What is work hardening?

What is work hardening?

• A. The process of heating a metal to soften it
• B. The process of heating and then rapidly cooling to harden it
• C. The process of continually bending, hitting or shaping a metal to increase hardness
• D. The process of applying a protective coating

Answer: (C)

Work hardening, also called strain hardening, strengthens a metal by deforming it at room temperature. When you repeatedly bend, hammer, or shape the metal, plastic deformation introduces more dislocations in the crystal structure. These dislocations jostle and interact, making it harder for new dislocations to move, so the metal becomes harder and stronger but less ductile. The described process of continually bending, hammering, or shaping fits this idea exactly because it creates that plastic deformation to increase hardness. The other options describe heat treatments or coatings, which change properties in different ways, not through cold working.

Work hardening, also called strain hardening, strengthens a metal by deforming it at room temperature. When you repeatedly bend, hammer, or shape the metal, plastic deformation introduces more dislocations in the crystal structure. These dislocations jostle and interact, making it harder for new dislocations to move, so the metal becomes harder and stronger but less ductile. The described process of continually bending, hammering, or shaping fits this idea exactly because it creates that plastic deformation to increase hardness. The other options describe heat treatments or coatings, which change properties in different ways, not through cold working.