Investigation on physical characteristics, chemical composition and mechanism of pipeline steel subjected to laser rust removal

In this work, we used continuous fiber laser to clean the rust layer of pipeline steel. The morphology, roughness and chemical composition of cleaned samples were analyzed. The influence of process parameters on the rust removal effect was carefully investigated, and the mechanism of continuous laser rust removal was also deeply discussed. The results showed that continuous laser met the requirements for pipeline steel rust cleaning under suitable process parameters, and the oxygen content could be greatly reduced. During the rust removal process, the remelting of the rust made the surface morphology smooth and the roughness reductive. The rust removal effect first increased, then decreased, and finally increased with the increase of power. The rust removal effect first increased and then decreased with the increase of cleaning speed and scanning width. It has been also found that the rust layer removal process mainly went through three reactions involving ablation vaporization, vibration peeling, and phase explosion. The main mechanisms of laser rust removal were mainly ablation vaporization and phase explosion.