A high temperature wear-resistant Ni-based alloy coating for coppery blast furnace tuyere application

Abstract

With the aim to improve the high temperature wear resistance of copper, a Ni-based coating was fabricated on its surface by plasma cladding. The coating has no crack defects and forms a metallurgical bonding with copper substrate (dilution rate 13.3 %). The γ-(Cu, Fe, Ni), Cr23C6, CrB, Fe3Ni and Ni3Si phases make the coating have strong bearing and plastic shear resistance, resulting in significantly higher wear resistance than the copper substrate. As the temperature increases, the wear resistance of the coating shows a trend of increasing first (about 400 °C and 500 °C) and then decreasing (above 600 °C). NiO oxide layer on the coating surface plays an important role in the transformation of wear resistance and wear mechanism. Heat transfer characteristics analysis results (based on the service conditions of blast furnace tuyere) show that manufacturing the coating on the inner wall of tuyere has no obvious effect on the overall temperature field distribution. The maximum temperature of the coating surface is only about 191.06 °C, which is far below its allowable temperature (600 °C). Therefore, the Ni-based coating can be applied to the surface strengthening for the inner wall of blast furnace tuyere.