High-temperature erosion investigations on HVOF-coated in 2.5Cr-1Mo boiler tube steel

This study systematically studied the high-temperature solid particle erosion behavior of SA213-T22 boiler tube steel coated with a nanocrystalline layer deposited by the High Velocity Oxy-Fuel (HVOF) technique. The coating characteristics, including microhardness, thickness, and adhesive bond strength, were evaluated to assess the integrity and quality of the deposited coatings. High-temperature erosion tests were conducted at 550 °C using a hot air jet erosion test rig with impingement angles of 15°, 30°, and 45°, varying the specimen orientation. The HVOF-coated specimens exhibited a significant reduction in material loss compared to the uncoated substrate, indicating improved resistance to high-temperature erosion. Enhanced microhardness and strong coating–substrate adhesion contributed to the superior erosion performance. The results confirm that nanocrystalline HVOF coatings provide adequate protection for SA213-T22 steel under elevated-temperature erosive conditions, demonstrating their potential application in boiler tube environments.