SLURRY EROSION RESISTANCE OF LASER CLAD Fe–Cr–B–Si COATINGS

The slurry erosion behaviour of laser clad Fe–Cr–B–Si alloy coatings was investigated at impact angles from 30u to 90u with an increment of 15u, and compared with the slurry erosion behaviour of two laser clad carbide coatings and a non-coated substrate made of AISI 4140 steel. The Fe–Cr–B–Si alloy coatings had slurry erosion resistance. Their overall slurry erosion resistance at impact angles from 30u to 90u was higher than both the carbide coatings and steel. The erosion resistance of the Fe–Cr–B–Si alloy coatings was less dependent on slurry impact angle. The Fe–Cr–B–Si alloy coatings consisted of the Fe–Cr solid solution matrix and the second phase Fe2B. The laser beam traverse rate had little effect on the erosion resistance and microstructures of the coatings. The liquid nitrogen cooling of the substrate resulted in a structural refinement of the deposited coating and increased the erosion resistance substantially. SE/S308