Effects of laser ablation coating removal (LACR) on a steel substrate: Part 1: Surface profile, microstructure, hardness, and adhesion

The effects of laser ablation coating removal (LACR) from a high strength shipbuilding steel have been assessed. The LACR process was shown to be effective for the removal of a typical epoxybased coating. However, multiple passes were required to remove the coating, with an increased number of passes required at higher sweep speeds. Scanning electron microscope (SEM) imaging of the surface and cross-sections reveals that the underlying metal substrate is melted and re-solidified during LACR. The appearance of the surface is clearly changed at the microscopic level. However, conventional surface roughness (profile) measurements indicate no statistically significant change in the roughness, using conventional metrics such as average roughness, Ra. Finally, studies performed on samples repainted after LACR confirm equivalent, or superior, adhesion as compared to the abrasive blasted and painted samples.