Corrosion behavior of HRB500aE seismic corrosion resistant reinforcement in sodium sulfite solution

In the alternate wet and dry environment of sodium sulfite solution, periodic corrosion tests were carried out for both the newly developed anti-seismic rebar resistant to industrial atmospheric corrosion and reference HRB400 ordinary rebar, in order to investigate its corrosion behavior in the simulated industrial atmospheric environment. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to analyze surface morphology and structure of corrosion resistant steel bars at different stages of corrosion time. The experimental results showed that after 72 hours of corrosion, the developed steel under test formed a dense α-FeOOH structure with internal rust layer, and its corrosion resistance and mechanical properties were significantly better than ordinary steel bars. The additions of Cr, Ni and Cu greatly reduce the corrosion sensitivity of HRB500aE matrix, and with corrosion time prolongs in sodium sulfite environment, the corrosion sensitivity is basically stable. The rust layer of HRB500aE is a double-layer structure, and Cu and Ni are enriched in the inner rust layer, which helps to form a dense inner rust layer.