Characterization and Modeling of the Ratcheting Behavior of the Ferritic-Martensitic Steel P91

The ratcheting behavior of 9% Cr-1% Mo ferritic-martensitic (FM) steel P91 is investigated by uniaxial cyclic loading tests. Strain-controlled tests are performed to evaluate the cyclic softening and stress-controlled tests are performed to evaluate the ratcheting behavior. A new constitutive model is proposed to fit the ratcheting behavior of P91. A new dynamic recovery rule is designed to fit the ratcheting rates under multiple loading conditions