Solid particle erosion studies of D-gun sprayed cermet coatings on ASTM A36 steel

Erosion studies were performed in simulated coal-fired boiler conditions with a view to compare the erosion behaviour of two different types of detonation gun (D-gun) sprayed cermet coating powders, i.e., WC-12%Co and Cr3C2-25%NiCr on ASTM A36 steel and bare (uncoated) ASTM A36 steel. During the erosion studies weight loss, erosion rates in terms of volume loss (mm3/g) and measurement of erosion profiles were determined utilising optical profilometer. All the two different types of D-gun sprayed cermet coatings had successfully protected the ASTM A36 steel from erosive wear at impingement angles of 45o, 60o and 90o. In the case of bare ASTM A36 steel specimens the solid particle erosion rates were maximal at an impingement angle of 45o that was reduced at an impingement angle of 60o and minimal at an impingement angle of 90o that is the typical erosive wear behaviour of ductile materials. WC-12%Co coated specimens exhibited erosive wear behaviour that is closer to the behaviour of ductile materials. Cr3C2-25%NiCr coated specimens exhibited the maximum volume erosion rate at an impingement angle of 90o which was reduced at an impact angle of 60o and minimum at an impingement angle of 45o hence depicted the typical behaviour of brittle materials.