Erosion of protective coatings

The room temperature erosion behavior of four different coatings on 1018 mild steel, namely clad WC+NiCrB, detonation gun Cr 3C 2, sputtered Cr 3C 2 and electroless Ni+P, were investigated. The erosion tests were carried out under conditions that were representative of those which could occur in coal particle, energy production systems, with the exception of the test temperature. It was determined that the clad WC+NiCrB coating had a low erosion rate compared with most other materials tested, and that the hardness of the coating did not relate directly to the erosion resistance. For the hard coatings tested at low particle velocity, the erosion mechanism appeared to be cracking and chipping. As the particle velocity increased, more plastic deformation of the clad alloy was observed.