Based on a non-classical theory of plasticity and the continuum damage mechanics, a damage evolution based on an ellipsoidal void model for mixed hardening materials is obtained. The damage evolution law is embedded in the adopted constitutive equation, and a damage constitutive equation is obtained for the ferrite phase. The overall constitutive description for a pearlitic colony is derived from the combination of constitutive models respectively for ferrite and cementite phases and the geometric characteristics with a mixture theory. And the constitutive model for the plasticity and damage description is further derived based on the Hill's self-consistent scheme. The comparison of the results for damaged and undamaged model also demonstrates the validity of the developed damaged constitutive description.