Ultraviolet laser cleaning and surface characterization of AH36 steel for rust removal

Laser cleaning of rusted surfaces has broad applications in marine ship industrial manufacturing. An ultraviolet nanosecond laser cleaning method was proposed to strip the rust layer from the surface of the AH36 steel to reduce surface roughness and increase corrosion resistance. Multi-pulse laser ablation was established to determine the single-pulse threshold fluence and pulse incubation coefficient of the substrate. Based on the experimental results, the surface cleaned at a fluence of 3.17 J/cm2 has the best combination of corrosion resistance and roughness. The chemical composition and microstructure of the sample surface were measured via X-ray photoelectron spectroscopy and scanning electron microscopy. Moreover, the corrosion resistance of the samples was evaluated with electrochemical measuring. The results showed that the laser-cleaned surface has approximately five times greater corrosion resistance than the rusted surface. The proposed method is an environmentally friendly approach that effectively increases corrosion resistance, which may subsequently extend the service lifetime of a ship. Hence, this study may contribute to the development of laser manufacturing.