A model has been developed to predict crack growth velocities at IGSCC for varied stress and ion concentration. The model is a coupling between Fick's second law and a newly developed cohesive element with degradation of damage resisting properties, implemented into a user element in ABAQUS. High stresses at the crack tip are assumed to drive the corrosion process and change the diffusivity. The stress and ion concentrations are varied which shows that higher stresses or higher ion concentrations gives different oxide thicknesses and higher crack propagation velocities.