Abstract:
To enhance the corrosion and wear resistance of the 304 stainless steel components, the metallic coatings with varying Ni625/TC4 mass ratios (3:1, 5:1, 7:1, and 9:1) were fabricated on 304 stainless steel substrate by laser cladding technology, using Ni625 and TC4 powders as raw materials. The microstructural morphology and phase composition of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion behavior and wear mechanisms were investigated through electrochemical testing and wear experiments, respectively. The results demonstrate that all four laser cladding coatings consist of body-centered cubic (BCC) Fe
3Ni
2, hexagonal-structured TiFe
2, and Ni
3Ti intermetallic phases. The contents of TiFe
2 and Ni
3Ti phases progressively decrease with Ni625 content increasing. The coatings with Ni625/TC4 ratio of 3:1 exhibit the optimal wear resistance, dominated by abrasive wear mechanisms. As the Ni625 content increases, the wear mechanism transitions to the oxidative wear. All coatings display the exceptional passivation behavior in artificial seawater solution, with the passivation current density progressively decreasing as the Ni625 content increases. The coatings with Ni625/TC4 ratio of 9:1 demonstrate the most superior corrosion resistance.