Which type of rolling typically results in an elongated grain structure?

• A. Hot rolling
• B. Warm rolling
• C. Cold rolling
• D. No rolling

Answer: (C)

Grain shape and orientation are controlled by the temperature during deformation. Cold rolling deforms the metal at or near room temperature, so dislocations accumulate and the grains are stretched along the rolling direction without time for recrystallization. This produces elongated grains aligned with the roll and a directional texture, along with increased strength from work hardening but reduced ductility. In hot rolling, the metal is heated above the recrystallization temperature, allowing new grains to form and the structure to become more equiaxed, not elongated. Warm rolling lies between, with partial recrystallization and less pronounced elongation. So, the type that typically yields elongated grain structure is cold rolling.