What characterizes annealing?

What characterizes annealing?

• A. Coating with protective oxide
• B. Heating and cooling a metal to soften it
• C. Rapid cooling to increase hardness
• D. Removing surface imperfections

Answer: (B)

Annealing is a heat treatment where a metal is heated to a specific temperature and then cooled slowly. This slow cooling lets the crystal grains rearrange and internal stresses relax, making the metal softer and more ductile so it’s easier to form, shape, or work with again. It can also restore ductility after prior deformation and improve machinability. Coating with protective oxide describes forming a surface oxide layer, not changing the metal’s interior properties. Rapid cooling to increase hardness refers to quenching, which hardens rather than softens. Removing surface imperfections is a finishing or polishing step, not a heat-treatment effect.

Annealing is a heat treatment where a metal is heated to a specific temperature and then cooled slowly. This slow cooling lets the crystal grains rearrange and internal stresses relax, making the metal softer and more ductile so it’s easier to form, shape, or work with again. It can also restore ductility after prior deformation and improve machinability.

Coating with protective oxide describes forming a surface oxide layer, not changing the metal’s interior properties. Rapid cooling to increase hardness refers to quenching, which hardens rather than softens. Removing surface imperfections is a finishing or polishing step, not a heat-treatment effect.