Transverse compressive pre-stress method for controlling welding hot cracking of aluminum thin-plate

By using the transvarestraint test,the welding hot cracking susceptibility of aluminium-lithium(Al-Li) alloy and 2024 alloy has been estimated.

In this dissertation, a new technology named Welding with Trailing Rolling and pressing (WTRP) is put forward to control welding distortion and prevent welding hot cracking.

In order to reduce the tendency of hot crack in thin plate welding, a new process named Welding with Trailing Peening (WWTP) is used to prevent the weldments from welding hot crack by experiments and measurements from the view of mechanics.

Basing on the fundamental principle of electromagnetic induction, a new technology of controlling welding hot crack by electromagnetic forces during welding is put forward.

Metal magnetic memory signal recognition by neural network for welding crack;

Available time and dubious zone size of welding crack by metal magnetic memory method;

Remedy and analysis of welding crack for cone-shaped variant section of thick wall pressure vessel on Q345·C;

Feature extraction of metal magnetic memory signal and its application for weld crack;

Reason and control countermeasure of the weld crack happened to the bulletproof steel plate of the naval ship;

Analysis on the weld crack in construction survey of the 3 000 t river-to-sea cargo ship;

Investigation on relationship between welding cracks stress and magnetic memory signal;

Analysis of the formation and characteristics of the TIG welding cracks for the AZ31B magnesium alloy;

According to many on the spot working tests,the characteristics,formation reasons,influence factors,technological methods and countermeasures of the pipeline welding cracks were analyzed.