Normalizing is a process that makes the grain size normal. This process is usually carried out after forging, extrusion, drawing or heavy bending operations.

When steel is heated to elevated temperatures to complete the above operations, the grain of the steel will grow. In other words, the steel experiences a phenomenon called “grain growth.”

This leaves the steel with a very coarse and erratic grain structure. Furthermore, when the steel is mechanically deformed by the aforementioned operations, the grain becomes elongated.

There are mechanical property changes that take place as a result of normalizing – inasmuch as the normalized steel is soft, but not as soft as a fully annealed steel. Its grain structure is not as coarse as an annealed steel, simply because the cooling rate is faster than that of annealing. Usually the steel is cooled in still air and free from air drafts. The process temperature is virtually the same as for annealing, but the results are different due to the cooling rate.

The process is designed to:

1) Give improved machining characteristics.

2) Ensure a homogenous structure.

3) Reduce residual stresses from rolling and forging.

4) Reduce the risk of “banding.”

5) Help to give a more even response to the steel when hardening.