The effects of solution concentration and temperature on the electrochemical behavior of the Fe-based amorphous (AMCs) coatings in NaCl solution were studied by using conventional electrochemical measurement and XPS analysis. Results indicated that as solution concentration and temperature increased, the current density for the Fe-based AMCs increased and the pitting potential decreased. This reduced corrosion resistance was derived from the decreased passivation index and polarization resistance, which contributed to the decrease of the induction time (t_m) for the initiation of corrosion pit. The passive films formed on Fe-based AMCs exhibit two types’ semiconductors higher and lower the flat band potential. The decrease of protectiveness of the passive film was mainly correlated with the reduction of Cr₂O₃ content, the increase of carrier density and the decrease of the work function (W_F).

As a key step in intensive additive repair, the design of intensive repair materials immediately needs to be explored. In this work, an intensive additive repair study based on laser cladding technology was performed using a self-designed Fe₂₀Co₂₅Ni₃₁Cr₈Al₉Ti₇ high-entropy alloy (HEA) powder and three types of substrates widely used in field equipment (namely, Q235, 17CrNiMo6H, and 304 stainless steel). The results revealed that the HEA repair layer (HEA-RL) consists of a dominant FCC phase and a small amount of BCC phase, and the microstructure shows the columnar-to-equiaxed grain transition behavior. The metallurgical bonding between the HEA-RL and the three substrates has almost no defects. Compared with the three substrates, the HEA-RL has a much higher microhardness (~340 HV) and decent corrosion resistance. Therefore, the underlying mechanisms for the microstructure and performance of the HEA-RL were also discussed. This work provides a new idea for the design of intensive repair materials.