cracks in crane wheel sets

cracks in crane wheel sets

How to Prevent Cracks in Crane Wheel Sets?

Crane wheel sets are generally mainly composed of wheels, shafts, bearings, seat covers, blank covers, end covers and other major parts. Among them, the quality of wheel forgings is particularly important. Generally, large-tonnage rail lifting equipment uses forgings in wheel selection. For example: port machinery and cranes for wharfs, electric flat cars for metallurgical equipment, bucket wheel machines and conveyors for mining equipment, and coke pushers and coke blockers for chemical equipment. Commonly used materials for crane wheel forgings include: 45#, 60#, 65Mn, 40Cr, 42CrMo, etc.

When manufacturing crane wheel sets, cracks will occur in the wheel sets. The reasons for cracks are as follows:

1. The wheel group strictly controls the deformation temperature

Deformation temperature has an important effect on the plasticity of the material, low temperature, serious cold deformation hardening, plasticity decline; The temperature is too high, easy to overheat, overburn. Magnesium alloy and other close-packed hexagonal lattice metal materials at room temperature only one set of slip surface (that is, the base surface), when the temperature exceeds 200℃ to add a new slip surface, therefore, it should be ensured that in the deformation process, can be fully recrystallized, and as far as possible in the single-phase state deformation.

2. Use appropriate strain speed for the wheel set

The strain rate has a great influence on low plasticity materials, and appropriate forging equipment should be selected according to the specific materials.

3. Perform intermediate annealing on the wheel set if necessary

When the degree of cold deformation is too large, it is easy to cause the crane wheel set to crack, and intermediate annealing is required to eliminate some defects caused by hardening and deformation.

4. The wheel set is deformed by hot pressing

During thermal deformation, defects caused by deformation are usually partially eliminated due to the smooth progress of the recrystallization process, thus improving the plasticity.

5. The wheel set improves the structure of the blank

In order to improve the plasticity of the material, low melting point substances and brittle compounds on the grain boundaries should be avoided in terms of structure.

6. The wheel set adopts high temperature homogenization

High temperature homogenization can improve the inhomogeneity of the structure and improve the plasticity of the material.

7. The wheel group increases the value of water purification pressure

It can be seen from the previous analysis that the generation of cracks is related to the stress situation and the plasticity of the material, which is a state of the material, which not only depends on the organizational structure of the deformed object, but also depends on the external conditions of the deformation (including the stress state, deformation temperature and deformation speed).

Three-dimensional isobaric stress will not cause cracks in the crane wheel set to expand. Even if there are tiny unoxidized cracks in the deformation, it can be forged under the action of high three-dimensional compressive stress. For low plasticity materials, reverse thrust extrusion and sleeve upsetting are used to increase the value of hydrostatic pressure to prevent cracking. Reducing additional tensile stress during extrusion and elongation is a very effective measure to prevent cracking (such as hydrostatic extrusion).

Through the above measures, we can prevent the crane wheels from cracks and ensure the quality of the crane wheels.

Glory Rail offers all types of Crane Wheels for sale. We have high-quality wheel producers. Can produce forged wheels, cast wheels as well as machined wheels. The material is made of high-quality special steel to ensure longer service life and better stability. We can customize wheels of various sizes according to your drawings. If you don’t have the exact wheel drawing, our engineers will propose a customized solution according to your usage. So no matter what your requirements are, just feel free to contact us!