Cyclic Plastic Deformation at Low Temperature in Liquid Nitrogen and Room Temperature Subsequent to Pre-Strain at Low Temperature in Liquid Nitrogen and Room Temperature
Yokotsuka Tomohito; Ikegami Kozo
Abstract:Cyclic loading tests are performed by using thin walled tubular specimens of SUS304 stainless steel at low temperature in liquid nitrogen (77K) and room temperature. Cyclic plastic deformation subsequent to pre-strain at 77K and room temperature is experimentally investigated under torsional, tensile and compressive loading conditions. At small cyclic numbers, the pre-strain perpendicular to cyclic loading direction results in large hardening, and cyclic plastic behavior subsequent to the pre-strain at 77K is more hardened than the pre-strain at room temperature. With increasing cyclic number, the effect of temperature on the hardening behavior becomes small. When the cyclic loadings are conducted in the same direction as the pre-straining direction, the effect of the pre-strain on hardening behavior is not remarkable at room temperature and 77K. The pre-strain at 77K influences the cyclic hardening at room temperature even for large cyclic number. Key Words:material testing, plasticity, low cycle deformation, pre-strain, cyclic loading