Metals that are rolled, hammered, or bent can become

• A. Hardened steel
• B. Cold worked or work hardened
• C. Annealed
• D. Brittle

Answer: (B)

Work hardening occurs when metals are deformed at or near room temperature by processes like rolling, hammering, or bending. This plastic deformation increases the dislocation density inside the metal’s crystal structure, making it harder for dislocations to move. As a result, the metal becomes stronger and harder (more resistant to further deformation), but its ability to stretch and duct under stress decreases. That’s why metals that have undergone these forming methods are described as cold worked or work hardened. Heating the metal in annealing, in contrast, allows dislocations to rearrange and rename, softening the metal and restoring ductility. While extreme cold work can lead to cracking, the standard outcome of these forming processes is work hardening rather than brittle failure.