A study of laser cleaning to remove by-products occurring after arc welding

Recently, demand for the welding process largely increases in the manufacturing fields. The welding process is an essential process but the formation of by-products including slag, oxide, and heat tint after welding adversely affect the corrosion resistance and painting performance of the products. The conventional cleaning method generates environmental pollution because of secondary waste. Besides, a worker is exposed to danger. The mechanical method is limited due to the difficulty to access curved geometry of the workpiece. However, laser cleaning can overcome these problems. Especially, this technique can remove the welding by-products with no critical damage on the surface and secondary waste is barely formed during processing. Thus, it can be considered as an eco-friendly processing method. To analyze the interaction characteristics between laser and material, different laser parameters such as pulse duration, laser power, and scanning speed are set. The microstructure and chemical composition are observed using a scanning electron microscope (SEM) and energy dispersive x-ray (EDX), respectively. Consequently, when the laser power increases, the oxygen component on the surface decrease because the heat tint and oxide layer are removed. Also, when the scanning speed decreases, the over-cleaning is generated on the surface and the surface of the substrate is damaged. •Laser cleaning is used to remove by-products formed around weld beads after arc welding.•The effect of laser parameters on the removal of by-products is investigated.•As laser power increases, the heat tint and oxide layer on the surface is significantly reduced.•To determine the laser parameter for removal of slag, characteristics of slag having a large amount of silicon dioxide should be considered.