Rework welding process for T-shaped connector full penetration weld of pivot steel structure of ocean engineering crane

Abstract

The invention relates to rework welding process for a T-shaped connector full penetration weld of a pivot steel structure of an ocean engineering crane. A bottom plate and lateral plates of the pivot steel structure are made of a high strength steel sheet E36 for a ship, the rework welding process is characterized by comprising the following steps of heating the position of a T-shaped connector through an electric heating block at the back of the bottom plate; after a weld joint with a problem is removed, aligning to a lateral plate on an extending path, and cutting weld joints with a length at the position of a lateral plate butt joint connector; ensuring all cracks are removed, conducting heating and welding again, conducting self-cooling after heat insulation for a period of time; ensuring that transverse cracks are thoroughly removed, and completing welding of the several weld joints cut in the position of the lateral plate butt joint connector. The rework welding process for the T-shaped connector full penetration weld of the pivot steel structure of the ocean engineering crane has the advantages that the welding process with reasonable welding sequence avoiding high constraint stress is adopted so as to reduce condensation stress to avoid the transverse cracks, after the weld joint welding is completed, heat insulation processing is continuously conducted by adopting the electric heating block, and the transverse cracks are further avoided.

Description

technical field [0001] The invention relates to a welding process, in particular to a welding process for repairing and repairing a T-shaped joint of a central steel structure of a marine engineering crane. Background technique [0002] With the downturn adjustment of the shipbuilding industry, marine engineering products have started a period of rapid development. The steel used in offshore products generally requires high strength, especially for offshore cranes. The welding of a large number of high-strength steel plates, especially ultra-thick plates, has high requirements on the welding process, and welding defects, especially cold cracks, will occur if there is a slight negligence. Generally, the higher the grade of high-strength steel, the greater its susceptibility to cold cracks [1] . And in cold cracks, delayed transverse cracks are generally less than longitudinal cracks, but because of their concealment, the damage caused is greater. [0003] For example, dur...

AI Technical Summary

Problems solved by technology

When repairing, heat the welds with transverse cracks, and then remove them by carbon planing. After confirming that all the cracks are cleared, perform preheating, welding and heat preservation according to the previous welding method. After 48 hours, ultrasonic testing finds that very few tiny transverse cracks appear. , and then the number of cracks increases with time, and the generation of transverse cracks is still unavoidable

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