Effects of Cutting Geometries and Cutting Parameters on the Surface Roughness and Kerf Width of X60 Steel Machined by Laser Beam

In this research, fiber laser technology, a relatively newer technology with more advanced features, was used. Within the scope of the research, the effects of cutting geometries and cutting parameters on the surface roughness and kerf width of API 5L X60 steel material machined by fiber laser were investigated. When the highest and lowest Ra values were compared according to 2 and 4 Bar gas pressures, it was found that Ra values obtained with 4 Bar gas pressure were 37.15% and 54.19% less, respectively. According to S/N ratios for Ra values, the optimum laser cutting parameters were found to be 2000 W laser power, 2400 mm/min cutting speed and 4 Bar gas pressure, respectively. It was observed that the surface roughness of the specimens cut in a quarter circle were higher than the surface roughness of the specimens cut in a straight line. When the highest and lowest kerf width values were compared according to 2 and 4 Bar gas pressures, it was found that the kerf width values obtained with 4 Bar gas pressure were 25.35% and 75.90% larger, respectively. Based on S/N ratios for the kerf width values, the optimum laser cutting parameters were found to be 1000 W laser power, 2400 mm/min cutting speed and 2 Bar gas pressure, respectively. It was seen that the kerf width values of the specimens cut in a quarter circle were larger than the kerf width values of the specimens cut in a straight line. Moreover, it was found that the kerf width ratios obtained at 2 Bar gas pressure were closer to 1 (best kerf quality ratio) and therefore more stable.