Topic: Manufacturing Engineering
Which of the following processes would produce strongest components?
- A. Hot rolling
- B. Extrusion
- C. Cold rolling
- D. Forging
Answer: C. Cold rolling
Explanation: Hot Rolling- Hot rolling is a mill process which involves rolling the steel at high temperature which is above the steel's recrystallization. Cold Rolling- Cold rolling is a metal working process in which metal is deformed by passing it through rollers at a temperature below its recrystallization. Cold Rolling increases the yield strength and hardness of metal by introducing defects into the metal's crystal structure. These defects prevent further slip and can reduce the grain size of the metal, resulting in Hall-Petch hardening. Since strength and hardness of a cold working component is always more than that of hot working due to strain hardening. Therefore cold working would be a better option as cold is specifically mentioned whereas in forging it could be hot or cold.