Localized Corrosion Induced by Nonmetallic Inclusions in Rebar HRB400E Alloyed with Rare Earth
摘要
In this study, the corrosion behavior of typical nonmetallic inclusions in rebars HRB400E alloyed with rare earth (RE) was investigated using scanning electron microscopy-energy-dispersive spectroscopy, scanning Kelvin probe force microscopy, and Pourbaix diagram. The results showed that the presence of micro-crevice affected the stability of MnS inclusions and the surrounding matrix. The corrosion process of MnS inclusions with micro-crevice was influenced by crevice corrosion, while MnS inclusions without micro-crevice exhibited comparatively good corrosion resistance. In addition, the dissolution of inclusions was also strongly affected by the chemical compositions, and the presence of RE elements (La and Ce) can improve the stability of the inclusions. Mechanism of the localized corrosion process induced by typical nonmetallic inclusions in rebars alloyed with RE in 2 wt.% NaCl environments was proposed.