Abstract
HY-80 steel is a critical structural alloy in naval applications. However, routine removal of marine corrosion via grit-blasting aggressively alters the surface by inducing severe plastic deformation and extreme surface roughness. Pulsed laser ablation has emerged as a promising alternative surface treatment, but its thermomechanical implications to previously kinetically altered surfaces remain underexplored. This study investigates the mechanical and microstructural alterations of HY-80 steel subjected to grit-blasting and a dual treatment of grit-blasting followed by laser ablation.Nanoindentation testing techniques were used to extract depth-dependent mechanical profiles of each test condition. Cross-section hardness mapping successfully isolated and quantified the severe plastic deformation zone induced by the primary grit-blasting impact. The results revealed a distinct work-hardened layer, characterized by elevated hardness gradients that decayed into the unaffected bulk material. Comparative analysis of the two test conditions showed that the thermal effects induced by the laser ablation process were confined to the extremely localized surface layer. Microstructural characterization via scanning electron microscopy validated these mechanical profiles. Imaging of the laser ablated sample revealed the formation of microcracking at the surface, a direct consequence of the rapid heating and self-quenching induced by the laser treatment. Ultimately, the mechanical and optical results confirm that the laser effectively alters the immediate surface topography without degrading the depth of the work-hardened zone established by the initial kinetic impact of grit-blasting.