Improving the slurry erosion resistance of multiphase ZrB2-based coated pipe fabricated by centrifugal self-propagating high-temperature synthesis

Ceramic coatings extend the lifespan of steel pipes used in hydroelectric power plants and mining industries by reducing erosion damage. This work employed the centrifugal self-propagating high-temperature synthesis approach to produce a ZrB 2 coating on the internal surface of the pipes. The as-coated samples were annealed for 2 to 6 h at 750 °C to improve the erosion resistance and microhardness. The microstructural analysis confirmed that a multiphase ZrB 2 -based coating was deposited, with minor cracks and pores, and that these were reduced after annealing. The sample treated at 750 °C for 4 h exhibited the maximum hardness of 1189.98 HV, showing improvements of 4.72 times over the substrate and 1.23 times over the as-coated sample. In addition, the slurry erosion test results showed that the annealed sample, which had the highest microhardness, exhibited superior erosion resistance across all test conditions compared to the as-coated and uncoated samples. Among the tested parameters, impact velocity (10–40 m/s) had the most pronounced effect on erosion rate, with erosion increasing substantially as impact velocity increased. These results showed that annealing significantly improved the microhardness and erosion behaviour of the ceramic-coated steel.