The invention discloses a CMT
electric arc welding method for
defect repair welding of a ZL114A aluminum
alloy casting, and belongs to the technical field of
defect repair of aluminum
alloy castings. The method aims at solving the problems that an existing repair
welding method for the ZL114A cast aluminum
alloy is high in heat input, large in deformation and low in repair efficiency. The method comprises the following steps: firstly, aiming at defects of different sizes,
machining the defects into regular spherical-crown-shaped grooves of different sizes by utilizing a cold
machining method; an electric steel
wire brush is used for
polishing the inner wall of the groove and
base metal around the groove, and surface stains and
oxide skin are removed; the
casting is placed on a welding
workbench;
robot CMT welding equipment is adopted for repair welding; and writing a welding gun repairing path on the
robot demonstrator. And repair welding is carried out according to the following principles: repair welding is carried out by utilizing an Al-Si welding characteristic curve, a repair welding piece is preheated to 250-350 DEG C,
shielding gas is started, and automatic repair is started according to the planned path, the wire feeding speed and the welding speed. By means of the method, high-quality repair welding seams without pores and cracks can be obtained.