Equal channel angular pressing (ECAP) process provides an efficient procedure for achieving ultrafine grained microstructures with excellent mechanical properties in metallic materials. In this article, a simulation scheme for predicting the mechanical behavior during and after ECAP was proposed. The proposed scheme was applied for interstitial-free (IF) steels, which are widely used for the automobile body applications. Plastic deformation behavior during several passes of ECAP in route Bc, including such aspect as deformed geometry, corner gap, forming load and strain uniformity, was predicted. Tensile testing responses of the ECAP-processed IF steel, including strain hardening, onset of necking, and post-necking behavior, were analyzed using the finite element method and compared with the experimental results. The predicted tensile curves, ultimate tensile strength, and elongation varying with the number of ECAP passes were in good agreement with experimental results. The computational scheme developed was demonstrated to successfully predict not only the plastic deformation behavior during ECAP but also the mechanical properties of the ECAP-processed material.