Flux-cored arc welding method for K-shaped groove of 80-mm super-thick steel plate

The invention relates to a flux-cored arc welding method for a K-shaped groove of an 80-mm super-thick steel plate. The groove takes a symmetric K-shaped groove; the upper opening angle and the lower opening angle of the groove are both 45-50 degrees; the root truncated edge of the groove is 0-1 mm; and the assembly interval of the groove is 0-3 mm. A solid gas protection welding wire under pulse current is adopted to implement the backing welding for a root run on the front surface of a test board of the K-shaped groove when welding, so that part of weld metal penetrates through the reverse side of the groove to finish the backing welding after the root run is molten thoroughly; and then the front surface flux-cored arc welding is carried out, and the reverse side back chipping is implemented when the groove is welded at the 2/3 depth; after that, the reverse side submerged-arc welding is carried out until the groove is fully filled; and finally, the front surface of the groove is welded for the left 1/3 depth after the reverse side is welded totally. The flux-cored arc welding method for the K-shaped groove of the 80-mm super-thick steel plate disclosed by the invention simplifies the welding operation, decreases the turning-over times, reduces the labor intensity, and improves the working efficiency; obtained soldering blocks have small residual deformation and high welding quality; and the welding method is suitable for the welding in the fields, such as ocean engineering and the like.