Corrosion performance of dual-phase steel embedded in concrete

Abstract

This paper presents results of experiments designed to evaluate corrosion performance of a dual-phase steel embedded in concrete. The dual-phase steel was produced by inter-critical annealing of conventional steel at 735 °C. Test specimens were initially cured in water for 14 days followed by accelerated corrosion curing in 3.5% chloride solution and sea water. Corrosion rates were measured using a modified 'ASTM G 109 tafel extrapolation corrosion test technique', which entails voltage control and current quantifications. In addition, the CMS-105 system was employed for weekly observations on steel bars immersed in similar curing conditions. The parameters measured include corrosion potential (Ecorr), corrosion current (Icorr), polarization resistance (Rp), and corrosion rate as well as anodic and cathodic tafel slopes ßa and ßc, respectively. In order to examine whether the microstructure has an effect on the corrosion of the steel, a metallographic study was carried out, and it was found that the dual-phase steel performs better than the conventional steel in resisting corrosion.