Abstract:The accelerated corrosion tests for reinforcing steel in concrete were carried out by chloride electromigration method. The morphology and distribution of corrosion products at the steel concrete interface for both low alloy(LA) and low carbon(LC) steels were observed by backscattered electron(BSE) images and energy dispersive X ray spectroscopy(EDS) analysis. The effect of surface condition with mill scale or pickled without mill scale of steels on their corrosion pattern was also investigated. The results indicate that the steel concrete interface is composed of corrosion layer, local pitting corrosion zone and corrosion filled paste after the accelerated corrosion. The resulted LC steel is seriously corroded with the formation of thick and widely distributed corrosion layer, whereas pickled LA steel exhibits high corrosion resistance in concrete due to the formation of thin and compact corrosion layer as well as the corrosion pits enriched with alloying element Cr.