A deformation and fracture model was developed for TC128B steel that is valid for temperatures between -80 and 24 °C and for various strain-rates. The Modified-Mohr-Coulomb (MMC) damage mechanics model was used in which the failure strain is dependant on both stress triaxiality and Lode angle. Several mechanical tests, finite element simulations and optimization methods are required to calibrate damage model parameters accurately. Calibration of damage models is often performed at only a single temperature, strain-rate and for a specific grade of steel. However, there are variations in the fracture response due to temperature, strain-rate, and nominal differences in the same grade of TC128B. The current work utilized a recent comprehensive damage model developed by Paredes et al. (2018) for a single grade of TC128 at room temperature as a starting point for model calibration. Damage model parameters were determined based on only a limited number of mechanical test data, mainly tensile and Charpy V-notch tests. It was found that the model could accurately capture the ductile fracture response of the material for a variety of temperatures and strain-rates. Distinct consideration was given to accurately capturing the brittle fracture response at low temperatures.