High-temperature solid particle erosion of Cr–Ni–Fe–C arc cladded coatings

Abstract In the present work two arc weld cladded alloys A (C3Cr25Ni3Si3) and B (C5Cr40Ni40Si2BZr) were tested under solid particle erosion at higher temperature (500 °C and 800 °C). The alloys were cladded using flux-cored strips PL-AN-101 and PL-AN-111, respectively. Alloy A is hypo-eutectic with a γFe + carbide M7C3 eutectic and austenite matrix. Alloy B is hyper-eutectic comprising coarse columnar M7C3 carbide, graphite flakes and an inhomogeneous austenitic matrix. It was found that alloy A presented a lower erosion rate of 18–41% at 500 °C due to the energy-consuming mechanisms of erosion (ploughing and poly-deformation). Alloy B was eroded by a low-cycle mechanism of carbide cracking/chipping. By increasing the testing temperature to 800 °C, the erosion rate of the alloys increased by 4.2–6.7 times. The erosion mechanism of the alloys at 800 °C was the formation and abrupt spalling of a depressed defective subsurface layer consisting of carbide fragments. Alloy A performed with a lower erosion rate of 39–44% at 800 °C due to a lower thickness of the defective layer. Oxidation had a negligible effect on the erosion rate of any of the alloys. The erosion rate of the coatings decreased with the distance from the coating top due to refinement of the carbide M7C3 and graphite inclusions.