Chain electric hoist chain maintenance misunderstanding

For the electric chain hoist, the chain is a very important device. The more frequently the chain electric hoist is used, the more serious the wear and crack of the chain. Can it be continued using by welded repairing chain? The answer is NO, the reasons are as follows:

The chain of the electric chain hoist is made by casting and then heat treated, the whole chain is integrated. The casting process is equivalent to the refinement of the internal structure of the metal and the arrangement of the metal fibers, and the heat treatment eliminates the internal stress and further Improve the mechanical properties of the metal, making the metal interior more compact.

But, the welding is a process of partially melting, fusing and solidifying the metal. It is not a re-heating of the whole, which greatly reduces the mechanical properties of the metal and leaves a great safety hazard.