The erosion of low-carbon steel, in the annealed and water-quenched condition, by coal particles, has been studied as a function of particle size, velocity, and angle of impingement. It was found that both unicrostructures, pearlitic and martensitic, showed a maximum erosion at an angle of impingement of between 20 and 30°. Under all condition of testing, the martensitic structure showed the higher rate of erosion. The coal particles were found to fracture on impact with the steel surfaces. The amount of fracture was found to increase will increased velocity and particle size. Erosion rate was found to increase with decreasing particle size and was related to particle velocity (V) through a power law relationship of the form: E = kVn, where the exponent (n) has valves between 2.6 and 3.7. Scanning electron microscopy studies indicated that only the harder mineral constituents in the coal, such as pyrite and quartz, were responsible for the erosion of the steel.Presented at the 40th Annual Meeting in Las Vegas, Nevada May 6–8, 1985