Module 4: Solidification and casting and finishing operations
  Lecture 32: Ingot casting
 

Ingot cracks


Surface cracks are formed due to friction between mold and ingot surface. The improper design of mold taper and corner radius cause surface cracks. Different types of cracks are:


Transverse cracks: They are parallel to the base of ingot and are formed due to longitudinal tension in the ingot skin. As the aspect ratio of the ingot increases, tendency to transverse crack formation increases.
Longitudinal cracks are formed due to lateral tension in the skin. They are parallel to vertical axis of ingot. Alloy steels are more prone to longitudinal cracks than mild steels.


Sub- cutaneous cracks are internal fissures close to the surface. The cracks are formed due to thermal shocks.

Restriction cracks can be near the corner radius of the ingot.

Smooth corners of the mould and gradual curvature minimize restriction cracks.


References:

RH Tupkary, VR Tupkary: An introduction to modern steel making.