What indication is likely found in heavy sections of a casting?

Heavy sections of a casting are more prone to thermal stresses and can experience various types of defects due to the cooling rate and the volume of material involved. Hot tears typically occur in thicker sections where solidification is uneven or where stresses from the cooling metal can exceed the ductility of the material. As the casting cools, it contracts and if this contraction is restrained or uneven, cracks can develop during the solidification process.

In the context of large sections, the temperature difference between the center and the outer layers of the casting can lead to significant thermal strain. This is especially true when the outer layers have already solidified while the inner sections are still in a molten or semi-solid state. Therefore, the presence of hot tears serves as a direct result of these conditions, making it a significant concern in heavy sections of castings.

Other defects, while possible, do not directly relate to the unique thermal and mechanical stresses experienced in heavy sections during the cooling process, confirming that hot tears are the most likely indication in such scenarios.