Hot erosion behavior of two new iron-based coatings sprayed by HVCC process

The hot erosion resistance of two new iron-based coatings sprayed by high velocity continuous combustion (HVCC) process was studied using a nozzle type elevated temperature erosion tester. The coating samples were prepared under as-deposited, post heat-treated and sealed plus heat-treated conditions. For comparison, AISI 1018 low carbon steel, two existing HVCC iron-based coatings, and two high velocity oxygen fuel (HVOF) sprayed carbide-cermet coatings were also tested. The morphology of samples was examined by light microscopy and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). It was found that these two new iron-based coatings exhibited better erosion behavior than the two existing iron-based coatings. One of the new coatings showed the same level of erosion resistance as the HVOF chromium carbide-cermet coating, but with much lower cost. In addition, heat-treatment at 500 °C and sealing treatment can improve erosion resistance of these two new coatings remarkably. The erosion mechanism of coatings was also discussed and compared.