Heat line forming is widely used in shipbuilding industry for the straightening of welded steel plates and beams, as well as for 3D shaping of plates. Actual industrial practice is based on manual flame heat forming, and the success of this process is strongly dependent on the skills of qualified staff.
This paper presents the study of the automated forming process of double curvature geometries, by means of line heat forming with CO2 laser. Tests have been carried out on shop-primed shipbuilding grade steel, inducing a thermal gradient by a unique heating line. Shop priming increases radiation laser absorption, facilitating the heat forming process and decreasing the laser beam reflection, with benefits in efficiency, process repeatability, and worker safety. In the tests, 6 to 12 mm thick plates were bent, with monitoring of strain and thermal field evolution. Numerical (FEM) modeling of the process allowed assessing the forming mechanism, edge effects and impact of material properties.
3D geometries were formed out from flat sheets, reproducing real pieces for a ship application. The test runs have shown a decrease in forming time of 80% compared with actual praxis, which means an increase of 5 times of the production yield.