The effect of erosion speed on the interaction between erosion and corrosion of the Fe–3.5 wt% B alloy in a flowing zinc bath has been investigated using a rotating-disk technique. The total erosion–corrosion rate increases rapidly, whereas the pure erosion rate tends to increase linearly with an increase in erosion speed and with low damage. The increase in total erosion–corrosion rate is strongly dependent on erosion–corrosion interaction. During the erosion–corrosion process, the severe corrosion reaction roughens the surface by forming a loose corrosion layer and cracks in the anticaustic Fe2B skeleton, which eventually facilitates erosion. The micromechanical scouring effect of liquid zinc worsens corrosion by accelerating the removal of corrosion products and causing spallation of anticaustic Fe2B. An increase in erosion speed intensifies the micromechanical scouring effect of flowing zinc significantly. A strong erosion–corrosion interaction occurs at high erosion speed, which leads to a greater material loss rate.

The erosion–corrosion properties and interface microstructure of a Fe–B alloy that contains 3.5 wt% B in flowing liquid zinc have been investigated by electron backscattered diffraction, x-ray diffraction, and scanning electron microscopy to clarify the flowing effect of liquid zinc on erosion performance using a rotating-disk technique. The Fe–B alloy erodes at a low and steady rate in flowing liquid zinc. Flowing liquid zinc can accelerate the iron and zinc mass transfer to form Fe–Zn compounds and promote the removal of loose FeZn13. Much residual corrosion-resistant Fe2B and some erosion products coexist at the erosion interface because of the chemical and micromechanical effects that are created by flowing liquid zinc. The failure of the Fe2B corrosion-resistant skeleton in flowing liquid zinc occurs because of the loss of supporting matrix and also the formation and spread of microcracks during erosion.