The Effect of Heat Treatment on the Corrosion Resistance of Fe-Based Amorphous Alloy Coating Prepared by High Velocity Oxygen Fuel Method

In this study, Fe40Cr19Mo18C15B8 amorphous coatings were prepared using high velocity oxygen fuel (HVOF) technology. Different temperatures were used in the heat treatment (600 degrees C, 650 degrees C, and 700 degrees C) and the annealed coatings were analyzed by DSC, SEM, TEM, and XRD. XRD and DSC results showed that the coating started to form a crystalline structure after annealing at 650 degrees C. From the SEM observation, it can be found that when the annealing temperature of the Fe-based amorphous alloy coating reached 700 degrees C, the surface morphology of the coating became relatively flat. TEM observation showed that when the annealing temperature of the Fe-based amorphous alloy coating was 700 degrees C, crystal grains in the coating recrystallized with a grain size of 5-20 nm. SAED analysis showed that the precipitated carbide phase was M23C6 phase with different crystal orientations (M = Fe, Cr, Mo). Finally, the corrosion polarization curve showed that the corrosion current density of the coating after annealing only increased by 9.13 mu A/cm(2), which indicated that the coating after annealing treatment still had excellent corrosion resistance. It also proved that the Fe-based amorphous alloy coating can be used in high-temperature environments. XPS analysis showed that after annealing FeO and Fe2O3 oxide components increased, and the formation of a large number of crystals in the coating resulted in a decrease in corrosion resistance.

Automated summary

Fe40Cr19Mo18C15B8 amorphous coatings were prepared using HVOF technology and heat treated at different temperatures. The coatings showed crystallization at 650 degrees C and a relatively flat surface morphology at 700 degrees C. Various analysis methods revealed that the coatings exhibited excellent corrosion resistance in high-temperature environments.