The invention discloses a method for reducing pores by repair
welding of internal defects of a thin-wall aluminum
alloy casting. The method comprises the following steps: confirming and marking X-
ray positions of the internal defects of the aluminum
alloy casting; internal defects at the marked position are cleaned, the defects are required to be completely eliminated, and the cleaning position is smooth and has a certain groove angle; cleaning oil stains and oxidation films at the repair
welding position of the
casting; preheating the whole casting;
welding a reverse support and adding a blowing protection tool; manual
argon arc welding filling surfacing is carried out, arc surfacing is carried out from the periphery to the center, and excess
weld metal is reserved; removing redundant weld joint materials of surfacing bulges of the casting; x-
ray detection is conducted on the repaired casting, whether the pore defects generated after surfacing repair can meet related requirements or not is emphatically confirmed, and if pores gathered on the
surface layer of a weld joint exist, the pores can be discharged through a
hot pressing method. According to the method, through hole internal defect cleaning, reverse supporting, blowing protection increasing and arc drawing surfacing methods are adopted for conducting surfacing repairing on the internal defects of the casting, the quality of aluminum
alloy casting products is guaranteed, and the
rejection rate and the production cost are reduced.