Why can't the hook of the crane be repaired and welded?

2025 08/12

Crane hook material

The crane hook material is made of high-quality low-carbon killed steel or low-carbon alloy, which is annealed after forging. Only when the hook is subjected to impact loads at work can the hook set have sufficient strength and toughness.

Crane hook production process

The hook head is made by forging and then heat treatment. The forging process is a method in the metal thermal processing process. The forging process is the process of refining the metal structure and arranging the metal fibers. The heat treatment is to eliminate internal stress and further improve the mechanical properties of the metal (it can be simply understood as making the internal structure of the metal more compact).

Disadvantages of repair welding of hook group

It is difficult to meet the principle quality standards for hook repair welding. Repair welding is the entire process of partial melting, fusion, and solidification of metal. During repair welding, part of the basic metal of the hook parent body close to the repair welding is heated and cooled to varying degrees due to heat conduction. It is like a heat treatment on this part, which changes the structure and performance of this part. Most of the welding is for the wear and depression of the crane hook, and the depression is on the same straight line as the vertical dangerous section. Repair welding refines the metal structure of the hook and destroys the sequential arrangement of metal fibers, destroying the toughness of the hook, thereby reducing the performance of the hook.

Previous:Mechanism and steel structure inspection when the double-girder crane is stopped for repairs

Next:Single girder bridge crane hook failure repair