Advantages of welding connection: the welding chamber can be directly connected, with simple structure and convenient manufacture; Do not weaken the section, save materials; Good connection tightness and high structural rigidity; It can realize automatic operation and improve the quality of welding structure.

Disadvantages of welding connection: in the heat affected zone near the weld, the metallographic structure of steel changes, resulting in local material brittleness; Welding residual stress and residual deformation reduce the bearing capacity of compression members; Welding structure is very sensitive to cracks, local cracks? Once it happens, it is easy to spread to the whole section, and the problem of low temperature cold brittleness is more prominent.