I. Bucket Materials and Their Weldability 1. Before welding, the weld area must be thoroughly cleaned—that is, the original cracked weld metal must be removed, either by grinding with an angle grinder or, where possible, by carbon arc gouging.

The main girder structure of overhead travelling crane will be deformed by various factors in the process of long-term application, and the deformation problem can not be completely avoided, for the deformation of the main girder structure.