The invention provides a
laser-arc composite
welding device based on heat
input control and a
welding method. The
laser-arc composite
welding device based on the heat
input control comprises a
laser device, a laser head, an arc-
welding power supply, a main consumable-
electrode welding gun and a wire feeding mechanism and also comprises a bypass welding gun and a rheostat, wherein the laser head is connected with the laser device, the laser head is arranged above a workpiece, the main consumable-
electrode welding gun and the bypass welding gun are symmetrically placed at both sides of a laser beam formed by the laser head, the main consumable-
electrode welding gun is connected with the positive pole of the arc-
welding power supply, the electrifying end of the workpiece is connected with the negative pole of the arc-
welding power supply, and the bypass welding gun is connected with the negative pole of the arc-welding power supply by the rheostat. According to the laser-arc composite welding device based on the heat
input control and the welding method, the welding heat input of a composite laser-arc heat source can be controlled, the
heat affected zone and the
welding deformation are reduced, and the metallurgical performance and the
microstructure of a welding seam are improved. The laser-arc composite welding device based on the heat input control and the welding method not only are suitable for the
fusion welding of homogeneous
metal but also are suitable for the braze (fusion) welding of
dissimilar metal, such as aluminum or steel and
magnesium or steel.