Residual Stress and Wear Resistance of HVOF Inconel 625 Coating on SS304 Steel Substrate

Inconel 625, Ni-based superalloy has been increasingly used as coatings for protecting metallic surfaces against wear, high temperatures, and corrosive environments. In this paper, the investigation of depositing Inconel 625 of varying coating thicknesses (250, 300, 400, and 500 µm) using high-velocity oxy-fuel technique on 304 stainless steel substrate was conducted. The residual stresses of the as-sprayed coatings were investigated using neutron diffraction technique as it can provide high resolution, penetration depth, and its insensitivity to the surface condition. Friction coefficient and wear of the coating were also determined using a ball on disk tribometer sliding against E52100 steel balls. The effect of coating thickness and loading force on the tribological behavior of Inconel films were considered. Compressive residual stresses measured by neutron diffraction were observed for all coating thicknesses, particularly the 400 µm thick coating having the highest compressive stress of − 330 ± 40 MPa. The wear results suggested that the load and coating thickness has a significant influence on the wear rate and the wear mechanism on the surface, which were distinctly discussed.