Annealing Temperature vs Normalizing Temperature

Annealing and normalizing are two heat treatment processes used to improve the mechanical properties of metals. Both processes involve heating the metal to a certain temperature and then cooling it down. However, the temperatures used in annealing and normalizing are different.

Annealing Temperature

Annealing is a heat treatment process used to make a metal softer and more ductile. In annealing, the metal is heated to a temperature below its melting point and then allowed to cool slowly. This slow cooling helps to remove internal stresses and makes the metal more ductile.

The temperature used in annealing depends on the type of metal being treated. For example, the annealing temperature for low carbon steel is around 650-700°C, while the annealing temperature for copper is around 400-600°C.

Normalizing Temperature

Normalizing is a heat treatment process used to make a metal stronger and more resilient. In normalizing, the metal is heated to a temperature above its critical temperature and then allowed to cool in still air. This rapid cooling helps to refine the grain structure of the metal and makes it stronger.

The temperature used in normalizing also depends on the type of metal being treated. For example, the normalizing temperature for low carbon steel is around 850-950°C, while the normalizing temperature for copper is around 800-900°C.

Comparison

From the above explanation, it is clear that the annealing temperature is less than the normalizing temperature. Therefore, the correct answer is option C - less than normalizing temperature.