The erosion and erosion-corrosion of chromized steel

The erosion and erosion-corrosion of chromized coatings on carbon and tool steels were investigated under test conditions which simulated those in the convection pass superheater tube banks of circulating fluidized-bed combustors. Coatings diffused by several different processes were obtained from coating suppliers and compared with a plasma-sprayed nickel-alloy-bonded chromium carbide composite. The two layers of chromized coatings, i.e. the hard brittle outer intermetallic layer and the more ductile Cr-Fe alloy layer eroded by different mechanisms at different rates. The plasma-sprayed nickel alloy-chromium carbide material had the lowest material wastage rate.