Laser shock-strengthening method of thin-plate welded structures

Abstract

The invention discloses a laser shock processing method of a thin plate welding structure. A welding connector of the thin plate welding structure is equally divided into a plurality of processing areas in the length direction of a welding seam from one end of the welding seam to the other end of the welding seam, the front and reverse faces of the first processing area are processed in sequence at first, and then the front and reverse faces of the rest of the processing areas are processed till the whole welding seam area is processed; a light spot advance path on each processing area forms a corresponding processing line, the processing lines are perpendicular to the welding seam direction, and a light spot shifts in the length direction of the welding seam to form a next processing line after one processing line is scanned till laser shock processing of the area is finished; a plurality of lapped processing lines perpendicular to the welding seam are formed in each processing area. The partition processing way is adopted for the welding connector of the large-size thin plate welding structure, deformation of the welding structure can be reduced, and the residual compressive stress attenuation degree, caused by deformation, of the surface processed earlier is weakened.

Description

technical field [0001] The invention relates to a laser processing technology, in particular to a laser shock strengthening method for strengthening the anti-fatigue surface of a large-scale sheet fusion welding structure. Background technique [0002] The advanced connection technology represented by laser welding is the key technology of lightweight integrated advanced manufacturing. The aircraft skin is large in size and complex in shape, and it is almost impossible to form it at one time. Laser welding is used to connect the block-formed skin into one, which not only greatly improves the overall performance, but also has a very significant weight reduction effect. [0003] Welded joints are often the fatigue weak link of welded structures. Residual tensile stress, undercut and spatter inside the weld are the main factors affecting the fatigue performance of laser welded joints. When the welded structure is subjected to external loads, the superposition of the residual ...

AI Technical Summary

Problems solved by technology

The existing technology is to scan the laser spot along the center of the weld from one end of the weld to the other end of the weld to form a row of strengthening areas, and then shift (move) the scanning path to form multiple rows parallel to the weld and overlapping each other. Strengthened area; thus, the plastic strain in the strengthened area will cause the strengthened surface area to become larger, and the strengthened area will protrude upwards, resulting in deformation of the welded structure

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