Erosion–corrosion of HVOF-sprayed Fe-based amorphous metallic coating under impingement by a sand-containing NaCl solution

• The coating shows higher resistance to slurry impingement than 304 stainless steel.
• The mass loss of the coating reaches the peak at an impact angle of 90°.
• Two impingement mechanisms of the coating were found out at various impact angles.
• Critical flow velocities were studied using potentiostatic tests under impingement.
• Passive films formed at different impact velocities are of different thicknesses.

Erosion–corrosion (E–C) behaviour of a Fe-based amorphous metallic coating (AMC) compared with 304 stainless steel (304 s.s.) was studied under a slurry impingement condition in a sand-containing NaCl solution. AMC exhibited much higher resistance to E–C than 304 s.s. The weight loss reached the maximum at an impact angle of 90° and the critical flow velocity was about 15 m/s for AMC, while 45° and 9 m/s for 304 s.s. The increment in passive current density under impingement for AMC was about 10 times lower than 304 s.s. Passive films formed at different impact velocities were of different thicknesses.