In this research, the hot deformation behavior of API X70 steel was investigated by hot compression tests. A temperature range between 950 and 1150 °C was used for experiments with different strain rates of 0.01, 0.1 and 1 s-1. The work hardening rate versus stress curves were used to reveal if dynamic recrystallization (DRX) occurred. The application of constitutive equations to determine the hot working constants for the tested steel was discussed. Using regression analysis, the stress multiplier (α), the apparent stress exponent (n), and the activation energy (Qd) for DRX were calculated as 0.016 and 4.420, and 382 kJ/mol, respectively. Furthermore, the effect of Zener–Hollomon parameter (Z) on the characteristic points of flow curves was investigated using the obtained relations. The dynamic recrystallization (DRX) kinetics of API X70 steel was also studied and its governing equation was derived.