Microstructure and corrosion behaviour of laser-cladded γ-Ni/Mo2Ni3Si alloy coating

Different γ-Ni/Mo 2 Ni 3 Si alloy coatings were fabricated on 0.45 wt-% C steel applying the DISTA300 semiconductor laser system. The microstructures, phase components and corrosion behaviour of the alloy coatings were investigated. Research results showed that laser-cladded coatings with different compositions were all composed of ductile phase γ-Ni and reinforced phase Mo 2 Ni 3 Si. Electrochemical parameters and anodic polarisation curves revealed that the γ-Ni/Mo 2 Ni 3 Si alloy coatings exhibited a good corrosion performance in 3.5% NaCl solution in comparison with 0Cr18Ni9Ti stainless steel. The corrosion current density of the laser-cladded layer increased first and then decreased with the increasing volume fraction of Mo 2 Ni 3 Si. Moreover, the addition of Cr can significantly improve the passivation and anti-pitting ability of the γ-Ni/Mo 2 Ni 3 Si alloy coating.