Fig. 6: DPP curve of Nb-containing rebar and CS rebar and fitting value of DPP curve after passivation for 10 d in SCPS with different pH.

a pH13.2. b pH12.5. c pH10.5. d pH9.0. The green dotted line frame was the passivation region.
a pH13.2. b pH12.5. c pH10.5. d pH9.0. The green dotted line frame was the passivation region.