Welding joint is to use the heat generated by arc to make the welding rod and weldment partially melt, and then condense into welded joint by cooling, so as to connect the weldment as a whole.
Advantages:
It has the advantages of simple structure, convenient manufacture, high connection stiffness, good sealing performance, easy to use under certain conditions, automatic operation and high production efficiency.
Disadvantages:
Because the welding temperature is too high, the HAZ near the weld may be brittle in some parts; In the welding process, the steel is subjected to uneven high temperature and cooling distribution, resulting in welding residual stress and deformation, which has a certain impact on the bearing capacity, stiffness and performance of the structure; Due to the high rigidity of the welded structure, once the local cracks appear, it is easy to spread to the whole, especially the brittle fracture at low temperature; The plasticity and toughness of welded joint are poor, so it is easy to produce defects and reduce fatigue strength.