Propagation across the grains is called what?

• A. Intergranular
• B. Transgranular
• C. Subgranular
• D. Intragranular

Answer: (B)

Propagation through the interior of the grains, crossing from one grain to another rather than following the boundaries, is described as transgranular propagation. This term contrasts with intergranular propagation, which runs along grain boundaries, and intragranular propagation, which stays within a single grain. So when cracks move through the grain bodies themselves, the behavior is transgranular, making it the correct description.