Slurry erosion resistance of fusion-bonded epoxy powder coating

Erosion resistance of fusion-bonded epoxy powder coating in emery sand slurry containing 1 wt.% NaCl has been investigated by using modified rotating disk rig. The effects of emery sand content, flow velocity and diameter of emery particle on the erosion resistance of the coating have been studied through mass loss test and SEM observation. The results showed that the mass loss rate of the coating increased according to a power law with the flow velocity (V), emery particle content (C) and diameter of emery particle (D). The mass loss rate (E) of the coating could be described by an empirical equation, namely E∝Vn1Cn2Dn3. The relative large values of n1 and n3 compared with n2 indicated that the flow velocity and diameter of emery particle were the dominant factors. The critical flow velocity of the coating in slurry containing 10, 15, 20 wt.% emery particle (112 μm) was about 7, 6, 5.8 m/s, respectively. Under the test conditions, the first critical diameter (FCD) and the second critical diameter (SCD) of emery particle were about 80 and 410 μm, respectively. Within 80–410 μm, the influence of mean diameter of emery particle on erosion was significant. Therefore, the coating is suitable for the relative mild conditions of liquid-particle two-phase flow such as low flow velocity and small particles.