This study focuses on developing a constitutive model to describe the dynamic plasticity and fracture behavior of arc-melted cladding for remanufacturing wind turbine gears. By combining quasi-static tensile tests and Split Hopkinson Tension Bar (SHTB) experiments, the research investigates the static and dynamic properties of Wire Arc Additive Manufacturing (WAAM) alloy cladding under various strain rates and high temperatures. Results reveal strain hardening, strain rate hardening, and thermal softening effects, leading to the establishment of J-C plasticity and failure equations. Finite element simulations validate the model, achieving an AARE of 8.670% and an R value of 0.9449, confirming the model’s accuracy and reliability for predicting the alloy’s dynamic behavior in remanufacturing applications.