Recent Results in High Power CO{sub}2-Laser Cutting for Shipbuilding Industry

摘要

In 1997 a high power laser cutting and welding test facility was established at the Danish shipyard Odense Steel Shipyard (OSS). This laser cell was equipped with state-of-the-art lens based cutting optics and optics for laser welding and shop primer removal. The laser was a 12 kW CO{sub}2-laser with motorized internal mode aperture, which could improve the beam quality at reduced laser power (approximately 6 kW). Initially laser cutting was performed with the lower order mode and lower power level. However, some research and development projects were initiated in order to establish the basis for applying the full power of the laser for laser cutting, by developing mirror based cutting systems. In this paper the results of these projects will be presented. Both off-axis and coaxial laser beam/gas jet configurations have been tested and results from both types are presented. The off axis nozzle arrangement demonstrates high cutting performance. However, such systems are very sensitive to the proper beam/nozzle alignment and though difficult to apply for contour cutting production. A novel cutting head, delivering coaxial laser beam and gas jet, has demonstrated more than a doubling of laser cutting speed, compared to state-of-the-art lens based laser cutting. This has been achieved by increasing the laser power at the workpiece from 4 kW to above 10 kW. The off-axis nozzle arrangement is showing higher performance at the same power level as the coaxial cutting heads. However, the coaxial cutting heads are much easier to operate in contour cutting.