Pulsed Arc Welding Applied to Robotized Joining of Thin Car-Body Steel Sheets

Abstract

The paper presents the potential of robotized welding applied for thin steel sheets using variable parameters of arc (different welding programs: Standard, Pulse, Twin Pulse, and Speed Pulse). Trial welded joints were made for sheets 0.8 to 1.25 mm thick and relevant welding parameters were selected for them during the first stage of examinations. The properties of welded joints were determined with non-destructive and destructive testing. In turn, visual inspection allowed to evaluate the shape and dimensional conformities of joints and to detect superficial imperfections. In order to improve detection accuracy, penetration testing was used for confirmation purposes. Tensile strength testing was also made to determine mechanical properties of the weld and the heat-affected zone. Metallographic examinations were used for sheets of all thickness values and for all welding programs to verify that the structure of joints was correct. All examinations and tests made on trial joints enabled to find how pulsing arc welding affects quality and strength properties of welds as compared with standard method.