MIG/MAG robotic welding – specific application aspects

The paper presents some specific aspects regarding the robotization of the MIG/MAG welding process. The advantages of robotization lie in the increase in productivity by 150–200%, the reduction of residual deformations from 5–7 mm to 1–2 mm, the improvement of weld quality through the constancy of angles and speed (50–80 cm/min compared to 30–40 cm/min manually), and the elimination of straightening and spatter removal operations. Working conditions are improved by protecting operators from radiation, smoke and burns, using various types of robots with programmable positioning. The criteria for robotization include large or medium production volumes, dimensional accuracy of parts and training of personnel for robot programming. The major challenges are the surface condition of the workpieces (which must be clean, free of oil or oxides), too large joints (max. 0.3 mm for 2 mm sheets), and the optimal positioning of the wireelectrode (e.g. 0.5 mm from the vertical sheet for 2 mm thicknesses). Tests carried out with the CLOOS Romat 320 robot have established the optimal parameters, such as 130 A current for 0.3 mm penetration in 2 mm sheets. Problems, such as inconsistent wire feed due to friction, are solved by weekly cleaning of the guide tube and maintaining the curvature radii above 500 mm. Corrections of the robot trajectory are made by touch sensors and monitoring the arc voltage. Robotization optimizes the process, reduces defects and increases efficiency, but requires investment in technology and training.