Shrinkage Cavity
Shrinkage cavity occurs during cooling of steels due to volume loss from atomic exchange. This can lead to stresses and cracks.
Physicochemical Mechanism of Action
When transitioning from liquid to solid state, many metals shrink because certain atomic arrangements in the crystal lattice are no longer possible. This volume loss leads to an internal cavity, the shrinkage cavity.
Metallurgical Relevance & Welding Risks
An excessively large shrinkage cavity can cause stresses in the weld. These stresses can result in cracks and deformation in the material, especially when the material is under mechanical load.
Workshop Practice & Instructions
To minimize shrinkage cavities, cooling should be controlled. This can be achieved by using cooling water or special cooling jackets. For heavy steels with high carbon content, slow cooling is particularly important.