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 30° to 90° with an increment of 15°, and compared with the slurry erosion behaviour of two laser clad carbide coatings and a non-coated substratemade of AISI 4140 steel. The Fe–Cr–B–Si alloy coatings had slurry erosion resistance. Their overall slurry erosion resistance at impact angles from 30° to 90° was higher than both the carbide coatings and steel. The erosion resistance of the Fe–Cr–B–Sialloy 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 ofthe coatings. The liquid nitrogen cooling of the substrate resulted in a structural refinement of the deposited coating and increased the erosion resistance substantially.