18Ni9) was studied experimentally at 250 °C and 700 °C. In the tests, the strain cyclic characteristics and ratcheting behavior of the material were observed under multiaxial cyclic straining/stressing at different loading rates and with various hold-times and non-proportional loading paths. The results show that the cyclic deformation behavior of the material is significantly influenced by the non-proportional loading paths and present apparent time dependence, especially at 700°C. Some significant conclusions useful for the design and assessment of pipe structures in nuclear engineering are obtained.