Cyclic Hardening and Softening Behavior of Tmcp440c Steel

To investigate the cyclic hardening and softening behavior of high-performance TMCP440C steel, fully reversed axial strain-controlled cyclic loading tests were conducted on round bar specimens at strain amplitudes ranging from 0.25% to 12%. The steel exhibited overall cyclic softening behavior, followed by slight cyclic hardening, depending on the applied strain amplitude. The expansion and contraction of the elastic range also depended on the applied strain amplitude. The Bauschinger curve varied with strain amplitude, showing a notable secondary increase in tangent stiffness at large strain levels. These findings provide insight into the material’s inelastic behavior under cyclic loading.