Application of Fluorescent Probe FD1 to Detection of T91 Steel Corrosion in 3% NaCl Solution

Fluorescent probe of di-N, N'-bis(rhodamine B) hydrazide-ethyl amine (FD1) was synthesized using rhodamine B as raw material. The early corrosion detection of T91 steel by FD1 was investigated by weight loss and solution analysis methods. Fluorescent microscope was used to check the corrosion morphology of T91 steel, and electrochemical measurement was employed to study the corrosion inhibition of FD1 to T91 steel in 3% (mass) NaCl solution. The results show that FD1 had high fluorescent response and selectivity to Fe³⁺ ion. The weight loss data of T91 steel had correlation with the fluorescence intensity and Fe³⁺ concentration in 3% NaCl solution. The fluorescent microscope can detect the initiation of pitting. FD1 has corrosion inhibition to T91 steel in 3% NaCl solution, and can improve its corrosion resistance. FD1 can be used to detect the early corrosion of T91 steel.